gastrins and gastrin-17

The manifestations of gastroesophageal reflux disease (GERD) have been recently classified into either esophageal or extra-esophageal syndromes. Clinical history, questionnaire data and response to antisecretory therapy are insufficient to make a conclusive diagnosis of GERD. Endoscopy had a low sensitivity. Recently, the availability of multichannel intraluminal impedance and pH-monitoring (MII-pH) has modified the diagnostic approach towards atypical manifestations of GERD. There is a rising consensus that this technique should be considered as the gold standard for GERD diagnosis. Gastrin 17 (G-17) has been proposed as a non-invasive marker of GERD, due to the negative feedback between acid and the hormone. G17 levels seem able to identify patients with acid and non-acid reflux.

Topics: Bilirubin; Body Fluids; Chest Pain; Diagnosis, Differential; Electric Impedance; Esophageal pH Monitoring; Gastrins; Gastroesophageal Reflux; Humans; Manometry; Monitoring, Ambulatory; Proton Pump Inhibitors; Symptom Assessment

Upper-GI diseases are one of the most relevant issue in primary care. Nowadays they are still responsible for about 100 million ambulatory care visits only in the US. The diagnosis of almost every upper-GI condition is still deputed to invasive tests such as upper gastrointestinal endoscopy, gastroesophageal manometry or radiography. The possibility of analysing serum markers like Pepsinogens I and II, produced by gastric mucosa, in order to assess the functional characteristics of the upper GI tract has spread itself since the 80's especially in the diagnosis of peptic ulcer. The discovery of Helicobacter pylori by Marshall and Warren in 1983 and the scientific consecration of its role in the pathogenesis of gastric cancer and peptic ulcer (crystallized in Peleo Correa's Cascade, 1992), led to an increase importance of non-invasive tests, raising the attention towards the assessment of both immunoglobulins anti-H.p. and Gastrin hormone produced by antral G cells, as an implementation of the panel of gastric markers. This narrative review aims to analyze the huge landscape of non-invasive tests for diagnosis of GI diseases, studying the literature of the recent years.

Topics: Antibodies, Bacterial; Biomarkers; Diagnostic Techniques, Digestive System; Dyspepsia; Endoscopy, Gastrointestinal; Esophageal Diseases; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Pepsinogens; Stomach Diseases

Autoimmune diseases, characterized by an alteration of the immune system which results in a loss of tolerance to self antigens often coexist in the same patient. Autoimmune atrophic gastritis, characterized by the development of antibodies agains parietal cells and against intrinsic factor, leads to mucosal destruction that affects primarily the corpus and fundus of the stomach. Autoimmune atrophic gastritis is frequently found in association with thyroid disease, including Hashimoto's thyroiditis, and with type 1 diabetes mellitus, Other autoimmune conditions that have been described in association with autoimmune atrophic gastritis are Addison's disease, chronic spontaneous urticaria, myasthenia gravis, vitiligo, and perioral cutaneous autoimmune conditions, especially erosive oral lichen planus. Interestingly, however, celiac disease, another frequent autoimmune condition, seems to play a protective role for autoimmune atrophic gastritis. The elevated prevalence of autoimmune disease clustering should prompt the clinicial to exclude concomitant autoimmune conditions upon diagnosis of any autoimmune disease.

Topics: Autoantibodies; Autoantigens; Autoimmune Diseases; Biomarkers; Comorbidity; Disease Susceptibility; Gastrins; Gastritis, Atrophic; Humans; Intrinsic Factor; Parietal Cells, Gastric; Pepsinogens; Prevalence; Sensitivity and Specificity

The combination of pepsinogen, gastrin-17 and anti-H. pylori antibodies serological assays (panel test) is a non-invasive tool for the diagnosis of atrophic gastritis. However, the diagnostic reliability of this test is still uncertain.. To assess the diagnostic performance of the serum panel test for the diagnosis of atrophic gastritis.. Medline via PubMed, Embase, Scopus, Cochrane Library databases and abstracts of international conferences proceedings were searched from January 1995 to December 2016 using the primary keywords "pepsinogens," "gastrin," "atrophic gastritis," "gastric precancerous lesions." Studies were included if they assessed the accuracy of the serum panel test for the diagnosis of atrophic gastritis using histology according to the updated Sydney System as reference standard.. Twenty studies with a total of 4241 subjects assessed the performance of serum panel test for the diagnosis of atrophic gastritis regardless of the site in the stomach. The summary sensitivity was 74.7% (95% confidence interval (CI), 62.0-84.3) and the specificity was 95.6% (95%CI, 92.6-97.4). With a prevalence of atrophic gastritis of 27% (median prevalence across the studies), the negative predictive value was 91%. Few studies with small sample size assessed the performance of the test in detecting the site of atrophic gastritis.. The combination of pepsinogen, gastrin-17 and anti-H. pylori antibodies serological assays appears to be a reliable tool for the diagnosis of atrophic gastritis. This test may be used for screening subjects or populations at high risk of gastric cancer for atrophic gastritis; however, a cost-effectiveness analysis is needed.

Topics: Cost-Benefit Analysis; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Hematologic Tests; Humans; Pepsinogen A; Prevalence; Reproducibility of Results; Sensitivity and Specificity; Stomach Neoplasms

A meta-analysis was performed to assess the diagnostic value of gastrin-17 (G-17) for the early detection of chronic atrophic gastritis (CAG).An extensive literature search was performed, with the aim of selecting publications that reported the accuracy of G-17 in predicting CAG, in the following databases: PubMed, Science Direct, Web of Science, Chinese Biological Medicine, Chinese National Knowledge Infrastructure, Wanfang, and VIP. To assess the diagnostic value of G-17, the following statistics were estimated and described: sensitivity, specificity, diagnostic odds ratios (DOR), summary receiver operating characteristic curves, area under the curve (AUC), and 95% confidence intervals (CIs).Thirteen studies that met the inclusion criteria were included in this meta-analysis, comprising 894 patients and 1950 controls. The pooled sensitivity and specificity of these studies were 0.48 (95% CI: 0.45-0.51) and 0.79 (95% CI: 0.77-0.81), respectively. The DOR was 5.93 (95% CI: 2.93-11.99), and the AUC was 0.82.G-17 may have potential diagnostic value because it has good specificity and a moderate DOR and AUC for CAG. However, more studies are needed to improve the sensitivity of this diagnostic tool in the future.

Topics: Area Under Curve; Biomarkers; Gastrins; Gastritis, Atrophic; Humans; ROC Curve

Atrophic gastritis (AG) results most often from Helicobacter pylori (H. pylori) infection. AG is the most important single risk condition for gastric cancer that often leads to an acid-free or hypochlorhydric stomach. In the present paper, we suggest a rationale for noninvasive screening of AG with stomach-specific biomarkers.. The paper summarizes a set of data on application of the biomarkers and describes how the test results could be interpreted in practice.. In AG of the gastric corpus and fundus, the plasma levels of pepsinogen I and/or the pepsinogen I/pepsinogen II ratio are always low. The fasting level of gastrin-17 is high in AG limited to the corpus and fundus, but low or non-elevated if the AG occurs in both antrum and corpus. A low fasting level of G-17 is a sign of antral AG or indicates high intragastric acidity. Differentiation between antral AG and high intragastric acidity can be done by assaying the plasma G-17 before and after protein stimulation, or before and after administration of the proton pump inhibitors (PPI). Amidated G-17 will rise if the antral mucosa is normal in structure. H. pylori antibodies are a reliable indicator of helicobacter infection, even in patients with AG and hypochlorhydria.. Stomach-specific biomarkers provide information about the stomach health and about the function of stomach mucosa and are a noninvasive tool for diagnosis and screening of AG and acid-free stomach.

Topics: Achlorhydria; Antibodies, Bacterial; Biomarkers; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Mass Screening; Pepsinogen A; Pepsinogen C; Stomach Neoplasms; Vitamin B 12

Gastrin measurements are performed primarily for the diagnosis of gastrin-producing tumors, gastrinomas, which cause the Zollinger-Ellison syndrome (ZES). Gastrin circulates as several bioactive peptides, however, and the peptide pattern in gastrinoma patients often deviates from normal. Therefore, it is necessary to measure all forms of gastrin.. Only immunoassays are useful for measurement of gastrin in plasma. The original assays were RIAs developed in research laboratories that used antibodies directed against the C terminus of gastrin peptides. Because the C-terminal tetrapeptide amide sequence constitutes the active site of gastrin peptides, these assays were well suited for gastrinoma diagnosis. More recently, however, most clinical chemistry laboratories have switched to commercial kits. Because of recent cases of kit-measured normogastrinemia in patients with ZES symptoms, the diagnostic sensitivity and analytical specificity of the available kits have been examined. The results show that gastrin kits frequently measure falsely low concentrations because they measure only a single gastrin form. Falsely high concentrations were also encountered, owing to overreactivity with O-sulfated gastrins or plasma proteins. Thus, more than half of the gastrin kits on the market are unsuited for diagnostics.. Gastrinomas are neuroendocrine tumors, some of which become malignant. A delay in diagnosis leads to fulminant ZES, with major, even lethal, complications. Consequently, it is necessary that the diagnostic sensitivity of gastrin kits be adequate. This diagnostic sensitivity requires antibodies that bind the C-terminal epitope of bioactive gastrins without the influence of O-sulfation.

Topics: Amino Acid Sequence; Antibody Specificity; Biomarkers, Tumor; Gastrinoma; Gastrins; Humans; Immunoassay; Molecular Sequence Data; Reagent Kits, Diagnostic; Sensitivity and Specificity; Zollinger-Ellison Syndrome

The gastrointestinal peptide hormone gastrin is responsible for initiating the release of gastric acid in the stomach in response to the presence of food and/or humoral factors such as gastrin releasing peptide. However, it has a role in the growth and maintenance of the gastric epithelium, and has been implicated in the formation and growth of gastric cancers. Hypergastrinemia resulting from atrophic gastritis and pernicious anemia leads to hyperplasia and carcinoid formation in rats, and contributes to tumor formation in humans. Additionally, gastrin has been suspected to play a role in the formation and growth of cancers of the colon, but recent studies have instead implicated gastrin processing intermediates, such as gastrin-17-Gly, acting upon a putative, non-cholecystokinin receptor. This review summarizes the production and chemical structures of gastrin and of the processing intermediate gastrin-17-Gly, as well as their activities in the gastrointestinal tract, particularly the promotion of colon cancers.

Topics: Animals; Cholecystokinin; Gastric Acid; Gastrins; Gastritis, Atrophic; Gastrointestinal Neoplasms; Gastrointestinal Tract; Humans; Rats; Receptor, Cholecystokinin B; Signal Transduction

Gastric cancer is the second most common cause of death from cancer in Asia. Although surgery is the standard treatment for this disease, early detection and treatment is the only way to reduce mortality. This Review summarises the epidemiology of gastric cancer, and the evidence for, and current practices of, screening in Asia. Few Asian countries have implemented a national screening programme for gastric cancer; most have adopted opportunistic screening of high-risk individuals only. Although screening by endoscopy seems to be the most accurate method for detection of gastric cancer, the availability of endoscopic instruments and expertise for mass screening remains questionable--even in developed countries such as Japan. Therefore, barium studies or serum-pepsinogen testing are sometimes used as the initial screening tool in some countries, and patients with abnormal results are screened by endoscopy. Despite the strong link between infection with Helicobacter pylori and gastric cancer, more data are needed to define the role of its eradication in the prevention of gastric cancer in Asia. At present, there is a paucity of quality data from Asia to lend support for screening for gastric cancer.

Topics: Adult; Aged; Asia; Female; Gastrins; Humans; Incidence; Male; Mass Screening; Middle Aged; Risk Factors; Stomach Neoplasms

Although the gastric cancer incidence is decreasing, this neoplasia remains one of the major causes of oncological mortality. Because of an insidious development, gastric cancer is often diagnosed in an advanced stage and consequently with a poor prognosis. Accurate non-invasive tests should be extremely useful in order to detect gastric neoplasm in an early phase. In clinical practice, there is no reliable bio-marker for detecting this malignant disease. However, intestinal as well as diffuse types of gastric cancer are preceded by gastric mucosa inflammation. Furthermore, the intestinal type of the neoplasia is, generally, related to chronic atrophic gastritis, especially if associated with intestinal metaplasia. In particular, the risk of the neoplasm is linked to both extension and severity of gastric atrophy. Serological parameters such as serum pepsinogens I (PGI) and II (PGII), gastrin-17 (G-17) cytokines (e.g. IL-8), antiparietal cells, IgG anti-Hp and CagA antibodies and lastly ghrelin supply information about either atrophic or inflammatory conditions characterising gastric mucosa. Low PGI and PGI/PGII ratio levels, especially if combined with high G-17 levels, are recognised bio-markers of corpus atrophic gastritis. Low G-17 levels could be, also, suggestive of antral atrophic gastritis. Furthermore, plasmatic ghrelin levels seem to be also a bio-marker of corpus atrophy. Anti-Hp IgG and CagA antibodies as well as PGII levels are able to detect gastric inflammation. Serological parameters could select subjects at risk for gastric mucosa alterations such as inflammation or atrophy, rather than gastric cancer itself. This review analyses the information derived from serological bio-markers as well as the involved clinical studies.

Topics: Biomarkers; Cytokines; Diagnosis, Differential; Evidence-Based Medicine; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Ghrelin; Humans; Interleukin-8; Pepsinogens; Stomach Diseases; Stomach Neoplasms

Topics: Biomarkers; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Pepsinogens; Risk Factors; Stomach Neoplasms

Aphton is developing an anti-gastrin vaccine [Anti-gastrin 17 immunogen, G17DT, Gastrimmune], which neutralises the gastrin 17 hormone and the Gly-G17 hormone. Gastrin 17 is a growth factor for pancreatic, stomach and colorectal cancers, and a potent stimulator of gastric acid secretion.The anti-gastrin immunogen, G17DT, consists of a large carrier protein, called Diptheria Toxoid (DT). A synthetic peptide, which is similar to a portion of the gastrin 17 hormone (GT), is attached to the carrier protein. These are then contained in a liquid suspension vehicle. When administered to patients, G17DT induces an immune response producing antibodies, which cross-react and neutralise the target hormone thus preventing its interaction with disease-causing or -participating cells. Aphton has entered into an agreement with Aventis Pasteur for the marketing of G17DT in all human cancer indications in North America and Europe. Under the terms of the agreement, Aphton is responsible for product development, clinical trials and regulatory agency approvals. The agreement was originally with Pasteur Mérieux Connaught, a subsidiary of Rhône-Poulenc. However, in December 1999, Rhône-Poulenc merged with Hoechst to form Aventis. As a result of the merger, Pasteur Mérieux Connaught underwent a name change to Aventis Pasteur. In July 2002, Aphton announced that it would negotiate with companies wanting to licence the vaccine in territories other than North America and Europe. In February 2003, Aphton announced it had received fast track designation for G17DT in combination with cisplatin and fluorouracil for use in stage IV gastric cancer to improve overall survival. In July 2002, the US FDA granted G17DT orphan drug status for the treatment of gastric cancer, an indication that was broader than the indication Aphton originally sought. The vaccine was also granted orphan drug status in Australia for gastric cancer in December 2002. In July 2002, Aphton announced that the US FDA had granted G17DT orphan drug status for the treatment of adenocarcinoma of the pancreas. In September 2002, the US FDA also granted G17DT, used in combination with gemcitabine, fast track status for the treatment of pancreatic cancer patients. In addition, the vaccine was also granted orphan drug status in Australia for pancreatic cancer in December 2002. In March 2003, Aphton announced that the Committee for Orphan Medicinal Products had recommended to the European Commission that G17DT be granted orph

Topics: Animals; Cancer Vaccines; Clinical Trials as Topic; Colorectal Neoplasms; Gastrins; Humans; Orphan Drug Production; Pancreatic Neoplasms; Peptic Ulcer; Rats; Stomach Neoplasms; Vaccines

On the basis of the levels of serum pepsinogen I (S-PGI) and gastrin-17 (S-G-17) as well as Helicobacter pylori - antibodies assayed from a blood sample it is possible to establish with high sensitivity and specificity whether the patient has gastritis, whether the gastritis is atrophic or not and in which part of the stomach the atrophic changes are located. The test enables the identification of patients whose risk of gastric cancer, of the consequences of vitamin B12 deficiency (e.g. elevated levels of homocysteine) or of peptic ulcer is considerably increased and who can then undergo gastroscopy. It also facilitates the diagnosis of non-atrophic Helicobacter gastritis enabling treatment before endoscopy.

Topics: Finland; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Humans; Pepsinogen A; Peptic Ulcer; Stomach Neoplasms; Vitamin B 12 Deficiency

G17DT or Gastrimmune, as it was formally known, is an antigastrin 17 immunogen producing neutralising high affinity antibodies directed against gastrin-17 (G17). Preclinical studies, initiated to identify biological functionality of G17DT-induced antibodies, confirmed that the antibodies both reduced G17 stimulated gastric acid secretion and inhibited gastrin from interacting with the CCK-2 receptor. Therapeutic efficacy of both passive and active immunisation with G17DT has been established in a number of tumour systems including both primary and metastatic disease. Furthermore, additive effects with 5-fluorouracil (5-FU)/leucovorin have been confirmed in both colon and gastric tumour models. Phase I/II studies in advanced gastrointestinal (GI) malignancies have shown no systemic or autoimmune reactions to active immunisation with G17DT. Use of an optimised dose has yielded a high proportion of responders (> 80%), with minimal side effects and antibody titres measurable within 2-4 weeks. Taken together these results suggest that the G17DT immunogen is a promising agent for the treatment of GI cancer and Phase III trials, currently underway, will definitively evaluate this early promise.

Topics: Adenocarcinoma; Animals; Antibodies; Antigens; Cancer Vaccines; Clinical Trials as Topic; Colonic Neoplasms; Diphtheria Toxoid; Gastrins; Gastrointestinal Neoplasms; Humans; Immunotherapy; Multicenter Studies as Topic; Neoplasm Metastasis; Stomach Neoplasms

Cholecystokinin (CCK) and gastrin stimulate growth of rodent pancreas in vivo. However, it remains unclear whether these growth effects are mediated specifically by CCK-A receptors, CCK-B receptors, or both. To clarify this issue, the present study examined the effect of highly selective and biologically active CCK agonists on pancreatic growth.. Rats were subcutaneously injected with either (1) CCK-8, a nonselective CCK agonist (2.50 micrograms/kg body wt); (2) A-71623, a selective CCK-A agonist, tert-butyl-oxycarbonyl-Trp-Lys (epsilon-N-2-methylphenylaminocarbonyl)-Asp-(N-methyl)-Phe-NH2 (1.84 micrograms/kg body wt); (3) SNF-8815; a selective CCK-B agonist, [(2R,3S)-beta-MePhe28, N-MeNle31]CCK26-33 (2.40 micrograms/kg body wt); or (4) saline (control) for 21 days. Rats were killed, and pancreatic weight, protein content, RNA content, DNA content, protein-DNA ratio, RNA-DNA ratio, pancreatic area per nucleus, and number of mitoses per 10,000 acinar cells were determined.. Nonselective CCK agonist significantly increased pancreatic weight, protein, RNA, and DNA contents, and number of mitoses per 10,000 acinar cells. Likewise, selective CCK-A agonist significantly increased pancreatic weight, protein, RNA, and DNA contents, protein-DNA ratio, RNA-DNA ratio, pancreatic area per nucleus, and number of mitoses per 10,000 acinar cells. In contrast, selective and biologically active CCK-B agonist had no effect.. These findings indicate that pancreatic growth is mediated specifically by CCK-A receptors in the rat in vivo.

Topics: Animals; Binding, Competitive; Cholecystokinin; DNA; Gastrins; Male; Mitosis; Pancreas; Peptide Fragments; Proteins; Rats; Rats, Inbred Lew; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; RNA; Tetragastrin

In contrast to healthy subjects, duodenal ulcer patients in the active phase contain large amounts of a peptide in serum and antrum which react with antiserum specific for the N-terminus, but not the C-terminus of gastrin-17. The immunochemical and chromatographic properties were similar to that of the N-terminal tridecapeptide sequence of gastrin-17. The peptide follows the clinical course of duodenal ulcer disease, as it disappears when the ulcer heals. The N-terminal tridecapeptide - lacking the bioactive tetrapeptide of gastrin-17 - is a potent inhibitor of gastric acid secretion, presumably by way of competitive antagonism to gastrin. It is suggested to participate in the regulation of gastric acid secretion in patients with active duodenal ulcer disease. To confirm the chemical structure of the peptide, antral and gastrinoma extracts were used for isolation, purification and amino acid analysis. We found two different peptides with the same N-terminus as gastrin-17, namely the previously known N-terminal tridecapeptide fragment of gastrin-17 and a new gastrin component, identical with a C-terminal glycine extended gastrin-17. Furthermore, a C-terminal glycine extended component, corresponding to each of the other molecular forms of gastrin were present. Thus, a variety of abnormally processed gastrins are synthesized and released to the circulation during the active period of duodenal ulcer disease.

Topics: Amino Acid Sequence; Animals; Chemical Phenomena; Chemistry; Duodenal Ulcer; Gastrins; Humans; Species Specificity; Terminology as Topic; Tissue Extracts

Develop a program to identify, treat, and prevent severe atrophic gastritis to reduce gastric cancer incidence and mortality.. In total, 2,847 people aged > 40 years old underwent serological noninvasive screening for atrophic gastritis by identifying postprandial gastrin-17 and pepsinogen-1 in the fasting state. Anti-H pylori IgG was found in 2,134 patients. Seven years later, 2,220 patientswho had undergone serological noninvasive screening were asked to fill out a questionnaire survey (were interviewed). We could not find any information on 627 of 2,847 patients. Next, 75 patients with multifocal atrophic gastritis who underwent gastroscopy and biopsies (the Updated Sydney System (USS)) were selected. To study gastrin-17 production, morpho-functional correlation was studies in 75 patients with multifocal atrophic gastritis.. During seven years, no reported case of gastric cancer was done among 2,220 persons who underwent serological screening and treatment. In the same population, 4.3 persons who did not receive screening during the same period, developed gastric cancer and died of it. In this study, we can say that 4.3 lives were saved out of 2,220 tested persons. The cost for screening this number of people amounted to €23,750. A comparison of the prevalence rate of the four stages of multifocal atrophic gastritis based on the data of the histopathology tests and noninvasive serologic screening in accordance with OLGA classification showed a strong correlation (the correlation coefficient is 0.812). This finding suggested that using this classification not only for histopathology tests for atrophic gastritis but also for serologic markers of antral mucosa and corpus ventriculi atrophy: gastrin-17 and pepsinogen-1.. Complex pathogenetic treatment of atrophic gastritis significantly reduced gastric cancer risk and incidence for such patients.
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Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Case-Control Studies; Female; Follow-Up Studies; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Male; Mass Screening; Pepsinogen A; Precancerous Conditions; Prognosis; Prospective Studies; Stomach Neoplasms

Helicobacter pylori (Hp) infection affects a substantial proportion of the world population and is a major risk factor of gastric cancer (GC). The caveats of common Hp-tests can be evaded by a serological biomarker test (GastroPanel®, Biohit Oyj, Helsinki), the most comprehensive Hp-test on the market. The clinical validation of Helicobacter pylori IgG ELISA of the new-generation GastroPanel® test is reported. The aim of the study is to validate the clinical performance of the Helicobacter pylori IgG ELISA test in diagnosis of biopsy-confirmed Hp-infection in gastroscopy referral patients.. A cohort of 101 patients (mean age=50.1 years) referred for gastroscopy at the outpatient Department of Gastroenterology (SM Clinic, St. Petersburg) were examined by two test versions to validate the new-generation GastroPanel®. All patients were examined by gastroscopy and biopsies, which were stained with Giemsa for specific identification of Hp in the antrum (A) and corpus (C).. Biopsy-confirmed Hp-infection was found in 64% of patients, most often confined to antrum. The overall agreement between Hp IgG ELISA and gastric biopsies in Hp-detection was 91% (95%CI=84.1-95.8%). Hp IgG ELISA diagnosed biopsy-confirmed Hp (A&C) with sensitivity (SE) of 92.3%, specificity (SP) of 88.6%, positive predictive value (PPV) of 93.8% and negative predictive value (NPV) of 86.1%, with AUC=0.904 (95%CI=0.842-0.967). In ROC analysis for Hp detection (A&C), Hp IgG ELISA shows AUC=0.978 (95%CI=0.956-1.000).. The Hp IgG ELISA test successfully concludes the clinical validation process of the new-generation GastroPanel® test, which retains the unrivalled diagnostic performance of all its four biomarkers, extensively documented for the first-generation test in different clinical settings.

Topics: Adolescent; Adult; Antibodies, Bacterial; Biopsy; Enzyme-Linked Immunosorbent Assay; Female; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Referral and Consultation; Stomach; Stomach Neoplasms; Young Adult

Helicobacter-induced atrophic gastritis with a hypochlorhydric milieu is a risk factor for gastric cancer. Microbes colonising acid-free stomach oxidise ethanol to acetaldehyde, a recognised group 1 carcinogen.. To assess gastric production of acetaldehyde and its inert condensation product, non-toxic 2-methyl-1,3-thiazolidine-4-carboxylic acid (MTCA), after alcohol intake under treatment with slow-release L-cysteine or placebo.. Seven patients with biopsy-confirmed atrophic gastritis, low serum pepsinogen and high gastrin-17 were studied in a cross-over single-blinded design. On separate days, patients randomly received 200 mg slow-release L-cysteine or placebo with intragastric instillation of 15% (0.3 g/kg) ethanol. After intake, gastric concentrations of ethanol, acetaldehyde, L-cysteine and MTCA were analysed.. Administration of L-cysteine increased MTCA (p < .0004) and decreased gastric acetaldehyde concentrations by 68% (p < .0001). The peak L-cysteine level was 7552 ± 2687 μmol/L at 40 min and peak MTCA level 196 ± 98 μmol/L at 80 min after intake. Gastric L-cysteine and MTCA concentrations were maintained for 3 h. The AUC for MTCA was 11-fold higher than acetaldehyde, indicating gastric first-pass metabolism of ethanol. With placebo, acetaldehyde remained elevated also at low ethanol concentrations representing 'non-alcoholic' beverages and food items.. After gastric ethanol instillation, slow-release L-cysteine eliminates acetaldehyde to form inactive MTCA, which remains in gastric juice for up to 3 h. High acetaldehyde levels indicate a marked gastric first-pass metabolism of ethanol resulting in gastric accumulation of carcinogenic acetaldehyde. Local exposure of the gastric mucosa to acetaldehyde can be mitigated by slow-release L-cysteine capsules.

Topics: Acetaldehyde; Adult; Carbolines; Carcinogenesis; Cross-Over Studies; Cysteine; Delayed-Action Preparations; Ethanol; Female; Gastric Juice; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter; Humans; Male; Middle Aged; Single-Blind Method; Stomach Neoplasms; Sweden

Epidemiological studies found a significant correlation between Helicobacter pylori infection and elevated serum pepsinogen, especially pepsinogen II (PGII), and reduced pepsinogen I (PGI)/PGII ratio. The study aimed to evaluate the association between abnormal gastric function risk and H. pylori infection assessed by H. pylori IgG assay and (14)C-urea breath test (UBT).. A total of 1555 subjects who underwent a health check were enrolled. Serum PGI, serum PGII, PGI/PGII ratio, gastrin 17 (G17), H. pylori IgG antibody titer, and UBT results were collected.. Median PGII and G17 levels were higher, but PGI/PGII ratio was lower in H. pylori-seropositive compared with seronegative participants (P<0.001, respectively). Similar effects were demonstrated by UBT. The consistency between H. pylori IgG assay, and UBT results were 86.9%, 82.29%, and 84.64% in individuals with normal gastric function, but only 73.4%, 67.98%, and 74.6% in those with abnormal gastric function. The correlation coefficients for H. pylori infection and abnormal gastric function diagnosed by PGI/PGII <7 were 0.336 (P<0.001) by H. pylori IgG assay and 0.231 (P<0.001) by UBT, diagnosed by PGII ≥ 8.25 µg/L were 0.594(P<0.001) by H. pylori IgG assay and 0.493 (P<0.001) by UBT, diagnosed by G17 >3 pmol/L was 0.469 (P<0.001) by H. pylori IgG assay and 0.394 (P<0.001) by UBT. The odds ratios (ORs) (95% confidence intervals) of abnormal gastric function were 7.477 (5.278-10.594), 19.204 (14.526-25.387), and 7.921 (6.286-9.982) comparing positive versus negative by H. pylori IgG assay and 4.084 (2.98-5.598), 9.552 (7.494-12.174), and 5.402 (4.335-6.731) comparing positive versus negative by UBT.. H. pylori infection assessments by antibody-based or bacterial component-based detection are both related with abnormal gastric function. Moreover, serum H. pylori IgG assay was stronger associated with abnormal gastric function than UBT assay.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Breath Tests; Enzyme-Linked Immunosorbent Assay; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Retrospective Studies; Stomach; Urea; Young Adult

This study aimed to investigate G17DT, an immunogen producing neutralizing antibodies against the tumor growth factors amidated and glycine-extended forms of gastrin-17, in the treatment of pancreatic cancer.. A randomized, double-blind, placebo-controlled, group-sequential multicenter trial of G17DT in patients with advanced pancreatic cancer unsuitable for or unwilling to take chemotherapy. Inclusion criteria were a Karnofsky performance score of 60 or higher and a life expectancy of more than 2 months. Patients received G17DT or placebo emulsion at weeks 0, 1, 3, 24, and 52. The primary end point was survival, and secondary end points were tolerability, Karnofsky performance.. A total of 154 patients were recruited: 79 G17DT and 75 placebo. A final analysis of the intention-to-treat population, using a proportional hazards model, stratifying by disease stage and adjusting for interim analysis, gave a hazard ratio for mortality of 0.75 (95% confidence interval, 0.51-1.10, P = 0.138; G17DT/placebo). A conventional analysis without adjustment for disease stage or interim analysis, censoring for chemotherapy and excluding protocol violators, gave median survival periods of 151 (G17DT) and 82 days (placebo) (log-rank test, P = 0.03).Patients developing anti-G17DT responses (73.8%) survived longer than nonresponders or those on placebo (median survival, 176 vs 63 vs 83; log-rank test, P = 0.003). G17DT was well tolerated.

Topics: Adult; Aged; Aged, 80 and over; Cancer Vaccines; Double-Blind Method; Europe; Female; Gastrins; Humans; Kaplan-Meier Estimate; Karnofsky Performance Status; Life Expectancy; Male; Middle Aged; Pancreatic Neoplasms; Placebos; Proportional Hazards Models; Prospective Studies; Time Factors; Treatment Outcome

Nonsteroid anti-inflammatory drugs represent an important osteoarthritis (OA) therapy component, but also a leading cause of gastropathy: one of the most frequent and serious OA therapy complications. The aim of the present study was to study the influence of GI health in an OA population receiving either ginger or diclofenac.. Forty-three (43) patients with confirmed OA (knee and hip) were included in a randomized controlled study. A ginger group of 21 patients (17 women, 4 men) was given a specific ginger combination daily (340 mg EV.EXT 35 Zingiber officinalis extract) for 4 weeks. A diclofenac group (positive control) of 22 patients (18 women, 4 men) received 100 mg diclofenac daily for the same period. Both groups also received 1000 mg glucosamine daily. Gastrointestinal pain and dyspepsia were evaluated according to the severity of dyspepsia assessment (SODA) form. Patients also underwent esophagogastroduodenoscopy (EGDS) including biopsy before and after the treatment. Serum gastrin-17 levels, and stomach mucosa prostaglandins (PG) E1, E2, F2α, and 6-keto PGF1α (PGI2) levels were measured. Arthritic pain was evaluated using the visual analogue scale (VAS) on standing and moving.. The ginger group showed a slight but significantly lowered SODA pain and no change of SODA dyspepsia. EGDS showed significantly increased levels of PGE1, PGE2, and PGF2α in the stomach mucosa. This rise in gastric mucosa PG levels correlated with an increase in serum gastrin-17. On the other hand, the diclofenac group showed increased SODA pain and dyspepsia values with a corresponding significant decrease of stomach mucosa prostaglandins and general negative stomach mucosa degeneration. Both groups showed a relevant and significantly lowered VAS pain both on standing and moving.. The ginger combination is as effective as diclofenac but safer in treating OA, being without effect on the stomach mucosa. The increased mucosal PGs synthesis in the ginger group supports an increased mucosa-protective potential. VAS; visual analogue scale, 0-100 mm.

Topics: Abdominal Pain; Alprostadil; Anti-Inflammatory Agents, Non-Steroidal; Diclofenac; Dinoprost; Dinoprostone; Dyspepsia; Endoscopy, Digestive System; Female; Gastric Mucosa; Gastrins; Hip; Hip Joint; Humans; Knee; Knee Joint; Male; Middle Aged; Osteoarthritis, Hip; Osteoarthritis, Knee; Pain Measurement; Phytotherapy; Plant Extracts; Severity of Illness Index; Zingiber officinale

The article presents the results of the first Russian open randomized comparative multicenter study on the effectiveness of Famotidine in the prevention of NSAID-gastropathy--Barrier. In addition, were showen the results of studies of the drugs effect used for prevention of NSAID gastropathy (Famotidine, Lansoprazole, Misoprostol) for the synthesis of prostaglandins in the gastric mucosa in patients with osteoarthritis. Was shown the impact of alternative anti-inflammatory drug on the basis of an extract of ginger as joint pain, and the mucous upper gastrointestinal tract in patients with osteoarthritis.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Anti-Ulcer Agents; Diclofenac; Famotidine; Gastric Mucosa; Gastrins; Humans; Middle Aged; Peptic Ulcer; Prostaglandins; Treatment Outcome

Serological biomarkers can be used for non-invasive diagnosis of gastritis and atrophic gastritis. The aim of this study was to compare the validity of serum levels of pepsinogen I (PGI) and II (PGII), gastrin-17 (G-17) and Helicobacter pylori antibodies (Hpab) with that of the gold standard histology for diagnosis of atrophic gastritis in a population sample from Northern Sweden.. In all, 1000 subjects underwent endoscopies with biopsies. Serum biomarkers were available in 976 subjects for independent diagnosis of gastric mucosal status using a predetermined diagnostic algorithm.. Overall agreement between histology and serological biomarkers in diagnosing corpus atrophy was 96% (CI 95%: 95-97%). Sensitivity and specificity of markers for atrophic gastritis were 71% (CI 68-74%) and 98% (CI 97-99%) respectively, corresponding to 69% (CI 95%: 66-72%) and 98% (95% CI 97-99%) positive and negative predictive values. The positive likelihood ratio was 35.5 (95% CI: 35.0-36.0%). In subgroups with normal stomachs, H. pylori non-atrophic gastritis and H. pylori-negative gastritis by histology, the prevalence of corpus atrophy diagnosed with the biomarkers was 0.8% and 4.9%, respectively. In total, 6.6% of subjects in the study population had corpus atrophy according to the serological biomarkers. CONCLUSIONS. Serological biomarkers show a high degree of accuracy as a non-invasive method to diagnose corpus atrophy, which is common in the general population.

Topics: Antibodies, Bacterial; Biomarkers; Female; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Reproducibility of Results; Sensitivity and Specificity

The aim of this study was to assess the gastric histopathology and serum gastrin-17 and pepsinogens profiles in patients with duodenal ulcer before and after Helicobacter pylori eradication in a population with a very high prevalence of H. pylori. At the same time we assessed the role of H. pylori density on these variables.. Eighty Caucasian patients with H. pylori-associated duodenal ulcer before treatment and 1 year after randomized eradication were studied. Among patients with unsuccessful eradication two groups were distinguished according to the data obtained after treatment: the group with negative rapid urease test and decreased bacterial density according to morphological score (partial elimination group); the group with positive rapid urease test and high bacterial density (failed eradication group).. One year after successful eradication, serum levels of gastrin-17, pepsinogen I and pepsinogen II decreased. Similar changes of serum pepsinogen I and pepsinogen II levels were observed in patients with partial elimination of H. pylori infection. In the group with successful eradication, inflammation, activity, atrophy and number of lymphoid follicles in the antral mucosa fell. In the group with partial elimination, antral mucosa activity and H. pylori score reduced. Other morphological changes were statistically non-significant.. Patients with duodenal ulcer after successful eradication have improvement of morphological and functional characteristics of gastric mucosa.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Antibodies, Bacterial; Biomarkers; Down-Regulation; Drug Therapy, Combination; Duodenal Ulcer; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Proton Pump Inhibitors; Time Factors; Treatment Failure; Treatment Outcome; Urease; Young Adult

Noninvasive diagnosis of atrophic gastritis would help to identify individuals at increased risk of gastric carcinoma. In the present study, we evaluated the utility of a serological panel combining pepsinogen I and II, gastrin-17, and anti-Helicobacter pylori antibodies (Gastropanel) as a screening method for atrophic gastritis.. The serological panel was evaluated in 56 patients divided in two groups: group 1 consisted of 47 patients with uninvestigated dyspepsia and group 2 was composed of nine consecutive patients with gastric carcinoma. In all patients, we performed endoscopy with biopsies of the gastric antrum and body. Levels of pepsinogen I and II, gastrin-17, and anti-H. pylori antibodies were determined through a specific EIA test (Biohit plc, Helsinki, Finland) in fasting serum samples.. Atrophic gastritis was significantly more frequent in patients with gastric carcinoma than in those with dyspepsia (56 vs 6%; p = 0.0015). Agreement between the Gastropanel and gastric histology was good (kappa = 0.68). The sensitivity and specificity of the Gastropanel in the diagnosis of atrophic gastritis was 87.5% and 100%, respectively. However, the Gastropanel would not have detected four of the nine cases of gastric carcinoma, since these tumors arose in stomachs with nonatrophic mucosa.. Gastropanel is a useful noninvasive method for the diagnosis of atrophic gastritis. However, its utility as a screening method is limited by cases of gastric carcinoma that arise in stomachs without atrophic mucosa.

Topics: Adult; Aged; Antibodies, Bacterial; Female; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Male; Pepsinogen A; Pepsinogen C; Serologic Tests

The article discloses the results of the duodenal ulcer treatment with a generic of omeprazole (Omizac) in the in-patient hospital and polyclinic conditions, dynamics of the serum gastrin level against the background of the drug application and after its withdrawal, and assessment of the intensity and duration of acid production inhibition in the stomach.

Topics: Adult; Anti-Ulcer Agents; Biomarkers; Dose-Response Relationship, Drug; Drug Administration Schedule; Duodenal Ulcer; Female; Gastrins; Humans; Male; Omeprazole; Treatment Outcome

To assess the possibility of non-invasive screening of atrophic chronic gastritis for preventing further development of gastric cancer.. One hundred and seventy-eight consecutive Helicobacter pylori (H pylori)-positive dyspeptic patients after detection of serum levels of pepsinogen-1 (PG-1) and gastrin-17 (G-17) by enzyme immunoassay were proposed for endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.. There was statistically significant reverse dependence between the grade of stomach mucosal antral or corpus atrophy and the proper decreasing of serum G17 or PG1 levels. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values.. Detection of serum G-17 and PG1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopy with mucosal biopsy, for revealing probable progressing of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer.

Topics: Atrophy; Biomarkers; Biopsy; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Immunoenzyme Techniques; Mass Screening; Pepsinogen A; Precancerous Conditions; Sensitivity and Specificity

The antral hormone gastrin is synthesized by processing progastrin into different peptides that stimulate gastric secretion. The effect on acid secretion depends mainly on the metabolic clearance rate of the peptides, but some of them may differ in potency and maximum acid output at similar concentrations in plasma. Sulfated and nonsulfated gastrin-6 are the smallest circulating bioactive gastrins in humans. Their effect and metabolism have now been investigated in nine normal subjects and compared with nonsulfated gastrin-17, a main product of progastrin. Maximum acid output after stimulation with gastrin-17, sulfated gastrin-6, and nonsulfated gastrin-6 were 28.3 +/- 2.0, 24.5 +/- 2.0 (P < 0.02), and 19.3 +/- 2. 3 (P < 0.05) mmol H(+)/50 min, respectively, and the corresponding EC(50) values were 43 +/- 6, 24 +/- 2 (P < 0.01), and 25 +/- 2 (not significant) pmol/l. The half-life of gastrin-17 was 5.3 +/- 0.3 min, the metabolic clearance rate (MCR) was 16.5 +/- 1.3 ml. kg(-1). min(-1), and the apparent volume of distribution (V(d)) was 124.3 +/- 9.6 ml/kg. The half-lives of sulfated and nonsulfated gastrin-6 were 2.1 +/- 0.3 and 1.9 +/- 0.3 min, the MCRs were 42.8 +/- 3.7 and 139.4 +/- 9.6 ml kg(-1) min(-1) (P < 0.01), and the V(d) were 139.0 +/- 30.5 and 392.0 +/- 81.6 (P < 0.01) ml kg(-1). All pharmacokinetic parameters differed significantly from gastrin-17 (P < 0.01). We conclude that gastrin 6 has a higher potency but a lower efficacy than gastrin-17. The efficacy of gastrin-6 is increased by tyrosine O-sulfation, which also enhances the protection against elimination.

Topics: Adult; Chromatography, Gel; Female; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Male; Peptide Fragments; Pyloric Antrum; Sulfates

Seven healthy volunteers were intubated with two double lumen nasogastric tubes, one in the stomach, the other in the duodenum. This system allows simultaneous sampling of gastric juice and separate intraduodenal perfusion with a dietary fat (fish oil, 1269 kJ). Gastrin-17 was infused i.v. at a rate of 40 pmol/kg/h throughout the study. Gastric lipase was measured at 15-min intervals as activity (tributyrin) and as immunoreactivity (ELISA). Infusion of gastrin-17 resulted in a stable increase in the plasma concentration from a basal concentration of 8.3 +/- 0.8 pmol/l to 41.4 +/- 4.2 pmol/l. Perfusion with fat reduced gastric lipase activity from 24.2 +/- 5.3 to 7.2 +/- 2.5 kU/l (P < 0.05), and immunoreactivity from 0.7 +/- 0.1 to 0.42 +/- 0.1 mg/l (P < 0.05). After termination of fat perfusion, gastric lipase secretion increased again, though not reaching preinhibitory concentrations. During the intraduodenal perfusion with fat the plasma concentrations of glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) increased from 6.9 +/- 0.5 to 15.1 +/- 1.5 pmol/l (P < 0.05) and from 1.2 +/- 0.4 to 3.8 +/- 0.9 pmol/l (P < 0.05). This study reveals a negative effect of fat in the duodenum on gastric lipase secretion. This effect may be mediated by GLP-1 and/or CCK.

Topics: Adult; Cholecystokinin; Duodenum; Fats; Female; Fish Oils; Gastric Acid; Gastrins; Glucagon; Glucagon-Like Peptide 1; Humans; Lipase; Male; Peptide Fragments; Protein Precursors; Reference Values; Secretin; Stomach

The effect of gastrin on the migrating motility complex (MMC) was studied in seven healthy subjects. It was hypothesized that a potential effect of gastrin on the MMC may result from intraluminal acidification through increased gastric acid secretion. Therefore, antroduodenal manometry and intraluminal acidity were recorded simultaneously. The effect of gastric acid inhibition, with and without administration of gastrin, on antroduodenal motility and intraluminal acidity was also evaluated and compared with saline infusion (control). Continuous infusion of gastrin-17 (20 pmol. kg-1. h-1) increased intragastric and intraduodenal acidity and suppressed phase II and phase III motor activity in both antrum and duodenum. Concomitant gastric acid inhibition with intravenous famotidine, as demonstrated by intragastric neutralization of pH, completely antagonized the effect of gastrin on the MMC. In fact, famotidine infusion, both with and without administration of gastrin, significantly shortened MMC cycle length. It is concluded that the effect of gastrin on interdigestive antroduodenal motility results from increased intraluminal acidity.

Topics: Adolescent; Adult; Duodenum; Famotidine; Female; Gastric Acid; Gastrins; Gastrointestinal Motility; Humans; Hydrogen-Ion Concentration; Infusions, Intravenous; Male; Middle Aged; Muscle, Smooth; Myoelectric Complex, Migrating; Single-Blind Method; Time Factors

We studied the effect of gastrin-17 on lower esophageal sphincter (LES) characteristics in man. Nine healthy volunteers participated in two experiments performed in random order during continuous infusion of saline (control) or gastrin-17 (15 pmol/kg/hr). LES pressure (LESP) and transient lower esophageal sphincter relaxations (TLESR), as most the important reflux mechanism, were measured with intraesophageal sleeve manometry combined with pH metry. Infusion of gastrin-17 resulted in plasma gastrin levels comparable to those reached after a mixed meal. During continuous gastrin infusion, LESP decreased significantly (P < 0.05) compared to control. The rate and duration of TLESR was not influenced by gastrin-17. Gastroesophageal reflux and the number of TLESR associated with reflux were significantly (P < 0.05) increased during gastrin infusion. These results suggest that in humans gastrin at physiological postprandial plasma concentrations decreases LESP, does not influence TLESR, but increases the percentage of TLESR associated with reflux.

Topics: Adult; Esophagogastric Junction; Female; Gastrins; Gastroesophageal Reflux; Hormones; Humans; Hydrogen-Ion Concentration; Injections, Intravenous; Male; Manometry; Muscle Relaxation

CCK8 is a poor stimulant of gastric acid secretion in vivo, but is equipotent to gastrin-17 (G17) in in vitro systems. To further evaluate the role of cholecystokinin (CCK) in regulating acid output in humans, dose-response curves were constructed to CCK8 or G17 (6.4-800 pmol kg-1 per h) with and without a specific CCK-A receptor antagonist (loxiglumide). During loxiglumide infusion, G17-stimulated acid output was unchanged, whereas CCK8-stimulated secretion increased significantly. Gastric somatostatin-14 release increased fivefold with CCK8 alone, but was blocked with loxiglumide administration. These data suggest that CCK8 directly stimulates acid secretion by binding to a CCK-B/gastrin receptor on parietal cells, but at the same time inhibits acid responses by stimulating gastric somatostatin release to a CCK-A receptor-mediated pathway. To test which action of CCK is relevant under physiological circumstances, the effect of loxiglumide on fasting and post-prandial acidity was measured through continuous pH-metry. After eating, gastrin levels increased fourfold compared to controls with concomitant increases in acid secretion. These results suggest that post cibum, CCK is an inhibitor of acid secretion by regulating gastrin through local somatostatin; they support the hypothesis that CCK acts as an enterogastrone.

Topics: Adult; Cholecystokinin; Dose-Response Relationship, Drug; Drug Interactions; Eating; Gastric Acid; Gastric Mucosa; Gastrins; Homeostasis; Hormones; Humans; Male; Middle Aged; Proglumide; Sincalide; Somatostatin

It is still controversial whether gastrin stimulates acid secretion by interacting with specific gastrin receptors on parietal cells or via endogenous mediators, e.g., histamine. Therefore, it was our aim to determine in healthy human volunteers (n = 14; 3 females, 11 males; age 23-28 years) the degree by which the specific histamine H2-receptor antagonist famotidine or the muscarinergic antagonist atropine block acid secretion in response to synthetic human gastrin (hG) (1-17). Famotidine was deliberately administered at a supramaximal dose (40 mg i.v. bolus) to reliably block any and all effects of endogenous histamine on the parietal cells. After an overnight fast famotidine or saline were injected i.v., and gastric secretions were collected via a nasogastric tube for the ensuing 60 min to assess basal secretion. Thereafter, hG (1-17) was infused for 60 min in randomized order at two different rates: 0.75 ng/kg/min resulting in postprandial plasma gastrin levels (55-66 pg/ml), and 1.5 ng/kg/min yielding supraphysiologic levels (110-136 pg/ml). Both rates increased basal acid secretion (meq/10 min) from 0.5 +/- 0.2 to 3.8 +/- 0.6 and 4.7 +/- 0.5, respectively. Famotidine abolished basal acid secretion and completely blocked acid and volume secretion in response to both hG (1-17) doses. After injection of famotidine both hG (1-17) doses resulted in plasma levels exceeding those in controls by 18-27 pg/ml. A similar increase (14-16 pg/ml) was observed after famotidine injection without simultaneous hG (1-17) infusion indicating that this increase was due to the release of endogenous gastrin when the acid feedback inhibition was blocked by famotidine. To study a potential additional role of cholinergic mechanisms the effect of atropine (7 micrograms/kg i.m.) on hG (1-17)-induced acid secretion was examined. Atropine reduced basal acid secretion from 0.8 +/- 0.1 to 0.1 +/- 0.08 meq/15 min. Similarly, the response to 0.75 ng/kg/min hG (1-17) was reduced by 72.9%. Basal gastrin release was not altered by atropine which, however, tended to increase serum gastrin levels during infusion of hG (1-17) by 16-24 pg/ml. We conclude that in man histamine and muscarinic mechanisms are essential mediators of gastrin-stimulated acid secretion. The present data argue against a significant direct effect of gastrin alone on human parietal cells but rather support potentiating interaction with histamine and cholinergic mechanisms.

Topics: Adult; Atropine; Eating; Famotidine; Female; Gastric Acid; Gastrins; Histamine H2 Antagonists; Humans; Hydrogen-Ion Concentration; Infusions, Intravenous; Injections, Intravenous; Male; Muscarinic Antagonists; Random Allocation

The metabolism of synthetic human sulfated heptadecapeptide gastrin (G-17) was studied in normal human volunteers. Plasma concentrations were measured by radioimmunoassay using antibodies specific for intact G-17, and for the C- and N- terminus of G-17, during and after infusion of both sulfated and unsulfated G-17. With all three antibodies, plasma concentrations at a steady state were higher during infusion of sulfated compared with unsulfated G-17. In addition, the half-life in plasma measured by the three antibodies was two to five times higher for sulfated G-17 compared with unsulfated G-17. The half-life measured by N-terminal-specific antibodies was greater than that with antibodies specific for C-terminal or intact G-17. The difference was accounted for by the production during infusion of N-terminal fragments of relatively long half-life. The pattern of fragments generated during infusion of sulfated G-17 resembled that during unsulfated G-17 infusion, but there was no evidence of desulfation in the systemic circulation. The results indicate that in humans, sulfation protects G-17 from metabolism.

Topics: Adult; Female; Gastrins; Half-Life; Humans; Male; Middle Aged; Protein Conformation; Radioimmunoassay; Random Allocation; Sulfates

Eighty women (40 for elective Caesarean section and 40 for elective gynaecological surgery) were randomly assigned to one of five treatment groups and received pre-operatively either no medication; magnesium trisilicate mixture (BP) 30 ml; metoclopramide 10 mg intramuscularly; ranitidine 150 mg orally on the night prior to, and the morning of, surgery; or metoclopramide 10 mg intramuscularly in combination with oral ranitidine 150 mg (the latter again given on the night prior, and the morning, of surgery). The effect of these medications on intragastric pH, volume and serum gastrin-17 was measured. No patient receiving ranitidine had a pH of less than 4. Magnesium trisilicate mixture resulted in the largest intragastric pH change although one woman in this group had a pH of 1.7. The largest intragastric volumes were seen in the patients who had received magnesium trisilicate mixture, whilst the patients who had received metoclopramide in combination with ranitidine had the smallest intragastric volumes. Magnesium trisilicate mixture and metoclopramide resulted in no change in serum gastrin levels. However, in the subjects who had received ranitidine on the night prior to surgery, the fasting serum gastrin was significantly higher (p less than 0.01) than the values in the remaining subjects, the mean (SEM) values being 60.3 (6.3) pg/ml in those not receiving ranitidine and 111.3 (19.5) pg/ml in those who had been given ranitidine.

Topics: Adult; Antacids; Drug Therapy, Combination; Female; Gastrins; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Silicates; Metoclopramide; Pneumonia, Aspiration; Pregnancy; Premedication; Ranitidine; Silicic Acid; Silicon Dioxide; Stomach

A highly sensitive and convenient amplified luminescent proximity homogeneous assay (AlphaLISA) method with high throughput and automation potential was developed for quantitation of serum Gastrin-17 (G-17) levels, which can facilitate the early diagnosis of atrophic gastritis in people at high risk of gastric cancer using a non-invasive approach. In this study, donor and acceptor beads with modified carboxyl groups on the surface were directly coupled to anti-G-17 antibodies through activation was proposed for application in the development of the new AlphaLISA, which can effectively simplify the steps and shorten the reaction time to achieve faster detection. Therefore, the G-17-AlphaLISA only needs to react for 15 min to obtain good analysis results. The proposed method has a wider detection range than commercial enzyme-linked immunosorbent assay (ELISA) kits (0.12-112.8 pmol/L > 0.5-40 pmol/L). In addition, results of G-17-AlphaLISA and ELISA had good correlation and agreement (ρ = 0.936). Importantly, the developed method may be more suitable for the large-scale screening of people at high risk for gastric cancer than traditional ELISA and provides a novel solution for other biomarkers that require accurate, highly sensitive, and high throughput detection.

Topics: Antibodies; Enzyme-Linked Immunosorbent Assay; Gastrins; Humans; Luminescent Measurements; Stomach Neoplasms

The aim of the study was to determine the proportion of gastric cancer patients with decreased levels of pepsinogen and gastrin-17 in plasma, with the goal of providing indirect evidence of the sensitivity of these biomarkers when applied in a cancer screening setting.. The levels of pepsinogens I and II, gastrin-17, and Helicobacter pylori immunoglobulin antibodies in plasma samples of gastric cancer patients were evaluated using the GastroPanel test system (Biohit Oyj, Helsinki, Finland). A decreased level of the pepsinogen I/II ratio was defined as less than three, while a decrease in gastrin-17 was defined as less than 1 pmol/L. Univariate analysis using non-parametric tests was used to investigate differences between normal and low concentrations of biomarkers.. In total, 481 plasma samples from patients (59.9% male) with a median age of 64 years (ranging from 27 to 88 years) were analyzed. Out of the 400 cases of gastric cancer (83.2% of the total), 182 were categorized as the intestinal type, 141 as the diffuse type, 60 as the mixed type, and 17 as indeterminate according to the Lauren classification system. The H. pylori immunoglobulin test was positive in 74.0% of the patients. Pepsinogen I/II ratio was decreased in 32.4% (36.8% of the intestinal type); gastrin-17 in 12.3% (10.1% of the antral region) of all cases.. The majority of gastric cancer patients had normal levels of pepsinogen and gastrin-17, suggesting that these biomarkers have limited application as screening tools in the Caucasian population.

Topics: Antibodies, Bacterial; Biomarkers; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Stomach Neoplasms

To analyze the difference of serum gastrin-17 (G17) level in healthy people with different sex, age, and body mass index (BMI), to explore the correlation between G17 and pepsinogen, and to study the influences of Helicobacter pylori (H. pylori) infection and various inflammatory factors on G17 secretion level.. A total of 531 subjects who received physical examination in our center from April 2019 to December 2019 were enrolled in the study. All subjects were tested for G17, pepsinogen I (PGI), pepsinogen II (PGII), PGI/PGII ratio (PGR), H. pylori, serum amyloid A (SAA), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The difference of G17 secretion in different subjects and its correlation with PG were analyzed to investigate H. pylori infection and expound the effects of inflammatory indicators on G17.. There was no significant difference in G17 secretion level in people with different sex, age and BMI (p > .05). G17 positively correlated with PGI and PGII, but negatively correlated with PGR. The G17 level of H. pylori-positive subjects was 10.16 ± 12.84, and prominently higher than that of H. pylori-negative subjects (3.27 ± 6.65). SAA and H. pylori infection were the greater risk factors for G17 abnormality among various indicators. CRP and ESR had no effect on G17 abnormality.. G17 secretion is closely related to PG and H. pylori. Combined screening contributes to early screening of gastrointestinal diseases in normal people or groups at high risk for gastric cancer, but the influence of inflammatory indicators on G17 should be excluded to improve the reliability of the results.

Topics: Gastric Mucosa; Gastrins; Humans; Pepsinogen A; Pepsinogen C; Physical Examination; Reproducibility of Results

In this study, we developed a novel magnetic lateral flow assay based on iron oxide decorated with platinum probes (Fe

Topics: Gastrins; Immunoassay; Limit of Detection; Magnetic Phenomena; Metal Nanoparticles; Peroxidase

Non-endoscopic tools for the diagnostic evaluation of patients should be promoted in the field of biomedical assay and the need for highly sensitive, efficient, low-cost, and user-friendly sensors must be considered. Optical fibers are widely used in sensors because their properties meet the physical requirements for biomedical detection. The spectrum responses of the sensor create changes in refractive index, wavelength shifts, and transmission loss. This study presents a double helix DNA-shaped optical fiber sensor for biosensors. The sensing principle of the DNA-shaped sensor is based on the whispering gallery mode (WGM) formed by the interference in the fiber's bending region. The refractive index interference changes corresponding to the core and cladding layers, which create shifts in the spectrum affected by the radius of the bend. A self-assembled sensor layer formed with nanoparticles was coated onto the DNA-shaped sensor in a sandwich structure. The wavelength shifts in spectral response are traced by the concentrations of gastrin-17 at 0.1, 1, 10, and 50 μg ml

Topics: DNA; Gastrins; Gold; Humans; Metal Nanoparticles; Optical Fibers

In Mongolia, gastric cancer morbidity and mortality are high, and more than 80 percent of cases are diagnosed at an advanced stage. This study aimed to evaluate pepsinogens (PGIs) and gastrin-17 (G-17) levels and to determine the diagnostic performances for gastric cancer and chronic atrophic gastritis among Mongolian individuals. We enrolled a total of 120 subjects, including gastric cancer (40), atrophic gastritis (40), and healthy control (40), matched by age (±2) and sex. Pepsinogen I (PGI), Pepsinogen II (PGII), G-17, and H. pylori IgG levels were measured using GastroPanel ELISA kit (Biohit, Helsinki, Finland). Also, PGI to PGII ratio (PGR) was calculated. For atrophic gastritis, when the optimal cut-off value of PGI was ≤75.07 ng/ml, the sensitivity and specificity were 75% and 50%, respectively; when the optimal cut-off value of PGR was ≤6.25, sensitivity and specificity were 85% and 44.7%, respectively. For gastric cancer, when the optimal cut-off value of PGI was ≤35.25 ng/ml, the sensitivity and specificity were 47.2% and 86.8%, respectively; when the optimal cut-off value of PGR was ≤5.27, sensitivity and specificity were 75% and 60.5%, respectively. Combinations of biomarkers with risk factors could improve diagnostic accuracy (AUC for atrophic gastritis 74.8, 95% CI 64.0-85.7, p<0.001; AUC for gastric cancer 75.5, 95% CI 64.2-86.8, p<0.001). PGI, PGR biomarkers combined with the risk of age, family history of gastric cancer, and previous gastric disease could not be an alternative test for upper endoscopy but might be a supportive method which is identifying individuals at medium- and high risk of gastric cancer and precancerous lesions who may need upper endoscopy.

Topics: Biomarkers; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Pepsinogen A; Pepsinogen C; Stomach Neoplasms

In this study, a novel, simple, and rapid immunoassay for the determination of gastrin-17 (G-17) in human serum was established by combining immunomagnetic beads with time-resolved fluorescence immunoassay (TRFIA).. Immunomagnetic beads were coated with anti-G-17 M01 antibody, anti-G-17 M02 antibody was labeled with Eu. A novel G-17-TRFIA detection method was successfully established to provide a reference for the early diagnosis of patients with atrophic gastritis in clinical research.

Topics: Antibodies; Enzyme-Linked Immunosorbent Assay; Fluoroimmunoassay; Gastrins; Humans; Immunomagnetic Separation; Time Factors

Prompted by the increasing demand of non-invasive diagnostic tools for screening of gastric cancer (GC) risk conditions, i.e., atrophic gastritis (AG) and Helicobacter pylori (Hp) infection, the GastroPanel. Altogether, 522 patients were enrolled among the patients referred for gastroscopy at the Gastro Center, Oulu University Hospital (OUH). All patients underwent gastroscopy with biopsies classified using the Updated Sydney System (USS), and blood sampling for GP testing.. The new generation GastroPanel

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biomarkers; Biopsy; Enzyme-Linked Immunosorbent Assay; Female; Finland; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Host-Pathogen Interactions; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Predictive Value of Tests; Referral and Consultation; Reproducibility of Results; Serologic Tests; Young Adult

In clinical practice, most patients with symptoms suggestive of gastroesophageal reflux disease (GERD) undergo esophago-gastro-duodenoscopy (EGD), despite its low sensitivity in detecting reflux stigmata. Gastrin 17 (G-17) has been proposed to be related with GERD, due to the negative feedback between acid secretion and this hormone. We assessed the clinical usefulness of fasting G-17 serum determination for a non-invasive diagnosis of GERD in patients with typical symptoms.. We consecutively enrolled patients complaining of typical GERD symptoms in two different settings: a single referral center and a primary care setting. Control groups consisted of dyspeptic patients. All subjects underwent assessment of serum levels of G-17 and EGD.. At the academic hospital, 100 GERD patients (n=89 with erosive esophagitis and 11 with Barrett's esophagus) had statistically significant low levels of G-17 as compared with 184 dyspeptic patients (1.7±1.2 pg/L vs 8.9±5.7 pg/L p<0.0001). Similarly, in the primary care setting, 163 GERD patients had statistically significant low levels of G-17 as compared with 132 dyspeptic patients (0.5±0.2 pg/L vs. 4.0±2.6 pg/L, p<0.0001). Moreover, in the primary care setting, no statistically significant differences were found for G-17 levels between patients with erosive and non-erosive reflux pattern (0.4±0.2 vs 0.7±0.3; p=0.08). In primary care, the accuracy of G-17 less than 1 pg/L to diagnose non-invasively GERD was 94.3%.. Low levels of G-17 were detected in patients with erosive esophagitis and Barrett's esophagus in a referral center and in patients with typical GERD symptoms in a sample of patients from a primary care setting.

Topics: Adult; Aged; Esophagitis, Peptic; Esophagoscopy; Female; Gastrins; Gastroesophageal Reflux; Humans; Male; Middle Aged

Gastric cancer (GC) is one of the most common cancers, with most patients often succumbing to death as a result of tumor metastasis. Recent work has demonstrated that gastrin is closely associated with GC metastasis. However, the specific molecular mechanisms underlying this relationship remain to be unveiled. In this study, we assessed the impact of gastrin and the Wnt/β-catenin inhibitor XAV939 on the epithelial-mesenchymal transition (EMT) of the SGC-7901 and MKN45 GC cell lines, and we determined that gastrin-17 significantly decreased E-cadherin expression and upregulated the expression of Snail1 and N-cadherin in GC cells. In addition, gastrin 17 also significantly increased the expression of Wnt3α in a dose-dependent manner. Consistent with these results, gastrin-17 promoted GC cell invasion, proliferation, and migration in a dose-dependent fashion, and these effects were inhibited by XAV939. Together, these results indicated that gastrin-17 induced GC cell EMT, migration, and invasion via the Wnt/β-catenin signaling pathway, which suggests that this gastrin/Wnt/β-catenin signaling axis may represent a therapeutic target for the prevention of GC metastasis.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Epithelial-Mesenchymal Transition; Gastrins; Humans; Snail Family Transcription Factors; Stomach Neoplasms; Wnt Signaling Pathway

Patients with autoimmune atrophic gastritis (AAG) often complain of acid reflux symptoms, despite the evidence of hypo-achlorhydria. Rome IV criteria are used to define functional esophageal disorders. Our aim was to characterize gastroesophageal reflux disease (GERD) phenotypes in patients with AAG.. Between 2017-2018, 172 AAG patients were evaluated at Gastro-Oncology outpatient clinic of University of Padua. Of them, 38 patients with reflux symptoms underwent high-resolution manometry (HRM) and multichannel intraluminal impedance-pH monitoring (MII-pH). Seventy-six AAG consecutive patients asymptomatic for gastroesophageal reflux were selected as age and gender matched controls. Serum biomarkers (pepsinogens, gastrin-17 and Helicobacter pylori antibodies), upper endoscopy, histology and clinical data were compared.. Out of 38/172 (22%) AAG patients with reflux symptoms, 2/38 had a GERD diagnosis based on abnormal esophageal acid exposure and 6/38 had a major motility disorder (i.e. outflow obstruction). Among the 30/38 patients with normal endoscopic findings, 9/30 had reflux hypersensitivity, 19 functional heartburn, 1 functional globus, 1 functional chest pain according to the Rome IV criteria. Antral atrophy, advanced corpus atrophy and OLGA stage were more frequent in controls than in reflux patients (p=0.01, p=0.031, p=0.01, respectively). No differences were found for serum biomarkers and symptom presentation. Most of the patients received proton pump inhibitors (PPIs) treatment (87%), with a minority (34%) reporting clinical benefit.. Reflux symptoms are relatively common in AAG patients, but a firm diagnosis of GERD is rare (5%), whereas most of the patients have a functional disorder. PPI treatment is mostly clinical ineffective and should not be largely indicated.

Topics: Aged; Antibodies, Bacterial; Autoimmune Diseases; Biomarkers; Endoscopy, Digestive System; Gastrins; Gastritis; Gastroesophageal Reflux; Helicobacter pylori; Humans; Italy; Male; Middle Aged; Pepsinogens; Prospective Studies; Proton Pump Inhibitors

In order to explore the changes of intestinal flora and serum levels of relevant substances in patients with gastric cancer before and after surgery with carbon nanoparticle laparoscopy, a total of 180 patients with early distal gastric cancer who adopted laparoscopic radical gastrectomy for distal gastric cancer in the general surgery department of TCM Hospital of Shi Jia Zhuang City from January 2018 to January 2020 were selected and randomly divided into two groups: traditional laparoscopic operation (control group) and carbon nanoparticle laparoscopic operation (experimental group) were adopted for treatment for the two groups, respectively. Postoperative evaluation included the difference between the two groups in the operative time, the efficiency of intraoperative lymph node dissection, and the number of lymph node detection. The adverse reactions, changes of intestinal flora before and after surgery in the two groups, and the serum levels of epidermal growth factor receptor (EGFR), interleukin-32 (IL-32), and gastrin 17 were evaluated. In the experimental group, the success rate of carbon nanoparticle tracer black staining reached 100%, and the operation time of the experimental group was significantly shorter than that of the control group (

Topics: Carbon; Dissection; ErbB Receptors; Female; Gastrectomy; Gastrins; Gastrointestinal Microbiome; Humans; Interleukins; Laparoscopy; Lymph Node Excision; Lymph Nodes; Lymphatic Metastasis; Male; Middle Aged; Nanoparticles; Sentinel Lymph Node; Stomach Neoplasms

We describe a case of Ménétrier disease, occurred in female patient.. We decide to assess by non-invasive way (serum pepsinogens and gastrin 17) the secretory status of gastric mucosa, to confirm previous data of the literature, claiming high levels of both acid secretion and hypergastrinemia in this rare pathological condition.. We find in the subject the highest values of pepsinogen 1 - a marker of acid secretion - never described in the literature to our knowledge: 1940 mcg/L, being normal values ranging from 30-160 mcg/L. Similarly, gastrin 17, produced 90% in the antrum and responsible for negative acid feedback, was very high: 139 pg/L, ranging normal values between 1-10 pg/L. (www.actabiomedica.it).

Topics: Female; Gastric Mucosa; Gastrins; Gastritis, Hypertrophic; Humans; Pepsinogen A

Two major forms of gastrin, gastrin-17 (G17) and gastrin-34 (G34), exist in blood. However, conventional immunoassay methods can only quantify total gastrin or G17 alone. Here, we aimed to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify G17 and G34 simultaneously.. Serum samples were prepared by anion-exchange solid-phase extraction. The analytical performance of the LC-MS/MS method was validated and the method was compared to chemiluminescence immunoassay (CLIA) and radioimmunoassay (RIA). The G17 and G34 concentrations in 245 serum samples from healthy controls, individuals with gastrinoma, and individuals with other diseases were analyzed.. The total runtime of the LC-MS/MS method was 6 min. No substantial matrix effect was observed with internal standard correction. The intraassay coefficients of variation (CVs) for G17 and G34 were 4.0%-14.2% and 4.4%-10.4%, respectively, and total CVs were 5.2%-14.1% and 4.6%-12.4%, respectively. The correlation coefficient between LC-MS/MS and CLIA was 0.87, and between LC-MS/MS and RIA was 0.84. The G17+G34 concentrations for 87.5% of individuals with gastrinoma were higher than the 95th percentile of healthy controls (18.1 pg/mL), whereas the concentrations for individuals with other diseases and gastrinoma overlapped. Based on the Youden indices calculated for G17+G34, G34, and G17, the most specific biomarker was G17 (96.9% clinical specificity at 209.8 pg/mL) for gastrinoma.. This method should aid in the diagnosis of diseases associated with increased gastrin concentrations.

Topics: Chromatography, Liquid; Gastrinoma; Gastrins; Humans; Pancreatic Neoplasms; Tandem Mass Spectrometry

A hospital-based cross-sectional study in SIGES project was conducted during 2016.5-2017.5 in West China Hospital. It was aimed to observe the prevalence of atrophic gastritis (AG) in southwest China, and assess the diagnostic strength of serum gastrin-17 (G-17) in predicting AG in Chinese population. Asymptomatic healthy controls from health check-up, cancer-free patients with unspecific upper gastrointestinal symptoms, and histologically proven gastric cancer patients were eligible, if serum pepsinogen-I (PG-I), PG-II, and G-17 were detected. AG status was classified by the accredited cutoffs of PG-I (<70 ug/L) and PG-I/II ratio (<3). Totally, healthy controls (n = 9,425), symptomatic patients (n = 671) and gastric cancer patients (n = 305) were simultaneously observed, in which the prevalence of AG in southwest China were estimated as 15.9/1,000, 28.3/1,000, and 55.7/1,000 persons, respectively. The age-specific prevalence of AG in healthy controls showed a significantly uphill trend (p for trend <0.001). Higher level of serum G-17 was significantly associated with increased risk of AG in healthy population (15-30 pmol/L, aOR = 20.67, 95% CI 9.17-46.55; >30 pmol/L, aOR = 314.41, 95% CI 166.10-595.12). Throughout the progression of stomach diseases, the diagnostic strength of serum G-17 for AG showed a downhill trend across more advanced situations. In despite of that, serum G-17 displayed a good performance in predicting AG in the entire cross-sectional population (AUC = 0.92, 95% CI 0.89-0.94; SEN = 85.5%; SPE = 93.2%; LR+ = 12.55; LR- = 0.11). Population in southwest China had intermediate prevalence of AG, while the prevalence was increased over age or disease progression. High level of serum G-17 might be a reliable non-invasive measurement to predict AG in southwest Chinese population.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Cross-Sectional Studies; Female; Gastrins; Gastritis, Atrophic; Humans; Male; Middle Aged; Odds Ratio; Prevalence; Prognosis; ROC Curve; Young Adult

Topics: Area Under Curve; Disease Progression; Early Detection of Cancer; Ethnicity; Gastrins; Gastroscopy; Humans; Male; Middle Aged; Neoplasm Staging; Pepsinogen A; Pepsinogen C; ROC Curve; Stomach Neoplasms

Analysis of serum biomarkers for the assessment of atrophic gastritis (AG), considered as gastric precancerous lesion, is of growing interest and recommended by current guidelines. Our aim was to evaluate the diagnostic performance of a panel of biomarkers (GastroPanel®) for the detection of AG in France, a country of a low gastric cancer (GC) incidence.. In this prospective, multicenter, cross-sectional study, consecutive patients considered at increased risk of GC and undergoing upper endoscopy with gastric biopsies were included. Blood samples were collected for the analysis of GastroPanel® (association of Pepsinogens I and II, Gastrin-17, and Helicobacter pylori serology) using ELISA. The results of GastroPanel® were compared to the results of histology considered as the reference.. Between 2016 and 2019, 344 patients (148 cases with AG, 196 controls without AG) were included. Sensitivity, specificity, positive, and negative predictive values for the detection of AG by GastroPanel® were of 39.9% (95% CI 31.9; 48.2), 93.4% (95% CI 88.9; 96.4), 81.9 (95% CI 71.1; 90.0), and 67.3 (95% CI 61.4; 72.8), respectively. The sensitivity was significantly higher for the detection of severe AG [60.8% (95% CI 46.1; 74.6) P = .015] and corpus AG [61.0% (95% CI 49.2; 72.0), P = .004]. Diagnostic performances of GastroPanel® tended to be better than those of Pepsinogen I alone, but the difference did not reach statistical significance (P = .068).. Serum pepsinogen and GastroPanel® tests show promising results for the detection of AG, especially of corpus AG and severe AG, in patients at high risk of GC in France.

Topics: Adult; Aged; Antibodies, Bacterial; Biomarkers; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; Female; France; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Humans; Incidence; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Prospective Studies; Sensitivity and Specificity; Stomach Neoplasms

Gastrin-17 (G-17) and Helicobacter pylori (H pylori) antibody are widely used in the screening of gastric diseases, especially in gastric cancer. In this study, we aimed to evaluate the value of G-17 and H pylori antibody in gastric disease screening.. Healthy males and females (1368 and 1212, respectively) aged between 21-80 years were recruited for the study. Serum G-17 value was measured using ELISA, and H pylori antibodies were measured using Western blotting. Statistical analyses were performed using the chi-square, Mann-Whitney U, and Kruskal-Wallis H tests.. Serum G-17 level was higher in the H pylori-positive group than in the negative group. Serum G-17 level was higher in the type 1 H pylori-positive group than in the type 2 H pylori-positive group. Further, serum G-17 level was higher in females than in males and showed significant differences among different age-groups, with changes in trend proportional to the age. The positive rate of H pylori infection in all the subjects was 58.29% and did not show a significant difference between males and females. However, it showed significant differences among different age-groups, with the changing trend proportional to the age.. Analysis of serum G-17 level and H pylori antibody typing is valuable in gastric disease screening. Every laboratory should establish its own reference interval for G-17 level.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; China; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Retrospective Studies; Stomach Diseases; Young Adult

Chronic atrophic autoimmune gastritis (CAAG) can lead to the development of gastric neuroendocrine tumors (gNETs) and can be accompanied by other autoimmune diseases. This study aimed to determine, in CAAG patients, the association of gNET development, the prevalence of autoimmune diseases other than CAAG, the association of autoimmunity, and gNET development with pepsinogen I, II, gastrin-17, and Helicobacter pylori infection analysis.. We determined the prevalence of gNETs and other autoimmune diseases and analyzed pepsinogen I and II, gastrin-17 serum levels, and H. pylori infection in all patients diagnosed with CAAG at our hospital between 2013 and 2017.. A total of 156 patients were studied and in 15.4% was observed concomitant gNET. Approximately 68.6% had at least 1 other autoimmune disease at diagnosis of CAAG. Approximately 60.9% had autoimmune thyroiditis, followed by diabetes (19.9%) and autoimmune polyendocrine syndrome (12.8%). CAAG patients with and without gNET had similar rates of comorbidity with other autoimmune diseases, but the pepsinogen I/II ratio was lower in patients with gNET (1.6 vs 4.5, P = 0.018). Receiver operating characteristic curve analyses identified a pepsinogen I/II ratio <2.3 and gastrin-17 levels >29.6 pmol/L as cutoffs distinguishing CAAG patients with gNET from those without. The combined use of these cutoff correctly identified 16 of the 18 CAAG patients with gNET (P = 0.007). H. pylori infection was observed in 28.7% of cases tested but did not associate with gNET.. This study suggests that a low pepsinogen I/II ratio and high gastrin-17 levels characterize patients with CAAG and gNET and confirms the frequent coexistence of CAAG with other autoimmune diseases.

Topics: Adolescent; Adult; Aged; Autoimmune Diseases; Biomarkers; Diagnosis, Differential; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Neuroendocrine Tumors; Pepsinogen A; Pepsinogen C; Prevalence; Retrospective Studies; ROC Curve; Stomach Neoplasms; Young Adult

Screening and timely treatment of precancerous gastric cancer diseases or of gastric cancer in the early stages has important significance in reducing the incidence and mortality of gastric cancer. Gastroscopy and histopathological biopsy are still the gold standards for the diagnosis of gastric diseases. But the application of astroscopy for the screening and diagnosis of gastric diseases is limited. In recent years, serum pepsinogen (PG), gastrin, and Helicobacter pylori (H. pylori) IgG antibodies have become indicators for "serological biopsy" of the gastric mucosa.. From January 2016 to January 2018, a total of 2,394 patients with digestive tract symptoms underwent gastroscopy. According to the endoscopic examination and pathological diagnosis, there were four case groups: 1,376 cases of chronic non-atrophic gastritis, 708 cases of chronic atrophic gastritis, 265 cases of gastric ulcer, and 45 cases of gastric cancer. Serological gastric biopsies were performed and analyzed.. The serum levels of PGI in the chronic atrophic gastritis group was significantly lower than that in the chronic non-atrophic gastritis group, gastric ulcer group, and gastric cancer group (p < 0.05). The serum levels of PGII and G-17 in the gastric cancer group were significantly higher than those in the chronic non-atrophic Gastritis group, chronic atrophic gastritis group, and gastric ulcer group (p < 0.05). The PGR in the gastric cancer group was significantly lower than that in the chronic non-atrophic gastritis group, chronic atrophic Gastritis group, and gastric ulcer group (p < 0.05). The H. pylori positive rates in the chronic atrophic gastritis group and gastric cancer group were higher than those in the chronic non-atrophic gastritis group and gastric ulcer Group (p < 0.05).. Serological gastric biopsy is closely correlated to gastric mucosal disease and can be used as a Screening tool in gastric disease.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biomarkers; Biopsy; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Sensitivity and Specificity; Stomach Neoplasms; Young Adult

Autoimmune atrophic gastritis (AAG) is an immune-mediated disorder characterised by destruction of gastric oxyntic mucosa AIM: To explore gastric histopathological evolution in a cohort of AAG patients over a prolonged follow-up METHODS: Single centre prospective study enrolling consecutive patients with histologically confirmed AAG between 2000 and 2018. All AAG patients undergoing endoscopic follow-up every 1-3 years were classified as having stages 1, 2 or 3 according to atrophy severity (mild, moderate and severe). AAG patients with either glandular or neuroendocrine dysplasia/neoplasia were classified as having stage 4. Disease stage progression, and changes in serum anti-parietal cell antibody (PCA), chromogranin A and gastrin-17 were assessed.. In total, 282 AAG patients (mean age 60.3 years; F:M ratio 2.4:1; median follow-up 3 years, interquartile range 1-7) were enrolled. All patients with stages 1 or 2 progressed to stage 2 or 3 over time with a steady trend (P = .243) and regression from a severe to a milder stage was never noticed. Disease progression of patients with stages 1 or 2 occurred within the first 3 years. PCA positivity rate did not change over time. Stage 3 patients had higher gastrin-17 levels compared to patients with stages 1 and 2 (median 606 vs 295 pg/mL; P < .001). In stage 3, the hazard ratio for the risk of developing stage 4 was 6.6 (95% CI 1.5-29; P = .001).. AAG is a steadily progressive disease, in which stages 1 and 2 always progress to stage 3. The risk of developing a complicated disease stage is greater in patients with more severe gastric lesions.

Topics: Adult; Aged; Autoimmune Diseases; Disease Progression; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Humans; Male; Middle Aged; Neuroendocrine Tumors; Prospective Studies; Severity of Illness Index; Stomach Neoplasms

International guidelines recommend endoscopic surveillance of premalignant gastric lesions. However, the diagnostic yield and preventive effect require further study. We therefore aimed to assess the incidence of neoplastic progression and to assess the ability of various tests to identify patients most at risk for progression.. Patients from the Netherlands and Norway with a previous diagnosis of atrophic gastritis (AG), intestinal metaplasia (IM) or dysplasia were offered endoscopic surveillance. All histological specimens were assessed according to the updated Sydney classification and the operative link on gastric intestinal metaplasia (OLGIM) system. In addition, we measured serum pepsinogens (PG) and gastrin-17.. 279 (mean age 57.9 years, SD 11.4, male/female 137/142) patients were included and underwent at least one surveillance endoscopy during follow-up. The mean follow-up time was 57 months (SD 36). Four subjects (1.4%) were diagnosed with high-grade adenoma/dysplasia or invasive neoplasia (ie, gastric cancer) during follow-up. Two of these patients were successfully treated with endoscopic submucosal dissection, while the other two underwent a total gastrectomy. Compared with patients with extended AG/IM (PGI/II≤3 and/or OGLIM stage III-IV), patients with limited AG/IM (PG I/II>3 and OLGIM stage 0-II) did not develop high-grade adenoma/dysplasia or invasive neoplasia during follow-up (p=0.02).. In a low gastric cancer incidence area, a surveillance programme can detect gastric cancer at an early curable stage with an overall risk of neoplastic progression of 0.3% per year. Use of serological markers in endoscopic surveillance programmes may improve risk stratification.

Topics: Biomarkers, Tumor; Disease Progression; Female; Gastrins; Gastroscopy; Humans; Incidence; Male; Middle Aged; Netherlands; Norway; Pepsinogen A; Population Surveillance; Precancerous Conditions; Risk Assessment; Risk Factors; Stomach Neoplasms

To develop a gastric cancer (GC) risk prediction rule as an initial prescreening tool to identify individuals with a high risk prior to gastroscopy.. This was a nationwide multicentre cross-sectional study. Individuals aged 40-80 years who went to hospitals for a GC screening gastroscopy were recruited. Serum pepsinogen (PG) I, PG II, gastrin-17 (G-17) and anti-. The novel GC risk prediction rule comprised seven variables (age, sex, PG I/II ratio, G-17 level,. The developed and validated prediction rule showed good performance on identifying individuals at a higher risk in a Chinese high-risk population. Future studies are needed to validate its efficacy in a larger population.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biomarkers, Tumor; Diet; Early Detection of Cancer; Female; Gastrins; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Male; Mass Screening; Middle Aged; Pepsinogen A; Pepsinogen C; Predictive Value of Tests; Random Allocation; Reproducibility of Results; Risk Factors; Secondary Prevention; Stomach Neoplasms

The aim of the study was to estimate the value of detecting pepsinogen (PG) I, PGII, and gastrin-17 (G-17) levels in serum for chronic atrophic gastritis (CAG) screening and to determine the clinical applicability of combined measurement of serum G-17, pepsinogens (PGI, PGII) and PGI/PGII ratio (PGR) as a screening test for CAG. The PGI, PGII, and G-17 levels were detected by ELISA in 68 patients with CAG and 86 healthy volunteers who underwent gastroscopy for gastroduodenal diseases at Taizhou Municipal Hospital between January 2016 and December 2016. Concentrations of all measured serum markers were lower in patients with CAG in comparison to healthy volunteers and achieved statistical significance (P<0.01) in PGI (93.25 vs 126.98) and PGR (12.67 vs 17.09). Receiver operating characteristic (ROC) curve analysis revealed the optimal cut-off values for PGI, PGII, PGR, and G-17 at 98.10 μg/l, 6.92 ng/l, 15.77 and 1.94 pmol/l, with sensitivities of 72.10%, 58.10%, 61.60%, and 59.30% and specificities of 61.8%, 51.50%, 77.90%, and 55.90%, respectively. The areas under the curve (AUCs) of PGI, PGR, and G-17 were 0.728, 0.726, and 0.556, respectively. The increase of AUC was observed only in PGR and G-17 combination (0.741) with increased sensitivity (69.10% vs 61.60%) of screening for CAG, whereas the specificity was reduced (72.10% vs 77.90%) in comparison to PGR alone. Combination of serum indicators can raise the diagnosis accuracy of CAG in some respects. However, further research including a larger sample size is necessary in order to accurately determine the sensitivity and specificity of combined detection of serum indicators.

Topics: Case-Control Studies; Early Detection of Cancer; Gastrins; Humans; Pepsinogen A; Pepsinogen C; Stomach Neoplasms

To investigate the correlations of Homocysteine (Hcy), vascular endothelial growth factor (VEGF), and serum gastrin 17 (G17) with gastric cancer and precancerous lesions.. A total of 56 patients with gastric cancer (gastric cancer group) and 53 patients with precancerous lesions (precancerous lesion group) admitted to Heze Municipal Hospital from January 2017 to October 2018 were selected, and 50 healthy subjects undergoing the physical examination in the same period were selected as control group. The levels of serum Hcy, VEGF, and G17 in the three groups were compared, and the relations of each index with clinicopathological characteristics of gastric cancer were analyzed.. The levels of serum Hcy, VEGF-A, VEGF-C, VEGF-D, and G17 in gastric cancer group and precancerous lesion group were higher than in control group, and those in gastric cancer group were higher than in precancerous lesion group (p<0.05). Besides, the high expression levels of serum Hcy, VEGF, and G17 had evident correlations with the tumor-node-metastasis (TNM) stage, Lauren type, infiltration depth, and lymph node metastasis of gastric cancer (p<0.05).. Hcy, VEGF, and G17 can exhibit different levels of expressions in precancerous lesions. They are also highly expressed in gastric cancer. Besides, they are involved in the occurrence and development of gastric cancer and can be regarded as crucial indexes with clinical significance for the differential diagnosis of gastric cancer and precancerous lesions in the early stage.

Topics: Case-Control Studies; Diagnosis, Differential; Female; Gastrins; Genes, Tumor Suppressor; Homocysteine; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Precancerous Conditions; Stomach Neoplasms; Vascular Endothelial Growth Factor A

Whether gastric hyperchlorhydria and Helicobacter pylori infection contribute to aspirin-induced gastroduodenal injury still lacks evidence. Because serum pepsinogens (PGs) and gastrin-17 (G17) can reflect gastric acid secretion, this study intended to elucidate whether serum PGs, serum G17, and H. pylori infection are associated with aspirin-induced gastrointestinal injury.. A total of 60 patients taking low-dose aspirin for more than 1 month were enrolled in this study. Serum PG I, PG II, and G17 were determined using ELISA. A 14C-urea breath test was used for the detection of an H. pylori infection. The modified Lanza score was used to evaluate the degree of gastroduodenal injury under endoscopy. The median serum PG I level was significantly higher in the intensive gastroduodenal injury (IGI) group compared to that in the mild gastroduodenal injury group (155.0 vs. 116.6 ng/mL, p = 0.006). The H. pylori infection rate was significantly higher in the IGI group (73 vs. 40%, p = 0.037). Receiver operator characteristic curves analysis revealed that the cutoff value of PG I was 123 ng/mL, with 80% sensitivity and 61.4% specificity. H. pylori infection combined with PG I at >123 ng/mL had an OR (95% CI) of 15.8 (2.4 ± 104.5) for the prediction of aspirin-induced gastroduodenal injury. Key Messages: Serum PG I and H. pylori infection could be used to identify potential high-risk aspirin-induced gastroduodenal injury patients.

Topics: Aged; Area Under Curve; Aspirin; Duodenum; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Multivariate Analysis; Pepsinogen A; Risk Factors; ROC Curve; Stomach

The objective of this study is to determine the immunogenicity and safety of our novel anti-gastrin vaccine that is composed of the common amino-terminal portions of human carboxy-amidated gastrin-17 (G17) and glycine-extended gastrin-17 (gly-G17) as well as the common carboxy-terminal portion of the gastrin precursor progastrin (in a 50:50 mixture) all covalently linked to tetanus toxoid (TT) via peptide spacers. The vaccine, or immunogen, was injected intramuscularly into the legs of BALB/c mice, which produced high serum titres of specific IgG antibodies and IFN-γ in their spleen cells, identifiable by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT), respectively. TT as the protein carrier effectively enhanced the antigenic epitopes' humoural and cellular immune responses, unlike the antigenic epitopes alone or the immunogen's adjuvant emulsion system (AES), all of which failed to provoke any obvious immune response. Notably, the animals' body weights increased significantly after immunization (P < .01), while their haematology and serum biochemistry were all generally normal, and the gross anatomy of their main organs (e.g., heart, liver, spleen, lung, kidney) showed no obvious histopathological changes.

Topics: Animals; Biomarkers; Cytokines; Female; Gastrins; Humans; Immunity, Cellular; Immunity, Humoral; Immunization; Immunogenicity, Vaccine; Mice; Mice, Inbred BALB C; Organ Specificity; Tetanus Toxoid; Vaccines

Modulation of cholecystokinin (CCK) receptors has been shown to influence pancreatic endocrine function.. We assessed the impact of the CCKA and CCKB receptor modulators, (pGlu-Gln)-CCK-8 and gastrin-17, respectively, on β-cell secretory function, proliferation and apoptosis and glucose tolerance, and investigating alterations of CCK and gastrin islet expression in diabetes.. Initially, the presence of CCK and gastrin, and expression of their receptors were evidenced in β-cell lines and mouse islets. (pGlu-Gln)-CCK-8 and gastrin-17 stimulated insulin secretion from BRIN-BD11 and 1.1B4 β-cells, associated with no effect on membrane potential or [Ca]i. Only (pGlu-Gln)-CCK-8 possessed insulin secretory actions in isolated islets. In agreement, (pGlu-Gln)-CCK-8 improved glucose disposal and glucose-induced insulin release in mice. In addition, (pGlu-Gln)-CCK-8 evoked clear satiety effects. Interestingly, islet colocalization of CCK with glucagon was elevated in streptozotocin- and hydrocortisone-induced diabetic mice, whereas gastrin coexpression in α cells was reduced. In contrast, gastrin colocalization within β-cells was higher in diabetic mice, while CCK coexpression with insulin was decreased in insulin-deficient mice. (pGlu-Gln)-CCK-8 and gastrin-17 also augmented human and rodent β-cell proliferation and offered protection against streptozotocin-induced β-cell cytotoxicity.. We highlight the direct involvement of CCKA and CCKB receptors in pancreatic β-cell function and survival.

Topics: Animals; Blood Glucose; Cell Proliferation; Cells, Cultured; Cholecystokinin; Diabetes Mellitus, Experimental; Gastrins; Glucose; Humans; Insulin; Insulin Secretion; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice, Inbred C57BL; Peptide Fragments; Peptides

The gastrointestinal hormone cholecystokinin (CCK) regulates digestive processes and satiety in addition to centrally mediated effects on nociception and anxiety. CCK signals through two seven-trans-membrane receptors named the CCK-1 receptor and the CCK-2 receptor. The expression pattern and biological effects mediated by the CCK-1 and CCK-2 receptors are highly divergent. The pig is a widely used preclinical animal model in medical research, but up until recently, the porcine CCK-2 receptor was described as a pseudogene in the publicly available genomic sequence databases. Thus, it was challenging to interpret data from this animal model in studies of CCK biology and pharmacology. Here we describe an in silico prediction of the porcine CCK-2 receptor and the subsequent cloning, expression, and in vitro pharmacological characterization. We find a high degree of sequence homology with the human orthologue as well as CCK-2 receptors of other major species used in pre-clinical research. We also show that the endogenous ligands CCK-8 and Gastrin-17 bind and activate the porcine CCK-2 receptor with similar affinities and potencies as seen for the human CCK-2 receptor. We conclude that the pig has a functional CCK-2 receptor which is highly comparable to the human orthologue and therefore the pig qualifies as a valid preclinical model for the study of human CCK biology and pharmacology.

Topics: Animals; Chlorocebus aethiops; Cholecystokinin; Computational Biology; Computer Simulation; COS Cells; Female; Gastrins; Models, Animal; Protein Structure, Secondary; Receptor, Cholecystokinin B; Sequence Homology, Amino Acid; Sincalide; Swine

Studies have suggested that Helicobacter pylori (Hp) infection is associated with atherosclerotic process, while the relationship between pepsinogens, gastrin and atherosclerosis is unknown.. The aim of the study was to observe association of Hp infection on atherosclerotic parameters and blood pressure, and explore the relationship between atherosclerotic parameters, blood pressure and gastric biomarkers in a healthy population.. 395 subjects were chosen and received physical examinations, carotid artery ultrasound, peripheral atherosclerosis measurement, and testing of serum pepsinogen (PG) I and II, Hp antibody, and gastrin-17 (G-17) levels. Analyses were conducted by Student's t-test, ANOVA, Pearson correlation, multiple linear regression and binary logistic regression.. In Hp-infected subjects, right carotid intima media thickness (R-CIMT) were higher (P = 0.027) and left ankle brachial index were higher in 45-64 years compared to 35-44 years group (P = 0.039, P = 0.016). Hp-IgG, PGI and G-17 respectively positively correlated with CIMT, pulse wave velocity and systolic blood pressure (P = 0.044, P = 0.013, P = 0.021). The unadjusted OR in subjects with elevated CIMT for quartile IV of PGI was 3.542 (95% CI, 1.491-8.411), the adjusted OR was 2.916 (95% CI, 1.035-8.216). The unadjusted OR in subjects with elevated CIMT for quartile III of G-17 was 4.351 (95% CI, 1.670-11.336) and for quartile IV was 3.108 (95% CI, 1.149-8.406), the adjusted OR for quartile III was 4.962 (95% CI, 1.515-16.258).. Hp infection, higher levels of PGI and G-17 may contribute to atherosclerotic process by influencing atherosclerotic parameters and blood pressure in a healthy population, the influence on CIMT was most significant.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Atherosclerosis; Biomarkers; Carotid Intima-Media Thickness; China; Cross-Sectional Studies; Female; Gastrins; Healthy Volunteers; Helicobacter Infections; Helicobacter pylori; Humans; Logistic Models; Male; Middle Aged; Pepsinogens; Pulse Wave Analysis; Risk Factors

Methods for the measure of gastric acid secretion include invasive and non-invasive tests. The gold-standard to measure the acid output is the collection of gastric after in basal condition (Basal Acid Output, B.A.O.) and after an i.m. injection of pentagastrin (Maximal Acid Output, M.A.O.). However, direct measurement of gastric acid production is out of order in clinical practice, but many GI symptoms are claimed to be related with acid disorders and empirically cured. Hypochlorhydria is associated with precancerous conditions such as chronic atrophic gastritis (CAG). Acid measurement with non-invasive methods (pepsinogens) is supported by international guidelines.

Topics: Achlorhydria; Biomarkers; Gastric Acid; Gastric Acidity Determination; Gastrins; Gastritis, Atrophic; Humans; Pentagastrin; Pepsinogens; Peptic Ulcer; Precancerous Conditions

We aimed to assess a serological biopsy using five stomach-specific circulating biomarkers-pepsinogen I (PGI), PGII, PGI/II ratio, anti-Helicobacter pylori (H. pylori) antibody, and gastrin-17 (G-17)-for identifying high-risk individuals and predicting risk of developing gastric cancer (GC).. Among 12,112 participants with prospective follow-up from an ongoing population-based screening program using both serology and gastroscopy in China, we conducted a multi-phase study involving a cross-sectional analysis, a follow-up analysis, and an integrative risk prediction modeling analysis.. In the cross-sectional analysis, the five biomarkers (especially PGII, the PGI/II ratio, and H. pylori sero-positivity) were associated with the presence of precancerous gastric lesions or GC at enrollment. In the follow-up analysis, low PGI levels and PGI/II ratios were associated with higher risk of developing GC, and both low (<0.5 pmol/l) and high (>4.7 pmol/l) G-17 levels were associated with higher risk of developing GC, suggesting a J-shaped association. In the risk prediction modeling analysis, the five biomarkers combined yielded a C statistic of 0.803 (95% confidence interval (CI)=0.789-0.816) and improved prediction beyond traditional risk factors (C statistic from 0.580 to 0.811, P<0.001) for identifying precancerous lesions at enrollment, and higher serological biopsy scores based on the five biomarkers at enrollment were associated with higher risk of developing GC during follow-up (P for trend <0.001).. A serological biopsy composed of the five stomach-specific circulating biomarkers could be used to identify high-risk individuals for further diagnostic gastroscopy, and to stratify individuals' risk of developing GC and thus to guide targeted screening and precision prevention.

Topics: Adenocarcinoma; Adult; Aged; Antibodies, Bacterial; Biomarkers; Biopsy; Cross-Sectional Studies; Female; Follow-Up Studies; Gastric Mucosa; Gastrins; Gastroscopy; Helicobacter pylori; Humans; Logistic Models; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Precancerous Conditions; Proportional Hazards Models; Risk Assessment; ROC Curve; Stomach Neoplasms

Serum pepsinogen (PG) test, as an indicator of gastric mucosal atrophy, reflects the functional and morphologic status of gastric mucosal and it is suggested to serve as a useful predictive marker for patients with gastric cancer (GC). The available classifications of gastritis, known as the Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastritis Intestinal Metaplasia (OLGIM), integrating the severity and topography of atrophy/intestinal metaplasia (IM), have been gradually accepted and used in screening for GC in recent years.. To assess whether serum pepsinogen test, including PGI, PGII, PGI/PGII and gastrin-17 (G-17) could reflect the extent and topography of gastric mucosal atrophy/IM. Furthermore, to discuss the relationship between OLGA/OLGIM staging system and serum pepsinogen test in assessment of gastric atrophy/IM.. A total of 177 non-atrophic gastritis and 154 atrophic gastritis were analyzed, among which 40 were antrum atrophy, 32 were corpus atrophy and 82 were pan-atrophy. All patients were assessed applying the OLGA/OLGIM criteria with a mean age of 54.7 ± 10.8 years. Patients among OLGA/OLGIM Stage III-IV were presented with a lower level of serum PGI and PGI/PGII (p < .05), especially for Stage IV (p = .01). For both Hp-positive patients and Hp-negative patients according to OLGA system, PGI/PGII level correlated inversely with the rising stage (p = .022; p = .028). As for OLGIM system, similar difference can be seen in PGI/PGII level in either Hp-positive patients, or Hp-negative patients (p = .036; p = .013). In addition, the percentage of G-17 <1 pmol/L combined with PG-negative in antrum atrophy group was much higher than that of non-atrophy group and corpus atrophy group (25 versus 15.8 versus 6.3%) (p = .029). The proportion of G-17 > 15 pmol/L combined with PG-positive was apparently higher in corpus atrophy group, compared with other two groups (25 versus 11.3 versus 8.1%) (p = .023). Logistic regression modeling showed there exist significant connections between OLGA/OLGIM stages and serum pepsinogen test in patient stratification for gastric mucosal atrophy assessment (p < .001, p < .001).. Serum pepsinogen test has a strong correlation with OLGA/OLGIM gastritis stage and could provide important information in assessment of atrophy/intestinal metaplasia.

Topics: Adult; Aged; Antibodies, Bacterial; Biomarkers; China; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter pylori; Humans; Logistic Models; Male; Metaplasia; Middle Aged; Pepsinogen A; Retrospective Studies; Risk Assessment; Risk Factors; Stomach Neoplasms

Morpho-functional modifications of the gastric remnant after Roux-en-Y gastric bypass (RYGB) have not been completely defined, due to its inaccessibility for bioptic mapping. The aim of the study is to evaluate such modifications using Gastropanel®, a non-invasive blood test cross-checking four gastric biomarkers, able to provide a snapshot of mucosa conditions.. Twenty-four women undergoing RYGB were prospectively enrolled. Gastropanel® parameters (pepsinogens, Gastrin-17 and immunoglobulins against Helicobacter pylori), biometrical/clinical data were collected preoperatively and at 6-months follow-up.. All parameters showed significant reduction (p < 0.05). Pepsinogen I reduction correlated with BMI percent decrease.. The exclusion of food transit is responsible for significant drop in gastric output, hardly representing a risk factor in the remnant carcinogenesis, being unexposed to alimentary carcinogenic agents.

Topics: Adult; Biomarkers; Female; Gastric Bypass; Gastric Stump; Gastrins; Helicobacter pylori; Humans; Immunoglobulin G; Longitudinal Studies; Middle Aged; Morbidity; Obesity, Morbid; Pepsinogens; Prospective Studies; Weight Loss

The aim of the study was to evaluate the anti-tumor mechanism of Z-360, a gastrin/cholecystokinin-2 receptor (CCK2R) antagonist, in MIA PaCa-2 cells and in a subcutaneous xenograft mice model.. The anti-tumor effects of Z-360 and/or gemcitabine were monitored using a MIA PaCa-2 xenograft model. The effect of Z-360 on apoptosis in the model was examined by TUNEL staining and real-time PCR analysis and the effect in MIA PaCa-2 cells stably expressing human CCK2R was also evaluated by caspase-3/7 activity.. In this xenograft model, Z-360 significantly reduced the tumor weight, increased TUNEL-positive cells and suppressed the expression of anti-apoptosis factors such as survivin, XIAP and Mcl-1, and these effects of Z-360 combined with gemcitabine were more effective. Furthermore, gastrin-17 and gastrin-34 inhibited apoptosis in vitro and Z-360 dose-dependently abrogated this effect.. These results suggest that Z-360 exerts an anti-tumor effect through a reduction in anti-apoptosis factors by blocking CCK2R.

Topics: Animals; Apoptosis; Benzodiazepinones; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Endopeptidases; Gastrins; Gemcitabine; Gene Expression Regulation, Neoplastic; Humans; Inhibitor of Apoptosis Proteins; Mice; Myeloid Cell Leukemia Sequence 1 Protein; Pancreatic Neoplasms; Receptor, Cholecystokinin B; Survivin; X-Linked Inhibitor of Apoptosis Protein; Xenograft Model Antitumor Assays

Serum pepsinogen I (PGI) and pepsinogen II (PGII) are noninvasive parameters in the detection of atrophic gastritis. The diagnostic add-on value of serum gastrin-17 (G-17) remains uncertain. The aim of this study was to assess the stability of these serum parameters over time and to evaluate the influence of clinical factors, such as upper gastrointestinal (GI) endoscopy and bowel cleansing, on serum PGI, PGII, and G-17 assessment.. A prospective study was carried out in healthy individuals and patients. For the stability analyses, the plasma and serum samples from 23 individuals were processed at different time points with and without the addition of a stabilizer. Ten patients were included to evaluate the influence of upper GI endoscopy and 18 patients to evaluate the effect of bowel cleansing before colonoscopy.. PGI, PGII, and G-17 levels were not statistically different in the serum and plasma. PGI and PGII serum levels were stable over time. G-17 is associated with time-dependent degradation (P=0.0001). The addition of the G-17 stabilizer showed no improvement in stability. Upper GI endoscopy and bowel preparation before colonoscopy were associated with minimal variations in PGI and PGII, whereas G-17 showed patient-specific alterations.. PGI and PGII serum levels are stable over time. However, G-17 stability is strongly dependent on the time of processing and storage; therefore, samples for G-17 analysis need to be processed no later than 6 h after blood collection. Upper GI endoscopy and colonoscopy preparation lead to minimal nonsignificant changes in basal PGI, PGII, and G-17 levels.

Topics: Adult; Aged; Blood Chemical Analysis; Cathartics; Endoscopy, Gastrointestinal; Excipients; Female; Gastrins; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Plasma; Prospective Studies; Serum; Specimen Handling; Time Factors

In patients with adenoma, assessing premalignant changes in the surrounding mucosa is important for surveillance. This study evaluated atrophic and metaplastic progression in the background mucosa of adenoma or early gastric cancer (EGC) cases.. Among 146 consecutive patients who underwent endoscopic resection for intestinal-type gastric neoplasia, the adenoma group included 56 patients with low-grade dysplasia and the ECG group included 90 patients with high-grade dysplasia or invasive carcinoma. For histology, 3 paired biopsies were obtained from the antrum, corpus lesser curvature (CLC), and corpus greater curvature (CGC). Serological atrophy was determined based on pepsinogen A (PGA), progastricsin (PGC), gastrin-17, and total ghrelin levels. Topographic progression of atrophy and/or metaplasia was staged using the operative link on gastritis assessment (OLGA) and operative link on gastric intestinal metaplasia assessment (OLGIM) systems.. Rates of moderate-to-marked histological atrophy/metaplasia in patients with adenoma were 52.7%/78.2% at the antrum (vs. 58.8%/76.4% in EGC group), 63.5%/75.0% at the CLC (vs. 60.2%/69.7% in EGC group), and 10.9%/17.9% at the CGC (vs. 5.6%/7.8% in EGC group). Serological atrophy indicated by PGA and PGC occurred in 23.2% and 15.6% of cases in the adenoma and ECG groups, respectively (p = 0.25). Mean serum gastrin-17 concentrations of the adenoma group and EGC group were 10.4 and 9.0 pmol/L, respectively (p = 0.54). Mean serum total ghrelin levels were 216.6 and 209.5 pg/mL, respectively (p = 0.71). Additionally, between group rates of stage III-IV OLGA and OLGIM were similar (25.9% vs. 25.0%, p = 0.90; 41.8% vs. 44.9%, p = 0.71, respectively).. Atrophic and metaplastic progression is extensive and severe in gastric adenoma patients. A surveillance strategy for metachronous tumors should be applied similarly for patients with adenoma or EGC.

Topics: Adenoma; Aged; Biomarkers; Disease Progression; Female; Follow-Up Studies; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Humans; Male; Metaplasia; Middle Aged; Neoplasms, Second Primary; Pepsinogen C; Risk Factors; Stomach Neoplasms

We previously identified an N-terminal fragment of progastrin in human antrum and plasma, where it circulates in high concentrations. In this study, we examined the effects of N-terminal progastrin fragments on gastric acid secretion by infusion in healthy individuals. Increasing doses of progastrin fragment 1-35 were infused intravenously during constant gastric acid stimulation by gastrin-17. In addition, the effects of progastrin fragment 1-35, fragment 6-35, and fragment 1-19 on gastrin-17 stimulated acid secretion were tested. The gastrin-17 stimulated acid secretion decreased 30% after administration of a high dose of progastrin fragment 1-35 (

Topics: Adult; Female; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Male; Peptide Fragments; Protein Precursors; Young Adult

To assess characteristics of oxyntic gastric atrophy (OGA) in autoimmune gastritis (AIG) compared with OGA as a consequence of Helicobacter pylori infection.. Patients undergoing oesophagogastroduodenoscopy from July 2011 to October 2014 were prospectively included (N=452). Gastric biopsies were obtained for histology and H. pylori testing. Serum gastrin-17 (G17), pepsinogen (PG) I, PGII and antibodies against H. pylori and cytotoxin-associated gene A protein were determined in all patients. Antibodies against parietal cells and intrinsic factor were determined in patients with advanced (moderate to severe) OGA. Areas under the receiver operating characteristic curves (AUCs) were calculated for serum biomarkers and compared with histology.. Overall, 34 patients (8.9%) had advanced OGA by histology (22 women, age 61±15 years). Current or past H. pylori infection and AIG were present in 14/34 and 22/34 patients, respectively. H. pylori-negative AIG patients (N=18) were more likely to have another autoimmune disease (OR 6.3; 95% CI 1.3 to 29.8), severe corpus atrophy (OR 10.1; 95% CI 1.9 to 54.1) and corpus intestinal metaplasia (OR 26.9; 95% CI 5.3 to 136.5) compared with H. pylori-positive patients with advanced OGA. Antrum atrophy was present in 39% of H. pylori-negative AIG patients. The diagnostic performance of G17, PG I and PGI/II was excellent for AIG patients (AUC=0.83, 0.95 and 0.97, respectively), but limited for H. pylori-positive patients with advanced OGA (AUC=0.62, 0.75 and 0.67, respectively).. H. pylori-negative AIG has a distinct clinical, morphological and serological phenotype compared with advanced OGA in H. pylori gastritis.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Atrophy; Autoimmune Diseases; Female; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Humans; Male; Middle Aged; Pepsinogen A; Prospective Studies; Young Adult

Gastric cancer is the most common epithelial malignancy and the second leading cause of cancer-related death worldwide; metastasis is a crucial factor in the progression of gastric cancer. The present study applied gastrin-17 amide (G-17) in SGC7901 cells. The results showed that G-17 promoted the cell cycle by accelerating the G0/G1 phase and by increasing the cell proliferation rate by binding to the gastrin receptor. The migratory and invasive abilities of the SGC7901 cells were increased by G-17. The expression levels of matrix metalloproteinase (MMP)-7, MMP-9 and vascular endothelial growth factor (VEGF) were enhanced by G-17 as well. Moreover, G-17 caused the overexpression of β-catenin and TCF-4. G-17 also caused a preferential cytoplasmic and nuclear localization of β-catenin with a high TOP-FLASH activity. Finally, axin reduced the migratory and invasive abilities of the SGC7901 cells, and inhibited the expression of β-catenin, TCF-4, MMP-7, MMP-9 and VEGF; these effects were counteracted by adding G-17. In summary, the present study confirmed the proliferation and metastasis-promoting role of G-17 via binding to the gastrin receptor, and the β-catenin/TCF-4 pathway was found to be essential for mediating G-17-induced metastasis in gastric cancer. These results may provide a novel gene target for the treatment of gastric cancer.

Topics: Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; G1 Phase; Gastrins; Gene Expression Regulation, Neoplastic; Humans; Matrix Metalloproteinase 7; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Neoplasm Metastasis; Receptor, Cholecystokinin B; Signal Transduction; Stomach Neoplasms; Transcription Factor 4; Transcription Factors; Vascular Endothelial Growth Factor A

Effectively managing precancerous lesions is crucial to reducing the gastric cancer (GC) burden. We evaluated associations of temporal changes in multiple serological markers (pepsinogen I [PGI], PGII, PGI/II ratio, gastrin-17 and anti-Helicobacter pylori IgG) with risk for progression of gastric precancerous lesions. From 1997 to 2011, repeated esophagogastroduodenoscopies with gastric mucosal biopsies and blood sample collections were conducted on 2,039 participants (5,070 person-visits) in the Zhuanghe Gastric Diseases Screening Program, Liaoning, China. Serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized histologic criteria. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using generalized estimating equations for correlated binary outcomes. The ORs for progression of gastric conditions comparing those whose serum PGI, PGII, and anti-H. pylori IgG levels increased ≥ 50% relative to those whose decreased ≥ 50% were, respectively 1.67 (CI, 1.22-2.28), 1.80 (CI, 1.40-2.33) and 1.93 (CI, 1.48-2.52). The OR for those whose PGI/II ratio decreased ≥ 50% relative to those whose increased ≥ 50% was 1.40 (CI, 1.08-1.81), and for those whose PGII and anti-H. pylori IgG levels both increased ≥ 50% relative to those whose levels both decreased ≥ 50% the OR was 3.18 (CI, 2.05-4.93). Changes in gastrin-17 were not statistically significantly associated with progression. These findings suggest that temporal changes in serum PGI, PGII, PGI/II ratio, and anti-H. pylori IgG levels (especially PGII and anti-H. pylori IgG combined) may be useful for assessing and managing risk for progression of gastric precancerous lesions.

Topics: Adult; Aged; Biomarkers, Tumor; Disease Progression; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Longitudinal Studies; Male; Middle Aged; Neoplasm Staging; Pepsinogen A; Pepsinogen C; Precancerous Conditions; Prognosis; Stomach Neoplasms

Gastric cancer is a major cause of mortality and morbidity around world. However the effectiveness of the current approaches to the diagnosis and treatment of gastric cancer is limited. Recombinant targeted toxins may represent a novel direction of cancer therapy. In this study, we aimed to explore whether recombinant toxins fused with the truncated forms of G17 could target to kill cancer cells by recognizing CCK2R. Four recombinant Pseudomonas toxins PE38 fused with the forward or reverse truncated forms of G17 (G14 and G13) were successfully constructed, expressed, and purified. Their characteristics were further analyzed by SDS-PAGE, western blot and indirect immunofluorescence assay. The cytotoxicity assay demonstrated that only reversely fused recombinant toxins rG14PE38 and rG13PE38 exhibited certain toxicity on several cancer cell lines, and a competition assay indicated that the binding of the reverse gastrin-endotoxin to CCK2R (+) cells may be mediated by interaction between gastrin/gastrin-like and CCK2R.

Topics: Blotting, Western; Cell Survival; DNA Primers; Electrophoresis, Polyacrylamide Gel; Exotoxins; Fluorescent Antibody Technique, Indirect; Gastrins; Humans; Neoplasms; Polymerase Chain Reaction; Pseudomonas; Receptor, Cholecystokinin B; Recombinant Proteins; Toxins, Biological; Tumor Cells, Cultured

Cholecystokinin (CCK) receptors are G-protein coupled receptors (GPCR) which are present on lung cancer cells. CCK-8 stimulates the proliferation of lung cancer cells, whereas the CCK2R receptor antagonist CI-988 inhibits proliferation. GPCR for some gastrointestinal hormones/neurotransmitters mediate lung cancer growth by causing epidermal growth factor receptor (EGFR) transactivation. Here, the role of CCK/gastrin and CI-988 on EGFR transactivation and lung cancer proliferation was investigated. Addition of CCK-8 or gastrin-17 (100 nM) to NCI-H727 human lung cancer cells increased EGFR Tyr(1068) phosphorylation after 2 min. The ability of CCK-8 to cause EGFR tyrosine phosphorylation was blocked by CI-988, gefitinib (EGFR tyrosine kinase inhibitor), PP2 (Src inhibitor), GM6001 (matrix metalloprotease inhibitor), and tiron (superoxide scavenger). CCK-8 nonsulfated and gastrin-17 caused EGFR transactivation and bound with high affinity to NCI-H727 cells, suggesting that the CCK2R is present. CI-988 inhibited the ability of CCK-8 to cause ERK phosphorylation and elevate cytosolic Ca(2+). CI-988 or gefitinib inhibited the basal growth of NCI-H727 cells or that stimulated by CCK-8. The results indicate that CCK/gastrin may increase lung cancer proliferation in an EGFR-dependent manner.

Topics: 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Dipeptides; ErbB Receptors; Gastrins; Gefitinib; Hormone Antagonists; Humans; Indoles; Lung Neoplasms; Meglumine; Pyrimidines; Quinazolines

Secretion of pepsinogen I (PgI), pepsinogen II (PgII), fasting gastrin-17 (fG-17) and stimulated gastrin-17 (sG-17) changes after Helicobacter pylori eradication. Few data are available on the long-term dynamics of gastric biomarkers after H. pylori eradication.The aim of this study was to investigate the dynamics of gastric biomarkers in H. pylori-positive patients after eradication over a 3-year period and to compare the levels with initially H. pylori-negative patients.. Blood samples for the detection of gastric biomarkers were obtained from dyspeptic patients coming for upper gastrointestinal endoscopy. In H. pylori-positive patients, after eradication therapy, three follow-up blood samples were drawn after 12, 24 and 36 months; in H. pylori-negative patients, two samples were taken - at 12 and after 30 months. Median values of biomarkers in follow-up samples were compared with the baseline sample.. The final sample included 110 patients (median age 67 years, M/F ratio 27/83). In patients after H. pylori eradication (n=83) PgI, PgII, fG-17 and sG-17 had decreased significantly during a 36-month period, whereas the PgI/PgII ratio had increased significantly from 5.59 to 11.64.. In H. pylori-positive dyspeptic patients, after eradication therapy, a decrease in PgI, PgII, fG-17 and sG-17 was observed after 36 months whereas an increase in the PgI/II ratio suggested an improvement in gastric atrophy. The median levels of gastric biomarkers in patients after H. pylori eradication therapy may become similar to biomarker levels among initially H. pylori-negative individuals.

Topics: Aged; Aged, 80 and over; Biomarkers; Dyspepsia; Endoscopy, Gastrointestinal; Fasting; Female; Follow-Up Studies; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Time Factors

Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790) and +1196 (rs4986791) in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001) and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390). Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion.

Topics: Adult; Aged; Aged, 80 and over; Female; Gastrins; Gastritis; Gene Frequency; Genetic Predisposition to Disease; Genotype; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Peptic Ulcer; Polymorphism, Single Nucleotide; Risk Factors; Stomach Neoplasms; Toll-Like Receptor 4; Young Adult

To detect the clinical diagnostic criteria for non-invasive diagnosis of erosive gastritis in children with juvenile arthritis have been studied the 92 children aged 9 to 16 years (mean age-13,9 ± 2,3 years) with verified diagnosis of juvenile arthritis, of whom 10 had erosive gastritis (group 1) and 82 without erosions (group 2). A comparison of the groups on 23 grounds by analysis of contingency tables and the subsequent discriminant analysis, has developed a new non-invasive method for determining the erosive lesions of the mucous membrane of the stomach in children with juvenile arthritis, including a score of history, complaints and the results of laboratory studies the level of the G-17, pepsinogen I, pepsinogen II, and the ratio of pepsinogen I to pepsinogen II, the presence of autoantibodies to the H+, K+/ATPase of the parietal cells of the stomach, the test for occult blood "Colon View Hb and Hb/Hp". Developed a diagnostic table, including 11 features with scores each. The total score 27 or higher allows a high degree of probability to determine the erosive lesions of the gastric mucosa in children with juvenile arthritis.

Topics: Adolescent; Arthritis, Juvenile; Autoantibodies; Child; Female; Gastric Mucosa; Gastrins; Gastritis; Humans; Male; Pepsinogen A; Pepsinogen C

The analysis of noninvasive diagnostics of a phenotype of gastritis among 1050 people aged from 18 till 80 years which consistently addressed to policlinic is presented in the article. The instrument of diagnostics was a <>, including a complex of biomarkers - so-called <> (pepsinogen I, pepsinogen II, gastrin-17 and IgG- antibodies to Helicobacter Pylori). High frequency of different variants of atrophic gastritis (25%) with a gastric cancer risk and conditions with a risk of erosive and ulcer damages of the stomach mucous (26 %) was shown. Clinical and economical expediency of noninvasive screening of a phenotype of gastritis is postulated.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Female; Gastrins; Gastritis; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Retrospective Studies

Atrophic gastritis (AG), first step in the cascade leading to gastric adenocarcinoma, is related to Helicobacter pylori (H. pylori) infection. Currently, the gold standard for the diagnosis of AG is esophagogastroduodenoscopy (EGD) with histological examination of the biopsy specimens. However, since the latter are taken in random order and the distribution of AG is often patchy, histology is only representative of mucosal status. Considering this limitation, a test named GastroPanel®, that measures the blood concentrations of pepsinogen I and II, gastrin-17 and H. pylori antibodies, has been developed as a potential non-invasive biopsy. Aim of this study has been to assess the accuracy of GastroPanel® in patients with AG.. Forty-seven dyspeptic patients (24 males, mean age 52.2±9.3 years), in follow-up for antral or diffuse AG, were enrolled. All underwent at least two EGDs with random biopsies and blood collection for GastroPanel® parameters examination.. Of the 47 patients, 16 (34.1%) had histological diagnosis of antral and 31 (65.9%) multifocal AG; 17 (36.2%) patients had mild and 30 (63.8%) had moderate-severe AG. H. pylori was detected in 39 (82.9%) and intestinal metaplasia was found in all patients. GastroPanel® showed 82.9% sensitivity for the diagnosis of AG and 53.8% for the diagnosis of H. pylori infection. The prediction of advanced atrophy was not sufficiently accurate, neither in patients with antral nor in those with multifocal AG.. GastroPanel® can be useful for detecting patients with AG. However, it does not reflect the severity of atrophy.

Topics: Adult; Antibodies, Bacterial; Biomarkers; Biopsy; Dyspepsia; Endoscopy, Digestive System; Female; Follow-Up Studies; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Predictive Value of Tests; Sensitivity and Specificity; Severity of Illness Index

It has been suggested that GastroPanel might be a useful tool for the diagnosis of chronic atrophic gastritis (CAG) measuring four biomarkers in blood: basal gastrin-17 (G17), pepsinogen I and II (PGI and PGII), and Helicobacter pylori antibodies.. To determine the accuracy of GastroPanel for the diagnosis of CAG.. This was a prospective, blinded, multicenter study that included dyspeptic patients. G17, PGI, and PGII were determined by enzyme immunoassays. Three antrum and two corpus biopsies were obtained for standard histological analysis and rapid urease test. Biopsies were analyzed by a single blinded expert pathologist.. Ninety-one patients were included (77% women, mean age 44 years, 51% H. pylori positive, 17% with CAG). G17 was reduced in patients with antrum CAG (5.4 vs. 13.4 pmol/l; P<0.01) and increased in patients with corpus CAG (11 vs. 24 pmol/l; P<0.05), but its accuracy was only acceptable in the case of corpus localization [area under the receiver operating characteristic curve (AUC), 74%]; PGII difference was almost statistically significant only when testing for corpus atrophy (33 vs. 21 μg/l; P=0.05; AUC=72%). The PGI and PGI/PGII ratio showed no significant differences (AUCs were all unacceptably low). Helicobacter pylori antibody levels were higher in H. pylori-infected patients (251 vs. 109 EIU, P=0.01; AUC=70). The accuracy of GastroPanel for the diagnosis of CAG was as follows: sensitivity 50%; specificity 80%; positive 25% and negative 92% predictive values; and positive 2.4 and negative 0.6 likelihood ratios.. GastroPanel is not accurate enough for the diagnosis of CAG; thus, its systematic use in clinical practice cannot be recommended.

Topics: Adult; Algorithms; Antibodies, Bacterial; Biomarkers; Biopsy; Chronic Disease; Double-Blind Method; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Predictive Value of Tests; Prospective Studies; Pyloric Antrum; Stomach

Pepsinogen levels in plasma are increased by inflammation in the gastric mucosa, including inflammation resulting from Helicobacter pylori infection. A decrease in pepsinogen II level has been suggested as a reliable marker to confirm the successful eradication of infection. The aim of our study was to evaluate the potential role of pepsinogens I and II, gastrin-17 and H. pylori antibodies in confirming successful eradication.. Altogether 42 patients (25 women, 17 men), mean age 45 years (range 23-74), were enrolled. Pepsinogens I and II, gastrin-17 and H. pylori IgG antibodies were measured in plasma samples using an ELISA test (Biohit, Oyj., Finland) before the eradication and 4 weeks after completing the treatment. The success of eradication was determined by a urea breath test.. Eradication was successful in 31 patients (74%) and unsuccessful in 11 patients (26%). Pepsinogen II decreased significantly in both the successful (P=0.029) and unsuccessful (P=0.042) eradication groups. Pepsinogen I decreased significantly in the successful (P=0.025) but not the unsuccessful (P=0.29) eradication group. The pepsinogen I/II ratio increased in the successful eradication group (P=0.0018) but not in the group in which treatment failed (P=0.12). There were no differences in gastrin-17 or H. pylori antibody values.. A decrease in pepsinogen II levels cannot be used as a reliable marker for the successful eradication of H. pylori 4 weeks after the completion of treatment. The increase in pepsinogen I/II ratio reflects differences in pepsinogen production following the eradication irrespective of improvement in atrophy.

Topics: Adult; Aged; Antibodies, Bacterial; Biomarkers; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Treatment Outcome; Young Adult

Fasting serum gastrin-17 (FsG17) is considered as a noninvasive biomarker reflecting the structure and functional status of gastric mucosa, but its clinical utility remains unclear. This study aimed to evaluate FsG17 comprehensively: establish the ranges and cut-off points of FsG17 levels in different gastric diseases, identify their influencing factors, and investigate the accuracy of FsG17 for identifying diseased stomach.. The study included 4064 participants from Northern China between 2008 and 2013. FsG17 and serum Helicobacter pylori IgG antibody levels were measured by enzyme-linked immunosorbent assay. Diagnostic accuracy was assessed by receiver operator characteristic curves. Multivariate logistic regression analysis was performed to determine the best predictors of gastric histopathological conditions.. Median FsG17 levels in healthy, non-atrophic, atrophic, and cancerous stomachs were 1.8, 4.0, 3.8, and 6.1 pmol/l, respectively. Age, smoking status, alcohol consumption, H. pylori infection, and predominant lesion site were factors that affected FsG17 levels. The optimal cut-off values for FsG17 were 3.0 pmol/l (sensitivity of 59.3% and specificity of 67.3%) for discriminating between healthy stomach and diseased stomach and 10.7 pmol/l (sensitivity of 37% and specificity of 83.7%) for discriminating between cancerous stomach and cancer-free stomach; the screening accuracy was higher (sensitivity of 50.0% and specificity of 83.0%) for gastric cancer in the corpus. Multivariate analysis showed that FsG17, gender, age, and H. pylori infection were independent predictors of cancerous stomach.. With the progression from health stomach to malignancy, FsG17 levels significantly increased and were influenced by other factors. FsG17 combined with age, gender, and H. pylori infection could distinguish between cancerous stomach and cancer-free stomach. The results will enhance our understanding of the potential clinical utility of FsG17.

Topics: Age Factors; Alcohol Drinking; Area Under Curve; Biomarkers; China; Fasting; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Predictive Value of Tests; ROC Curve; Smoking; Stomach Neoplasms

Gastric cancer (GC) is the second cause of cancer related death in the world. It may develop by progression from its precancerous condition, called gastric atrophy (GA) due to gastritis. The aim of this study was to evaluate the accuracy of serum levels of pepsinogens (Pg) and gastrin-17 (G17) as non-invasive methods to discriminate GA or GC (GA/GC) patients.. Subjects referred to gastrointestinal clinics of Golestan province of Iran during 2010 and 2011 were invited to participate. Serum levels of PgI, PgII and G17 were measured using a GastroPanel kit. Based on the pathological examination of endoscopic biopsy samples, subjects were classified into four groups: normal, non-atrophic gastritis, GA, and GC. Receiver operating curve (ROC) analysis was used to determine cut-off values. Indices of validity were calculated for serum markers.. Study groups were normal individuals (n=74), non-atrophic gastritis (n=90), GA (n=31) and GC patients (n=30). The best cut-off points for PgI, PgI/II ratio, G17 and HP were 80 μg/L, 10, 6 pmol/L, and 20 EIU, respectively. PgI could differentiate GA/GC with high accuracy (AUC=0.83; 95%CI: 0.76-0.89). The accuracy of a combination of PgI and PgI/II ratio for detecting GA/GC was also relatively high (AUC=0.78; 95%CI: 0.70-0.86).. Our findings suggested PgI alone as well as a combination of PgI and PgI/II ratio are valid markers to differentiate GA/GC. Therefore, Pgs may be considered in conducting GC screening programs in high-risk areas.

Topics: Adult; Antibodies, Bacterial; Case-Control Studies; Cross-Sectional Studies; Early Detection of Cancer; Female; Gastrins; Gastritis; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Iran; Male; Middle Aged; Pepsinogen A; Pepsinogen C; ROC Curve; Sensitivity and Specificity; Stomach Neoplasms

In Fujian Province, China, gastric cancer is one of the leading causes of mortality among all malignant tumors. Nanjing county and Minqing county are located in inland Fujian and have similar general demographics. However, the adjusted mortality rate of gastric cancer in Minqing was found to be much higher than that in Nanjing. We sought to explore factors associated with this increased risk of gastric cancer between the two counties.. We recruited 231 and 224 residents from Nanjing and Minqing, respectively, and analyzed differences between their dietary habits, Helicobacter pylori infection rates, and concentrations of serum pepsinogen I, pepsinogen II, gastrin-17, and ratio of pepsinogen I:II.. Subjects in Minqing had more first-degree relatives who had been diagnosed with upper gastrointestinal tumor, more unhealthy dietary habits, a higher Helicobacter pylori positive rate, and greater proportion of abnormal serum gastrin-17 than those in Nanjing did.. The factors that differed between these two counties might indicate that residents in Minqing have a higher risk for developing gastric cancer than those in Nanjing do.

Topics: Adult; Aged; China; Feeding Behavior; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Risk Factors; Stomach Neoplasms

The aim of this study was to investigate the value of serum gastric markers to differentiate between patients with precancerous lesions and nonatrophic chronic gastritis.. Serum samples of 128 patients with dyspepsia who were candidates for endoscopic examination were tested for pepsinogen (PG I and PG II), PG I/II ratio, gastrin 17(G-17), anti-Helicobacter pylori (anti-H pylori ) and anti- CagA antibodies. Two sample t-tests, chi-square tests and Pearson's correlation analyses were used for analysis using SPSS (version 20).. PGI, PG I/II ratio values were decreased significantly in the precancerous lesion group (0.05, 0.001 respectively). The frequency of H pylori infection was significantly (p=0.03) different between the two groups ofthe study.. We suggest PGI and the PG I/II ratio as valuable markers for screening of premalignant gastric lesions.

Topics: Aged; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Proteins; Biomarkers; Chronic Disease; Cross-Sectional Studies; Dyspepsia; Female; Follow-Up Studies; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Iran; Male; Pepsinogen A; Pepsinogen C; Precancerous Conditions; Prognosis; Stomach Neoplasms

The article is devoted to the problem of diagnostics of atrophic gastritis. The main principles of morphological diagnostics are presented. The endoscopic findings are discussed. The authors had used the mathematical regression model to reveal groups of patients with some specific signs of atrophic gastritis, such as endoscopic sings, morphological and clinical signs. This model can be used to put a diagnosis and to look after the patients with metaplasia, dysplasia and early cancer.

Topics: Biopsy; Decision Trees; Diagnosis, Differential; Endoscopy, Gastrointestinal; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen-Ion Concentration; Metaplasia; Models, Biological; Pepsinogens; Prognosis

Gastric cancer is increasingly recognized in Zambia. Although nutritional factors contribute to gastric cancer risk, their effect in Zambia is unknown.. The objective was to investigate the association between intake of dietary antioxidants, urinary 8-iso prostaglandin F2α (8-iso PGF2α) as a marker of oxidative stress, and gastric cancer.. This was a case-control study at the University Teaching Hospital in Zambia. Gastric cancer cases were compared with age- and sex-matched controls. Urine 8-iso PGF2α was measured primarily by ELISA, and by gas chromatography-mass spectrometry in a subset, expressed as a ratio to creatinine. Blood was collected for Helicobacter pylori, HIV serology, gastrin-17, and pepsinogen 1 and 2 concentrations. Clinical and dietary data were collected by using questionnaires. Food items were broadly classified into 7 major categories (fruit, vegetables, fish, meat, insects, cereals, and starches).. Fifty cases with gastric cancer (mean age: 61 y; n = 31 males) and 90 controls (mean age: 54 y; n = 41 males) were enrolled. Median urinary 8-iso PGF2α excretion was higher in cases (0.014; IQR: 0.008-0.021) than in controls (0.011; IQR: 0.006-0.018; P = 0.039). On univariate analysis, habitual fruit intake was lower in cases than in controls during the dry season (P = 0.02). On multivariate analysis, smoking (OR: 7.22; IQR: 1.38-37.9) and gastric atrophy (OR: 2.43; IQR: 1.12-5.13) were independently associated with cancer, and higher fruit intake was protective (OR: 0.44; IQR: 0.20-0.95). Isoprostane excretion was inversely correlated with total fruit intake (ρ = -0.23; n = 140; P = 0.006).. Urinary 8-iso PGF2α excretion was associated with the risk of gastric cancer, as were smoking and gastric atrophy, but increased fruit intake conferred protection. This trial was registered at www.pactr.org as ISRCTN52971746.

Topics: Adult; Antioxidants; Biomarkers; Case-Control Studies; Creatinine; Dinoprost; Energy Intake; Feeding Behavior; Female; Fruit; Gas Chromatography-Mass Spectrometry; Gastrins; Helicobacter pylori; HIV; Humans; Isoprostanes; Logistic Models; Male; Middle Aged; Multivariate Analysis; Nutritional Status; Oxidative Stress; Pepsinogen A; Pepsinogen C; Prospective Studies; Risk Factors; Smoking; Stomach Neoplasms; Surveys and Questionnaires; Vegetables; Zambia

The gastrin and the gastrin/CCK-B receptor genes are co-expressed in several carcinomas. The primary translational product, progastrin, however, is processed to several peptides of which only those that are α-amidated at their C-terminus are receptor ligands. So far, characterization of the progastrin-derived peptides in gastric cancer has not been reported. The authors therefore examined the molecular nature of gastrin and its receptor in human gastric carcinomas.. Twenty patients with adenocarcinoma underwent partial or total gastrectomy. In samples from each carcinoma, gastrin peptides were characterized, using a library of sequence-specific immunoassays. Expression was also demonstrated by immunohistochemistry. In addition, the gastrin and gastrin/CCK-B receptor gene expression was quantitated using real-time PCR, and the receptor protein demonstrated by western blotting.. α-Amidated gastrins were detectable in 16 of 20 carcinomas (median concentration 2.1 pmol/g tissue; range 0-386 pmol/g tissue). The tissue concentrations correlated closely to the gastrin mRNA contents (r = 0.75, p < 0.0001). Moreover, progastrin and non-amidated processing intermediates, including glycine-extended gastrins, were detected in 19 carcinomas. Immunohistochemistry corroborated gastrin expression in carcinoma cells. Chromatography revealed extensive progastrin processing with α-amidated gastrin-34 and -17 (tyrosyl-sulfated as well as non-sulfated) as major products. Finally, gastrin/CCK-B receptor mRNA and protein were detected in all tumors.. The results show that the elements for a local loop of α-amidated gastrins and their receptor are detectable in 80% of human gastric adenocarcinomas. Therefore, the results support the contention that locally expressed gastrin may be involved in the tumorigenesis of gastric adenocarcinomas.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Female; Gastrins; Gene Expression; Humans; Male; Middle Aged; Protein Precursors; Receptor, Cholecystokinin B; RNA, Messenger; Stomach Neoplasms

Helicobacter pylori-infection associated gastritis is known to be a significant risk factor of gastric cancer. Serum levels of Gastrin-17 and Pepsinogen1which are respectively biomarkers of gastric antral and corpus mucosal activity are well known parameters of atrophic gastritis.. To determine the prevalence of Helicobacter pylori and atrophic gastritis amongst dyspeptic patients and to compare the production of PGI and G-17 in the various atrophic stages.. A total of 139 dyspeptic patients aged 46.68±15.50 years [females 106 aged47.23±15.51years, males 33 aged 44.48±14.62] were included during the one year period, March 2008-april 2009 at the district hospital Tombel. The degree of atrophy was determined by the levels of serum pepsinogen1, and gastrin-17 and the presence of Helicobacter pylori antibodies detected by an enzyme immunoassay.. The prevalence of Helicobacter pylori was 79.82% and that for atrophic gastritis was 6.6%. A decrease in mean serum levels of gastin-17 along with increasing antral atrophy was observed; the mean serum levels of pepsinogen1 were reduced during progression of corpus atrophy.. A weak reverse correlation(r =-0.036) was found between Gastrin-17 and Helicobacter pylori antibodies.

Topics: Adult; Aged; Aged, 80 and over; Algorithms; Antibodies, Bacterial; Cameroon; Cross-Sectional Studies; Dyspepsia; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immunoenzyme Techniques; Male; Middle Aged; Pepsinogen A; Prevalence; Risk Factors; Socioeconomic Factors; Surveys and Questionnaires; Young Adult

Health authorities of Kazakhstan are seeking for effective measures to interrupt the untoward trend, projected to increase the current number of gastric cancer (GC) cases (n=3,316) by 50% until the year 2030.. Use of a non-invasive blood test with four stomach-specific biomarkers [Pepsinogen-I (PG-I) and -II (PG-II), amidated gastrin-17 (G-17), and Helicobacter pylori (HP) IgG antibodies], to assess for the prevalence of stomach conditions: Helicobacter pylori (HP) infection and atrophic gastritis (AG), both known to increase GC risk of in Kazakhstan.. A cohort of 835 (symptomatic and asymptomatic) cases (473 women and 362 men)(median age 46.8 years; range 13.6-74.8) was examined with a panel of biomarkers. Results were assigned in five categories: 1) Healthy stomach, 2) HP infection, 3) atrophic gastritis (AG) of the antrum, 4) AG of the corpus, and 5) AG of both antrum and corpus (pangastritis).. The distribution in these five categories was identical in both sexes (p=0.259). Healthy stomach was detected only in 196 (23.5%) subjects, whereas the vast majority, 62.3% (n=519) had HP infection (with no AG). In 118 (14.1%) subjects, results were consistent with AG; in antrum (n=72), corpus (n=42) or pangastritis (n=4). Prevalence of AG increased with patient's age in both sexes. There was no age-related pattern in biomarker levels, and only slight differences between the genders.. While capable of detecting the subjects at risk for GC (HP or AG), GP seems to be a cost-effective means to intervene the current ominous trend in GC incidence in Kazakhstan.

Topics: Adolescent; Adult; Aged; Antibodies, Bacterial; Biomarkers; Dyspepsia; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Kazakhstan; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Phenotype; Prevalence; Sex Distribution; Young Adult

The aim of this study was to investigate the association between serum pepsinogens, serum gastrin, serum vascular endothelial growth factor, serum interleukin-1 Beta, serum toll-like receptor-4 levels and Helicobacter pylori Cag A status in patients with various gastric precancerous lesions.. One hundred and sixty two consecutive patients with various gastric lesions [38 (23.5%) H. pylori positive chronic non-atrophic gastritis, 45 (27.8%) autoimmune gastritis, 42 intestinal metaplasia and 37 dysplasia] were enrolled into the study. Serum pepsinogen I and II, gastrin 17, vascular endothelial growth factor, interleukin-1 Beta, toll-like receptor-4 levels, H. pylori Cag A status were evaluated.. H. pylori was positive in 98 (60.5%) patients and 38 of these patients were Cag A positive. Serum pepsinogen level was significantly lower in patients with autoimmune atrophic gastritis compared to the patients with non-atrophic chronic gastritis (p<0.001), intestinal metaplasia (P<0.001) and dysplasia (P=0.002). Mean serum gastrin was 1209.6±268.48 pg/mL in patients with autoimmune atrophic gastritis and 234.95±184.018 pg/mL in patients with chronic non-atrophic gastritis. Mean toll-like receptor-4 level was 0.56±0.098 ng/mL in patient with dysplasia, and this value was higher compared to patients with chronic non-atrophic gastritis (P=0.007), autoimmune atrophic gastritis (P=0.003) and intestinal metaplasia (P=0.006). Interleukin-1 Beta level was significantly lower in patients with dysplasia compared to patients with chronic non-atrophic gastritis (P=0.034).. Serum pepsinogens, serum gastrin and H. pylori Cag A status are important tests in detecting gastric precancerous lesions. However, toll-like receptor-4 may be a sensitive test to differentiate the patients with dysplasia from the other precancerous gastric lesions. Non-invasive tests are sensitive in the diagnosis of gastric precancerous lesions.

Topics: Adult; Aged; Antigens, Bacterial; Bacterial Proteins; Biomarkers; Female; Gastrins; Gastritis; Helicobacter pylori; Humans; Interleukin-1beta; Male; Metaplasia; Middle Aged; Pepsinogen A; Pepsinogen C; Precancerous Conditions; Sensitivity and Specificity; Stomach; Stomach Neoplasms; Toll-Like Receptor 4; Vascular Endothelial Growth Factor A

Gastrin/cholecystokinin subtype 2 receptor (CCK2R) is overexpressed in several types of tumors. Gastrin-17 (G17) peptide has a high affinity with CCK2R. These characters suggest that G17 may be useful for target cancer therapy.. Construct a new immunotoxin (IT) targeting of CCK2R overexpressed gastric cancer.. Two ITs were generated using forward and reverse G17 peptides fused with PE38. To get a high yield, codon optimized gene and optimized fermentation parameters were used in large-scale protein expression. An immunoaffinity technique was introduced into pseudomonas exotoxin (PE)-derived IT purification procedure. G17 competition, GST pull-down and indirect immunoflourescence assays were carried out to confirm the interaction between rG17 and CCK2R. Then, several cytotoxic assays were carried out on 18 cell lines, and an in vivo antitumor activity experiment was tested in nude mice.. The rG17PE38 showed specific cytotoxicity on three gastric cancer cells, while G17PE38 did not. After optimization, the expression level reached about 40% in medium deprived of NaCl. Next, 15-27.5 mg of pure rG17PE38 per 1 L of cultures was obtained. Results of G17 competition, GST pull-down and indirect immunoflourescence assays demonstrated that rG17 have a specific interact with CCK2R. Purified rG17PE38 showed high cytotoxicity on gastric cancer cell lines with the IC50 value of 0.6-4 ng·mL(-1). Treatment of nude mice inoculated with BGC-823 tumor xenografts with rG17PE38 efficiently inhibited tumor size.. The present study demonstrates that reversed G17 could be used as target moiety of PE-derived IT and the rG17PE38 could be developed as a new immunotherapy agent. Codon optimized gene could increase the rG17PE38 expression level in E. coli and furthermore NaCl inhibits the rG17PE38 expression in large scale. Meanwhile, our present study inducts an immunoaffinity method in the IT purification procedure, which could purify the PE-derived ITs in native form.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Codon; Female; Gastrins; HeLa Cells; Hep G2 Cells; Humans; Immunotoxins; K562 Cells; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Receptor, Cholecystokinin B; Sodium Chloride; Stomach Neoplasms

In porcine coronary artery endothelial cells (PCAEC), gastrin-17 has recently been found to increase nitric oxide (NO) production by the endothelial NO synthase (eNOS) isoform through cholecystokinin 1/2 (CCK1/2) receptors and the involvement of protein kinase A (PKA), PKC and the β2-adrenoreceptor-related pathway. As eNOS is the Ca(2)(+)-dependent isoform of the enzyme, we aimed to examine the effects of gastrin-17 on Ca(2)(+) movements. Thus, experiments were performed in Fura-2-acetoxymethyl-ester-loaded PCAEC, where changes of cytosolic Ca(2)(+) ([Ca(2)(+)]c) caused by gastrin-17 were analysed and compared with those of CCK receptors and β2-adrenoreceptors agonists/antagonists. In addition, some experiments were performed by stimulating cells with gastrin-17 in the presence or absence of cAMP/PKA activator/inhibitor and of phospholipase C (PLC) and Ca(2)(+)-calmodulin dependent protein kinase II (CaMKII) blockers. The results have shown that gastrin-17 can promote a transient increase in [Ca(2)(+)]c mainly originating from an intracellular pool sensitive to thapsigargin and from the extracellular space. In addition, the response of cells to gastrin-17 was increased by the adenylyl cyclase activator and the β2-adrenoreceptor agonists and affected mainly by the CCK2 receptor agonists/antagonists. Moreover, the effects of gastrin-17 were prevented by β2-adrenoreceptors and CaMKII blockers and the adenylyl cyclase/PKA and PLC inhibitors. Finally, in PCAEC cultured in Na(+)-free medium or loaded with the plasma membrane Ca(2)(+) pump inhibitor, the gastrin-17-evoked Ca(2)(+) transient was long lasting. In conclusion, this study shows that gastrin-17 affected intracellular Ca(2)(+) homeostasis in PCAEC by both promoting a discharge of an intracellular pool and by interfering with the operation of store-dependent channels through mainly CCK2 receptors and PKA/PLC- and CaMKII-related signalling downstream of β2-adrenoreceptor stimulation.

Topics: Animals; Calcium; Cells, Cultured; Coronary Vessels; Endothelial Cells; Extracellular Space; Gastrins; Receptors, Cholecystokinin; Swine

In a prospective study the risk of subsequent gastric cancer (GC) was assessed in persons aged 45-69 over 5 years after the initial testing with a set of serological tests (pepsinogen I, pepsinogen II, gastrin-17, antibodies to Helicobacter pylori). The presence of gastric atrophy markers was a significant predictor of GC in the forthcoming years. Non-invasive techniques may be used in the formation of high-risk groups, followed by GC active surveillance.

Topics: Aged; Antibodies, Bacterial; Biomarkers; Cohort Studies; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Pepsinogens; Retrospective Studies; Serologic Tests; Stomach Neoplasms

In anesthetized pigs gastrin-17 increased coronary blood flow through CCK1/CCK2 receptors and β(2)-adrenoceptors-related nitric oxide (NO) release. Since the intracellular pathway has not been investigated the purpose of this study was to examine in coronary endothelial cells the CCK1/CCK2 receptors-related signaling involved in the effects of gastrin-17 on NO release. Gastrin-17 caused a concentration-dependent increase of NO production (17.3-62.6%; p<0.05), which was augmented by CCK1/CCK2 receptors agonists (p<0.05). The effect of gastrin-17 was amplified by the adenylyl-cyclase activator and β(2)-adrenoceptors agonist (p<0.05), abolished by cAMP/PKA and β(2)-adrenoceptors and CCK1/CCK2 receptors blockers, and reduced by PLC/PKC inhibitor. Finally, Western-blot revealed the preferential involvement of PKA vs. PKC as downstream effectors of CCK1/CCK2 receptors activation leading to Akt, ERK, p38 and endothelial NOS (eNOS) phosphorylation. In conclusion, in coronary endothelial cells, gastrin-17 induced eNOS-dependent NO production through CCK1/CCK2 receptors- and β(2)-adrenoceptors-related pathway. The intracellular signaling involved a preferential PKA pathway over PKC.

Topics: Animals; Cells, Cultured; Coronary Vessels; Endothelial Cells; Enzyme Activation; Gastrins; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase Type III; Nitroso Compounds; Pentagastrin; Proto-Oncogene Proteins c-akt; Receptors, Cholecystokinin; Sincalide

Non-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.. Histological and serological samples of 118 patients with gastric cancer have been assessed for tumor specific characteristics (Laurén type, localisation), degree of mucosal abnormalities (intestinal metaplasia, atrophy) and serological parameters (PG1, PG2, PG1/2-ratio, G17, H. pylori IgG, CagA status). Association of the general factors to the different serological values have been statistically analyzed.. Patients with intestinal type gastric cancer had lower PG1 levels and a lower PG1/2-ratio compared to those with diffuse type cancer (p = 0.003). The serum levels of PG2 itself and G17 were not significantly altered. H. pylori infection in general had no influence on the levels of PG1, PG2 and G17 in the serum of gastric cancer patients. There was a trend towards lower PG1 levels in case of positive CagA-status (p = 0.058). The degree of both intestinal metaplasia and atrophy correlated inversely with serum levels for PG1 and the PG1/2-ratio (p < 0.01). Laurén-specific analysis revealed that this is only true for intestinal type tumors. Univariate ANOVA revealed atrophy and CagA-status as the only independent factors for low PG1 and a low PG1/2-ratio.. Glandular atrophy and a positive CagA status are determinant factors for decreased pepsinogen 1 levels in the serum of patients with gastric cancer. The serological assessment of gastric atrophy by analysis of serum pepsinogen is only adequate for patients with intestinal type cancer.

Topics: Adenocarcinoma; Aged; Antibodies, Bacterial; Antigens, Bacterial; Atrophy; Bacterial Proteins; Biomarkers, Tumor; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Precancerous Conditions; Retrospective Studies; Stomach Neoplasms

Rational engineering methods can be applied with success to optimize physicochemical characteristics of antibodies. Application of in silico analysis and prediction methods to antibody Fv regions can help to find residues affecting antibody-antigen affinity when high-resolution antibody structures or antibody-antigen complex structures are known. In these cases, the identification of residues affecting affinity can facilitate the selection of candidates for guided maturation by PCR using degenerate oligonucleotides. Here, we describe the utilization of a semi-rational approach to enhance the affinity of antibodies by combining in silico and traditional wet lab-based methods.

Topics: Amino Acids; Antibody Affinity; Antigen-Antibody Complex; Antigens; Binding Sites; Enzyme-Linked Immunosorbent Assay; Epitopes; Gastrins; Gene Expression; Humans; Immunoglobulin Variable Region; Models, Molecular; Molecular Biology; Mutation; Peptide Library; Protein Structure, Tertiary; Single-Chain Antibodies

Gastric cancer is one of the most common malignant tumors causing death in Fujian Province, China. However, the mortality of gastric cancer is greatly varied in different areas in Fujian; for example, the mortality in Changle City is 7.4 times higher than that in Fuan City. In this study, we compared the differences in serological parameters, pepsinogen (PG) I, PG II, gastrin-17 (G-17), and Helicobacter pylori (H. pylori) antibody, between the two cities. It has been reported that low serum PG I is correlated with atrophic gastritis, a high-risk condition for developing gastric cancer, while high serum G-17 has been used for serological detection of atrophic corpus gastritis. We recruited 224 healthy subjects in Changle and 229 healthy subjects in Fuan, matched in age and sex. The serum levels of PG II and G-17 were significantly higher in Changle than those in Fuan. Importantly, the frequency of the subjects with low serum PG I (< 25 μg/L) was significantly higher in Changle than in Fuan, although the serum PG I levels were similar between the two cities. Moreover, the percentage of the subjects with high serum G-17 (≥ 2 pmol/L) and the positive rate of serum IgG antibody against H. pylori were significantly higher in Changle than those in Fuan. The detected differences in these serological parameters are consistent with the notion that the prevalence of atrophic gastritis may be higher in Changle than in Fuan, which results in a higher risk condition for developing gastric cancer in Changle.

Topics: Adult; Aged; Antibodies, Bacterial; China; Cities; Female; Gastrins; Geography; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Pepsinogens; Residence Characteristics; Stomach Neoplasms

The release of gastrointestinal hormones has been reported to modulate reflex cardiovascular responses caused by gastric distension, although the role played by gastrin 17 is as yet unknown. The present study was therefore planned to determine the primary in vivo effect of gastrin 17 on coronary blood flow and cardiac function and the involvement of autonomic nervous system, CCK1/2 receptors, and nitric oxide (NO). In 40 anesthetized pigs, gastrin 17 was infused into the left anterior descending coronary artery at constant heart rate and arterial blood pressure. In 35 of the 40 pigs, the mechanisms of the observed hemodynamic responses were analyzed by repeating gastrin 17 infusion after autonomic nervous system and NO blockade, and after specific CCK receptors agonists/antagonists administration. Intracoronary gastrin 17 administration caused dose-related increases of both coronary blood flow and cardiac function. The intracoronary co-administration of CCK33/pentagastrin and gastrin 17 potentiated the coronary effects observed when the above agents were given alone (P <0.05). The potentiation of the cardiac response was observed only with the co-administration of pentagastrin and gastrin 17 (P <0.05). Moreover, blockade of muscarinic cholinoceptors (intravenous atropine) and of α-adrenoceptors (intravenous phentolamine) did not abolish the hemodynamic responses to gastrin 17. The cardiac and vascular effects of the hormone were prevented by blockade of β-adrenoceptors (intravenous atenolol and butoxamine), CCK1/2 receptors (intracoronary lorglumide and CAM-1028), and NO synthase (intracoronary Nω-nitro-l-arginine methyl ester). In conclusion, gastrin 17 primarily increased coronary blood flow and cardiac function through the involvement of CCK receptors, β-adrenoceptors, and NO release.

Topics: Anesthetics, General; Animals; Autonomic Nervous System; Blood Flow Velocity; Blood Pressure; Coronary Circulation; Gastrins; Heart; Nitric Oxide; Receptors, Cholecystokinin; Swine

An algorithm (GastroPanel) for the non-invasive diagnosis of atrophic gastritis has been previously proposed, based on serum pepsinogen-I, gastrin-17, and Helicobacter pylori (H. pylori) antibodies. The aim of the present study was to evaluate whether serum markers correlate with and predict gastric atrophy in gastroesophageal reflux disease (GERD) patients.. The baseline data of the prospective ProGERD study, a study on the long-term course of GERD (n=6215 patients), served to select patients with atrophic gastritis diagnosed in biopsies from gastric antrum and corpus, and control cases without atrophy. A total of 208 pairs were matched for age, sex, GERD status (erosive vs non-erosive), presence of Barrett's esophagus, and histological H. pylori status were retrieved. Serum pepsinogen-I, gastrin-17, and H. pylori antibodies were determined using specific enzyme immunoassays.. A significant negative correlation was found between the degree of corpus atrophy and the level of serum pepsinogen-I. A previously-reported negative correlation between the degree of antral atrophy and serum gastrin-17 could not be confirmed. The low sensitivity (0.32) and specificity (0.70) of the GastroPanel algorithm were mainly due to over diagnosis and under diagnosis of advanced atrophy in the antrum.. The diagnostic validity of the GastroPanel algorithm to diagnose gastric atrophy non-invasively is not sufficient for general use in GERD patients.

Topics: Adult; Aged; Aged, 80 and over; Algorithms; Barrett Esophagus; Biomarkers; Biopsy; Case-Control Studies; Endoscopy, Gastrointestinal; Europe; Female; Gastrins; Gastritis, Atrophic; Gastroesophageal Reflux; Helicobacter pylori; Humans; Immunoenzyme Techniques; Male; Matched-Pair Analysis; Middle Aged; Pepsinogen A; Predictive Value of Tests; Prospective Studies; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Young Adult

Atrophic gastritis (AG) is a well-recognized high-risk condition for developing gastric cancer (GC). Gastrin 17 (G17), a hormone secreted from antral G cells, regulates gastric acid secretion, and its serum level is a possible indicator of antral atrophy. Serum pepsinogen is well established as the indicator of AG involving the corpus. Here we investigated whether serum PG and G17 levels would be useful for determining the topographic pattern of AG and estimating the risk of GC. Enrolled were 122 Japanese patients with early GC (114 well- to moderate-differentiated cancers and 8 poorly-differentiated cancers). In addition, 178 subjects without GC were recruited as control from those undergoing endoscopic examination (non-GC group). All subjects were histologically assigned to the following four groups: non-AG, antrum-predominant AG, corpus-predominant AG, and multifocal AG, affecting the antrum and corpus. Serum concentrations of pepsinogen and G17 were determined using ELISA. Multifocal AG was more frequent in the GC group than in the adjusted non-GC group, and had the highest risk of GC (OR 25.1). Serum G17 was significantly decreased with the exacerbation of antral atrophy in the coexistence of corpus atrophy. Serum biomarker profiles showed that the low levels of pepsinogen and G17 could discriminate between multifocal AG and other types of AG, but not with pepsinogen level alone. Serologically defined multifocal AG had the highest cancer risk among other serologically defined AG groups (OR 26.9). In conclusion, the low serum levels of pepsinogen and G17 are predictive of extensive gastric atrophy with high-risk of early GC.

Topics: Adult; Age of Onset; Aged; Aged, 80 and over; Asian People; Atrophy; Biomarkers, Tumor; Case-Control Studies; Demography; Female; Gastrins; Helicobacter pylori; Hematologic Tests; Humans; Japan; Male; Middle Aged; Pepsinogen A; Risk Assessment; Risk Factors; Stomach Neoplasms

The relationship between gastroesophageal reflux disease (GERD) and Helicobacter pylori is controversial. We evaluated endoscopic, 24-h gastric and esophageal acid profile among patients with GERD in relation to H. pylori, as the latter might alter gastric acid secretion.. Patients with GERD (n = 123), who were not on acid-suppressive drugs, and had not received anti-H. pylori therapy, underwent gastroduodenoscopy and tests for H. pylori detection. Esophageal manometry, 24-h pH metry, serum pepsinogen-I (PG-I), PG-II and gastrin-17 ELISA were done in all these patients. Univariate and multivariate analyses were performed to assess independent predictors for erosive esophagitis (EE).. Of 123 patients (mean age 40.5 [13.1] years, 85 [69.1%] men), 59 (47.9%) had H. pylori infection. EE was more common in H. pylori non-infected than infected (49 vs. 32, p < 0.001). Among patients older than 40 years, absence of H. pylori was associated with lower esophageal pH and longer reflux (p = 0.02 and p < 0.001, respectively). PG-I/PG-II ratio was lower in H. pylori infected subjects (p < 0.001). In patients with higher LA grade of esophagitis, elevated PG-I levels and PG-I/PG-II ratio were associated with more acidic stomach (p = 0.04 and p = 0.01, respectively). Multivariate analyses showed low gastrin-17 (p = 0.016), higher age (p = 0.013), hiatus hernia (p = 0.004) and absence of H. pylori (p = 0.03) were independent predictors for risk of EE.. H. pylori infection is associated with less acidic stomach and less severe GERD. Low gastrin-17, higher age, hiatus hernia and absence of H. pylori were the best predictors for EE risk.

Topics: Adult; Age Factors; Endoscopy, Digestive System; Esophagitis, Peptic; Esophagus; Female; Gastric Acid; Gastric Mucosa; Gastrins; Gastroesophageal Reflux; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen-Ion Concentration; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Prospective Studies; Severity of Illness Index; Sex Factors

Dietary-free L-glutamate (Glu) in the stomach interacts with specific Glu receptors (T1R1/T1R3 and mGluR1-8) expressed on surface epithelial and gastric gland cells. Furthermore, luminal Glu activates the vagal afferents in the stomach through the paracrine cascade including nitric oxide and serotonin (5-HT).. To elucidate the role of dietary Glu in neuroendocrine control of the gastrointestinal phase of gastric secretion.. In Pavlov or Heidenhain gastric pouch dogs, secretion was measured in the pouch while monosodium glutamate (MSG) was intubated into the main stomach alone or in combination with liquid diets.. In both experimental models, supplementation of the amino acid-rich diet with MSG (100 mmol/l) enhanced secretions of acid, pepsinogen and fluid, and elevated plasma gastrin-17. However, MSG did not affect secretion stimulated by the carbohydrate-rich diet and had no effect on basal secretion when applied in aqueous solution. Effects of MSG were abolished by denervation of the stomach and proximal small intestine with intragastrically applied lidocaine and partially suppressed with the 5-HT(3) receptor blocker granisetron.. Supplementation of amino acid-rich liquid diets with MSG enhances gastrointestinal phase secretion through neuroendocrine pathways which are partially mediated by 5-HT. Possible mechanisms are discussed.

Topics: Amino Acids; Animals; Diet; Dietary Carbohydrates; Dogs; Female; Gastric Acid; Gastric Mucosa; Gastrins; Male; Models, Theoretical; Neurosecretory Systems; Pepsinogens; Receptors, Serotonin, 5-HT3; Sodium Glutamate; Stomach

This study was designed to determine the effects of gastrin on the circulating levels of ghrelin, growth hormone (GH), insulin, glucagon and glucose in ruminants. Two experiments were done in eight Holstein steers. Animals were randomly assigned to receive intravenous bolus injections: (1) 0.1% bovine serum albumin in saline as vehicle, 0.8, 4.0 and 20.0 μg/kg body weight (BW) of bovine sulfated gastrin-34; (2) vehicle, 0.53 μg/kg BW of bovine sulfated gastrin-17 alone or combined with 20.0 μg/kg BW of [D-Lys(3)]-GHRP-6, the selective antagonist of GHS-R1a. Blood samples were collected from -10 to 150 min relative to injection time. Concentrations of acyl and total ghrelin in response to gastrin-34 injection were significantly increased in a dose-dependent manner. Concentrations of GH were also markedly elevated by gastrin-34 injection; however, the effect of 20.0 μg/kg was weaker than that of 4.0 μg/kg. The three doses of gastrin-34 equally decreased insulin levels within 15 min and maintained the level until the time of last sampling. Gastrin-34 had no effect (P > 0.05) on the levels of glucagon and glucose. Levels of acyl ghrelin increased after administration of gastrin-17 alone or combined with [D-Lys(3)]-GHRP-6; however, [D-Lys(3)]-GHRP-6 did not block the elevation of GH by gastrin-17. The present results indicate that sulfated gastrin stimulates both ghrelin and GH release, but the GHS-R1a may not contribute to the release of GH by gastrin. Moreover, sulfated gastrin seems to indirectly maintain the homeostasis of blood glucose through the down-regulation of insulin in ruminants.

Topics: Animals; Blood Glucose; Cattle; Dose-Response Relationship, Drug; Gastrins; Ghrelin; Glucagon; Growth Hormone; Injections, Intravenous; Insulin; Insulin Secretion; Male; Protein Precursors; Ruminants; Signal Transduction; Stomach, Ruminant; Sulfates

Decreased plasma gastrin-17 (G-17), particularly after protein stimulation, is indicative of atrophy in the antral stomach mucosa. Available data on the value of this biomarker is inconclusive. Our study was aimed to evaluate the performance of the G-17 test in Caucasian and Asian patients for antral atrophy evaluation either in fasting state or after protein stimulation.. 241 dyspeptic patients aged 55 and above from Latvia (125), Lithuania (76) and Taiwan (40) were enrolled. G-17 levels were detected in plasma samples obtained either during fasting or after a protein-rich test meal. Levels <1 pmol/L at fast and <5 pmol/L after stimulation were considered indicative of atrophy.. The sensitivity of the test was 15.8%, its specificity 88.7%, and the overall accuracy 83% in the fasting state, and 36.8, 86.5, and 82.6%, respectively, after stimulation. In the Caucasian subgroup, the corresponding figures were 15.4, 91.5, and 86.6% in the fasting state and 30.8, 92.6, 88.6% after stimulation; but for the Asian subgroup the corresponding figures were 16.7, 73.5, and 65% (fasting) and 50, 52.9, and 52.5% (stimulated).. The performance of G-17 was better after protein stimulation. G-17 was highly specific in the Caucasian, but not in the Asian subgroups. Still the low test sensitivity either at fast or following protein stimulation does not allow us to recommend it for wide screening purpose to diagnose antral atrophy.

Topics: Aged; Aged, 80 and over; Atrophy; Biomarkers, Tumor; Dietary Proteins; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Humans; Male; Middle Aged; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity

To establish optimal cutoff values for serologic diagnosis of fundic atrophy in a high-risk area for oesophageal squamous cell carcinoma and gastric cancer with high prevalence of Helicobacter pylori (H. pylori) in Northern Iran, we performed an endoscopy-room-based validation study.. We measured serum pepsinogens I (PGI) and II (PGII), gastrin 17 (G-17), and antibodies against whole H. pylori, or cytotoxin-associated gene A (CagA) antigen among 309 consecutive patients in two major endoscopy clinics in northeastern Iran. Updated Sydney System was used as histology gold standard. Areas under curves (AUCs), optimal cutoff and predictive values were calculated for serum biomarkers against the histology.. 309 persons were recruited (mean age: 63.5 years old, 59.5% female). 84.5% were H. pylori positive and 77.5% were CagA positive. 21 fundic atrophy and 101 nonatrophic pangastritis were diagnosed. The best cutoff values in fundic atrophy assessment were calculated at PGI<56 µg/l (sensitivity: 61.9%, specificity: 94.8%) and PGI/PGII ratio<5 (sensitivity: 75.0%, specificity: 91.0%). A serum G-17<2.6 pmol/l or G-17>40 pmol/l was 81% sensitive and 73.3% specific for diagnosing fundic atrophy. At cutoff concentration of 11.8 µg/l, PGII showed 84.2% sensitivity and 45.4% specificity to distinguish nonatrophic pangastritis. Exclusion of nonatrophic pangastritis enhanced diagnostic ability of PGI/PGII ratio (from AUC = 0.66 to 0.90) but did not affect AUC of PGI. After restricting study samples to those with PGII<11.8, the sensitivity of using PGI<56 to define fundic atrophy increased to 83.3% (95%CI 51.6-97.9) and its specificity decreased to 88.8% (95%CI 80.8-94.3).. Among endoscopy clinic patients, PGII is a sensitive marker for extension of nonatrophic gastritis toward the corpus. PGI is a stable biomarker in assessment of fundic atrophy and has similar accuracy to PGI/PGII ratio among populations with prevalent nonatrophic pangastritis.

Topics: Antigens, Bacterial; Area Under Curve; Bacterial Proteins; Female; Gastric Fundus; Gastrins; Gastritis; Gastritis, Atrophic; Helicobacter pylori; Humans; Male; Mass Screening; Middle Aged; Pepsinogen A; Pepsinogen C; Reference Values

Atrophic gastritis is defined as a chronic inflammatory process in gastric mucosa leading to loss of glandular cells. It is considered a precancerous condition, thus its early diagnosis is of importance. Although histo-pathologic studies remain as the gold standard of diagnosis, non-invasive methods suitable for screening purposes are being developed. This includes measurement of serum gastric profile.. Two hundred and fifty 250 patients who were planned to undergo upper gastrointestinal endoscopy were randomly selected to be included in this study. Serum levels of pepsinogen I and II, gastrin-17 and anti-Helicobacter pylori (Hp) antibody were measured and the results were compared with that of histopathologic assessment of biopsy specimens obtained during endoscopy.. IgG anti-Hp, PGII and PGI/PGII ratio showed correlation with age. PGI/PGII ratio showed best sensitivity (96.1%) and negative predictive value (97.7%). PGI has the highest specificity (94.6%), and PGII also had a high negative predictive value (90.7%). IgG anti-Hp showed poor sensitivity and specificity (58.8% and 26.5%, respectively).. Pepsinogen I/II ratio appears to be the most suitable single measurement for screening purposes in atrophic gastritis.

Topics: Adult; Antibodies, Bacterial; Biopsy; Female; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Male; Pepsinogen A; Pepsinogen C; Predictive Value of Tests; Sensitivity and Specificity

to study the specific features of working conditions in workers from the chemical plants manufacturing nitrogen compounds by the groups under study and by the time course of changes in the serum levels of gastrin-17 (G-17) and pepsinogen-1 (P-1) in relation to the chemical composition of noxious substances, the length of service, the stage of the disease, and the performed therapy.. A test GastroPanel was used to study the serum levels of G-17 and P-1 in 54 patients with duodenal peptic ulcer (DPU) who worked at the chemical plants manufacturing nitrogen compounds (a study group) and in 15 healthy individuals (a control group).. The objective data on the time course of changes in the functional characteristics (G-17 and P-1) of the gastric mucosa (GM) in patients with DPU vary with the chemical composition of noxious substances and the length of service in chemical industry. The basic therapy for PDU contributes to a positive change in the functional parameters reflecting the state of GM.. In patients with DPU, the working conditions at the chemical plants manufacturing nitrogen compounds result in changes in the functional parameters reflecting the state of GM

Topics: Adult; Biomarkers; Chemical Industry; Diagnostic Techniques, Digestive System; Duodenal Ulcer; Endoscopy, Gastrointestinal; Follow-Up Studies; Gastric Mucosa; Gastrins; Humans; Male; Nitrogen Compounds; Occupational Diseases; Occupational Exposure; Pepsinogen A; Prognosis; Retrospective Studies; Siberia

To assess the efficiency of eradication therapy in long-term period using the main signs of functional activity of gastric mucosa (gastrin-17, pepsinogen I, pepsinogen II) and serum antibodies to H. pylori.. 113 patients with chronic gastritis were examihed using clinical, endoscopic and laboratory-based methods of investigation, including GastroPanel Biohit, Finland.. It was observed that after 12 month of successful eradication therapy the titer of IgG to H. pylori did not exceed 60 IU/l, with pepsinogen I and pepsinogen II cut-off values set under 150 microg/l and 15 microg/l respectively.. The decrease of the titer of IgG to H. pylori and concentrations of pepsinogen I and II can be used as criteria of successful eradication therapy in long-term period.

Topics: Adult; Aged; Antibodies, Bacterial; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Time Factors

The gastric hormone gastrin regulates the expression of a variety of genes involved in control of acid secretion and also in the growth and organization of the gastric mucosa. One putative target is plasminogen activator inhibitor-2 (PAI-2), which is a component of the urokinase activator system that acts extracellularly to inhibit urokinase plasminogen activator (uPA) and intracellularly to suppress apoptosis. Previous studies have demonstrated that gastrin induces PAI-2 both in gastric epithelial cells expressing the gastrin (CCK-2) receptor and, via activation of paracrine networks, in adjacent cells that do not express the receptor. We have now sought to identify the response element(s) in the PAI-2 promoter targeted by paracrine mediators initiated by gastrin. Mutational analysis identified two putative response elements in the PAI-2 promoter that were downstream of gastrin-activated paracrine signals. One was identified as a putative MAZ site, mutation of which dramatically reduced both basal and gastrin-stimulated responses of the PAI-2 promoter by a mechanism involving PGE(2) and the small GTPase RhoA. Yeast one-hybrid screening identified the other as binding the activating signal cointegrator-1 (ASC-1) complex, which was shown to be the target of IL-8 released by gastrin. RNA interference (RNAi) knockdown of two subunits of the ASC-1 complex (p50 and p65) inhibited induction of PAI-2 expression by gastrin. The data reveal previously unsuspected transcriptional mechanisms activated as a consequence of gastrin-triggered paracrine networks and emphasize the elaborate and complex cellular control mechanisms required for a key component of tissue responses to damage and infection.

Topics: Base Sequence; Binding Sites; Cell Line, Tumor; Chromatin Immunoprecipitation; Dinoprostone; DNA-Binding Proteins; Gastric Mucosa; Gastrins; Humans; Interleukin-8; Molecular Sequence Data; Mutation; Paracrine Communication; Plasminogen Activator Inhibitor 2; Response Elements; rhoA GTP-Binding Protein; RNA Interference; RNA, Small Interfering; Signal Transduction; Transcription Factors; Transcriptional Activation; Transfection; Two-Hybrid System Techniques; Up-Regulation

The combined evaluation of serum pepsinogens A (PGA) and C (PGC), gastrin-17 (G17) and anti-H. pylori antibodies (anti-H. pylori)(GastroPanel) has recently been proposed as a useful aid for investigating H. pylori-associated gastric mucosal inflammation. Our aim was to evaluate whether GastroPanel can correctly classify children who need or not endoscopy (EGD).. GastroPanel was performed in 554 consecutive children subjected to EGD.. PGC and anti-H. pylori were sensitive (82.5% and 73.1%) and specific (58.1% and 84.0%) indices of H. pylori infection. Antral H. pylori colonization density, inflammation and activity grades were correlated with PGC. PGC and G17 were significantly higher in children with celiac disease (14.9+/-0.88 microg/L and 5.6+/-0.79 pmol/L) than in controls (8.5+/-0.38 microg/L and 2.4+/-0.24 pmol/L). The best cut-offs to distinguish H. pylori infected children from controls were 7.45 microg/L for PGC, 4.2 pmol/L for G17, 18 U for anti-H. pylori and 25 microg/L for PGA. With these cut-offs, GastroPanel had a NPV of 89.6% and a PPV of 66.8%.. A negative GastroPanel result in children with upper abdominal non alarm symptoms, should allow the paediatrician to reasonably rule out the presence of major gastro-duodenal diseases and therefore avoid EGD.

Topics: Adolescent; Antibodies, Bacterial; Celiac Disease; Child; Child, Preschool; Endoscopy, Gastrointestinal; Female; Gastric Mucosa; Gastrins; Gastritis; Gastrointestinal Diseases; Helicobacter Infections; Helicobacter pylori; Humans; Infant; Logistic Models; Male; Pepsinogen A; Pepsinogen C; Sensitivity and Specificity

To study the value of serum biomarker tests to differentiate between patients with healthy or diseased stomach mucosa: i.e. those with Helicobacter pylori (H pylori) gastritis or atrophic gastritis, who have a high risk of gastric cancer or peptic ulcer diseases.. Among 162 Japanese outpatients, pepsinogen I (Pg I) and II (Pg II) were measured using a conventional Japanese technique, and the European GastroPanel examination (Pg I and Pg II, gastrin-17 and H pylori antibodies). Gastroscopy with gastric biopsies was performed to classify the patients into those with healthy stomach mucosa, H pylori non-atrophic gastritis or atrophic gastritis.. Pg I and Pg II assays with the GastroPanel and the Japanese method showed a highly significant correlation. For methodological reasons, however, serum Pg I, but not Pg II, was twice as high with the GastroPanel test as with the Japanese test. The biomarker assays revealed that 5% of subjects had advanced atrophic corpus gastritis which was also verified by endoscopic biopsies. GastroPanel examination revealed an additional seven patients who had either advanced atrophic gastritis limited to the antrum or antrum-predominant H pylori gastritis. When compared to the endoscopic biopsy findings, the GastroPanel examination classified the patients into groups with "healthy" or "diseased" stomach mucosa with 94% accuracy, 95% sensitivity and 93% specificity.. Serum biomarker tests can be used to differentiate between subjects with healthy and diseased gastric mucosa with high accuracy.

Topics: Adult; Aged; Biopsy; Diagnosis, Differential; Gastrins; Gastritis; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Japan; Middle Aged; Outpatients; Pepsinogen A; Pepsinogen C; Peptic Ulcer; Prevalence; Reference Values; Risk Factors; Stomach; Stomach Neoplasms; Young Adult

Proton-pump inhibitors (PPIs), H(2) receptor antagonists (H(2)RAs) and antacids/alginates reduce intragastric acidity and may thus influence normal gastric physiology. The purpose of this study was to examine the effect of these compounds on serum levels of amidated gastrin-17 (G-17) and pepsinogens (PGI & PGII) in a large, random, adult Swedish population sample with uninfected stomach mucosa.. The initial sample subjects (n=1000, mean age 50 years, range 20-80 years) completed a questionnaire on the use of acid inhibitory drugs 1 week and/or 3 months before study entry. All subjects (n=590) with normal gastric mucosa as delineated by serum biomarkers were included. Among them, serum levels of PGI, PGII and G-17 were compared between those who used acid inhibitory drugs and those who did not.. The serum levels of G-17 or pepsinogens in the subjects who reported use of H(2)RAs (n=18) or antacid/alginates (n=66) during the previous 3 months did not differ from those in non-users (n=471). However, the median levels of G-17 and pepsinogens were significantly (p<0.001) higher among the PPI users (n=35) than among non-users: the levels were approximately doubled. The ratio of PGI/PGII was, however, similar between PPI users and non-users, or those using antacids/alginates or H(2)RAs. Among subjects using PPIs, the serum levels of pepsinogens correlated positively (p<0.01) with the serum levels of G-17.. PPIs but not antacids/alginates or H(2)RAs markedly increase the fasting levels of serum amidated G-17 and pepsinogens among ordinary patients in everyday clinical practice.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Cohort Studies; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Follow-Up Studies; Gastric Acid; Gastric Mucosa; Gastrins; Histamine H2 Antagonists; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Pepsinogens; Probability; Proton Pump Inhibitors; Risk Assessment; Statistics, Nonparametric; Surveys and Questionnaires; Young Adult

Topics: Gastrins; Helicobacter Infections; Helicobacter pylori; Humans

Atrophy of the stomach mucosa is considered to be premalignant lesion for gastric cancer development; easy identification of this condition from a blood-sample would allow identifying the group of individuals at increased risk for cancer development.. The objective of the current study was to validate a biomarker method (pepsinogen I/II ratio and gastrin-17) for indirect detection of atrophy of the stomach mucosa versus standard histopathology in Caucasian and Asian populations.. Altogether, 241 patients aged 55 and above referred for upper endoscopy due to dyspeptic symptoms (125 from Latvia, 76 from Lithuania, and 40 from Taiwan) were enrolled. Pepsinogen I, pepsinogen II, gastrin-17 (the latter after stimulation with protein-rich meal) and IgG/IgA antibodies to Helicobacter pylori infection were determined by ELISA method; standard histopathology according to the updated Sydney classification read by two independent expert pathologists was used for the comparison.. Pepsinogen I/II ratio below 3 was well related to atrophy (moderate to severe) in the corpus part of the stomach (P < 0.0001) with 83.3% sensitivity and 87.1% specificity. Gastrin-17 below 5 pmol/L was related to atrophy in the antral part (P = 0.007) with 36.8% sensitivity and 86.5% specificity.. Decreased pepsinogen I/II ratio is a reliable marker for atrophy in the corpus, and may be recommended for identification of individuals with this type of atrophy. The utility of gastrin-17 for the detection of atrophy in the antral part of the stomach still requires further evaluation due to the low sensitivity.

Topics: Aged; Biomarkers; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Gastroscopy; Humans; Latvia; Lithuania; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Sensitivity and Specificity; Taiwan

Gastrin-17-Gly (G17-Gly) has been shown to bind to non-CCK nanomolar and micromolar affinity sites on DLD-1 and HT-29 human colonic carcinoma cells and to stimulate cellular proliferation. However, in previous studies, we showed that C-terminal truncation of the gastrin-17 (G17) to the G17 analog G17(1-12) and then to G17(1-6)-NH(2) did not remove the ability to bind to DLD-1 cells or to activate proliferation. This implies that residues and/or structural motifs required for bioactivity at these receptors rest in the N-terminal region of G17. In this work, radioligand binding studies conducted with further C-terminally truncated analogs revealed that sequences as short as G17(1-4) still bind to a single receptor with micromolar affinity. Additionally, cell proliferation assays showed that G17(1-12) stimulates proliferation of DLD-1 cells, as of HT-29 cells, but the sequences shorter than G17(1-6)-NH(2), including non-amidated G17(1-6), were incapable of stimulating proliferation. These observations indicate that the tetrapeptide pGlu-Gly-Pro-Trp is the minimum N-terminal sequence for binding to the probable growth-promoting site on DLD-1 cells. Since analogs shorter than G17(1-6) are able to bind the receptor, these peptides may be of use for developing selective antagonists.

Topics: Cell Line, Tumor; Cell Proliferation; Gastrins; Humans; Peptides; Structure-Activity Relationship

Gastrin-17 (G17) processing intermediates bind to non-CCK receptors which mediate growth of the colonic mucosa but also the formation and development of colonic cancers. In previous studies, we removed the C-terminal region of G17 to form G17(1-12) and considerably shorter C-terminally amidated and non-amidated analogs. Peptides as short as G17(1-4) continued to bind to a single site on DLD-1 human colonic carcinoma cells, while only the G17(1-6)-NH(2) and G17(1-12) peptides retained the ability to activate the receptor and stimulate cell proliferation in vitro. In this report, we studied the structure of these analogs, using a combination of ECD and VCD spectroscopy and replica exchange molecular dynamics (REMD) simulations in water, TFE, and membrane-mimicking environments, in order to determine preferred conformations that may have importance in promoting the biological activities. Mostly random meander structures, punctuated by a beta-turn at residues 1-4, were found in most peptides by REMD simulations. G17(1-3)-NH(2), which cannot form a beta-turn, failed to bind the non-CCK receptor, suggesting the importance of this feature for binding. Additionally, the beta-turn appeared more frequently in longer sequences, possibly explaining the higher affinity of the non-CCK receptor for these peptides seen previously. Finally, C-terminally amidated peptides generally showed greater formation of turn structure than their non-amidated counterparts as shown by ECD spectra, suggesting the importance of peptide length in stabilizing turn structure in N-terminal sequences, and perhaps explaining the ability of G17(1-6)-NH(2) to activate the non-CCK receptor where as the non-amidated G17(1-6) and shorter peptides do not.

Topics: Cell Line, Tumor; Circular Dichroism; Gastrins; Humans; Molecular Dynamics Simulation; Peptides

The levels of serum gastrin-17 (G-17) and pepsinogen-1 (P-1) were studied in 54 patients with duodenal ulcerative disease (UD) who worked at chemical plants manufacturing nitrogenous compounds and in 15 healthy individuals (a control group). There are objective data on the time course of changes in the functional characteristics (G-17 and P-1) of the gastric mucosa (GM) in the patients with duodenal UD, which vary with the chemical compositions of hazardous substances and the length of service at a chemical plant. Basic therapy for UD causes positive changes in the functional parameters reflecting the state of GM.

Topics: Adult; Chemical Industry; Duodenal Ulcer; Gastrins; Humans; Male; Middle Aged; Nitro Compounds; Occupational Exposure; Pepsinogen A

Cellular synthesis of peptide hormones requires PCs (prohormone convertases) for the endoproteolysis of prohormones. Antral G-cells synthesize the most gastrin and express PC1/3, 2 and 5/6 in the rat and human. But the cleavage sites in progastrin for each PC have not been determined. Therefore, in the present study, we measured the concentrations of progastrin, processing intermediates and alpha-amidated gastrins in antral extracts from PC1/3-null mice and compared the results with those in mice lacking PC2 and wild-type controls. The expression of PCs was examined by immunocytochemistry and in situ hybridization of mouse G-cells. Finally, the in vitro effect of recombinant PC5/6 on progastrin and progastrin fragments containing the relevant dibasic cleavage sites was also examined. The results showed that mouse G-cells express PC1/3, 2 and 5/6. The concentration of progastrin in PC1/3-null mice was elevated 3-fold. Chromatography showed that cleavage of the Arg(36)Arg(37) and Arg(73)Arg(74) sites were grossly decreased. Accordingly, the concentrations of progastrin products were markedly reduced, alpha-amidated gastrins (-34 and -17) being 25% of normal. Lack of PC1/3 was without effect on the third dibasic site (Lys(53)Lys(54)), which is the only processing site for PC2. Recombinant PC5/6 did not cleave any of the dibasic processing sites in progastrin and fragments containing the relevant dibasic processing sites. The complementary cleavages of PC1/3 and 2, however, suffice to explain most of the normal endoproteolysis of progastrin. Moreover, the results show that PCs react differently to the same dibasic sequences, suggesting that additional structural factors modulate the substrate specificity.

Topics: Amino Acid Sequence; Animals; CHO Cells; Cricetinae; Cricetulus; Gastrin-Secreting Cells; Gastrins; Humans; Immunohistochemistry; Mice; Mice, Knockout; Molecular Sequence Data; Proprotein Convertase 1; Proprotein Convertase 2; Proprotein Convertase 5; Protein Precursors; Pyloric Antrum; Recombinant Proteins

Gastrin and pepsinogens reflect the functional state of the gastric mucosa.. To evaluate whether serum gastrin and pepsinogens correlate with the different grades of severity of gastro-oesophageal reflux disease (GERD).. In all, 388 patients with heartburn not taking any form of acid suppressive therapy were matched-controlled for age and gender and sub-classified into four groups: group 1 non-erosive reflux disease (NERD); group 2, erosive reflux disease (ERD) Los Angeles (LA) A and B, group 3, ERD LA C and D; group 4 Barrett's oesophagus (BO). Fasting serum was analysed for gastrin 17, pepsinogen I, pepsinogen II und Helicobacter pylori using specific EIA tests (GastroPanel; Biohit, Plc).. Kruskal-Wallis test and analysis of variance.. There was a significant difference among the four groups with respect for pepsinogen I, but not for pepsinogen II, the pepsinogen I pepsinogen II ratio, H. pylori serology and gastrin levels. Pepsinogen I was the lowest in NERD and the highest in BO (median 91.6, mean +/- standard deviation 106.2 +/- 51.6 vs. median 114.7, mean +/- standard deviation 130.4 +/- 70.6; P = 0.046). Pepsinogen I levels were higher in H. pylori positive subjects. After adjusting for H. pylori status, the differences in pepsinogen I across patient groups were no longer statistically significant (P = 0.298).. Serum gastrin and pepsinogen I and II do not correlate with the different grades of severity of GERD. The non-invasive GastroPanel is not useful for the differentiation of the various forms of GERD.

Topics: Antibodies, Bacterial; Biomarkers; Case-Control Studies; Endoscopy, Gastrointestinal; Female; Gastric Acid; Gastric Mucosa; Gastrins; Gastroesophageal Reflux; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogens; Prospective Studies

Rational engineering methods can be applied with reasonable success to optimize physicochemical characteristics of proteins, in particular, antibodies. Here, we describe a combined CDR3 walking randomization and rational design-based approach to enhance the affinity of the human anti-gastrin TA4 scFv. The application of this methodology to TA4 scFv, displaying only a weak overall affinity for gastrin17 (K(D) = 6 microM), resulted in a set of nine affinity-matured scFv variants with near-nanomolar affinity (K(D) = 13.2 nM for scFv TA4.112). First, CDR-H3 and CDR-L3 randomization resulted in three scFvs with an overall affinity improvement of 15- to 35-fold over the parental. Then, the modeling of two scFv constructs selected from the previous step (TA4.11 and TA4.13) was followed by a combination of manual and molecular dynamics-based docking of gastrin17 into the respective binding sites, analysis of apparent packing defects, and selection of residues for mutagenesis through phage display. Nine scFv mutants were obtained from the second maturation step. A final 454-fold improvement in affinity compared with TA4 was obtained. These scFvs showed an enhanced potency to inhibit gastrin-induced proliferation in Colo 320 WT and BxPc3 tumoral cells. In conclusion, we propose a structure-based rational method to accelerate the development of affinity-matured antibody constructs with enhanced potential for therapeutic use.

Topics: Amino Acid Sequence; Antibodies; Antibody Affinity; Cell Line, Tumor; Cell Proliferation; Complementarity Determining Regions; Computational Biology; Gastrins; Humans; Immunoglobulin Variable Region; Kinetics; Models, Molecular; Molecular Sequence Data; Mutagenesis; Mutant Proteins; Mutation; Neutralization Tests

Cyclooxygenase-2 (COX-2) is expressed in colonic neoplasms, where it supports cell proliferation via prostaglandin E(2) (PGE(2)) production. This study investigated the effects of somatostatin-14 on COX-2 expression, PGE(2) production and proliferation in colon cancer cells.. Human colon adenocarcinoma cell lines Caco-2, HT-29 and HCT116 were used. The following techniques were employed: colourimetric assay for cell growth; 5-bromo-2'-deoxyuridine assay for DNA synthesis; enzyme immunoassay for PGE(2); COX-2 mRNA silencing; RT-PCR or Western blot for somatostatin receptor subtypes, cyclooxygenase isoforms, phosphorylated-ERK-1/ERK-2 and phosphorylated-Akt.. HT-29 and Caco-2 cells expressed COX-2 and somatostatin receptors (sst(3/4/5) and sst(3/5), respectively). HCT116 cells did express somatostatin receptors (sst(2/3/5)), but not COX-2. Somatostatin-14 inhibited basal COX-2 expression, PGE(2) production, DNA synthesis and growth in Caco-2 cells and these effects were prevented by BN81658 (sst(3) receptor antagonist). Basal proliferation of HT-29, HCT116 and COX-2-silenced Caco-2 cells was not affected by somatostatin-14. Stimulation of HT-29 cells with gastrin-17 elicited increments of ERK-1/ERK-2 and Akt phosphorylation, COX-2 expression, PGE(2) production, DNA synthesis and cell growth, which were all counteracted by somatostatin-14. Somatostatin-14-induced inhibition of COX-2 expression, PGE(2) production and DNA synthesis were blocked by BIM23056 (sst(5) receptor antagonist).. Somatostatin decreases COX-2 expression and function in colon cancer cells via activation of sst(3) or sst(5) receptors, and these effects contribute to the inhibitory action of somatostatin on cell proliferation. These findings can be relevant to the development of therapeutic strategies based on the modulation of the COX-2 pathway.

Topics: Caco-2 Cells; Cell Proliferation; Colon; Colonic Neoplasms; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Down-Regulation; Gastrins; HT29 Cells; Humans; Mitogen-Activated Protein Kinase 1; Oligopeptides; Protein Kinase C; Protein Tyrosine Phosphatases; Somatostatin

The peptide hormone gastrin is a key factor in regulation of gastric acid secretion. It has also been implicated in the development or maintenance of various types of cancer, such as pancreatic and stomach carcinoma. Inhibition of gastrin activity has potential for therapeutic use as a suppressor of acid secretion as well as an inhibitor of gastrin-responsive tumors. XPA067.06 is an affinity matured, 30 pM fully human anti-gastrin monoclonal antibody that was generated. The antibody was tested in a mouse gastric pH model to determine its effect on acid secretion. In this model, animals were treated with human gastrin, XPA067.06, and H2R or M1 receptor antagonists. Gastric fluid was collected and acid output was measured as a function of pH. XPA067.06 was shown to significantly inhibit gastrin-17-stimulated acid output for at least 48h. These results demonstrate that XPA067.06 effectively binds and neutralizes human gastrin-17 in vivo with rapid onset and prolonged duration of efficacy.

Topics: Animals; Antibodies, Monoclonal; Antibody Affinity; Binding Sites, Antibody; Cloning, Molecular; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Gastric Acid; Gastrins; Humans; Immunoglobulin Fc Fragments; Immunoglobulin G; Kinetics; Mice; Peptide Library; Recombinant Fusion Proteins

Prevalence of atrophic gastritis in various population of Siberia with serological tests was studied. Representative samples of Novosibirsk adult population and also urban and rural population of Yakutia were examined. 348 persons at the age more than 45 years (180 males and 168 females) were studied. Concentration of pepsinogen I, gastrin 17 and antibodies to Helicobacter pilori in blood serum was estimated with immune-enzyme analysis ("Biohit GastroPanel", "Biohit", Finland). In addition, domestic test-systems were used for detection cytotoxic (expressing CagA-protein) strains H. pylori. Level of markers (pepsinogen, gastrin, antibodies to Helicobacter pilori and antibodies to CagA H. pilori) in observing populations had no difference between males and females, and also did not depend on age. Occurrence of atrophy in body of stomach in Novosibirsk population, urban and rural population of Yakutia was 10.1, 16.7 and 25.6% respectively, and in antral part--10.7, 25.6 and 8.9% respectively. Total atrophy was registered in 1% in all groups. Helicobacter infection was detected in 78-88% of population. Domestic immune-enzyme test-systems were comparable with data of histological examination and demonstrated greater sensitivity at H. pylori detection vs. foreign. High prevalence of atrophic gastritis in various groups of Siberia population was noticed, which must be was bounded with great level of H. pylori infection in population.

Topics: Aged; Antibodies, Bacterial; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Immunoenzyme Techniques; Male; Middle Aged; Pepsinogen A; Population Surveillance; Prevalence; Rural Population; Siberia; Urban Population

Cancer of stomach is currently regarded as the final result of a staged multifactor process during which the microenvironment affects cells and causes their changes. One of the main triggering factors is Hp infection. Adenocarcinoma of stomach develops via stages of gastritis, precancerous changes, and cancer. The possibility to prevent cancer ensues from the potential irreversibility of premalignant processes in gastric mucosa, in the first place its atrophy; hence, the importance of its early diagnosis. The state of the endoscopic service in this country is inadequate for mass screening of patients with symptoms of dyspepsia. "GastroPanel", a new serological test for the diagnosis of gastric pathology provides information about histological and functional characteristics of gastric mucosa in the antral and fundal regions of the stomach. The method determines serum gastrin-17, pepsinogen-1, and IgG expressed in response to Hp infection. Our results demonstrate high diagnostic efficiency of "GastroPanel" as a screening technique for atrophic gastritis and assessment of stomach cancer risk.

Topics: Adolescent; Adult; Aged; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Mass Screening; Middle Aged; Neoplasm Staging; Pepsinogen A; Peptide Fragments; Stomach Neoplasms; Young Adult

Gastrin is known to enhance the growth of pancreatic carcinoma via the cholecystokinin (CCK)-2/gastrin receptor. We investigated the anti-tumor effect of Z-360 (calcium bis [(R)-(-)-3-[3-{5-cyclohexyl-1-(3,3-dimethyl-2-oxo-butyl)-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl}ureido]benzoate]), a novel orally active CCK-2 receptor antagonist alone or combined with the chemotherapeutic agent, gemcitabine in human pancreatic adenocarcinoma cell lines.. Z-360 potently inhibited specific binding of [3H]CCK-8 to the human CCK-2 receptor, with a Ki value of 0.47 nmol/l, and showed antagonistic activity for this receptor. The anti-tumor effect of Z-360 alone or combined with gemcitabine was assessed using subcutaneous xenografts of MiaPaCa2 and PANC-1 and an orthotopic xenograft model (PANC-1). Oral administration of Z-360 significantly inhibited the growth of MiaPaCa2 (41.7% inhibition at 100 mg/kg, P<0.01). Combined administration of Z-360 and gemcitabine significantly inhibited subcutaneous PANC-1 tumor growth compared with either agent alone (27.1% inhibition compared to effect with gemcitabine, P<0.05), and significantly prolonged survival compared with the vehicle control (median survival of 49 days in vehicle compared to 57 days in the combination group, P<0.05). In vitro studies showed that Z-360 significantly inhibited gastrin-induced proliferation of human CCK-2 receptor-expressing cells, and also significantly reduced gastrin-induced PKB/Akt phosphorylation to the level of untreated controls.. In the present study, we have shown that Z-360 combined with gemcitabine can inhibit pancreatic tumor growth and prolong survival in a pancreatic carcinoma xenograft model, on a possible mode of action being the inhibition of gastrin-induced PKB/Akt phosphorylation through blockade of the CCK-2 receptor. Our results suggest that Z-360 may be a useful adjunct to gemcitabine for the treatment of pancreatic carcinoma and a therapeutic option for patients with advanced pancreatic cancer.

Topics: Adenocarcinoma; Administration, Oral; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzodiazepinones; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Disease Models, Animal; Female; Gastrins; Gemcitabine; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Receptor, Cholecystokinin B; Survival Rate; Xenograft Model Antitumor Assays

Gastrin contributes to the growth and proliferation of gastric cancer cells and it is related to the effect of tyrosine kinase. This study was to investigate the effect of gastrin on tyrosine phosphorylation of focal adhesion kinase (FAK) in human gastric cancer cell line SGC7901.. The vector pCR3.1/GR, that expresses human gastrin receptor (GR) stably, was transfected into SGC7901 cells (SGC7901-GR). The expression of GR was tested by reverse transcription-polymerase chain reaction (RT-PCR). SGC7901-GR and SGC7901 cells were treated with L-365260, an antagonist of GR, and stimulated with gastrin at different concentrations for different time. The tyrosine phosphorylation level of FAK was detected by immunoprecipitation and Western blot.. When treated with different concentrations of gastrin for 1 min, the tyrosine phosphorylation levels of FAK were significantly higher in SGC7901-GR cells than in SGC7901 cells (0.64+/-0.06 vs. 0.40+/-0.05 at 0.1 nmol/L, 0.91+/-0.10 vs. 0.52+/-0.07 at 1 nmol/L, and 1.00+/-0.10 vs. 0.62+/-0.06 at 10 nmol/L, P<0.01). When treated with 10 nmol/L gastrin for different time, the tyrosine phosphorylation levels of FAK were also significantly higher in SGC7901-GR cells than in SGC7901 cells (0.72+/-0.08 vs. 0.59+/-0.05 at 1 min, 0.83+/-0.05 vs. 0.65+/-0.07 at 5 min, 0.88+/-0.06 vs. 0.58+/-0.03 at 10 min, and 1.00+/-0.08 vs. 0.47+/-0.10 at 20 min, P<0.05). L-365260 decreased the tyrosine phosphorylation levels of FAK from 1.00+/-0.07 to 0.72+/-0.07 in SGC7901-GR cells (P<0.01), and from 0.62+/-0.06 to 0.45+/-0.05 in SGC7901 cells (P<0.01). The protein levels of FAK in different cells remained unchanged during these experiments (P>0.05).. FAK is a pivotal signal transducer in downstream of gastrin with GR. Tyrosine phosphorylation is the symbol of FAK activation.

Topics: Benzodiazepinones; Cell Line, Tumor; Focal Adhesion Kinase 1; Gastrins; Genetic Vectors; Humans; Phenylurea Compounds; Phosphorylation; Receptor, Cholecystokinin B; Signal Transduction; Stomach Neoplasms; Transfection

Gastrin and its derivatives are becoming important targets for immunotherapy of pancreatic, gastric and colorectal tumors. This study was conducted to design antibodies able to block gastrin binding to the gastrin/cholecystokinin-2 (CCK-2) receptor in order to delay tumor growth. The authors have used different gastrin molecules, combined with the diphtheria toxoid, to generate and select human single chain variable fragments (scFvs) as well as mouse monoclonal antibodies and scFvs against different regions of gastrin. There was a remarkable conservation in the antibody repertoire against gastrin, independently of the approach and the species. The germlines most frequently used in gastrin antibody formation were identified. Three different epitopes were identified in the gastrin molecule. The resulting mouse monoclonal antibodies and scFvs were analyzed for gastrin neutralization using Colo 320 WT cells, which overexpress the CCK-2 receptor. The gastrin neutralizing activity assay showed that N-terminal specific mouse monoclonal antibodies were more efficient to inhibit proliferation of Colo 320 WT cells than the anti-C terminal antibodies. Moreover, the human antigastrin scFvs obtained in this study inhibited significantly the proliferation of Colo 320 tumoral cells. These findings should contribute to a more rational design of antibody-based antigastrin therapies in cancer, including passive administration of human antibodies with blocking activity.

Topics: Animals; Antibodies, Blocking; Antibodies, Monoclonal; Cell Proliferation; Colonic Neoplasms; Diphtheria Toxoid; Enzyme-Linked Immunosorbent Assay; Gastrins; Humans; Immunization; Immunoglobulin Variable Region; Mice; Peptide Library; Receptor, Cholecystokinin B; Spleen; Surface Plasmon Resonance; Tumor Cells, Cultured

First-degree relatives of gastric cancer patients are at risk for developing precancerous conditions. The aim of this study was to investigate the potential of biomarkers pepsinogen I (PGI), pepsinogen II (PGII), their ratio (PG I:II), as well as gastrin 17 for screening of precancerous conditions and corpus predominant gastritis.. First-degree relatives of gastric cancer patients underwent endoscopy. Three biopsy specimens from the antrum and 3 from the corpus were evaluated according to the Sydney classification. Serum was taken for the measurement of fasting PGI, PGII, and gastrin 17 by enzyme-linked immunosorbent assay kits.. A total of 481 patients were examined (age, 47.8 +/- 6.7 y). With the extension of gastritis, PGII was increased up to 2.5 times (6.6 +/- 2.8 microg/mL in normal mucosa, 9.5 +/- 6.7 microg/mL in antral gastritis, and 16.9 +/- 12.4 microg/mL in corpus-predominant gastritis; P < .01), PGI increased slightly (88.3 +/- 29.4 microg/mL in normal mucosa and 111.2 +/- 71.4 microg/mL in corpus-predominant gastritis), and gastrin 17 was increased substantially in corpus-predominant gastritis (15.3 +/- 19.5 pmol/mL vs 3.8 +/- 5.7 pmol/mL in normal mucosa). By using a cut-off value of 7.5 microg/mL for PGII, any type of gastritis from normal mucosa can be diagnosed with a sensitivity and specificity of 80%. The sensitivity and specificity of the PG I:II ratio (< or =3) and gastrin 17 (>17 pmol/mL) together were 9.4% and 99% for screening corpus-predominant gastritis and 14.8% and 97.8%, respectively, for screening intestinal metaplasia in the corpus.. PGII is a suitable marker for screening any gastritis from normal mucosa, but neither PGI, the PG I:II ratio, gastrin 17, nor their combination were able to select those with precancerous conditions and corpus-predominant gastritis among the first-degree relatives of gastric cancer patients.

Topics: Adult; Biomarkers; Biopsy; Enzyme-Linked Immunosorbent Assay; Family; Female; Gastric Mucosa; Gastrins; Gastritis; Gastroscopy; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Sensitivity and Specificity; Serum; Stomach Neoplasms

The interaction of gastrin with the cholecystokinin 2 (CCK2)/gastrin receptor has been studied extensively in relation to gastric acid secretion. However, not much is known about the contribution of individual amino acids of gastrin interacting with the CCK2 receptor, when gastrin is acting as a tumor growth factor. The purpose of the present study was to determine the significance of each individual amino acid residue of human gastrin-17 with respect to CCK2 receptor-mediated cell proliferation. Activation of this receptor was assessed using an in vitro bioassay based on gastrin-induced expression of a c-fos-luciferase reporter, transfected in AR42JB13 and Colo 320 cells, a rat pancreatic and human colorectal cell line respectively. Gastrin-17 dose dependently increased c-fos induction in both cancer cell lines. L365,260, a known CCK2 receptor antagonist, completely blocked the gastrin signal, demonstrating the specificity of this assay. We demonstrated for the first time that four carboxy-terminal amino acids of gastrin-17 are essential for activation of the CCK2 receptor with respect to c-fos induction. Also other residues of gastrin-17, notably glycine-2 for the rat CCK2 receptor and glutamic acid 8-10 and tyrosine-12 for the human receptor, were found to be important, although to a lesser extent. Alanine-substitution variants of each of the four carboxy-terminal amino acids of gastrin-17 showed strongly reduced receptor activation but did not act as competitive inhibitors of gastrin-17. Identification of the essential role of the carboxy-terminal tetrapeptide of gastrin-17 in CCK2 receptor-mediated c-fos induction indicates that gastrin inhibitory therapeutic strategies should mainly be targeted toward this region of gastrin.

Topics: Alanine; Amino Acid Substitution; Animals; Cell Proliferation; Colorectal Neoplasms; DNA Primers; Gastrins; Genes, fos; Humans; Luciferases; Pancreatic Neoplasms; Pentagastrin; Promoter Regions, Genetic; Protein Precursors; Rats; Receptor, Cholecystokinin B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured

To analyse diagnostic potential of "serological gastrobiopsy" in patients with various gastroduodenal diseases.. A total of 244 patients with gastroduodenal pathology have been examined. The diagnoses made morphologically were compared with those made by the serological method. The diagnosis of duodenal ulcer, gastric ulcer, atrophic gastritis, nonatrophic gastritis was made in 155, 31, 43 and 15 patients, respectively. The type of chronic gastritis was diagnosed by the levels of gastrin-17, pepsinogen I, pepsinogen II and antibodies to Helicobacter pylori in blood serum. The diagnoses made serologically were compared with those made morphologically.. The highest accuracy of a serological diagnosis of mucosal atrophy of the antral stomach was observed in gastric ulcer (80.6%) and duodenal ulcer (71.6%) in high sensitivity and low specificity. The accuracy of the diagnosis of gastric body mucosa atrophy in atrophic gastritis was 60.5%, in gastric ulcer--51.6%, in duodenal ulcer 58.7% in high specificity and low sensitivity. Serological diagnosis of gastric atrophy was accurate in 71.7%. In weak morphological picture of gastric body atrophy false negative serological diagnosis is possible. No false positive results occurred in diagnosis of gastric body mucosal atrophy (specificity 100%). A negative correlation was found between the severity of gastric body atrophy and pepsinogen I serum level (r = -0.380), pepsinogen I to pepsinogen II in blood serum (r = -0.392). No differences were revealed in gastrin-17 levels in the serum in different atrophy severity in the antral mucosa.. "Serological gastrobiopsy"provides satisfactory accuracy of atrophic gastritis diagnosis in gastroduodenal diseases.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biopsy; Diagnosis, Differential; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Immunoenzyme Techniques; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Sensitivity and Specificity; Serologic Tests

Gastrin induces the expression of cyclooxygenase (COX)-2 and interleukin (IL)-8; however, the mechanism(s), especially in gastric epithelial cells, is not well understood. Here, we have determined the intracellular mechanisms mediating gastrin-dependent gene expression.. AGS-E human gastric cancer cell line stably expressing cholecystokinin-2 receptor was treated with amidated gastrin-17. Real-time polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay were performed to determine COX-2 and IL-8 expression and Akt, Erk, and p38 phosphorylation. Gene promoter activity was determined by luciferase assay. Electrophoretic mobility shift assay analysis was performed for nuclear factor kappaB (NF-kappaB) and activator protein-1 activity. RNA stability was determined after actinomycin D treatment. HuR localization was determined by immunocytochemistry.. Gastrin induced COX-2 and IL-8 expression in AGS-E cells, which was inhibited by phosphatidylinositol 3' kinase (PI3K) and p38 inhibitors. Gastrin-mediated Akt activation was observed to be downstream of p38. IL-8 expression was dependent on COX-2-mediated prostaglandin E(2) synthesis. In the presence of an NF-kappaB inhibitor MG132, IL-8 transcription was inhibited, but not that of COX-2. This was confirmed after knockdown of the p65 RelA subunit of NF-kappaB. Further studies showed that COX-2 gene transcription is regulated by activator protein-1. Gastrin increased the stability of both COX-2 and IL-8 messenger RNA (mRNA) in a p38-dependent manner, the half-life increasing from 31 minutes to 8 hours and approximately 4 hours, respectively. Gastrin, through p38 activity, also enhanced HuR expression, nucleocytoplasmic translocation, and enhanced COX-2 mRNA binding.. Gastrin differentially induces COX-2 and IL-8 expression at the transcriptional and posttranscriptional levels by PI3K and p38 mitogen-activated protein kinase pathways, respectively.

Topics: Adenocarcinoma; Blotting, Western; Cell Line, Tumor; Cyclooxygenase 2; Dinoprostone; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Gastric Mucosa; Gastrins; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Immunoprecipitation; Interleukin-8; Oncogene Protein v-akt; p38 Mitogen-Activated Protein Kinases; RNA Stability; RNA, Neoplasm; Stomach Neoplasms; Transcription, Genetic

Cholecystokinin (CCK) and gastrin exert their influences via CCK receptors. This research was conducted to look at the responses of the sling and clasp fibers forming the human lower esophageal sphincter (LES) to CCK and gastrin, and the role of CCK receptors in the responses.. Muscle strips of sling and clasp fibers from the LES were obtained from patients undergoing subtotal esophagectomy. Isometric tension responses of the strips to CCK-8 and gastrin-17 were studied, and the maximum effect (E(max)) for each agonist was derived. CCK-A receptor antagonist, CR1409 and CCK-B antagonist, CR2945 were applied to sling and clasp fibers and their pK(B) values were calculated.. Sling fibers produced significant contractions following exposure to CCK-8 and gastrin-17, while clasp fibers had less responses to the two agents. CR1409 and CR2945 inhibited responses of sling to CCK-8 in a concentration-dependent fashion. The inhibition effects of the two antagonists on clasp fibers were not measurable because there was a mild contraction of the fiber in response to CCK-8.. The contractions generated by sling fibers following exposure to CCK and gastrin are greater than that produced by clasp fibers. CCK-A receptors are more important for the generation of contractions by the sling fibers, whereas both CCK-A and CCK-B receptors are involved in the functional regulation of the clasp fibers. [Corrections added after online publication 28 April 2008: in the Background and Aims section of the preceding abstract, all instances of 'CKK' were corrected to 'CCK'. In the final sentence of the abstract 'CCKA'was corrected to 'CCK-A'. In the article title '(CKK)' was corrected to '(CCK)'.].

Topics: Adult; Benzodiazepines; Dose-Response Relationship, Drug; Esophageal Sphincter, Lower; Esophagectomy; Female; Gastrins; Humans; In Vitro Techniques; Male; Middle Aged; Muscle Contraction; Myocytes, Smooth Muscle; Proglumide; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Sincalide

Sulfation is a potentially important post-translational modification of proteins and has been demonstrated in a number of polypeptides, notably in gastrointestinal hormones. In contrast to phosphorylation, however, the investigation of sulfation patterns in tissues and on purified proteins has been complicated by the absence of specific immunoreagents (antibodies) for this modification as well as the chemical lability of the sulfate group. Here, we investigate the properties of a novel mAb against sulfated tyrosyl groups (anti-Tyr(SO(3)H) antibody) using CE and a panel of sulfated and nonsulfated peptides and proteins. The data show that the anti-Tyr(SO(3)H) antibody is completely specific for compounds containing sulfated tyrosyls. Affinity electrophoresis experiments allowed us to estimate dissociation constants for sulfated hirudin fragment (56-65), gastrin-17, and cholecystokinin octapeptide (CCK8) in the 1-3 microM range. The affinity of the antibody toward complement 4 protein that contains three sulfotyrosines was analyzed by surface plasmon resonance technology and modeled according to a bivalent-binding model which yielded a K(d1) of 20.1 microM for the monovalent complex. The same binding was studied by CE and found to be in the micromolar scale albeit with some uncertainty due to complex separation patterns. The work illustrates the amount of information on antibody-antigen interactions that may be obtained with microelectrophoretic methods consuming minute quantities of material. Furthermore the specificity of this antibody could be confirmed in one operation using an array of sulfated and nonsulfated compounds.

Topics: Antibodies, Monoclonal; Antibody Affinity; Antibody Specificity; Complement C4; Electrophoresis, Capillary; Gastrins; Hirudins; Immunoglobulin G; Peptide Fragments; Protein Binding; Sincalide; Surface Plasmon Resonance; Tyrosine

GastroPanel (Biohit, Helsinki, Finland) is a serum test kit that measures Helicobacter pylori antibodies (HPABs) and pepsinogens I and II and gastrin 17, which reflect the degree of atrophic gastritis. We assessed whether GastroPanel can replace endoscopic biopsies in the diagnostics of H. pylori in children and whether the H. pylori-infected children show markers for atrophic gastritis. Eighty children (median age, 6.8 years; range, 0.6-18.7 years) underwent gastroscopy for H. pylori-related abdominal complaints (n = 40), surveillance after surgery for gastrointestinal tract malformations (n = 20), gastroesophageal reflux (GER) (n = 10), and miscellaneous diseases (n = 10). Gastric biopsies and a serum sample were obtained from all 80 children. HPAB levels of 38 and 15 IU were tested as cutoff values for H. pylori gastritis. The biopsies showed H. pylori-positive gastritis in 30 children, 9 had gastritis not associated with H. pylori, and 41 had normal biopsies. Atrophic gastritis was not found. The sensitivity and specificity of HPAB for H. pylori were 47% and 98% (cutoff, 38 IU), and 73% and 85% (cutoff, 15 IU), respectively. The assays of pepsinogens and gastrin did not improve sensitivity. None of the markers of pepsinogen (PG) I, PGII, and gastrin 17 (G17) indicated atrophic gastritis. GastroPanel is too insensitive for H. pylori screening and does not replace endoscopy. Markers indicative of atrophic gastritis were negative in all children with H. pylori gastritis.

Topics: Adolescent; Antibodies, Bacterial; Child; Child, Preschool; Endoscopy; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Infant; Pepsinogen A; Reagent Kits, Diagnostic

Our previous studies have shown that stimulation of proliferation of DLD-1 and HT29 human colonic cancer cells by nanomolar gastrin (G17) and carboxymethyl gastrin (G17Gly) and reversal of growth by micromolar G17 and G17Gly involves binding sites which can neither be CCK1 nor CCK2 receptors; the N terminal fragment, G17(1-12), is sufficient to increase the number of HT-29 cells by binding the higher affinity binding site but is without a suppressing effect through the lower affinity site. In this study with DLD-1 cells, competitive binding using 125I-G17(1-12) showed that G17(1-12) binds both high and low affinity sites, as do G17 and G17Gly. G17(1-6)-NH2, even without the central-to-C-terminal portion of G17, was still able to bind a single site and to promote a dose-dependent increase in cell number at nanomolar concentrations. The results indicate the presence of a non-CCK receptor on human colonic cancer cells which could mediate the tumor-promoting activity of the N-terminal-to-central portion of G17Gly which, unlike G17, is produced by such cells.

Topics: Carcinogens; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Gastrins; Humans; Peptide Fragments; Radioligand Assay; Receptors, Cholecystokinin

Cholecystokinin and related peptides are involved in the control of intestinal motility and cholecystokinin receptor ligands might represent new pharmacological tools for the treatment of symptoms associated with functional bowel disorders. However, the respective roles played by cholecystokinin receptor subtypes and the mechanisms underlying these regulatory actions remain undetermined. This study was designed to examine the influence of cholecystokinin receptor subtypes on the motor activity of guinea-pig distal colon. The effects of drugs acting on CCK1 and CCK2 receptors were assessed in vitro on the contractile activity of longitudinal smooth muscle, both under basal conditions and in the presence of transmural electrical stimulation or KCl-induced contractions. The application of cholecystokinin octapeptide sulphate (cholecystokinin-8S) to colonic preparations induced concentration-dependent contractions which were prevented by devazepide (CCK1 receptor antagonist), enhanced by GV150013 (CCK2 receptor antagonist) or N(omega)-nitro-L-arginine methylester (L-NAME, nitric oxide synthase inhibitor), and unaffected by tetrodotoxin. The application of gastrin-17 to colonic preparations resulted in relaxant responses which were insensitive to devazepide, and prevented by GV150013, L-NAME or tetrodotoxin. L-NAME, N(omega)-propyl-L-arginine (NPA, neuronal nitric oxide synthase inhibitor) or GV150013 enhanced electrically evoked contractile responses, whereas devazepide did not. When tested in the presence of L-NAME or NPA the enhancing effect of GV150013 on electrically induced contractions no longer occurred. In the presence of KCl-induced pre-contractions, cholecystokinin-8S or gastrin-17 evoked concentration-dependent relaxations, which were unaffected by devazepide and were counteracted by GV150013, L-NAME, NPA or tetrodotoxin. In conclusion, the present results indicate that, at level of distal colon, CCK1 receptors mediate direct contractile effects on smooth muscle, whereas CCK2 receptors on enteric neurons mediate relaxant responses via nitric oxide release.

Topics: Adamantane; Animals; Cholecystokinin; Colon; Devazepide; Dose-Response Relationship, Drug; Drug Combinations; Drug Interactions; Electric Stimulation; Enzyme Inhibitors; Gastrins; Guinea Pigs; Hormone Antagonists; Male; Muscle Contraction; Muscle, Smooth; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase Type I; Nootropic Agents; Perfusion; Phenylurea Compounds; Potassium Chloride; Receptor, Cholecystokinin B; Sincalide

Currently the screening and diagnosis of gastric cancer and atrophic gastritis are mainly made by endoscopy and biopsy. The aim of this study was to evaluate the use of serum tests: serum pepsinogen I (PGI pepsinogen I/II ratio (PGR), gastrin-17 (G-17) and H. pylori-immunoglobulin G (IgG) antibodies to screen atrophic gastritis and gastric cancer.. A total of 458 patients were recruited, and each underwent endoscopy with biopsies before the serum tests were performed. These patients were divided into five groups based on the endoscopic and histological findings: 92 patients in the atrophic gastritis group, 58 in the gastric ulcer group, 90 in the duodenal ulcer group, 141 in the gastric cancer group (40 early gastric cancer and 101 advanced gastric cancer) and 77 (including mild non-atrophic gastritis) served as a control group. Serum samples for PGI and II, G-17, and H. pylori-IgG antibodies estimation were analyzed by ELISA.. PGI and PGR values decreased significantly both in atrophic gastritis and gastric cancer groups (P<0.01). For the best discrimination of atrophic gastritis, the cut-off values of PGI and PGR were 82.3 microg/L and 6.05, respectively. The PGI, PGR and G-17 values were related significantly with the grades and/or sites of atrophic gastritis (P<0.01). Patients with atrophic corpus gastritis had low PGI and PGR values and high G-17 level, and patients with atrophic antral gastritis had low G-17 level. G-17 increased significantly in the gastric cancer group (P<0.01). PGI and PGR values were significantly lower in patients with advanced gastric cancer than in patients with early gastric cancer, while there was no difference in G-17 level between them. The positivity rate of H. pylori-IgG antibodies was 54.55% in the control group. The PGI level was higher in H. pylori positive patients than in H. pylori negative ones (P<0.001), while there was no difference in G-17 level between them. The positivity rates of H. pylori-IgG antibodies were over 85% in all other four groups.. Low serum PGI, PGR and G-17 values are biomarkers of atrophic antral gastritis. Atrophic be screened by serum PGI and PGR values. Gastric cancer can be screened on the basis of increased serum G-17 and remarkedly low serum PGI and PGR values. The H. pylori infection is related to the change of PG level.

Topics: Antibodies, Bacterial; Biomarkers; Biomarkers, Tumor; Endoscopy, Gastrointestinal; Female; Gastrins; Gastritis, Atrophic; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogens; Stomach Neoplasms

Tyrosine O-sulfation is a posttranslational modification of secretory and membrane proteins transported through the Golgi apparatus, which is widespread among higher eukaryotes. O-Sulfated tyrosines are not immediately identified during sequencing of peptides and proteins, because the sulfate ester is acid labile and rapidly hydrolyses to tyrosine in strong acidic solutions. Little is known about the hydrolysis at mildly acidic solutions, which are used during several protein purification and analysis procedures. We have examined the stability of tyrosine sulfate using sulfated gastrin-17, caerulein, and drosulfokinin as models for tyrosine O-sulfated peptides. The peptides were incubated in acidic solutions in a pH range of 1 to 3 at different temperatures and time spans. Only marginal hydrolysis of gastrin-17 was observed in triflouroacetic acid at room temperature or below. Comparison of the acid hydrolysis of the three peptides showed that hydrolysis rate depends mainly on the primary amino acid composition of the peptide. The activation energy (E(a)) for the hydrolysis of sulfated gastrin-17 was found to be E(a)=98.7+/-5 kJ mol(-1). This study serves as a general reference for handling tyrosine sulfated peptides in aqueous acidic solutions. We conclude that tyrosine sulfate is more stable under normal protein purification conditions than previously assumed.

Topics: Ceruletide; Gastrins; Hydrogen-Ion Concentration; Hydrolysis; Neuropeptides; Oligopeptides; Peptide Fragments; Protein Processing, Post-Translational; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Temperature; Time Factors; Tyrosine

Proper absorption of vitamin B12 requires gastric corpus mucosa that functions appropriately and secretes intrinsic factor needed as an essential cofactor for the absorption of dietary vitamin B12 in the small bowel. Here we describe the prevalence of vitamin B12 deficiency and atrophic corpus gastritis (ACG) in patients with coronary heart disease. Fasting serum was obtained from patients who were admitted for cardiovascular diseases at the Coronary Care Unit in Nijmegen, the Netherlands. The status of gastric mucosa was assessed by using the serum levels of pepsinogens I and II, gastrin-17, and Helicobacter pylori IgG antibodies and analyzed over vitamin B12 level subgroups. The study population consisted of 376 patients (mean age, 65 years [SD, 13 years], 227 [60%] males). Low vitamin B12 levels (<150 pM) were detected in 28 patients (7%). Of these 28 patients, 5 (18%) had ACG according to the biomarker assays. Altogether, another 140 patients (37%) had vitamin B12 levels between 150 and 250 pM, of whom 10 (7%) had ACG. Of the remaining patients, five (2%) had ACG. Deficiency of vitamin B12 is common among subjects with coronary heart disease. Up to 20% of these deficiencies are related to ACG.

Topics: Aged; Biomarkers; Coronary Disease; Enzyme-Linked Immunosorbent Assay; Female; Gastric Mucosa; Gastrins; Gastritis; Humans; Male; Middle Aged; Pepsinogens; Retrospective Studies; Vitamin B 12

Previously we showed that a probiotic combination with L. rhamnosus GG was beneficial as an adjuvant therapy during H. pylori eradication.. To evaluate whether probiotic combination with LGG adheres to the upper gastrointestinal mucosa and modifies H. pylori colonisation and H. pylori induced inflammation.. Thirteen patients referred for gastroduodenoscopy received a drink consisting of equal doses (2.5x10(9)CFU) of LGG, L. rhamnosus LC705, Propionibacterium freudenreichii JS and Bifidobacterium lactis Bb12 daily. Recovery of probiotics in biopsies (antrum, corpus, duodenum) and faecal samples was evaluated by strain-specific quantitative polymerase chain reaction. H. pylori colonization and gastric inflammation was investigated by urease activity ((13)C-urea breath test), histology and serum pepsinogen I, II and gastrin-17 measurements.. Twelve patients were fully investigated; of these three of the patients had LGG adhering to the biopsies at end of the intervention. Other probiotic strains were not detected, even though the recovery of all individual probiotic strains from the faeces was significantly increased (p<0.01). After the treatment, the level of (13)C-urea breath test (p=0.063) and gastrin-17 (p=0.046) decreased.. The decreases in (13)C-urea breath test and gastrin-17 indicate that the probiotic combination exerts a beneficial effect on gastric mucosa in H. pylori infected patients. LGG showed marginal ability to adhere to the upper gastrointestinal tract mucosa.

Topics: Adult; Aged; Biomarkers; Biopsy; DNA, Bacterial; Feces; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogens; Probiotics

To investigate the influence of gender, age, site of lesion, disease type and Helicobacter pylori (H. pylori) infection on the human serum gastrin-17 level and to study the diagnostic value of serum gastrin-17 in gastric precancerous lesions and gastric cancer.. Serum gastrin-17 and serum H. pylori IgG antibody were detected by the ELISA method. The different gastric disease groups were confirmed by endoscopy and histopathology.. Among the 3906 serum samples according to the gender, age, site of lesion and the data of different gastric disease groups, the serum gastrin-17 level was markedly higher in people>or=60 years old than that in younger age groups. The serum gastrin-17 level increased progressively in the following order: healthy control group, nonatrophic gastritis group, gastric ulcer group, and the serum gastrin-17 level was higher in the atrophic gastritis with dysplasia group than that without it, the lowest level being in the gastric cancer group. Among the 2946 serum samples matched with the site of the lesion, the serum gastrin-17 level was higher in those with antral diseases than in those with gastric corpus diseases. Among the 3805 serum samples matched with the H. pylori infection data, the serum gastrin-17 level was higher in the H. pylori-positive group than in the H. pylori-negative group.. In people over 60 years of age, the serum gastrin-17 level tends to increase. In subjects with precancerous gastric lesions, it may increase significantly with the progression of gastric disease, and ultimately decrease in gastric cancer. Serum gastrin-17 is a good biomarker to differentiate benign from malignant gastric diseases. The site of the gastric lesions is an important factor affecting the serum gastrin-17 level, whereas H. pylori infection is usually associated with its increment.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; China; Female; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Precancerous Conditions; Retrospective Studies; Stomach Neoplasms

To investigate the associations of serum gastrin-17 (G-17) concentration with helicobacter pylori (Hp) infection.. A (13)C-urea breath and ELISA test to determine the Helicobacter pylori status and to detect the serum gastrin concentration was conducted in 242 villagers in Linqu of Shandong Province, a high gastric cancer prevalence area in China.. Of 242 subjects, 65 of 111 were found Hp-positive in males (58.56%), compared with 65 of 131 in females (49.62%) (chi(2) = 1.932, P = 0.165). The statistical difference was not observed among different age groups (chi(2) = 4.185, P = 0.123). The average level of G-17 among 242 subjects was (24.43 +/- 25.46) pmol/L and it was statistically higher in females (29.87 +/- 28.18) pmol/L than that in males (18.01 +/- 20.11) pmol/L (Z = -3.618, P < 0.001). However, there was no statistical difference found among age groups (chi(2) = 1.948, P = 0.378). The G-17 level in Hp-negative group (35.50 +/- 30.92) pmol/L was observed significantly higher than in Hp-positive group (14.90 +/- 13.79) pmol/L (Z = 5.368, P = 0.0001).. The G-17 concentration was found higher in Hp-negative subjects than in Hp-positive subjects, and higher in female than in male, but no difference was found among age groups.

Topics: Adult; China; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Rural Population; Sampling Studies

To explore the molecular mechanism of increasing the invasion of colon cancer cells by gastrin 17.. The plasmid pCR 3.1/GR expressing the gastrin receptor cholecystokinin-2 receptor (CCK-2R) was transfected into colonic carcinoma cells of the line Colo320 by Lipofectamine 2000. The clones expressing stably CCK-2R were screened by G418 and named as Colo320WT cells. The expression levels of gastrin receptor of the Colo320 and Colo320WT cells were assayed by RT-PCR and Western blotting. The Colo320WT cells were treated by gastrin-17, and the expression levels of phosphorylated FAKTyr397 and total focal adhesion kinase (FAK) in the Colo320WT cells at the time points 0, 1, 6, 12, 24, and 48 h were detected by Western blotting. Another Colo320WT cells were treated by L365, 260, gastrin17 receptor blocker, for 30 minutes firstly and then treated by gastrin17 again for 12 hours, and then Western blotting was used to detect the expression levels of phosphorylated FAKTyr397 and total focal adhesion kinase (FAK) at the time points 0, 1, 6, 12, 24, and 48 h. Confocal microscopy was used to observe the phosphorylated FAKTyr397 localizing in the lamellipodia. The information of FAK-Src-p130(Cas)-Dock180 signaling complex was assayed by coimmuniprecipation and immunity blotting. The level of Rac-GTPase was tested by pull down assay.. The level of phosphorylated FAKTyr397 expression in the Colo320WT cells after the gastrin17 intervention increased time-dependently and peaked at the time point of 12 h, and the phosphorylated FAKTyr397 expression in the Colo320WT cells treated by L365, 260 decreased remarkably, but the level of total FAK remained unchanged. The phosphorylated FAKTyr397/FAK levels were 2.82%, 9.28%, 22.62%, 38.59%, 28.41%, and 14.94%, 0, 1, 6, 12, 24, and 48 h after the gastrin17 treatment respectively, and the level was 7.21% after L365, 260 treatment. The amount of phosphorylated FAKTyr397 localizing in the lamellipodia of the Colo320WT cells that were treated by gastrin17 increased time-dependently and peaked at the time-point 12 h. FAK-Src-p130(Cas)-Dock180 signaling complex was formed in the Colo320WT cells stimulated with gastrin17. Gastrin17 activated Rac, but did not affect the total Rac expression.. The mechanism of increasing the colon cancer cells' invasion by gastrin17 is probably that gastrin17 makes FAK-Tyr397 phosphorylated and be localized to lamellipodia, causes the forming of FAK-Src-p130(Cas)-Dock180 signaling complex when it is bound to its receptor CCK-2, and activation of Rac.

Topics: Benzodiazepinones; Blotting, Western; Cell Line, Tumor; Cell Movement; Colonic Neoplasms; Focal Adhesion Protein-Tyrosine Kinases; Gastrins; Humans; Neoplasm Invasiveness; Phenylurea Compounds; Phosphorylation; Receptor, Cholecystokinin B; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Tyrosine

Non-invasive methods are advisable for the detection of Helicobacter pylori-related chronic gastritis in pediatric patients. Serum pepsinogens I and II (sPGII and sPGII), gastrin-17 (G-17) and anti-H. pylori antibodies (IgG-Hp) have been proposed as a 'serological gastric biopsy'.. To assess H. pylori infection and to evaluate gastric mucosa status in a pediatric population by means of serological parameters such as sPGI, sPGII, G-17 and IgG-Hp.. 45 consecutively children evaluated for upper gastrointestinal symptoms were analyzed. All children were submitted to upper gastrointestinal endoscopy with biopsies. Serum samples were analyzed for IgG-Hp, sPGII, sPGI and G-17 (Biohit, Helsinki, Finland).. 18 children had H. pylori-related mild or moderate non-atrophic chronic gastritis. They presented significantly higher mean levels of sPGII and of IgG-Hp than negative ones, either under or up to 10 years. sPGI showed significantly increased levels in H. pylori-positive patients only over 10 years. G-17 levels were not different between H. pylori-positive and -negative ones. The best cut-offs of IgG-Hp, sPGII and of product IgG-Hp x sPGII, to identify H. pylori infection, were 30 IU/l, 9 microg/l, and 241 IU/l x microg/l, respectively. The product IgG-Hp x sPGII identified H. pylori infection with a 100% sensitivity, 92% specificity, 90% positive predictive value and 100% negative predictive value. IgG-Hp and IgG-Hp showed a correlation (r = 0.94; p < 0.001).. Combined analysis of sPGII and IgG-Hp antibody levels could be recommended as a non-invasive panel for the assessment of H. pylori-related histological alterations of gastric mucosa in childhood.

Topics: Adolescent; Biomarkers; Biopsy; Child; Child, Preschool; Female; Gastric Mucosa; Gastrins; Gastritis; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Pepsinogens

To explore the effects of human FRNK gene on E-cadherin/beta-catenin complex in colon cancer cell line Colo320WT cells stimulated with extrinsic gastrinl7.. AdEasy system was used to construct pAdhFRNK expressing human FRNK gene by recombination in E. coli. BJ5283. pCR3.1/GR plasmid expressing gastrin receptor CCK-2 was transfected into colon cancer cell line Colo320 cells by Lipofectamine 2000 and expressing stably CCK-2R clones were screened by G418 (500 pg/ml). The expression levels of gastrin receptor in Colo320 cells and the transfected Colo320WT cells were assayed by RT-PCR. Colo320WT cells were treated by 10(-8) mol/L gastrinl7 for 12 h; and after Colo320WT cells were infected by pAdhFRNK (MOI: 100) for 2 d the cells were treated by gastrin17 for 12 h again. The expression levels of E-cadherin and beta-catenin in TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells were assayed by co-immunoprecipation and Western blot. E-cadherin and beta-catenin's distribution in Colo320WT cells were detected by immunocytochemistry.. When 10(-8) mol/L gastrin17 stimulated Colo320WT cells for 12 h, the expression levels of E-cadherin and beta-catenin in TX-100-soluble fraction decreased apparently, while the expression levels of E-cadherin and beta-catenin in TX-100-insoluble fraction increased markedly. When pAdhFRNK infected Colo320WT cells for 2 d and 10(-8) mol/L gastrin17 treated the cells for 12 h, the expression levels of E-cadherin and beta-catenin in TX-100-soluble fraction increased apparently again, and the expression levels of E-cadherin and beta-catenin in TX-100-insolutble fraction decreased markedly. Immunocytochemistry showed that the distribution of E-cadherin and beta-catenin was translocated from plasma membrane into cytoplasm and nucleus in the cells stimulated with gastrinl7, and after the cells were infected with pAdhFRNK and stimulated by gastrinl7 again. beta-catenin was mainly observed in cytoplasm and little nuclear immunoreactivity.. An adenovirus vector pAdhFRNK can inhibit abnormal distribution of E-cadherin and beta-catenin in the gastrin17-stimulated cells. The mechanism is probably that hFRNK can disphosphorylate phosphorylated FAK and block FAK pathway.

Topics: Adenoviridae; beta Catenin; Blotting, Western; Cadherins; Cell Line, Tumor; Cell Membrane; Cell Nucleus; Colonic Neoplasms; Cytoplasm; Gastrins; Genetic Vectors; Humans; Immunohistochemistry; Immunoprecipitation; Lipids; Protein Binding; Protein Transport; Protein-Tyrosine Kinases; Receptor, Cholecystokinin B; Transfection

A comparison of the conformational characteristics of the related hormones [Nle(15)] gastrin-17 and [Tyr(9)-SO(3)] cholecystokinin-15, in membrane-mimetic solutions of dodecylphosphocholine micelles and water, was undertaken using NMR spectroscopy to investigate the possibility of a structural motif responsible for the two hormones common ability to stimulate the CCK(2) receptor. Distance geometry calculations and NOE-restrained molecular dynamics simulations in biphasic solvent boxes of decane and water pointed to the two peptides adopting near identical helical C-terminal configurations, which extended one residue further than their shared pentapeptide sequence of Gly-Trp-Met-Asp-Phe-NH(2). The C-terminal conformation of [Nle(15)] gastrin-17 contained a short alpha-helix spanning the Ala(11)-Trp(14) sequence and an inverse gamma-turn centered on Nle(15) while that of [Tyr(9)-SO(3)] cholecystokinin-15 contained a short 3(10) helix spanning its Met(10) to Met(13) sequence and an inverse gamma-turn centered on Asp(14). Significantly, both the C-terminal helices were found to terminate in type I beta-turns spanning the homologous Gly-Trp-Met-Asp sequences. This finding supports the hypothesis that this structural motif is a necessary condition for CCK(2) receptor activation given that both gastrin and cholecystokinin have been established to follow a membrane-associated pathway to receptor recognition and activation. Comparison of the conformations for the non-homologous C-terminal tyrosyl residues of [Nle(15)] gastrin-17 and [Tyr(9)-SO(3)] cholecystokinin-15 found that they lie on opposite faces of the conserved C-terminal helices. The positioning of this tyrosyl residue is known to be essential for CCK(1) activity and non-essential for CCK(2) activity, pointing to it as a possible differentiator in CCK(1)/CCK(2) receptor selection. The different tyrosyl orientations were retained in molecular models for the [Nle(15)] gastrin-17/CCK(2) receptor and [Tyr(9)-SO(3)] cholecystokinin-15/CCK(1) receptor complexes, highlighting the role of this residue as a likely CCK(1)/CCK(2) receptor differentiator.

Topics: Amino Acid Motifs; Amino Acid Sequence; Cholecystokinin; Gastrins; Models, Molecular; Molecular Sequence Data; Nuclear Magnetic Resonance, Biomolecular; Phosphorylcholine; Protein Binding; Protein Structure, Secondary; Protein Structure, Tertiary; Receptor, Cholecystokinin B

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Chronic Disease; Duodenal Ulcer; Female; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Pyloric Antrum; Retrospective Studies; Stomach Neoplasms; Stomach Ulcer

The authors describe a current approach to the laboratory diagnosis of chronic gastritis, by using the plates of serological tests: pepsinogen I (PG-I), gastrin 17, and antibodies to Helicobacter pylori (HP). These tests and a questionnaire were used to examine 168 persons aged 45-70 years, who were a random population sample. Almost a fourth of the adult population was observed to have pronounced gastric mucosal atrophic changes, which might be associated with the high prevalence of HP infection. The concentration of PG-I is high in the persons infected with HP, its cytotoxic strains in particular, its elevated level servers as a valid marker of peptic ulcer disease and gastroesophageal reflux.

Topics: Aged; Aged, 80 and over; Antibodies, Bacterial; Female; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Sensitivity and Specificity; Serologic Tests

Cancer risk is directly correlated with the severity and extent of mucosal atrophy, making identification of atrophy a goal in cancer prevention programs. The aim of this study was to compare targeted histology with noninvasive testing for the identification of antral and/or corpus atrophy in North America.. In a cross-sectional study of a random sample of households, 8 gastric biopsy specimens were obtained from defined locations in the antrum and corpus. Biopsies were scored for the presence of Helicobacter pylori and gastric atrophy (defined as loss of normal glandular components). Atrophy was scored by using the Sydney system and a system based on the number and location of corpus biopsies with atrophy. Patients' sera were examined for pepsinogen I, pepsinogen II, and gastrin-17 (fasting and stimulated).. One hundred eighty volunteers, approximately 30 per age group and ranging in age from 18-82 years, participated. There were 76 men. The overall weighted prevalence of a corpus atrophy was 4.7% (95% confidence interval, 2.3-7.0). There was a significant inverse relationship between the grade of corpus atrophy and the pepsinogen I/pepsinogen II ratio (R = -0.31, P < .01). We failed to confirm the usefulness of the proposed algorithm by using gastrin-17, H. pylori serology, and serum pepsinogens to categorize the gastric histology. The Sydney system underestimated the prevalence of corpus atrophy by approximately 25%.. Noninvasive testing is both possible and practical by using pepsinogen assays for the identification of the precancerous condition of moderate to severe corpus atrophy in North American Hispanic patients.

Topics: Adolescent; Adult; Antibodies, Bacterial; Atrophy; Biopsy; Cross-Sectional Studies; Female; Gastric Mucosa; Gastrins; Gastroscopy; Helicobacter pylori; Humans; Immunoglobulin G; Male; Mexico; Middle Aged; Pepsinogens; Serologic Tests

This study examined whether gastrin modulates endothelial cell activity via heparin-binding epidermal growth factor-like growth factor (HB-EGF) expression. Human umbilical vascular endothelial cells (HUVEC) were assessed for tubule formation in the presence of amidated gastrin-17 (G17) and glycine-extended gastrin-17 (GlyG17) peptides. HB-EGF gene and protein expressions were measured by quantitative reverse transcription-PCR, immunocytochemistry, and Western blotting, and HB-EGF shedding by ELISA. Matrix metalloproteinases MMP-2, MMP-3, and MMP-9 were assessed by Western blotting. Chick chorioallantoic membrane studies measured the in vivo angiogenic potential of gastrin and microvessel density (MVD) was assessed in large intestinal premalignant lesions of hypergastrinaemic APC(Min) mice. MVD was also examined in human colorectal tumor and resection margin normals and correlated with serum-amidated gastrin levels (via RIA) and HB-EGF protein expression (via immunohistochemistry). HUVEC cells showed increased tubule and node formation in response to G17 (186%, P < 0.0005) and GlyG17 (194%, P < 0.0005). This was blockaded by the cholecystokinin-2 receptor (CCK-2R) antagonists JB95008 and JMV1155 and by antiserum to gastrin and HB-EGF. Gastrin peptides increased HB-EGF gene expression/protein secretion in HUVEC and microvessel-derived endothelial cells and the levels of MMP-2, MMP-3, and MMP-9. G17 promoted angiogenesis in a chorioallantoic membrane assay, and MVD was significantly elevated in premalignant large intestinal tissue from hypergastrinaemic APC(Min) mice. In terms of the clinical situation, MVD in the normal mucosa surrounding colorectal adenocarcinomas correlated with patient serum gastrin levels and HB-EGF expression. Gastrin peptides, acting through the CCK-2R, enhance endothelial cell activity in models of angiogenesis. This may be mediated through enhanced expression and shedding of HB-EGF, possibly resulting from increased activity of matrix metalloproteinases. This proangiogenic effect translates to the in vivo and human situations and may add to the tumorigenic properties attributable to gastrin peptides in malignancy.

Topics: Animals; Cell Differentiation; Chick Embryo; Colonic Neoplasms; Endothelial Cells; Epidermal Growth Factor; Gastrins; Gene Expression; Heparin-binding EGF-like Growth Factor; Humans; Immune Sera; Intercellular Signaling Peptides and Proteins; Isoenzymes; Metalloendopeptidases; Mice; Neovascularization, Physiologic; Omeprazole; Receptor, Cholecystokinin B

To construct two kinds of anti-gastrin immunogen based on P64K protein from Neisseria meningitids and to compare their immunogenic effect.. G17P64K gene was cloned and ligated into pET28a plasmid, then transformed into BL21(DE3). After inoculation of LB medium and IPTG induction, the recombinant protein was solubly expressed at a high level. The purification of G17P64K fusion protein was similar to that of P64K. An initial step of purification consisting of 30% saturated ammonium sulfate precipitation was done. Additional fine optimizations included phenyl-sepharose, G200 Sephadex gel filtration and Q-sepharose anion exchanger chromatography. Highly purified protein was obtained and sequenced at the N-terminal amino acid residues. Polypeptide was synthesized by Fmoc solid phase chemical method and cross-linked to carrier protein P64K and DT mutant by MBS method and then the rabbit anti-gastrin 17 antibody was prepared by immunizing rabbit with cross-linked and fused protein. The titer and the activity in vitro of antibody were assessed.. G17P64K gene and the recombinant bacteria were obtained. After four steps purification, protein sample that has the purity above 90% was achieved. At the 84(th) day after the first immunization, the titer of antibody against cross-linked protein reached 51,200. Evaluation of the antibody in vitro manifested that it had a high inhibitory activity on the growth of tumor cell SW480.. The P64K-polypeptide cross-linked immunogen immunized rabbit and achieved a higher titer antibody against gastrin 17 than the G17P64K fusion protein immunogen, which could inhibit the growth of the tumor cell SW480.

Topics: Amino Acid Sequence; Animals; Antibodies; Bacterial Outer Membrane Proteins; Cancer Vaccines; Gastrins; Immunization; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Rabbits; Recombinant Fusion Proteins; Stomach Neoplasms

To study trends in morphological changes of gastric mucosa (GM) and its functional characteristics (serum gastrin-17, pepsinogens I and II) in eradication of Helicobacter pylori (HP) in patients with duodenal ulcer (DU).. HP infection was detected with a rapid urease test, morphological study of gastrobiopsies and polymerase chain reaction in 59 patients with DU. The results of HP eradication were assessed two months after the treatment. Morphological study of gastrobiopsies, assays for gastrin-17, pepsinogens I and II in blood serum were made before the treatment and one year after HP eradication.. By the results of eradication two groups were formed: with effective eradication and uneffective eradication of H. pylori. Examination of GM one year after successful H. pylori eradication in DU patients GM inflammation relieved: reduction in polymorphonuclear (by 42.6%), mononuclear (by 29.3%) infiltration and number of lymphocytic follicules (16.8-fold). GM atrophy decreased by 47.8%. In patients with uneffective eradication the above positive changes were not registered. After H. pylori eradication, serum gastrin-17 lowered by 46. 7%, pepsinogen I--by 30.5%, pepsinogen II--by 36.9%. In uneffective eradication this decrease did not occur.. H. pylori eradication leads to positive changes in morphological and functional indices reflecting GM condition.

Topics: Adult; Anti-Bacterial Agents; Biomarkers; Biopsy; DNA, Bacterial; Duodenal Ulcer; Female; Follow-Up Studies; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Intestinal Mucosa; Male; Pepsinogen A; Pepsinogen C; Polymerase Chain Reaction; Treatment Outcome

A number of growth factors affect the regeneration of intestinal epithelia following injury, but the effects of amidated gastrin have not previously been assessed. We therefore investigated the effects of gastrin on intestinal regeneration following a range of stimuli.. Intestinal crypt regeneration was assessed in transgenic mice overexpressing amidated gastrin (INS-GAS) and mice in which hypergastrinemia was induced using omeprazole, following gamma-radiation, 5-fluorouracil, and dextran sulphate sodium (DSS). Abundance of the CCK-2 receptor was assessed in intestinal epithelia and IEC-6 intestinal epithelial cells following gamma-radiation.. Four days following 14 Gy gamma-radiation, or 2 injections of 400 mg/kg 5-fluorouracil, INS-GAS mice exhibited significantly increased small intestinal and colonic crypt survival compared with their wild-type counterparts (FVB/N). INS-GAS mice treated with 3% DSS for 5 days showed less weight loss and increased colonic crypt regeneration at 8 days compared with FVB/N. Increased small intestinal and colonic crypt survival was also demonstrated following gamma-radiation in FVB/N mice rendered hypergastrinemic using omeprazole. The increased crypt survival in INS-GAS mice following 14 Gy gamma-radiation was inhibited by administration of a CCK-2 receptor antagonist (YF476). Increased abundance of the CCK-2 receptor was demonstrated in intestinal epithelia following 14 Gy gamma-radiation by Western blotting and immunohistochemistry. Similarly, increased CCK-2 receptor mRNA abundance and increased 125I-gastrin binding was demonstrated in IEC-6 cells following 4 Gy gamma-radiation.. Hypergastrinemia increases regeneration of intestinal epithelia following diverse forms of injury. Induction of the CCK-2 receptor in damaged epithelium confers potential for protection against injury by administration of gastrin.

Topics: Animals; Benzodiazepinones; Cell Line; Cell Proliferation; Colitis; Dextran Sulfate; Enteritis; Enzyme Inhibitors; Fluorouracil; Gamma Rays; Gastrins; Growth Substances; Intestinal Mucosa; Mice; Mice, Inbred Strains; Mice, Transgenic; Omeprazole; Phenylurea Compounds; Proton Pump Inhibitors; Receptor, Cholecystokinin B; Regeneration; Wounds and Injuries

Acid secretion is intimately associated with most upper gastrointestinal diseases. Helicobacter pylori infection is a major environmental factor modifying acid secretion.. To study the association between the pattern of H pylori gastritis and gastric secretory function in a large number of subjects without specific upper gastrointestinal disease.. Maximal acid output (MAO) was measured in 255 patients with dyspepsia showing normal endoscopy. Activity and severity of gastritis, atrophy and H pylori infection were assessed in body and antral biopsies. The correlations of histological parameters as well as age, sex, height, weight, smoking, serum gastrin, pepsinogen I and II, and their ratio with MAO were determined. Multiple linear regression was used to show the best possible predictors of MAO.. Negative relationships: Body atrophy and body-combined (active and chronic) inflammatory scores showed a potent inverse correlation with MAO (correlation coefficients (CC) 0.59 and 0.50, respectively). Body:antral chronic gastritis ratio and body:antral combined inflammation ratio (both with CC = 0.49) and age (CC = 0.44) were also inversely correlated with MAO. Intestinal metaplasia at both antral and body sites had negative relationships with acid output with CC = 0.23 and 0.20, respectively. Positive relationships: Serum pepsinogen I, body H pylori density:combined inflammation ratio and pepsinogen I:II ratio with CC of 0.38, 0.38 and 0.30, respectively, correlated with MAO. The H pylori density: combined inflammation of both antrum and body positively correlated with MAO (CC = 0.29 and 0.38, respectively). Male sex and patient height also positively correlated with acid output. Modelling showed that body combined inflammatory score, body atrophy, age and serum pepsinogen I are independent predictors of acid output (R(2) = 0.62).. Combination of body gastritis, body atrophy, age and serum pepsinogen I can be used as predictors of acid-secretory state in populations infected with H pylori.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Antigens, Bacterial; Bacterial Proteins; Biomarkers; Biopsy; Chronic Disease; Female; Gastric Acid; Gastric Acidity Determination; Gastrins; Gastritis; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Linear Models; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Pyloric Antrum

The rationale for bariatric surgery is to reduce food intake by gastric restriction and/or malabsorption by intestinal bypass. Unlike ghrelin, gastrin is released in response to food intake. Here we studied the possible role of gastrin in the reduction of body weight after gastric bypass surgery.. Rats were divided into four experimental groups and were subjected to different treatments: sham operation, gastric bypass, sham operation + gastrin infusion, and gastric bypass + gastrin infusion. The gastric bypass was done by anastomosing the esophagus to the duodenal bulb without bypassing the intestine. Gastrin-17 was infused continuously for 2 months via subcutaneously implanted osmotic minipumps. Body weights were recorded; serum gastrin and ghrelin levels were measured, and the stomachs were analyzed morphologically.. Gastric bypass resulted in reducing the body weight, stomach weight, thickness of the oxyntic mucosa, serum gastrin concentration, and activity of the ECL cells. Gastrin infusion prevented mucosal atrophy and ECL cell inactivation, and attenuated the body weight reduction that occurred following gastric bypass. Circulating ghrelin and ghrelin-producing A-like cells in stomachs that had undergone gastric bypass were unchanged with or without gastrin infusion and are thus unlikely to be responsible for the reduced body weight.. We suggest that hypogastrinemia and impaired ECL cell function in the oxyntic mucosa of the stomach might be partially responsible for the reduction in body weight that occurs after gastric bypass.

Topics: Anastomosis, Surgical; Animals; Duodenum; Enterochromaffin Cells; Esophagus; Gastric Bypass; Gastric Mucosa; Gastrins; Ghrelin; Infusion Pumps, Implantable; Male; Organ Size; Parietal Cells, Gastric; Peptide Hormones; Rats; Rats, Sprague-Dawley; Weight Loss

To validate a non-invasive method to detect gastric mucosal atrophy in a Chilean population with high prevalence of gastric cancer and a poor survival rate.. We first determined the optimal cut-off level of serum pepsinogen (PG)-1, PG-1/PG-2 ratio and 17-gastrin in 31 voluntary symptomatic patients (mean age: 66.1 years), of them 61% had histologically confirmed gastric atrophy. Then, in a population-based sample of 536 healthy individuals (209 residents in counties with higher relative risk and 327 residents in counties with lower relative risk for gastric cancer), we measured serum anti-H pylori antibodies, PG and 17-gastrin and estimated their risk of gastric cancer.. We found that serum PG-1 < 61.5 microg/L, PG-1/PG-2 ratio < 2.2 and 17-gastrin > 13.3 pmol/L had a high specificity (91%-100%) and a fair sensitivity (56%-78%) to detect corpus-predominant atrophy. Based on low serum PG-1 and PG-1/PG-2 ratio together as diagnostic criteria, 12.5% of the asymptomatic subjects had corpus-predominant atrophy (0% of those under 25 years and 20.2% over 65 years old). The frequency of gastric atrophy was similar (12% vs 13%) but H pylori infection rate was slightly higher (77% vs 71%) in the high-risk compared to the low-risk counties. Based on their estimated gastric cancer risk, individuals were classified as: low-risk group (no H pylori infection and no atrophy; n = 115; 21.4%); moderate-risk group (H pylori infection but no atrophy; n = 354, 66.0%); and high-risk group (gastric atrophy, with or without H pylori infection; n = 67, 12.5%). The high-risk group was significantly older (mean age: 61.9+/-13.3 years), more frequently men and less educated as compared with the low-risk group.. We propose to concentrate on an upper gastrointestinal endoscopy for detection of early gastric cancer in the high-risk group. This intervention model could improve the poor prognosis of gastric cancer in Chile.

Topics: Adult; Aged; Aged, 80 and over; Atrophy; Chile; Female; Gastric Mucosa; Gastrins; Humans; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Reference Values; Risk Factors; Stomach Neoplasms

To explore the effect of gastrin 17 (G17) on beta-catenin/T cell factor-4 (Tcf-4) signaling in colonic cancer cell line Colo320WT.. The pCR3.1/GR plasmid, which expresses gastrin receptor, cholecystokinin-2 receptor (CCK-2R), was transfected into a colonic cancer cell line Colo320 by Lipofectamine (TM)2000 and the stably expressing CCK-2R clones were screened by G418. The expression levels of gastrin receptor in the Colo320 and the transfected Colo320WT cell line were assayed by RT-PCR. Colo320WT cells were treated with G17 in a time-dependent manner (0, 1, 6, 12, 24 and 48 h), then with L365,260 (Gastrin(17) receptor blocker) for 30 min, and with G17 again for 12 h or L365,260 for 12 h. Expression levels of beta-catenin in a TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells treated with G17 were detected by co-immuniprecipation and Western blot. Immunocytochemistry was used to examine the distribution of beta-catenin in CoLoWT320 cells. Expression levels of c-myc and cyclin D1 in Colo320WT cells treated with G17 were assayed by Western blot.. Expression levels of beta-catenin in the TX-100 solution fraction decreased apparently in a time-dependent fashion and reached the highest level after G17 treatment for 12 h, while expression levels of beta-catenin in the TX-100 insoluble fraction were just on the contrary. Immunocytochemistry showed that beta-catenin was translocated from the cell membranes into the cytoplasm and nucleus under G17 treatment. Expression levels of c-myc and cyclin D1 in the G17-treated Colo320WT cells were markedly higher compared to the untreated Colo320WT cells. In addition, the aforementioned G17-stimulated responses were blocked by L365,260.. Gastrin17 activates beta-catenin/Tcf-4 signaling in Colo320WT cells, thereby leading to over-expression of c-myc and cyclin D1.

Topics: Base Sequence; beta Catenin; Cell Line, Tumor; Colonic Neoplasms; Cyclin D; Cyclins; DNA, Complementary; Gastrins; Humans; Proto-Oncogene Proteins c-myc; Receptor, Cholecystokinin B; Recombinant Proteins; TCF Transcription Factors; Transcription Factor 7-Like 2 Protein; Transfection

To investigate the effects of gastrin and cholecystokinin (CCK) and their specific antagonists on the growth of pancreatic and biliary tract cancer cell lines.. Five pancreatic and 6 biliary cancer cell lines with 2 conrtol cells were used in this study. Cell proliferation study was done using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test and direct cell count method. Reverse transcription-polymerase chain reaction (RT-PCR) and slot blot hybridization were performed to examine and quantify the expression of hormonal receptors in these cell lines.. SNU-308 showed a growth stimulating effect by gastrin-17, as did SNU-478 by both gastrin-17 and CCK-8. The trophic effect of these two hormones was completely blocked by specific antagonists (L-365, 260 for gastrin and L-364, 718 for CCK). Other cell lines did not respond to gastrin or CCK. In RT-PCR, the presence of CCK-A receptor and CCK-B/gastrin receptor mRNA was detected in all biliary and pancreatic cancer cell lines. In slot blot hybridization, compared to the cell lines which did not respond to hormones, those that responded to hormones showed high expression of receptor mRNA.. Gastrin and CCK exert a trophic action on some of the biliary tract cancers.

Topics: Biliary Tract Neoplasms; Cell Count; Cell Division; Cell Line, Tumor; Cholecystokinin; Gastrins; Hormone Antagonists; Humans; Pancreatic Neoplasms; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Reverse Transcriptase Polymerase Chain Reaction; Tetrazolium Salts; Thiazoles

Corpus dominant gastritis and intestinal metaplasia (IM) are considered markers of increased risk of gastric carcinoma. The aim of our study was to determine serum and histologic risk markers of gastric cancer. Antral and corpus histology, pepsinogen and gastrin 17 levels were compared among patients with history of endoscopic mucosal resection (EMR) for early gastric cancer and controls. Serum pepsinogen (PG) and gastrin 17 levels were measured by RIA. There were 53 gastric cancer patients and 75 controls. The scores for IM in each region and atrophy at the lesser curvature of the corpus were significantly higher in the cancer group than in the H. pylori-positive control group. IM at the greater curvature of the corpus and atrophy at the lesser curvature of the corpus were associated with multiple malignant lesions. Although corpus gastritis was associated with an increased risk of gastric cancer (odds ratio [OR] = 3.4; 95% confidence interval [CI] 1.6-7.0) (p = 0.001), the most important marker was the presence of IM at the lesser curvature of the corpus (OR = 15.1; 95% CI 4.3-52.6) (p < 0.001)). The best cut-off points of serum markers for gastric cancer were a PG I concentration of 45 ng/mL or less and a gastrin 17 >60 pg/mL (sensitivity = 83%; specificity = 68%). IM at the lesser curvature of the corpus and the combination of serum gastrin 17 and PG I identified a group at high risk for development of gastric cancer. Annual endoscopic follow-up is warranted for patients with IM found at the greater curvature of the corpus.

Topics: Aged; Biomarkers; Case-Control Studies; Endoscopy; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Intestinal Mucosa; Male; Metaplasia; Pepsinogen A; Pepsinogen C; Pyloric Antrum; Stomach Neoplasms

As gastrin may play a role in the pathophysiology of gastrointestinal (GI) malignancies, the elucidation of the mechanisms governing gastrin-induced proliferation has recently gained considerable interest. Several studies have reported that a large percentage of colorectal tumours overexpress or stabilise the beta-catenin oncoprotein. We thus sought to determine whether gastrin might regulate beta-catenin expression in colorectal tumour cells. Amidated gastrin-17 (G-17), one of the major circulating forms of gastrin, not only enhanced beta-catenin protein expression, but also one of its target genes, cyclin D1. Furthermore, activation of beta-catenin-dependent transcription by gastrin was confirmed by an increase in LEF-1 reporter activity, as well as enhanced cyclin D1 promoter activity. Finally, G-17 prolonged the tau(1/2) of beta-catenin protein, demonstrating that gastrin appears to exert its mitogenic effects on colorectal tumour cells, at least in part, by stabilising beta-catenin.

Topics: Animals; beta Catenin; Blotting, Northern; Blotting, Western; Cell Line, Tumor; Colorectal Neoplasms; Cyclin D1; Cytoskeletal Proteins; Gastrins; Mice; Promoter Regions, Genetic; Trans-Activators; Transcription, Genetic

Helicobacter pylori-associated atrophic gastritis is known to be a significant risk factor for gastric cancer. Among the well-known parameters of atrophic gastritis are the levels of serum gastrin-17 (G-17) and pepsinogen I (PG1), which are biomarkers of gastric antral and corpus mucosal activity, respectively. The aim of study was to compare the production of G-17 and PG1 in patients with or without stomach mucosal atrophy and to investigate the utility of serum PG1 and/or G-17 concentrations for the objective evaluation of atrophic gastritis.. A total of 178 dyspeptic Helicobacter pylori-positive patients underwent diagnostic upper gastrointestinal endoscopy with biopsy. The degree of histologic gastric mucosal atrophy was compared with the fasting levels of PG1, and to the postprandial levels of G-17 detected by enzyme immunoassay.. A decrease in serum G-17 levels along with worsening of the antral atrophy was observed; the serum levels of PG1 were reduced during progression of the corpus atrophy. In the multifocal atrophic gastritis, values for PG1 and G-17 serum concentrations were significantly lower than the respective cut-off values. Statistical analysis revealed statistically significant differences between the serum levels of PG1 and G-17 measured at different stages of stomach mucosal atrophy.. A strong reverse correlation was found between histologic/ endoscopic antral atrophy and serum G-17 levels, and between corpus atrophy and serum PG1 levels.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biomarkers; Biopsy; Endoscopy, Digestive System; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immunoenzyme Techniques; Middle Aged; Pepsinogen A; Pyloric Antrum; Sensitivity and Specificity; Severity of Illness Index

Although expression of the gastrin/cholecystokinin-2 receptor (CCK2R) is widely reported in human colorectal cancer, little is known on its role in mediating mature amidated gastrin (gastrin-17 amide, G-17) induced intracellular signal transduction in colon cancer cells. The purpose of this study was to explore the intracellular events of colorectal cancer cells after gastrin binding to CCK2R. Meanwhile, the influence of a natural point mutation 286V-->F in the third intracellular loop of CCK2R on gastrin-envoked intracellular signal transduction was also investigated. Firstly, Colo320 cells were stably transfected with wild type (Colo320 WT) and mutant CCK2R (Colo320 M), respectively. The intracellular signal transduction events in response to gastrin were investigated in both Colo320 WT and Colo320 M cells. In Colo320 WT cells, G-17 induced formation of intracellular cyclic AMP and inositol 1,4,5-trisphosphate, and stimulated intracellular calcium mobilization. G-17 also stimulated tyrosine phosphorylation of ERKl/2, p38, FAK, and paxillin, and up-regulated the mRNA expression of early response gene c-Jun and c-Fos. However, G-17 inhibited proliferation and induced apoptosis in Colo320 WT cells. Mutation 286V-->F in the third intracellular loop of CCK2R blocked G-17 induced biological without affecting binding affinity of CCK2R to G-17. Our results suggest that activation of CCK2R by gastrin stimulates heterotrimeric G-protein Gq and G(12/13) mediated intracellular signal transduction pathway in colon cancer cells. The valine-287 residue in third intracellular loop of CCK2R plays a pivotal role in CCK2R mediated intracellular signal transduction.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Cyclic AMP; Focal Adhesion Kinase 1; Gastrins; Genes, Immediate-Early; Humans; Inositol 1,4,5-Trisphosphate; Paxillin; Phosphorylation; Point Mutation; Protein Structure, Secondary; Receptor, Cholecystokinin B; RNA, Messenger; Signal Transduction; Transfection; Tyrosine; Up-Regulation; Valine

Several tests have been proposed for evaluating dyspeptic symptoms and their relationship to the underlying gastric disease. Serum pepsinogens and gastrin-17 are known to be useful biomarkers for the detection of gastric pathologies.. To evaluate the capability of screening dyspeptic patients in the primary care by analyses of serum pepsinogens I (sPGI) and II (sPGII), gastrin-17 (sG-17) and the IgG anti-Helicobacter pylori antibodies (IgG-Hp).. Three hundred and sixty-two consecutive patients with dyspeptic symptoms (208 females, mean age 50.6 +/- 16 years, range 18-88 years) referred by general practitioners for upper gastrointestinal endoscopy were enrolled. A blood sample was taken from each subject for IgG-Hp, sPGI, sPGII and sG-17 analyses.. Two hundred and eighty-seven patients had a complete screening; of these, 132 resulted positive for Hp infection. Patients with atrophic chronic gastritis showed significantly lower serum pepsinogen I levels and sPGI/sPGII ratio than patients with non-atrophic chronic gastritis. Moreover, by calculating the values of sPGI by sG-17 and sG-17 by sPGII/sPGI, subjects with atrophic chronic gastritis could be distinguished from those with non-atrophic chronic gastritis and from those with normal mucosa, respectively. sG-17 levels were found to be a useful biomarker for the detection of antral atrophic gastritis, while the combination of sPGI, the sPGI/sPGII ratio and sG-17 was found effective in identifying corpus atrophy.. A panel composed of PGI, PGII, G-17 and IgG-Hp could be used as a first approach in the 'test and scope' and/or 'test and treat' strategy in the primary care management of dyspeptic patients.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Chronic Disease; Dyspepsia; Female; Gastrins; Gastritis; Gastroscopy; Helicobacter pylori; Humans; Immunoglobulin G; Male; Mass Screening; Middle Aged; Pepsinogen A; Pepsinogen C; Primary Health Care

To investigate the expression of gastrin in human gastric cancer cell line SGC-7901 and the effects of gastrin-17 and anti-gastrin mAb on its growth.. The expression of gastrin was determined by immunohistochemistry with anti-gastrin mAb prepared by our group. In a series of experiments, the growth of SGC-7901 cells was evaluated by MTT assay on cells grown in serum-free medium and treated with gastrin-17 and/or anti-gastrin mAb.. Immunohistochemical examination of SGC-7901 cells revealed a specific gastrin immunoreactivity. Gastrin-17 significantly stimulated cell growth at the concentrations of 1 x 10(-9) mol/L approximately 1 x 10(-5) mol/L in a dose-dependent manner. The growth of SGC-7901 cells treated with anti-gastrin mAb, either alone or in combination with gastrin-17 (1 x 10(-7) mol/L), was significantly inhibited.. Growth of human gastric cancer cells SGC-7901 can be stimulated in an autocrine fashion. The gastrin-stimulated growth of gastric cancer cells can be blocked by anti-gastrin mAb bound specifically with gastrin. Further study on the significance of anti-gastrin mAb in designing immunotherapy targeting to gastrin or gastrin receptor is warranted.

Topics: Antibodies, Monoclonal; Cell Line, Tumor; Cell Proliferation; Gastrins; Humans; Receptor, Cholecystokinin B; Stomach Neoplasms

Topics: Adult; Antibodies; Enzyme-Linked Immunosorbent Assay; Female; Gastrin-Secreting Cells; Gastrinoma; Gastrins; Humans; Male; Pancreatic Neoplasms; Radioimmunoassay

The third intracellular loop domain of G protein-coupled receptors regulates their desensitization, internalization, and resensitization. Colorectal and pancreatic cancers, but not the nonmalignant tissue, express a splice variant of the cholecystokinin 2 receptor (CCK2R) called CCK(2i4sv)R that, because of intron 4 retention, contains an additional 69 amino acids within its third intracellular loop domain. This structural alteration is associated with agonist-independent activation of Src kinase (Olszewska-Pazdrak, B., Townsend, C. M., Jr., and Hellmich, M. R. (2004) J. Biol. Chem. 279, 40400-40404). The purpose of the study was to determine the roles of intron 4 retention and Src kinase on CCK(2i4sv)R desensitization, internalization, and resensitization. Gastrin1-17 (G17) binds to both CCK2R and CCK(2i4sv)R and induces intracellular Ca2+ ([Ca2+]i) increases. Agonist-induced increases in [Ca2+]i were used to assess receptor activity. Src kinase activity was inhibited by transducing cells with a retrovirus containing a dominant-negative mutant Src (A430V). The subcellular location of enhanced green fluorescent protein-tagged receptors was monitored using laser scanning confocal microscopy. Both receptor variants desensitized at the same rate; however, CCK(2i4sv)R resensitized five times faster than CCK2R. Without agonist, 80% of CCK(2i4sv)R is located in an intracellular compartment. In contrast, 80% of CCK2R was located on the plasma membrane. Treatment with inverse agonist (YM022) or expression of dominant-negative Src blocked the constitutive internalization of CCK(2i4sv)R, resulting in its accumulation on the plasma membrane. Expression of dominant-negative Src slowed the rate of CCK(2i4sv)R resensitization. Inhibition of Src did not affect G17-induced internalization of either receptor variant. Constitutive internalization of CCK(2i4sv)R increases its rate of resensitization by creating an intracellular pool of receptors that can rapidly recycle back to the plasma membrane.

Topics: Alternative Splicing; Amino Acid Sequence; Benzodiazepines; Calcium; Carbocyanines; Cell Line; Cell Membrane; Clone Cells; Fluorescent Dyes; Gastrins; Genetic Variation; Green Fluorescent Proteins; Hormone Antagonists; Humans; Introns; Kinetics; Microscopy, Confocal; Models, Biological; Protein Structure, Tertiary; Receptor, Cholecystokinin B; Retroviridae; src-Family Kinases; Transduction, Genetic

To examine whether the fasting levels of serum gastrin-17 (G-17) are lower in Barrett's esophagus (BE) patients than in non-Barrett controls.. Nineteen patients with BE (presenting with a tubular segment > or =2 cm long in lower esophagus and intestinal metaplasia of incomplete type ("pecialized columnar epithelium") in endoscopic biopsies from the tubular segment below the squamocolumnar junction were collected prospectively from outpatients referred to diagnostic gastroscopy. The controls comprised 199 prospectively collected dyspeptic outpatients without BE or any endoscopically visible lesions in the upper GI tract. Fasting levels of serum G-17 (G-17fast) were assayed with an EIA test using a mAb highly specific to amidated G-17. None of the patients and controls received therapy with PPIs or other antisecretory agents.. The mean and median levels of G-17fast in serum were significantly lower (P = 0.001) in BE patients than in controls. The positive likelihood ratios (LR+) of low G-17fast to predict BE in the whole study population at G-17fast levels <0.5, <1, or <1.5 pmol/L were 3.5, 3.0, and 2.8, respectively. Among patients and controls with healthy stomach mucosa, the LR+ were 5.6, 3.8, and 2.6, respectively. In the whole study population, serum G-17 was below 2 pmol/L in 15 of 19 BE patients (79%). The corresponding prevalence was 66 of 199 (33%) in controls (P<0.001). The G-17fast was 5 pmol/L or more in only one of the 19 BE patients (5%). In controls, 76 of the 199 patients (38%) had such high serum G-17fast levels (P<0.01).. Serum levels of G-17fast tend to be lower in native patients with BE than in healthy controls.

Topics: Aged; Barrett Esophagus; Case-Control Studies; Esophagoscopy; Female; Gastrins; Humans; Male; Middle Aged; Prospective Studies

Cell division is brisk in the ulcer margin and many of the new cells will migrate over and cover the ulcer bed. The aim of this study was to determine how agents that promote or delay gastric ulcer healing influence cell proliferation in the gastric epithelium.. Acetic acid ulcers were produced in the rat gastric corpus; non-ulcer rats served as controls. All rats were given a continuous infusion of (3)H-thymidine. Some rats were also given gastrin or indomethacin, or infected with Helicobacter pylori. The rats were killed after 1, 2, 6 or 13 days, and the ulcer margin and undamaged corpus were excised for determination of labeling index (LI) by autoradiography. Antrum, duodenum and colon were also studied. Silver grain counting was carried out in some groups.. LI in the ulcer margin grew exponentially, reaching 84% after 6 days; gastrin increased, and indomethacin decreased LI significantly. In 6-day ulcer rats that were given 3H-thymidine only during the first day LI was 5%, while in those given 3H-thymidine only during the last day LI was 27%. LI and silver grain counting results indicated that during the first 6 days of healing the epithelial cells in the ulcer margin divide twice. In the undamaged epithelium of the 1-day ulcer rats LI was

Topics: Acetic Acid; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Proliferation; Epithelial Cells; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Indomethacin; Rats; Rats, Sprague-Dawley; Stomach Ulcer; Thymidine; Wound Healing

Histology is the gold standard for diagnosis of atrophy but is hampered by observer variation. A reliable method to overcome this issue is morphometric analysis of gastric mucosa. Serum pepsinogens and gastrin have been proposed in the diagnostic work-up of gastric atrophy although diagnostic accuracy of these tests is considered unsatisfactory.. To evaluate the diagnostic accuracy of gastric serum profile in relation both to morphological and morphometric diagnosis of gastric atrophy.. Ninety-four dyspeptic out-patients underwent upper endoscopy and evaluation of serum levels of PGI, PGII and 17-gastrin. Diagnostic accuracy of gastric serum profile was tested by receiver operating characteristic curves and by evaluation of sensitivity and specificity in relation to both histology and morphometric analyses.. As far as concern to histological evaluation, only PGI/PGII ratio showed an acceptable diagnostic accuracy in discrimination of gastric atrophy, while, when morphometric analysis was considered as reference, both serum PGI level and PGI/PGII ratio showed an excellent performance. However, both PGI and PGI/PGII ratio showed low sensitivity and high specificity.. Serological gastric profile corresponds better with the morphometric diagnosis of atrophy, even if, because of the low sensitivity, today this could only be used as screening test of chronic atrophic gastritis.

Topics: Adult; Aged; Chronic Disease; Dyspepsia; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Humans; Male; Middle Aged; Pepsinogens; ROC Curve; Sensitivity and Specificity

To evaluate serum pepsinogen I (PG I) and gastrin-17 (G-17) levels in patients with Helicobacter pylori (H. pylori)-associated chronic atrophic gastritis, with reference to endoscopical Kimura-Takemoto's staging, chromoendoscopical and histological features.. 267 dyspeptic H. pylori-infected patients were examined by chromoendoscopy with biopsy sampling according to the Sydney System and according to Kimura-Takemoto's scale. Simultaneous assessment of serum pepsinogen I (PG I) and gastrin-17 (G-17) levels by enzyme immunoassay was performed. The serologic and morphologic results were compared with correlation analysis.. There was strong reverse correlation between the stomach mucosal atrophy (antral part or corpus) and the proper serologic markers (respectively, G-17 or PG I) in H. pylori-associated chronic gastritis when gastric biopsies taken according to the Sydney System were assessed. The use of Kimura-Takemoto's scale has revealed the decrease of serum PG I levels only at 0-2 and 0-3 grades of the corpus mucosa atrophy. Probably, these results reflects the development of functional failure of the stomach corpus mucosa at late stages of atrophy when its compensatory capacity becomes insufficient. There were not any advantages in sampling biopsies for the detecting of intestinal metaplasia (IM) by the Sydney System, or by Kimura-Takemoto's scheme. The obvious concordance between histologically proven extent of IM and the number of IM foci detected by chromoendoscopy has been revealed.. The biopsy sampling for the diagnosis of precancerous changes of the stomach mucosa after non-invasive screening of atrophic gastritis (e.g., by means of EIA) should be based preferably on the visual signs acquired via chromoendoscopy than through routine endoscopy, independently of the scheme of examination of stomach mucosa, either according to the Sydney System, or to the Kimura-Takemoto's scale.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Atrophy; Endoscopy; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immunoenzyme Techniques; Male; Middle Aged; Pepsinogen A

Bioactivation of prohormones occurs in the granules of the regulated secretory pathway of endocrine cells, which release hormones in response to external stimulation. How secretory granules are formed and how the cargo is selected is still unclear, but it has been shown for several prohormones and processing enzymes that domains within the prohormone structure can act as "sorting signals" for this pathway. The domains mediate interactions with other proteins or with the membrane or facilitate aggregation of the (pro)peptides. We have now searched for domains in progastrin that are active in sorting the prohormone into secretory granules. Truncation studies showed that the N-terminal 30 residues of progastrin are dispensable, whereas the last 49 residues are sufficient for correct biosynthesis of bioactive gastrin. Thus, further N-terminal truncation abolished gastrin expression. C-terminal truncation of 8 residues resulted in an increase in basal secretion as did point mutations in the dibasic processing sites of progastrin. These mutants, however, still responded to secretagogues, suggesting a residual sorting capacity to the regulated pathway. Amino acid substitutions in an acidic, polyglutamate motif within gastrin-17, the main bioactive, cellular gastrin form, did not alter secretion per se, but when these residues were substituted in C-terminally truncated mutants, double mutants increased in basal secretion and did not respond to secretagogue stimulation. This implies that the mutants are constitutively secreted. Our data suggest that the dibasic processing sites constitute the most important sorting domain of progastrin, and these sites act in synergy with the acidic domain.

Topics: Amino Acid Motifs; Amino Acid Sequence; Animals; Cricetinae; Gastrins; Genetic Vectors; Glutamic Acid; Hormones; Humans; Mesocricetus; Molecular Sequence Data; Mutation; Peptides; Point Mutation; Protein Precursors; Protein Sorting Signals; Protein Structure, Tertiary; Radioimmunoassay; Sequence Homology, Amino Acid; Transfection

In the digestive tract, the transit of ingested food induces a local contraction-relaxation reflex of which the smooth muscle cell (SMC) represents the functional unit. Although freshly isolated SMCs have been extensively used for in vitro studies, in specific cases cultured cells appear necessary. Because conventionally cultured SMCs lose their contractile properties, we have developed: (1) differentiated, contractile rabbit gastric SMCs (D-stim cells), cultured in a medium supplemented with insulin, and (2) proliferative, dedifferentiated rabbit gastric SMCs (P-stim cells), cultured in a medium supplemented with insulin, fetal serum, EGF and b-FGF. The proliferative index was 5 +/- 4% and 82 +/- 10%, respectively, for D-stim and P-stim cells. Expression of SM-myosin heavy chain was observed in 90% of D-stim cells, whereas it was progressively lost in P-stim cells. Carbachol (1-100 nM), glicentin (2 nM) and gastrin-17 (100 nM) induced contraction of D-stim cells cultured for 3 or 6 days, whereas they did not induce the contraction of P-stim cells; in contrast, gastrin-17 (10 nM) was able to stimulate DNA synthesis (1.86 +/- 0.09-fold increase) in P-stim cells. The coupling of muscarinic receptors to intracellular transduction pathways was evaluated in D-stim cells: at day 3, carbachol (100 nM) induced a twofold increase in the production of inositol tri-tetra-phosphates; in parallel, a phosphorylation of ERK MAP kinases occurred within 1 min of carbachol stimulation. In conclusion, cultured functional myocytes derived from mature tissue may be used for long-term studies concerning the events coupled either to proliferation or to motility regulation of differentiated SMCs due to the activation of G-protein-coupled receptors.

Topics: Animals; Carbachol; Cell Differentiation; Cell Proliferation; Cells, Cultured; Extracellular Signal-Regulated MAP Kinases; Gastrins; Glicentin; Glucagon; Glucagon-Like Peptides; Inositol Phosphates; Muscle Contraction; Muscle, Smooth; Myosin Heavy Chains; Peptide Fragments; Protein Precursors; Pyloric Antrum; Rabbits; Receptors, Muscarinic; Signal Transduction

Ghrelin release in man depends on the macronutrient composition of the test meal. The mechanisms contributing to the differential regulation are largely unknown. To elucidate their potential role, glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), insulin, gastrin and somatostatin were examined on isolated rat stomach ghrelin secretion, which offers the advantage of avoiding systemic interactions. Basal ghrelin secretion was in a range that did not permit to consistently evaluate inhibiting effects. Therefore, the effect of gastrointestinal hormones and insulin was analyzed during vagal prestimulation. GLP-1(7-36)amide 10(-8) and 10(-7) M decreased ghrelin secretion significantly. In contrast, GIP 10(-8) and 10(-7) M augmented not only prestimulated, but also basal ghrelin secretion (p<0.05). Insulin reduced ghrelin at 10(-10), 10(-8) and 10(-6) M (p<0.05). Both gastrin 10(-8) M and somatostatin 10(-6) M also significantly inhibited ghrelin secretion. These data demonstrate that GLP-1(7-36)amide, insulin, gastrin and somatostatin are potential candidates to contribute to the postprandially observed inhibition of ghrelin secretion with insulin being the most effective inhibitor in this isolated stomach model. GIP, on the other hand, could attenuate the postprandial decrease. Because protein-rich meals do not effectively stimulate GIP release, other as yet unknown intestinal factors must be responsible for protein-induced stimulation of ghrelin release.

Topics: Animals; Dose-Response Relationship, Drug; Gastric Inhibitory Polypeptide; Gastric Mucosa; Gastrins; Ghrelin; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Insulin; Male; Peptide Fragments; Peptide Hormones; Protein Precursors; Radioimmunoassay; Rats; Rats, Wistar; Somatostatin; Time Factors

Gastrin and its precursors promote proliferation in different gastrointestinal cells. Since mature, amidated gastrin (G-17) can induce cyclin D1, we determined whether G-17-mediated induction of cyclin D1 transcription involved Wnt signaling and CRE-binding protein (CREB) pathways. Our studies indicate that G-17 induces protein, mRNA expression and transcription of the G(1)-specific marker cyclin D1, in the gastric adenocarcinoma cell line AGSE (expressing the gastrin/cholecystokinin B receptor). This was associated with an increase in steady-state levels of total and nonphospho beta-catenin and its nuclear translocation, indicating the activation of the Wnt-signaling pathway. In addition, G-17-mediated increase in cyclin D1 transcription was significantly attenuated by axin or dominant-negative (dn) T-cell factor 4(TCF4), suggesting crosstalk of G-17 with the Wnt-signaling pathway. Mutational analysis indicated that this effect was mediated through the cyclic AMP response element (CRE) (predominantly) and the TCF sites in the cyclin D1 promoter, which was also inhibited by dnCREB. Furthermore, G-17 stimulation resulted in increased CRE-responsive reporter activity and CREB phosphorylation, indicating an activation of CREB. Chromatin immunoprecipitation studies revealed a G-17-mediated increase in the interaction of beta-catenin with cyclin D1 CRE, which was attenuated by dnTCF4 and dnCREB. These results indicate that G-17 induces cyclin D1 transcription, via the activation of beta-catenin and CREB pathways.

Topics: beta Catenin; Cyclic AMP Response Element-Binding Protein; Cyclin D1; Cytoskeletal Proteins; G1 Phase; Gastrins; Humans; Proto-Oncogene Proteins; S Phase; Signal Transduction; Stomach Neoplasms; Trans-Activators; Transcription, Genetic; Wnt Proteins; Zebrafish Proteins

Amidated forms of the peptide hormone gastrin act via the cholecystokinin-2 receptor to stimulate gastric acid secretion, whereas non-amidated forms stimulate colonic mucosal proliferation via a novel, as yet uncharacterised, receptor. Nuclear magnetic resonance (NMR) and fluorescence spectroscopic studies have revealed that glycine-extended gastrin17 bound two ferric ions, and that ferric ion binding was essential for biological activity. We have therefore investigated the role of ferric ions in the biological activity of amidated gastrin17. As with glycine-extended gastrin17, fluorescence quenching experiments indicated that Glu7 Ala and Glu8,9 Ala mutants of amidated gastrin17 each bound only one ferric ion. The affinity of the mutant peptides for the cholecystokinin-2 receptor on transfected COS-7 cells or on Tlymphoblastoid Jurkat cells, and their potency in stimulation of proliferation in Jurkat cells and inositol phosphate production in transfected COS-7 cells, were similar to the values obtained for amidated gastrin17. In addition, the iron chelator desferrioxamine did not significantly inhibit either binding of amidated gastrin17 to the cholecystokinin-2 receptor, or stimulation of inositol phosphate production by amidated gastrin17 in transfected COS-7 cells. We conclude that, in contrast to glycine-extended gastrin17, binding of ferric ions is not essential for the biological activity of amidated gastrin17. Our results support the concept of distinct modes of action for amidated and non-amidated gastrins, and raise the possibility of developing selective antagonists of the actions of non-amidated and amidated gastrins.

Topics: Animals; Cell Division; COS Cells; Gastric Acid; Gastrins; Humans; Inositol Phosphates; Ions; Iron; Jurkat Cells; Mutation; Receptor, Cholecystokinin B; Spectrometry, Fluorescence

Atrophic gastritis is a precancerous condition that is commonly caused by chronic Helicobacter pylori (H. pylori) infection. This blinded, controlled study was designed to determine if serum gastrin and pepsinogens were reliable markers of atrophy in asymptomatic patients.. One hundred and forty-seven asymptomatic patients underwent endoscopy with multiple gastric biopsies obtained for histology, culture, and rapid urease test. Fasting serum gastrin (total and G-17) and serum pepsinogens (I-II) were determined by standard immunoassays. Gastric atrophy was histologically assessed in accordance with internationally accepted criteria; three main patterns of gastritis were distinguished: (a) nonatrophic gastritis, (b) atrophic antrum-restricted and antrum-predominant gastritis, and (c) corpus-restricted gastritis. Receiving operating characteristic (ROC) analysis was used to determine the best cut-off for each serum test in nonatrophic gastritis versus antrum-restricted/antrum-predominant atrophic gastritis.. No significant differences in serum gastrin and pepsinogens I-II were detected in nonatrophic gastritis versus patients with antrum-restricted/antrum-predominant atrophic gastritis. The positive likelihood ratios for an abnormal serum test to detect antrum-restricted/antrum-predominant atrophy in the gastric body were total serum gastrin 2.13 (95% CI 0.99, 4.6), gastrin-17: 1.55 (95% CI 0.75, 36.17), pepsinogen I: 2.74 (1.4, 5.4), pepsinogen II: 1.74 (1.27, 2.39), and the ratio of pepsinogen I and II: 1.8 (1.2-2.8). Negative likelihood ratios ranged from 0.20 to 0.65.. In an asymptomatic population, serum gastrin (total and G-17) and pepsinogens I-II (and their ratio) do not discriminate nonatrophic versus antrum-restricted/predominant atrophic gastritis.

Topics: Atrophy; Biomarkers; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Multivariate Analysis; Pepsinogen A; Reproducibility of Results; Single-Blind Method; Stomach

Disruption of histamine H2 receptor and gastrin receptor had different effects growth of gastric mucosa: hypertrophy and atrophy, respectively. To clarify the roles of gastrin and histamine H2 receptors in gastric mucosa, mice deficient in both (double-null mice) were generated and analyzed. Double-null mice exhibited atrophy of gastric mucosae, marked hypergastrinemia and higher gastric pH than gastrin receptor-null mice, which were unresponsive even to carbachol. Comparison of gastric mucosae from 10-week-old wild-type, histamine H2 receptor-null, gastrin receptor-null and double-null mice revealed unique roles of these receptors in gastric mucosal homeostasis. While small parietal cells and increases in the number and mucin contents of mucous neck cells were secondary to impaired acid production, the histamine H2 receptor was responsible for chief cell maturation in terms of pepsinogen expression and type III mucin. In double-null and gastrin receptor-null mice, despite gastric mucosal atrophy, surface mucous cells were significantly increased, in contrast to gastrin-null mice. Thus, it is conceivable that gastrin-gene product(s) other than gastrin-17, in the stimulated state, may exert proliferative actions on surface mucous cells independently of the histamine H2 receptor. These findings provide evidence that different G-protein coupled-receptors affect differentiation into different cell lineages derived from common stem cells in gastric mucosa.

Topics: Animals; Atrophy; Carbachol; Cell Differentiation; Cell Lineage; Cell Proliferation; Female; Gastric Acidity Determination; Gastric Mucosa; Gastrins; Histamine; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptor, Cholecystokinin B; Receptors, Histamine H2

Topics: Child; Diagnosis, Differential; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Pepsinogen A; Pepsinogen C; Sensitivity and Specificity

This study aims to investigate the role of gastrin-17 (G17) on angiogenesis features in gliomas both in vitro and in vivo.. The influences of G17 and G17 receptor antagonists were characterized in vitro in terms of angiogenesis on human umbilical vein endothelial cell (HUVEC) tubulogenesis processes on Matrigel and in vivo with respect to U373 orthotopic glioma xenografts. The influence of phosphatidylinositol 3'-kinase, protein kinase C, and nuclear factor-kappaB inhibitors was characterized in vitro on G17-mediated HUVEC tubulogenesis. G17-mediated release of interleukin (IL)-8 from HUVECs and G17-induced modifications in nuclear factor-kappaB DNA binding activity were characterized by means of specific enzyme-linked immunosorbent assays. The influence of G17 on E- and P-selectin expression was determined by means of computer-assisted microscopy, whereas the influence of E- and P-selectin on HUVEC migration was approached by means of antisense oligonucleotides. The chemotactic influence of G17 and IL-8 on HUVEC migration was characterized by means of computer-assisted videomicroscopy with Dunn chambers.. Messenger RNAs for cholecystokinin (CCK)A, CCKB, and CCKC receptors were present in HUVECs and microvessels dissected from a human glioblastoma. Whereas G17 significantly increased the levels of angiogenesis in vivo in the U373 experimental glioma model and in vitro in the HUVECs, the CCKB receptor antagonist L365,260 significantly counteracted the G17-mediated proangiogenic effects. G17 chemoattracted HUVECs, whereas IL-8 failed to do so. IL-8 receptor alpha (CXCR1) and IL-8 receptor beta (CXCR2) mRNAs were not detected in these endothelial cells. Gastrin significantly (but only transiently) decreased the level of expression of E-selectin, but not P-selectin, whereas IL-8 increased the expression of E-selectin. Specific antisense oligonucleotides against E- and P-selectin significantly decreased HUVEC tubulogenesis processes in vitro on Matrigel.. The present study shows that gastrin has marked proangiogenic effects in vivo on experimental gliomas and in vitro on HUVECs. This effect depends in part on the level of E-selectin activation, but not on IL-8 expression/release by HUVECs.

Topics: Animals; Benzodiazepinones; Brain Neoplasms; Cell Movement; Collagen; Drug Combinations; E-Selectin; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Gastrins; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; In Vitro Techniques; Interleukin-8; Laminin; Mice; Mice, Nude; Neovascularization, Pathologic; NF-kappa B; P-Selectin; Phenylurea Compounds; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase C; Proteoglycans; Rats; Rats, Nude; Receptors, Cholecystokinin; Receptors, Interleukin-8A; Receptors, Interleukin-8B; Transplantation, Heterologous; Tumor Cells, Cultured; Umbilical Veins

To detect the Helicobacter pylori (H. pylori)-induced gastric precancerous lesions leading to cancer formation, and to evaluate the possibility of non-invasive screening of dyspeptic patients to identify those having high risk of gastric cancer.. 178 consecutive H. pylori-positive dyspeptic patients after assessment of serum pepsinogen-1 (PG-1) and gastrin-17 (G-17) levels by enzyme immunoassay were examined with endoscopy and histology. The serologic and morphologic results were compared with estimating the sensitivity, specificity and prognostic values of the tests.. There was statistically significant reverse dependence between the presence and severity of stomach mucosal atrophy (in antrum or corpus) and the proper serologic markers of stomach functional activity (G-17 or PG-1). On the other hand, the presence and the degree of intestinal metaplasia, dysplasia and gastric cancer did not correspond to the serum levels of G-17 or PG-1. The serologic method was quite sensitive in the diagnosis of non-atrophic and severe antral and corpus gastritis. Also, it was characterized by the high positive and negative prognostic values. Additionally, we have established the obvious advantage of the chromoendoscopy method in the diagnosis of intestinal metaplasia in the stomach epithelium.. The assays of serum G-17 and PG-1 levels can be offered as the screening tool for atrophic gastritis. The positive serologic results require further chromoendoscopic examination with mucosal biopsy to disclose the probable progression of atrophic process with development of intestinal metaplasia, dysplasia or gastric cancer.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Atrophy; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Precancerous Conditions; Predictive Value of Tests; Risk Factors; Sensitivity and Specificity; Stomach Neoplasms

Gastrin is a gastrointestinal (GI) peptide that possesses potent trophic effects on most of the normal and neoplastic mucosa of the GI tract. Despite abundant evidence for these properties, the mechanisms governing gastrin-induced proliferation are still largely unknown. To elucidate the mechanisms by which gastrin might influence mitogenesis in gastric adenocarcinoma, we analyzed its effects on the human cell line AGS-B. Amidated gastrin (G-17), one of the major circulating forms of gastrin, induced a concentration-dependent increase in [3H]thymidine incorporation of cells in culture, with the maximum effective concentration occurring with 20 nM G-17. This effect was significantly attenuated by the gastrin-specific receptor antagonist L-365260. In addition, we found that G-17 induced a significant increase in the levels of cyclin D1 transcripts, protein, and promoter activity. The results of these studies indicate that gastrin appears to exert its mitogenic effects on gastric adenocarcinoma, at least in part, through changes in cyclin D1 expression.

Topics: Adenocarcinoma; beta Catenin; Cell Division; Cyclin D1; Cytoskeletal Proteins; Dose-Response Relationship, Drug; Gastrins; Gene Expression Regulation, Neoplastic; Hormones; Humans; Promoter Regions, Genetic; RNA, Messenger; Stomach Neoplasms; Trans-Activators; Tumor Cells, Cultured

Hypergastrinaemia stimulates cell proliferation in the oesophageal epithelium of the rat. In the present study, we tested whether hypergastrinaemia also affected cell turnover time and structure of the oesophageal epithelium.. Seventy-two female adult Sprague-Dawley rats, divided into 12 equal groups, were given 3H-thymidine by infusion/injection. Groups 1-6 were control rats, groups 7-9 were provided with a minipump releasing synthetic rat gastrin-17, and groups 10-12 were given injections of omeprazole twice daily. The rats in the control groups were killed after 1 h, and after 1, 6, 9, 17 or 25 days. The rats given gastrin or omeprazole were killed after 1, 6 or 9 days. Tissue samples of oesophagus were processed for light microscopic autoradiography and the labelling index (LI) was calculated. Morphometric data of the oesophageal epithelium were also obtained, as well as plasma gastrin concentrations.. LI in the control rats increased continuously up to 9 days when about 90% of the cells were labelled. Extrapolation indicates a mean cell turnover time of 10.4 +/- 0.58 days. Plasma gastrin levels were significantly elevated in the rats given gastrin or omeprazole. In these animals, average cell turnover times were reduced to 9.1 +/- 0.11 and 9.4 +/- 0.18 days, respectively, and the epithelium was almost 20% thinner than in the controls. Moreover, in the gastrin-treated rats the number of epithelial cells/mm was decreased by almost 20%.. Hypergastrinaemia reduces cell turnover time in rat oesophageal epithelium. This is independent of stimulation of acid secretion. The concomitant epithelial hypotrophy may be explained by a premature shedding of the epithelial cells or by acceleration of cell maturation.

Topics: Animals; Anti-Ulcer Agents; Autoradiography; Cell Cycle; Epithelium; Esophagus; Gastrins; Hormones; Mitotic Index; Omeprazole; Rats; Rats, Sprague-Dawley

Factors associated with the development and malignant progression of Barrett's esophagus are poorly understood. Gastrin is a mitogen capable of inducing growth in normal and malignant gastrointestinal mucosa. It is unknown whether gastrin can influence cellular events in the esophagus in Barrett's.. Reverse-transcription polymerase chain reaction (RT-PCR) and northern analysis for the cholecystokinin (CCK(2)) receptor were performed on normal, inflamed, metaplastic, and malignant esophageal mucosa. Real-time PCR quantified expression of the receptor. [(125)I]-G17-autoradiography localized the CCK(2) receptor in mucosal sections. [(3)H]-thymidine and bromodeoxyuridine (BrdU) incorporation determined proliferation in response to G17 in biopsy specimens incubated ex vivo. Proliferation and signaling studies were performed on OE33(E) cells transfected with the CCK(2) receptor.. RT-PCR identified receptor expression in 3 of 9 controls, 5 of 7 patients with esophagitis, 10 of 10 patients with Barrett's metaplasia, and 7 of 12 esophageal adenocarcinomas. Real-time PCR quantified expression in 10 patients with Barrett's showing a level of expression 2 orders of magnitude higher than in 12 control patients. [(125)I]-G17 bound to epithelia within glandular regions of Barrett's mucosa. Ten nmol/L G17 induced a 2-fold (n = 7, P = 0.0257, t test) increase in [(3)H]-thymidine incorporation in mucosal biopsy specimens, abolished by the addition of the CCK(2) receptor antagonist L-740, 093. One nmol/L G17 induced a 1.94- +/- 0.13-fold (n = 6, t test, P = 0.001) increase in [(3)H]-thymidine incorporation in OE33(E)(GR) cells, abolished by L-740, 093.. Gastrin induces proliferation via the CCK(2) receptor in Barrett's mucosa. This may have implications for the management of patients with Barrett's esophagus in whom gastrin is elevated by acid-suppression therapy.

Topics: Adult; Aged; Aged, 80 and over; Autoradiography; Barrett Esophagus; Binding, Competitive; Blotting, Northern; Cell Division; Computer Systems; Female; Gastric Mucosa; Gastrins; Humans; Iodine Radioisotopes; Male; Metaplasia; Middle Aged; Radioimmunoassay; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Reverse Transcriptase Polymerase Chain Reaction; Thymidine; Tumor Cells, Cultured

This report describes the molecular cloning and pharmacological characterization of a transiently expressed chicken brain cholecystokinin receptor (CCK-CHR) in COS-7 cells. A polymerase chain reaction (PCR)-based cloning strategy was applied using: (1) an initial PCR with deoxyinosine-containing primers designed to target conserved regions in CCK receptors, followed by (2) rapid amplification of cDNA ends (RACE), and (3) full-length PCR of the CCK-CHR cDNA. The full-length cloned bicistronic CCK-CHR cDNA contained a short upstream open reading frame (uORF) coding for a putative six-amino-acid-long peptide of unknown function, followed by a long open reading frame (lORF) encoding the 436-amino-acid-long CCK-CHR receptor protein. At the amino acid level, the CCK-CHR shared approximately 50% homology with mammalian and Xenopus laevis CCK receptors. The pharmacological profile of CCK-CHR resembled that of CCK-B receptors using agonists (CCK-8, CCK-4, gastrin-17), whereas CCK-CHR showed higher affinity for the CCK-A receptor antagonist, devazepide, than for the CCK-B receptor antagonist, L-365,260. To the best of our knowledge, this is the first description and functional expression study of a cloned chicken CCK receptor cDNA.

Topics: Amino Acid Sequence; Animals; Benzodiazepinones; Brain; Chickens; Cloning, Molecular; COS Cells; Devazepide; DNA, Complementary; Gastrins; Inosine; Molecular Sequence Data; Phenylurea Compounds; Polymerase Chain Reaction; Radioligand Assay; Receptors, Cholecystokinin; RNA, Messenger; Sequence Homology, Amino Acid; Sincalide; Tetragastrin

Serum levels of gastrin-17 (S-G-17) and pepsinogen I (S-PGI) are biomarkers of gastric antral and corpus mucosa, respectively. In a prospective multicentre investigation, we determined whether these tests, together with the assay of Helicobacter pylori antibodies, are a non-endoscopic tool for the diagnosis of atrophic gastritis.. The series comprised 404 consecutive adult outpatients undergoing diagnostic upper-gastrointestinal endoscopy for various dyspeptic symptoms in five outpatient clinics. Gastric biopsies from the antrum and corpus (at least two biopsies from both sites) were available from all patients, and they were evaluated according to the guidelines of the updated Sydney system. S-PGI and S-G-17 were assayed with ELISA methods using monoclonal antibodies to pepsinogen I and amidated gastrin-17. In addition to the fasting level (S-G-17(fast)), a postprandial S-G-17 (S-G-17(prand)) level was measured 20 min after ingestion of a protein-rich drink. H. pylori antibodies were determined using a polyclonal EIA method.. S-G-17(prand) (and S-G-17(fast)) and S-PGI levels decreased with increasing grade of atrophy of the antrum or corpus, respectively. S-G-17(prand) levels were significantly lower in patients with advanced (moderate or severe) atrophic antral H. pylori gastritis than in those with non-atrophic H. pylori gastritis. All patients with a resected antrum demonstrated S-G-17(prand) levels that were almost undetectable. Of the nine patients with an H. pylori-positive moderate or severe atrophic antral gastritis, six had S-G-17(prand) levels below 5 pmol/l. Similarly, S-PGI levels were significantly lower in patients with advanced corpus atrophy than in those without. Of the 45 patients with moderate or severe corpus atrophy in endoscopic biopsies, 35 patients had S-PGI levels < 25 microg/l. By using the cut-off levels for S-G-17(prand) and S-PGI with the best discrimination, the sensitivity and specificity of the blood test panel in delineation of patients with advanced atrophic gastritis (either in the antrum or the corpus, or both) were 83% and 95%, respectively. The predictive values of the positive and negative test results were 75% and 97%, respectively. In the diagnosis of atrophic gastritis, the application of S-G-17(fast) showed a slightly lower sensitivity and specificity than the application of S-G-17(prand) as a biomarker for antral atrophy.. The diagnosis of atrophic gastritis obtained with the blood test panel of S-G-17, S-PGI and H. pylori antibodies is in good agreement with the endoscopic and biopsy findings. The panel is a tool for non-endoscopic diagnosis and screening of atrophic gastritis.

Topics: Adult; Aged; Antibodies, Bacterial; Atrophy; Biomarkers; Enzyme-Linked Immunosorbent Assay; Female; Gastric Mucosa; Gastrins; Gastritis; Helicobacter pylori; Hematologic Tests; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Prospective Studies; Pyloric Antrum

We recently reported that downregulation of gastrin gene expression in colon cancer cells significantly suppresses relative levels of mitochondrial cytochrome c (cyt c) oxidase Vb (Cox Vb) RNA and protein. These unexpected findings suggested the possibility that gastrin gene products [mainly progastrin (PG)] may be directly or indirectly mediating the observed effects in colon cancer cells. Because colon cancer cells do not respond to exogenous PG, we examined the possibility of whether PG regulates Cox Vb expression in gastrin-responsive intestinal epithelial cells (IECs) in vitro. Levels of Cox Vb RNA and protein were significantly increased in a dose-dependent manner in response to PG. Mitochondrial synthesis of ATP was also increased by approximately three- to fivefold in response to optimal concentrations (0.1-1.0 nm) of PG. Possible antiapoptotic effects of PG were additionally examined, because activation of caspases 9 and 3 had been noted in colon cancer cells downregulated for gastrin gene expression. We measured a significant loss in the levels of cyt c in the cytosol of PG-treated vs. control IEC cells, which correlated with a significant loss in the activation of caspases 9 and 3, resulting in a significant loss in DNA fragmentation on PG treatment of the cells. Our results thus suggest the novel possibility that the precursor PG peptide exerts direct antiapoptotic effects on IECs, which may contribute to the observed growth effects of PG on these cells. Additionally, Cox Vb gene appears to be an important intracellular target of PG, resulting in an increase in ATP levels, which may also contribute to the observed increase in the growth of target cells in response to PG.

Topics: Adenosine Triphosphate; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Camptothecin; Caspase 3; Caspase 9; Caspases; Cell Line; Colonic Neoplasms; Electron Transport Complex IV; Enzyme Activation; Gastrins; Intestinal Mucosa; Mitochondria; Promoter Regions, Genetic; Protein Precursors; Rats; RNA, Messenger; Up-Regulation

The protease domains of the evolutionarily related alpha and beta subunits of meprin metalloproteases are approximately 55% identical at the amino acid level; however, their substrate and peptide bond specificities differ markedly. The meprin beta subunit favors acidic residues proximal to the scissile bond, while the alpha subunit prefers small or aromatic amino acids flanking the scissile bond. Thus gastrin, a peptide that contains a string of five Glu residues, is an excellent substrate for meprin beta, while it is not hydrolyzed by meprin alpha. Work herein aimed to identify critical amino acids in the meprin active sites that determine the substrate specificity differences. Sequence alignments and homology models, based on the crystal structure of the crayfish astacin, showed electrostatic differences within the meprin active sites. Site-directed mutagenesis of active site residues demonstrated that replacement of a hydrophobic residue by a basic amino acid enabled the meprin alpha protease to cleave gastrin. The meprin alphaY199K mutant was most effective; the corresponding mutation of meprin betaK185Y resulted in decreased activity toward gastrin. Peptide cleavage site determinations and kinetic analyses using a variety of peptides extended evidence that meprin alphaTyr-199/betaLys-185 are substrate specificity determinants in meprin active sites. These studies shed light on the molecular basis for the substrate specificity differences of astacin metalloproteinases.

Topics: Amino Acid Sequence; Amino Acid Substitution; Animals; Binding Sites; Cell Line; Cholecystokinin; Gastrins; Humans; Metalloendopeptidases; Mice; Mutagenesis, Site-Directed; Peptides; Protein Subunits; Rats; Recombinant Proteins; Sequence Alignment; Static Electricity; Substrate Specificity

Relatives of patients with gastric cancer are at increased risk of developing this disease, especially if they are infected by Helicobacter pylori. Moreover, H. pylori-related atrophic gastritis and hypochlorhydria are well-documented risk factors for noncardia gastric cancer. Serum pepsinogen I (sPGI) and II (sPGII) levels are low in this condition. The aim of our study was to assess by means of a 'Gastropanel' blood test, including sPGI, sPGII, gastrin-17 (G-17) and antibodies anti-H. pylori (IgG-Hp). both functional and morphological features of gastric mucosa in Hp + ve subjects with a family history of gastric cancer.. Twenty-five Hp + ve subjects consecutively referred to our department for gastrointestinal complaints, selected as first-degree relatives of patients suffering from gastric cancer, were enrolled in the study and then matched for sex and age with 25 dyspeptic and Hp + ve subjects with no family history of gastric neoplasia. Blood samples were taken for determination of gastropanel in all patients; in addition, antibodies against CagA were analysed.. No statistically significant differences were detected between the two groups as regards alcohol consumption, coffee intake and smoking habits. Mean sPGI levels in Group A (83.4 +/- 58.4 microg/L) were significantly lower than those in Group B (sPGI 159.5 +/- 80.6 microg/L; P < 0.0001) as well as sPGII (12.5 microg/L = 6.24 versus 20.6 +/- 58 microg/L; P < 0.006). No statistical difference was found between the two groups in relation to G-17 levels, IgG-Hp titres and antibodies against CagA.. First-degree relatives of patients with noncardia gastric cancer affected by H. pylori infection present lower sPGI and sPGII levels, possibly due to the increased frequency of atrophic lesions in these patients.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Proteins; Biomarkers; Dyspepsia; Family Health; Female; Gastrins; Gastritis, Atrophic; Genetic Predisposition to Disease; Helicobacter Infections; Helicobacter pylori; Humans; Immunoglobulin G; Male; Middle Aged; Pepsinogen A; Pepsinogen C; Stomach Neoplasms

Gastrin is one of the principle hormonal mediators of gastric acid secretion, and its cognate receptor (CCK-B) is a member of the superfamily of GPCRs. Patients with hypergastrinemia may present with a variety of symptoms, including gastric ulcers or malignant tumors. Thus, the molecular mechanisms that terminate CCK-B receptor signaling, as well as an ability to measure gastrin bioactivity in a timely manner, have important clinical implications. In order to assess CCK-B receptor regulation, we have constructed a single cell biosensor containing the CCK-B receptor and an arrestin/GFP chimera. The gastrin biosensor responded to both immunologically detectable gastrin-17 and undetectable pentagastrin, and was able to determine the gastrin bioactivity of serum from a patient with clinical hypergastrinemia. We determined that the CCK-B receptor binds arrestin with a pharmacology mirroring CCK-B receptor signaling through inositol phosphate, and that the rate of arrestin dissociation from internalized receptor mirrors receptor recycling to the plasma membrane. Moreover, the CCK-B recycling rate is intermediate between that of Class A GPCRs such as the beta2-adrenergic receptor and Class B GPCRs such as the vasopressin type 2 receptor. Mathematical modeling of these results indicates that a common receptor conformation may underlie both CCK-B signaling and desensitization. In addition to its use in drug screening, this methodology should generalize to other receptors for use in diagnosis and monitoring of bioactive ligands involved in GPCR-based disease.

Topics: Arrestin; Arrestins; beta-Arrestins; Biosensing Techniques; Cell Line; Gastrins; Humans; Inositol; Kinetics; Microscopy, Fluorescence; Pentagastrin; Protein Binding; Receptor, Cholecystokinin B; Signal Transduction; Transfection

Epithelial organization is maintained by cell proliferation, migration, and differentiation. In the case of the gastric epithelium, at least some of these events are regulated by the hormone gastrin. In addition, gastric epithelial cells are organized into characteristic tubular structures (the gastric glands), but the cellular mechanisms regulating the organization of tubular structures (sometimes called branching morphogenesis) are uncertain. In the present study, we examined the role of the gastrin-cholecystokinin(B) receptor in promoting branching morphogenesis of gastric epithelial cells. When gastric cancer AGS-G(R) cells were cultured on plastic, gastrin and PMA stimulated cell adhesion, formation of lamellipodia, and extension of long processes in part by activation of protein kinase C (PKC) and phosphatidylinositol (PI)-3 kinase. Branching morphogenesis was not observed in these circumstances. However, when cells were cultured on artificial basement membrane, the same stimuli increased the formation of organized multicellular arrays, exhibiting branching morphogenesis. These effects were reversed by inhibitors of PKC but not of PI-3 kinase. We conclude that, in the presence of basement membrane, activation of PKC by gastrin stimulates branching morphogenesis.

Topics: Basement Membrane; Cell Adhesion; Gastrins; Humans; Lysophospholipids; Protein Kinase C; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Stomach Neoplasms; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

Gastrin is a gastrointestinal peptide that possesses potent trophic properties on both normal and neoplastic cells of gastrointestinal origin. Previous studies have indicated that chronic hypergastrinaemia increases the risk of colorectal cancer and cancer growth and that interruption of the effects of gastrin could be a potential target in the treatment of colorectal cancer. Here we demonstrate that gastrin leads to a dose-dependent increase in colon cancer cell proliferation and tumour growth in vitro and in vivo, and that this increment is progressively reversed by pretreatment with the cyclo-oxygenase-2 inhibitor NS-398. Gastrin was able to induce cyclo-oxygenase-2 protein expression, as well as the synthesis of prostaglandin E2, the major product of cyclo-oxygenase. Moreover, gastrin leads to approximately a two-fold induction of cyclo-oxygenase-2 promoter activity in transiently transfected cells. The results of these studies demonstrate that cyclo-oxygenase-2 appears to represent one of the downstream targets of gastrin and that selective cyclo-oxygenase-2 inhibition is capable of reversing the trophic properties of gastrin and presumably might prevent the growth of colorectal cancer induced by hypergastrinaemia.

Topics: Adenocarcinoma; Animals; Cell Division; Colonic Neoplasms; Cyclin D1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; DNA Replication; Dose-Response Relationship, Drug; Gastrins; Gene Expression Regulation, Neoplastic; Genes, Reporter; Isoenzymes; Male; Mice; Mice, Inbred BALB C; Neoplasm Proteins; Neoplasm Transplantation; Nitrobenzenes; Proliferating Cell Nuclear Antigen; Promoter Regions, Genetic; Prostaglandin-Endoperoxide Synthases; Receptors, Cholecystokinin; Substrate Specificity; Sulfonamides; Transfection; Tumor Cells, Cultured

Helicobacter pylori infection is often diagnosed with non-endoscopic methods, such as serology or breath or antigen stool tests. These tests provide information on the presence or absence of the H. pylori gastritis only. We investigated whether atrophic gastritis can be diagnosed and typed non-endoscopically if the serum levels of pepsinogen I (S-PGI) and gastrin-17 (S-G-17) are assayed in connection with H. pylori testing.. The present investigation is an observational case-control study comprising 100 selected dyspeptic outpatients with (cases) or without (controls) advanced (moderate or severe) atrophic gastritis. Before the blood tests, all patients underwent a diagnostic gastroscopy with multiple biopsies. The series of cases includes 56 patients. Eight had an advanced antrum limited atrophic gastritis, 13 had resected antrum (in two of whom the corpus mucosa in the stump was atrophic), and 30 had corpus-limited atrophic gastritis. Four patients had an advanced atrophic gastritis in both the antrum and corpus (multifocal atrophic gastritis), and the whole stomach was removed in one patient. Twenty of the 44 controls had a non-atrophic H. pylori gastritis. Both the antrum and corpus were normal and healthy in 24 patients. The S-PGI and S-G-17 were determined with EIA methods using monoclonal antibodies to PGI and amidated G-17. Postprandial S-G-17 (S-G-17prand) was measured 20 min after a protein-rich drink. The H. pylori antibodies were assayed with a polyclonal EIA method.. A low S-PGI (<25 microg/l; an empirical cut-off with best discrimination) was found in 31 of 37 patients (84%) with and in 3 of 63 patients (5%) without corpus atrophy in the biopsy specimens. A low S-G-17prand (<5 pmol/l) was found in all 8 patients with H. pylori-associated antral atrophy and in 11 of 14 patients (79%) with resected antrum but in 3 of 20 control patients (15%) with H. pylori-related non-atrophic gastritis. Median and mean values of both S-G-17prand and S-PGI decreased with increasing grade of antral and corpus atrophy, respectively. Among all patients with atrophic gastritis (multifocal atrophic gastritis, or atrophic gastritis limited to antrum or corpus) or resected stomach, 50 of 56 patients (89%; Cl 95%: 81%-97%) had a low S-PGI and/or a low S-G-17prand with positive H. pylori serology. Such low values werc found in 3 of the 44 control patients (7%; CI 95%: 0%-14%).. Low serum levels of G-17prand and PGI are conceivable biomarkers of atrophic antral and corpus gastritis, respectively. A low S-G-17prand is a sign of the multifocal or antrum-limited atrophic gastritis in patients infected with H. pylori.

Topics: Antibodies, Bacterial; Antibodies, Monoclonal; Biomarkers; Case-Control Studies; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pepsinogen A; Sensitivity and Specificity

It has been suggested that processing variants of gastrin, such as glycine-extended gastrin (G17-Gly), are enterotrophic to the colon.. Cell proliferation and crypt branching were studied in total parenteral nutrition (TPN) and orally fed rats after infusion of G17-Gly or gastrin-17.. Gastrin produced an increase in the weight of the stomach and small intestine and a marked proliferative action on the proximal small intestine, which diminished distally. No proliferative effects of gastrin were seen in the colon. G17-Gly was associated with a small, but significant, increase in colonic weight but had little effect on cell proliferation, except in the gastric fundus. In the distal colon, G17-Gly was associated with a significant decrease in proliferation. Neither agent affected crypt branching in the small intestine or colon, but both proliferation and branching were significantly decreased by TPN.. Gastrin was trophic to the stomach and the proximal small intestine but not the colon. G17-Gly had only modest proliferative actions on the intestinal epithelium in this study.

Topics: Animals; Cell Division; Colon; Gastrins; Hormones; Hydrogen-Ion Concentration; Intestinal Mucosa; Intestine, Small; Male; Parenteral Nutrition, Total; Rats; Rats, Wistar; Stomach

Hypergastrinemia and a reduction in tissue somatostatin occur in Helicobacter pylori-infected patients. We investigated whether the D cell may be a direct target of gastric inflammation and hypergastrinemia. D cells were quantified by morphometry and flow cytometry in 16-wk-old wild-type (G+/+) and gastrin-deficient (G-/-) mice. Hypochlorhydric G-/- mice were treated with either antibiotics for 20 days or infused with gastrin (G-17) for 14 days. G+/+ mice were made hypochlorhydric by treating them with omeprazole for 2 mo. G-/- mice showed significant inflammation compared with the G+/+ mice, which resolved after 20 days of antibiotic treatment. D cell numbers were not significantly different between G-/- and G+/+ mice. After G-17 was infused, fundic and antral D cell numbers decreased in the G-/- mice. G+/+ animals made hypergastrinemic with omeprazole exhibited decreased D cell numbers. When omeprazole-treated mice were treated with antibiotics alone, elevated plasma gastrin levels returned to baseline and D cell numbers returned to resting levels despite persistent hypochlorhydria. Hypergastrinemia, induced by inflammation, results in decreased D cell numbers. Thus the stomach responds to the presence of inflammation by reducing somatostatin levels, thereby releasing the inhibition on the G and parietal cells to maximize gastric acid output.

Topics: Animals; Anti-Ulcer Agents; Female; Gastric Acid; Gastric Fundus; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Omeprazole; Parietal Cells, Gastric; Pyloric Antrum; Somatostatin

Cellular synthesis of neuroendocrine peptides requires prohormone convertases (PCs). In order to determine the role of PC2 for gastrin synthesis, we examined antral extracts from mice lacking PC2 or its chaperone, 7B2. The overall concentrations of precursors and alpha-amidated gastrins were similar in all mice. Chromatography, however, revealed that while the K(53)-K(54) site was almost fully cleaved in controls and half cleaved in PC2 null mice, only 23% was cleaved in 7B2 null mice. The results show that PC2 and 7B2 both are required for synthesis of the main form of gastrin (gastrin-17), and that 7B2 exhibits effects beyond PC2-mediated cleavages.

Topics: Animals; Chromatography, Gel; Female; Gastrins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Chaperones; Nerve Tissue Proteins; Neuroendocrine Secretory Protein 7B2; Neurosecretory Systems; Pituitary Hormones; Proprotein Convertase 2; Protein Precursors; Protein Processing, Post-Translational; Subtilisins

The effects of gastrin precursors have been discussed during recent years. However, the mechanism for their action, whether through a novel receptor on the parietal cell or a cholecystokinin-2 (CCK-2) receptor on the enterochromaffin like (ECL) cells, is still not settled. This study examines the effect of glycine-extended gastrin-17 (Gly-G-17), the main non-amidated gastrin precursor, on gastric acid secretion and histamine release in the totally isolated vascularly perfused rat stomach. Glycine-extended gastrin-17 at the concentrations from 0.52 to 520 nmol L(-1) was administered to the totally isolated vascularly perfused rat stomach. Glycine-extended gastrin-17 at 52 or 520 nmol L(-1), and gastrin-17 at 0.52 nmol L(-1)were co-administered to examine whether glycine-extended gastrin augmented maximal gastrin stimulated acid secretion and histamine release. Both Gly-G-17 at 52 nmol L(-1) and gastrin-17 (G-17) at 0.52 nmol L(-1) were administered together with the histamine-2 receptor antagonist ranitidine at 10 micromol L(-1). Gastric acid and venous histamine output were measured. Glycine-extended gastrin-17 at lower concentrations from 0.52 to 5.2 nmol L(-1) did not stimulate gastric acid output or histamine release, whereas higher concentrations from 52 to 520 nmol L(-1) elicited a concentration-dependent increase in acid secretion and histamine release. The outputs of acid and histamine at 520 nmol L(-1) Gly-G-17 were at the same level as those found for G-17 at its maximally effective concentration of 0.52 nmol L(-1). Glycine-extended gastrin-17 at maximally effective concentration of 520 nmol L(-1) did not augment maximal gastrin stimulated acid secretion or histamine release. Ranitidine inhibited G-17 and Gly-G-17 stimulated acid secretion to a similar degree. This study confirms that the stimulatory effect of Gly-G-17 on gastric acid secretion is via a CCK-2 receptor on the ECL cell.

Topics: Animals; Dose-Response Relationship, Drug; Drug Combinations; Enterochromaffin Cells; Gastric Acid; Gastric Mucosa; Gastrins; Histamine; In Vitro Techniques; Male; Perfusion; Ranitidine; Rats; Rats, Wistar; Receptors, Cholecystokinin; Stomach

The relationship between plasma gastrin levels and colorectal cancer is controversial. When confounding factors which increase plasma gastrin levels are taken into account, it has been shown that gastrin levels are not elevated in patients with colorectal cancer. However, these studies only measured amidated gastrin. Total gastrin (which includes unprocessed, partially processed, and mature forms of gastrin) has been shown to be elevated in patients with colorectal cancer.. The aim of this study was to determine whether fasting plasma levels of progastrin, amidated gastrin, or glycine extended gastrin are elevated in patients with colorectal cancer or colorectal polyps compared with controls.. Progastrin, amidated gastrin, and glycine extended gastrin were estimated by radioimmunoassay using the following antibodies: L289, 109-21, and L2. Blood samples were analysed for Helicobacter pylori by an enzyme linked immunosorbent assay.. Median progastrin levels were significantly higher in the cancer group (27.5 pmol/l) than in the polyp (< or =15 pmol/l) or control (< or =15 pmol/l) group (p=0.0001 There was no difference in median levels of amidated gastrin between groups. Median levels of amidated gastrin were significantly higher in H pylori positive patients (19 pmol/l) than in H pylori negative patients (8 pmol/l) (p=0.0022). Median plasma progastrin levels were significantly higher for moderately dysplastic polyps (38 pmol/l) compared with mildly dysplastic (15 pmol/l) and severely dysplastic (15 pmol/l) polyps (p=0.05).. Plasma levels of progastrin, but not amidated gastrin or glycine extended gastrin, are significantly elevated in patients with colorectal cancer compared with those with colorectal polyps or controls, irrespective of their H pylori status. We conclude that measuring plasma progastrin levels in patients with colorectal cancer is warranted.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Bacterial; Biomarkers, Tumor; Carcinoma; Case-Control Studies; Colonic Polyps; Colorectal Neoplasms; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Protein Precursors

Gastrin17gly acts as a growth factor for the colonic mucosa. Studies on the binding properties of the receptor involved in transducing the proliferative effects have generally been confined to colorectal carcinoma cell lines, and no investigation of gastrin17gly receptors on normal colonocytes has yet been reported. The aim of this study was to investigate the binding of 125I-[Met15]-gastrin17gly to normal colonic crypts.. Crypts were released from normal rat and rabbit colonic mucosa by treatment with EDTA and isolated by centrifugation. The binding of 125I-[Met15]-gastrin17gly was measured in displacement experiments with increasing concentrations of either gastrin17gly, gastrin17 or gastrin receptor antagonists. The concentrations required for 50% inhibition were determined by the use of curve fitting.. 125I-[Met15]-Gastrin17gly bound to both rat and rabbit crypts, and displacement experiments with unlabeled gastrin17gly revealed that the IC50 values were 1.0 +/- 0.6 and 0.6 +/- 0.2 micromol/L, respectively. Binding was also competed by gastrin17, with IC50 values of 2.4 +/- 1.7 and 2.4 +/- 0.7 micromol/L, respectively. Binding was inhibited by the non-selective gastrin/CCK receptor antagonists proglumide and benzotript, but not by the cholecystokinin (CCK)-A receptor antagonist L364 718, or the gastrin/CCK-B receptor antagonist L365 260.. We conclude that the gastrin17gly binding site on normal colonic crypts has properties consistent with the gastrin/CCK-C receptor.

Topics: Animals; Binding Sites; Chromatography, High Pressure Liquid; Colon; Gastrins; Intestinal Mucosa; Models, Animal; Peptides; Protein Precursors; Rabbits; Rats; Receptors, Cholecystokinin

The ECL cells control parietal cells by releasing histamine in their immediate vicinity. Gastrin and pituitary adenylate cyclase-activating peptide (PACAP) stimulate histamine secretion from isolated ECL cells, while somatostatin and galanin inhibit stimulated secretion. Prostaglandin E2 and related prostaglandins likewise suppress ECL-cell histamine secretion. Conceivably, that is how they inhibit acid secretion. In the present study, we examined if prostaglandin E2 can be generated by isolated ECL cells. Rat stomach ECL cells were purified (>90% purity) by counterflow elutriation and gradient centrifugation and cultured for 48 h. ECL cell stimulants (gastrin and PACAP) and inflammatory agents (interleukin-1 beta, tumor necrosis factor-alpha and bradykinin) were tested for their ability to induce prostaglandin E2 accumulation (24-h incubation), measured by radioimmunoassay. Gastrin and PACAP did not affect prostaglandin E2 accumulation but interleukin-1 beta (300 pg/ml), tumor necrosis factor-alpha (10 ng/ml) and bradykinin (1 microM) induced a 2- to 3-fold increase in the amount of prostaglandin E2 accumulated. While the combination of interleukin-1 beta and bradykinin induced a 9-fold increase, the combination interleukin-1 beta+tumor necrosis factor-alpha and bradykinin + tumor necrosis factor-alpha induced additive effects only. The combination of interleukin-1 beta + tumor necrosis factor-alpha + bradykinin did not induce a greater effect than interleukin-1 beta + bradykinin. The effect of interleukin-1 beta + bradykinin was abolished by adding 10 nM hydrocortisone (suppressing phospholipase A2 and cyclooxygenase) or 1 microM indomethacin (inhibiting cyclooxygenase). Incubating ECL cells in the presence of interleukin-1 beta+bradykinin for 24 h reduced their ability to secrete histamine in response to gastrin. The inhibitory effect was reversed by 1 microM indomethacin. Also, increasing the concentrations of hydrocortisone in the medium resulted in an enhanced gastrin-stimulated histamine secretion. Hence, the previously described acid-inhibiting effect of inflammatory agents may be explained by inhibition of ECL-cell histamine mobilization, consequent to enhanced formation of prostaglandin E2 by cells in the oxyntic mucosa, including the ECL cells themselves.

Topics: Animals; Anti-Inflammatory Agents; Bradykinin; Cells, Cultured; Dinoprostone; Dose-Response Relationship, Drug; Enterochromaffin-like Cells; Gastrins; Histamine Release; Humans; Hydrocortisone; Indomethacin; Interleukin-1; Male; Models, Biological; Neuropeptides; Pituitary Adenylate Cyclase-Activating Polypeptide; Rats; Rats, Sprague-Dawley; Stomach; Tumor Necrosis Factor-alpha; Vasodilator Agents

Gastrin (G-17) and its precursor glycine-extended gastrin (G-17-gly) have been shown to be trophic to some gastrointestinal tumors. This in vitro study assessed the effect of G-17, G-17-gly, anti-gastrin antibodies (anti-G-17), and the CCK-B receptor antagonist PD135,158 on three hepatoma cell lines (PLC/PRF/5, HepG2 and MCA-RH7777) and an embryonic liver cell line (WRL68). The pancreatic adenocarcinoma cell line AR42J was used as a positive control. G-17 and G-17-gly caused significant proliferation of AR42J and WRL68 cell lines. G-17-gly but not G-17 induced significant proliferation of the PLC/PRF/5 cell line. Anti-G-17 and PD135,158 significantly inhibited unstimulated AR42J and WRL68 cell lines. Anti-G-17 also inhibited the proliferative effects of G-17 and G-17-gly on AR42J, WRL68, and PLC/PRF/5 cell lines, whereas PD135,158 inhibited the proliferative effect of G-17 only. G-17 and G-17-gly as well as anti-G-17 and PD135,158 had no effect on HepG2 and MCA-RH77777 cell lines. It is concluded that G-17-stimulated proliferation is mediated via the CCK-B receptor and G-17-gly via a separate, as yet uncharacterized, receptor. There may therefore be a role for gastrin in embryonic hepatocellular proliferation and perhaps also in the proliferation of some hepatocellular tumors.

Topics: Animals; Antibodies; Cell Division; Cell Line; Gastrins; Hepatocytes; Indoles; Liver Neoplasms, Experimental; Meglumine; Receptor, Cholecystokinin B; Receptors, Cholecystokinin

There is increasing evidence for a direct interaction of the enteric nervous and immune system. Receptors for neuropeptides such as VIP, somatostatin, and substance P have been characterised in human immuno-haematopoietic cells but little is known about the functional significance and expression of receptors for cholecystokinin (CCK) on cells of the immune system. There are only few studies that describe the expression of CCK receptors on human leukaemia-derived cell lines but the receptor structure and function in normal leukocytes have not been clearly established. We therefore sought to determine CCK receptor expression, structure, and function in nontransformed human peripheral blood mononuclear cells.Full-length cDNA clones encoding the human CCK-A and CCK-B/gastrin receptor are expressed in peripheral blood mononuclear cells from healthy volunteers without haematopoietic malignancy. In addition to wild-type CCK-B/gastrin receptor cDNAs, we isolated a splice variant with an in frame insertion of 69 amino acids within its putative third intracellular receptor loop. Dideoxy sequence analysis revealed that the cDNA of this splice variant comprises exons 1-4 but retains intron 4 (207 bp) in the absence of mutations within the splice donor sites. Transient expression of this splice variant in COS-7 cells reveals wild-type affinity for CCK-8, Gastrin-17, and antagonist L-365,260. Affinity for glycine-extended gastrin-17 was not increased when compared to the wild-type CCK-B/gastrin receptor. In vitro, gastrin decreased 3H-thymidine labelling in phytohaemagglutinin-pretreated mononuclear cells at a half-maximally effective concentration of 1.5 nM. We also isolated a cDNA encoding another splice variant of the CCK-B/gastrin receptor with a 158 bp deletion of the entire exon 4 sequence. We conclude that wild-type transcripts of both CCK receptor subtypes and splice variants of the CCK-B/gastrin receptor are expressed in nontransformed human mononuclear cells and that gastrin exhibits antiproliferative effects.

Topics: Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Benzodiazepinones; Binding, Competitive; Cell Division; Cloning, Molecular; COS Cells; Gastrins; Humans; Leukocytes, Mononuclear; Lymphocyte Activation; Molecular Sequence Data; Phenylurea Compounds; Radioligand Assay; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Sequence Analysis, DNA; Sincalide; Transcription, Genetic; Transfection

Mature amidated gastrin (G17 amide) mediates its effects in the gastrointestinal tract by activating G protein-coupled CCK-B/gastrin receptors. Although trophic actions of gastrin on the gastric mucosa have been well-established, the effect of G17 amide, progastrin and intermediates to colon neoplasia in humans is controversial. While epidemiological evidence from patients with elevated serum gastrin levels related to pernicious anaemia does not support an increased risk for colon cancer, a recent study suggests that prolonged hypergastrinaemia is associated with an increased risk for colon cancer. The extent to which trophic actions of gastrin in colorectal cancer are mediated by functional gastrin receptors remains to be defined. The aim of the present study was to determine CCK-B/gastrin receptor expression, structure, and function in 79 patients with colon cancer.. CCK-B/gastrin receptor cDNAs were isolated from 79 human colorectal cancer specimens and 15 control tissues, subcloned into the eukaryotic expression vector pCR3.1 and subjected to DNA sequence analysis. Wild-type and mutant cDNAs were transiently expressed in COS-7 cells to determine ligand affinities by 125I-labelled CCK-8S competition binding. Activation of the MAP kinase signalling cascade by G17 amide was determined in transfected Colo 320 cells expressing the wild-type or mutant CCK-B/gastrin receptors. Clonal expansion of single cells was quantified in transfected Colo 320 cells.. Gastrin mRNA is expressed in 44% of colorectal cancers and in 13% of control tissues. CCK-B/gastrin receptor mRNA is expressed in 38% of colorectal cancers and 13% of normal colonic tissue. Co-expression of gastrin and CCK-B/gastrin receptor message is significantly increased in colorectal cancer specimens (32% vs. 0%). There is no correlation between CCK-B/gastrin receptor expression and disease stage or histological grading. DNA sequence analysis revealed one spontaneous CCK-B/gastrin receptor mutation within the third intracellular loop with an exchange of valine-287 for phenylalanine. Pharmacological characterisation of the 287V --> F CCK-B/gastrin receptor reveals wild-type affinities for G17 amide, glycine-extended gastrin, CCK-8S and L-365,260. Mutation 287V --> F is associated with a loss of gastrin-induced MAPK p44/p42 signalling in Colo 320 cells while clonal expansion from single cells is increased by 53.1 +/- 15.9% when compared to Colo 320 cells expressing wild-type CCK-B/gastrin receptors.. Structural alterations of CCK-B/gastrin receptors may account for increased growth-promoting effects of amidated gastrins in colorectal cancer.

Topics: Aged; Amino Acid Sequence; Animals; Antibodies; Colorectal Neoplasms; COS Cells; Female; Gastrins; Gene Expression Regulation, Neoplastic; Humans; Iodine Radioisotopes; Male; Middle Aged; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Phosphorylation; Point Mutation; Rabbits; Radioligand Assay; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; RNA, Messenger; Transfection; Tumor Cells, Cultured

Astrocytic tumors are the most common and the most malignant primary tumors of the central nervous system. We had previously observed that gastrin could significantly modulate both cell proliferation and migration of astrocytoma cells. We have investigated in the present study which genes could be targeted by gastrin in tumor astrocyte migration. Using a subtractive hybridization PCR technique we have cloned genes differentially over-expressed in human astrocytoma U373 cells treated or not with gastrin. We found about 70 genes over-expressed by gastrin. Among the genes overexpressed by gastrin, we paid particular attention to tenascin-C, S100A6 and MLCK genes because their direct involvement in cell migration features. Their gastrin-induced overexpression was quantitatively determined by competitive RT-PCR technique. We also showed by means of a reporter gene system that S100A6 and tenascin-C respective promoters were upregulated after gastrin treatment. These data show that gastrin-mediated effects in glioblastoma cells occur through activation of a number of genes involved in cell migration and suggest that gastrin could be a target in new therapeutic strategies against malignant gliomas.

Topics: Actins; Amino Acid Sequence; Biopolymers; Brain Neoplasms; Cell Cycle Proteins; Cell Movement; DNA, Complementary; Gastrins; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes, Reporter; Glioblastoma; Humans; Molecular Sequence Data; Myosin-Light-Chain Kinase; Neoplasm Invasiveness; Neoplasm Proteins; Promoter Regions, Genetic; Protein Biosynthesis; Proteins; Reverse Transcriptase Polymerase Chain Reaction; rhoA GTP-Binding Protein; RNA, Messenger; RNA, Neoplasm; S100 Calcium Binding Protein A6; S100 Proteins; Stress Fibers; Subtraction Technique; Tenascin; Transfection; Tumor Cells, Cultured; Wiskott-Aldrich Syndrome Protein Family

Gastrimmune is an immunogenic form of gastrin. It raises in situ antibodies against two proliferative forms of gastrin: amidated and glycine-extended gastrin-17. It has been shown to have a therapeutic action in several in vivo tumour models. Following immunization, due to the complex equilibrium that exists between the antibodies and gastrin, it is not technically feasible to assay for free gastrin.. To determine the effect of Gastrimmune-induced antigastrin antibodies on acid secretion.. A rat gastric fistula model was used. Animals (six per group) were immunized with a control immunogen or ascending doses of Gastrimmune. Acid output was measured following infusion of increasing doses of gastrin-17 and pentagastrin.. Gastrimmune-induced antibodies significantly reduced gastrin-17-stimulated acid output compared to control animals (Gastrimmune at 200 microg/rat vs. control; acid output following 30 ng gastrin-17, 0.01 vs. 0.16, P < 0.001; following 120 ng gastrin-17, 0.022 vs. 0.29, P < 0.001).. Gastrimmune significantly inhibits gastrin-17-stimulated acid output. This biological assay suggests that the antigastrin antibodies effectively bind gastrin-17. In addition to its use as an antineoplastic agent, Gastrimmune may have a role as an acid-decreasing agent in oesophagogastric pathology.

Topics: Animals; Antibodies; Cancer Vaccines; Diphtheria Toxoid; Disease Models, Animal; Female; Gastric Acid; Gastric Fistula; Gastrins; Gastrointestinal Agents; Immunization; Male; Pentagastrin; Rats; Rats, Wistar

1. The ECL cells control gastric acid secretion by mobilizing histamine in response to circulating gastrin. In addition, the ECL cells are thought to operate under nervous control and to be influenced by local inflammatory processes. 2. The purpose of the present study was to monitor histamine mobilization from ECL cells in conscious rats in response to locally applied regulatory peptides, candidate neurotransmitters and inflammatory mediators. 3. Microdialysis probes were implanted in the submucosa of the acid-producing part of the rat stomach. Three days later, the agents to be tested were administered via the microdialysis probe and their effects on basal (48 h fast) and stimulated (intravenous infusion of gastrin-17, 3 nmol kg(-1) h(-1)) mobilization of ECL-cell histamine was monitored by continuous measurement of histamine in the perfusate (radioimmunoassay). 4. Locally administered gastrin-17 and sulfated cholecystokinin-8 mobilized histamine as did pituitary adenylate cyclase-activating peptide-27, vasoactive intestinal peptide, peptide YY, met-enkephalin, endothelin and noradrenaline, adrenaline and isoprenaline. 5. While gastrin, sulfated-cholecystokinin-8, met-enkephalin and isoprenaline induced a sustained elevation of the submucosal histamine concentration, endothelin, peptide YY, pituitary adenylate cyclase activating peptide, vasoactive intestinal peptide, noradrenaline and adrenaline induced a transient elevation. 6. Calcitonin gene-related peptide, galanin, somatostatin and the prostanoid misoprostol inhibited gastrin-stimulated histamine mobilization. 7. The gut hormones neurotensin and secretin and the neuropeptides gastrin-releasing peptide, neuropeptide Y and substance P failed to affect ECL-cell histamine mobilization, while motilin and neuromedin U-25 had weak stimulatory effects. Also acetylcholine, carbachol, serotonin and the amino acid neurotransmitters aspartate, gamma-aminobutyric acid, glutamate and glycine were inactive or weakly active as was bradykinin. 8. In summary, a range of circulating hormones, local hormones, catecholamines, neuropeptides and inflammatory mediators participate in controlling the activity of rat stomach ECL cells in situ.

Topics: Animals; Consciousness; Dose-Response Relationship, Drug; Enterochromaffin-like Cells; Fasting; Gastric Mucosa; Gastrins; Gastrointestinal Hormones; Histamine; Histamine Release; Humans; Inflammation Mediators; Infusions, Intravenous; Microdialysis; Neuropeptides; Neurotransmitter Agents; Radioimmunoassay; Rats; Rats, Sprague-Dawley

Evidence is accumulating that gastrin precursors may act as growth factors for the colonic mucosa in vivo and for colorectal carcinoma cell lines in vitro. The effect of short term administration of synthetic gastrins on the colonic mucosa in vivo, however, has not been reported. The aim of our study was to determine whether continuous systemic infusion of glycine-extended gastrin(17) stimulated proliferation and accelerated carcinogenesis in the colorectal mucosa. A significant increase in colonic mucosal proliferation as assessed by metaphase index was seen in the caecum (23%, p < 0.02) and distal colon (27%, p < 0.001), but not the rectum, after treatment of intact rats with glycine-extended gastrin(17) for 1 week using implanted miniosmotic pumps. Defunctioning of the rectum reduced both the proliferative index and crypt height of the rectal mucosa of untreated rats. Treatment of rectally defunctioned animals with glycine-extended gastrin(17) for either 1 or 4 weeks resulted in a significant increase in both the proliferative index (40% and 93%, respectively) and crypt height (11% and 19%, respectively) of the rectal mucosa. The total number of aberrant crypt foci in intact rats treated with the procarcinogen azoxymethane plus glycine-extended gastrin(17) was increased by 48% compared to the value in controls treated with azoxymethane only (p = 0.01). We conclude that short term administration of glycine-extended gastrin(17) to mature rats not only has a proliferative effect upon colonic mucosa, but also increases the number of aberrant crypt foci formed in the colorectal mucosa after treatment with azoxymethane. Glycine-extended gastrin(17) could thus potentially act as a promoter of carcinogenesis.

Topics: Animals; Azoxymethane; Carcinogens; Cell Division; Colon; Colonic Neoplasms; Gastrins; Glycine; Hormones; Male; Mucous Membrane; Precancerous Conditions; Rats; Rats, Sprague-Dawley; Time Factors

Rat stomach ECL cells are rich in histamine and chromogranin A-derived peptides, such as pancreastatin. Gastrin causes the parietal cells to secrete acid by flooding them with histamine from the ECL cells. In the past, gastric histamine release has been studied using anaesthetized, surgically manipulated animals or isolated gastric mucosa, glands or ECL cells. We monitored gastric histamine mobilization in intact conscious rats by subjecting them to gastric submucosal microdialysis. A microdialysis probe was implanted into the submucosa of the acid-producing part of the stomach (day 1). The rats had access to food and water or were deprived of food (48 h), starting on day 2 after implantation of the probe. On day 4, the rats received food or gastrin (intravenous infusion), and sampling of microdialysate commenced. Samples (flow rate 1.2 microl min(-1)) were collected every 20 or 60 min, and the histamine and pancreastatin concentrations were determined. The serum gastrin concentration was determined in tail vein blood. Exogenous gastrin (4-h infusion) raised microdialysate histamine and pancreastatin dose-dependently. This effect was prevented by gastrin receptor blockade (YM022). Depletion of ECL-cell histamine by alpha-fluoromethylhistidine, an irreversible inhibitor of the histamine-forming enzyme, suppressed the gastrin-evoked release of histamine but not that of pancreastatin. Fasting lowered serum gastrin and microdialysate histamine by 50%, while refeeding raised serum gastrin and microdialysate histamine and pancreastatin 3-fold. We conclude that histamine mobilized by gastrin and food intake derives from ECL cells because: 1) Histamine and pancreastatin were released concomitantly, 2) histamine mobilization following gastrin or food intake was prevented by gastrin receptor blockade, and 3) mobilization of histamine (but not pancreastatin) was abolished by alpha-fluoromethylhistidine. Hence, gastric submucosal microdialysis allows us to monitor the mobilization of ECL-cell histamine in intact conscious rats under various experimental conditions not previously accessible to study. While gastrin receptor blockade lowered post-prandial release of ECL-cell histamine by about 80%, unilateral vagotomy reduced post-prandial mobilization of ECL-cell histamine by about 50%. Hence, both gastrin and vagal excitation contribute to the post-prandial release of ECL-cell histamine.

Topics: Animals; Benzodiazepines; Chromogranin A; Enterochromaffin-like Cells; Enzyme Inhibitors; Fluorescent Antibody Technique; Food; Gastric Mucosa; Gastrins; Histamine; Hormone Antagonists; Male; Methylhistidines; Microdialysis; Pancreatic Hormones; Rats; Rats, Sprague-Dawley; Time Factors; Vagotomy, Proximal Gastric

Although ectopic expression of the cholecystokinin B/gastrin receptor (CCK-BR) is widely reported in human colorectal cancers, its role in mediating the proliferative effects of gastrin1-17 (G-17) on these cancers is unknown. Here we report the isolation of a novel splice variant of CCK-BR that exhibits constitutive (ligand-independent) activation of pathways regulating intracellular free Ca(2+) ([Ca(2+)](i)) and cell growth. The splice variant (designated CCK-BRi4sv for intron 4-containing splice variant) is expressed in colorectal cancers but not in normal colonic mucosa adjacent to the cancer. Balb3T3 cells expressing CCK-BRi4sv exhibited spontaneous, ligand-independent, oscillatory increases in [Ca(2+)](i), whereas cells expressing wild-type CCK-BR did not. Primary cultures of cells isolated from resected colorectal cancers also exhibited a similar pattern of spontaneous [Ca(2+)](i) oscillations. For both Balb3T3 and primary tumor cells, application of G-17 (10 and 200 nm, respectively) caused an increase in [Ca(2+)](i). Selective CCK-BR antagonists blocked the G-17-stimulated Ca(2+) responses but not the spontaneous [Ca(2+)](i) oscillations. Cells expressing CCK-BRi4sv exhibited an increased growth rate ( approximately 2.5-fold), in the absence of G-17, compared with cells expressing wild-type CCK-BR. The selective pattern of expression, constitutive activity, and trophic action associated with CCK-BRi4sv suggest that this variant may regulate colorectal cancer cell proliferation though a gastrin-independent mechanism.

Topics: 3T3 Cells; Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Binding, Competitive; Calcium; Calcium Signaling; Cell Division; Cloning, Molecular; Colorectal Neoplasms; Female; Gastrins; Gene Expression Regulation, Neoplastic; Humans; Introns; Male; Mice; Molecular Sequence Data; Neoplasm Staging; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Tumor Cells, Cultured

The kinetics and metabolism in various organs of three bioactive products of progastrin, the small sulfated and nonsulfated gastrin-6 and the large nonsulfated gastrin-52, were examined during intravenous administration in anesthetized pigs. The kidney, hindlimb, liver, head, and gut eliminated the hexapeptides efficiently, with a fractional extraction ranging from 0.50 to 0.28 (P<0.001-0.05). No metabolism was recorded in the lungs, and sulfation was without influence on the extraction of gastrin-6. Gastrin-52 was eliminated only in the kidney and the head, with a fractional extraction between 0.23 and 0.11 (P<0.01-0.05). The half-life of sulfated and nonsulfated gastrin-6 was 1.5+/-0.4 and 1.4+/-0.3 min, the metabolic clearance rate (MCR) was 80.8+/-7.6 and 116.0+/-13.5 ml x kg(-1) x min(-1) (P<0.05), and the apparent volume of distribution (V(dss)) was 199.3+/-70.1 and 231.4+/-37.3 ml/kg, respectively. The decay of gastrin-52 in plasma was biexponential. The half-lives of this biexponential after a bolus injection were 3.9+/-0.5 (T(1/2alpha)) and 25.7+/-1.4 (T(1/2beta)) min, and the MCR and V(dss) were 4.2+/-0.4 ml. kg(-1) x min(-1) and 116.2+/-16.2 ml/kg(1). We conclude that there is a differential elimination of progastrin products in splanchnic and nonsplanchnic tissue, which depends on the chain length of the peptides. Sulfation of gastrin-6 had no influence on the organ-specific extraction but reduced the MCR. Our results are in keeping with previous studies of nonsulfated gastrin-17, which is extracted in the kidney, head, limb, and gut but not in the liver.

Topics: Anesthesia; Animals; Chromatography, Gel; Gastrins; Hemodynamics; Hormones; Injections, Intravenous; Intestinal Mucosa; Kidney; Kinetics; Liver; Peptide Fragments; Portal System; Protein Precursors; Radioimmunoassay; Sulfates; Swine

Studies in gastrin-deficient mice have demonstrated critical roles for gastrin peptides in the regulation of gastric acid secretion, but the relative contributions of amidated (G-17) and glycine-extended (G17-Gly) gastrin remain unclear. We examined the effects of these 2 forms of gastrin on acid secretion in gastrin-deficient mice.. Sixty gastrin-deficient mice received infusions of saline, or 1, 6, or 14 days of amidated gastrin 17 (G-17), G17-Gly, or both G-17 and G17-Gly at 10 nmol. kg(-1). h(-1). Twenty-four gastrin-deficient mice were then infused for 14 days with 1, 2, or 5 nmol. kg(-1). h(-1) of G-17 or G-17 and G17-Gly. Acid secretion was determined 4 hours after pyloric ligation, and gastric tissue was processed for histology, immunohistochemistry, and electron microscopy.. Infusion of G-17 increased acid secretion in a dose-dependent manner with a peak at 5 nmol. kg(-1). h(-1) and a subsequent decrease in acid secretion at higher doses. Infusion of G17-Gly alone had no effect on acid secretion, but coinfusion with G-17 resulted in significantly higher levels of acid secretion at all doses examined than infusion with G-17 alone. The potentiating effect of G17-Gly on G-17-induced acid secretion was associated with increased parietal cell activation but was independent of changes in parietal and enterochromaffin-like cell number, fundic proliferation rates, and H(+),K(+)-adenine triphosphatase expression. G17-Gly also prevented the formation of vacuolar canaliculi and lipofuscin bodies in the parietal cells induced by G-17.. G17-Gly appears to synergize with G-17 to up-regulate acid secretion and prevent parietal cell degradation. These results suggest that G17-Gly plays an important role in parietal cell function.

Topics: Animals; Cell Division; Drug Synergism; Gastric Acid; Gastric Mucosa; Gastrins; H(+)-K(+)-Exchanging ATPase; Hyperplasia; Mice; Mice, Knockout; Parietal Cells, Gastric; Stomach

Although physiological functions of the CCK-B/gastrin receptor are well explored, little is known about its role during healing. Here, we evaluated the role of this receptor in the rat oxyntic mucosa following the introduction of a cryoulcer. In this model, we located and quantified CCK-B/gastrin receptors by reverse transcriptase PCR and receptor autoradiography. Rats with cryoulcers were treated with placebo, omeprazole, the CCK-B/gastrin receptor antagonist YF-476, omeprazole plus YF-476, gastrin-17, and gastrin 17 plus YF-476. During wound healing, CCK-B/gastrin receptors were specifically expressed and localized to the regenerative mucosal ulcer margin. This high expression was limited in time, and the pattern of expression of CCK-B/gastrin receptors correlated closely with the proliferative activity of the regenerative mucosa. Functionally, omeprazole and gastrin-17 caused profound hypergastrinemia, increased cell proliferation in the mucosal ulcer margin and accelerated the late ulcer healing phase. These effects were completely reversed by cotherapy with YF-476. These in vivo and vitro data suggest that CCK-B/gastrin receptors in regenerative rat gastric oxyntic mucosa enhance trophic effects during wound healing.

Topics: Animals; Benzodiazepinones; Female; Freezing; Gastric Mucosa; Gastrins; Omeprazole; Parietal Cells, Gastric; Phenylurea Compounds; Rats; Rats, Wistar; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Regeneration; Stomach Ulcer; Wound Healing

The renal handling of carboxyamidated gastrins, NH2-terminal progastrin fragments, and glycine-extended gastrins was examined in healthy volunteers. The respective urinary clearances after a meal amounted to 0.09 +/- 0.02%, 0.17 +/- 0.04% (P < 0.05), and 0.04 +/- 0.01% (P < 0.01) of the glomerular filtration rate. During intravenous infusion of carboxyamidated gastrin-17, progastrin fragment-(1-35), and glycine-extended gastrin-17, the respective urinary clearances amounted to 0.08 +/- 0.02, 0.46 +/- 0.08, and 0. 02 +/- 0.01%, respectively, of the glomerular filtration rate. The metabolic clearance rate of the three peptides was 24.4 +/- 1.3, 6.0 +/- 0.4, and 8.6 +/- 0.7 ml. kg-1. min-1. A maximum rate for tubular transport or degradation of the peptides could not be determined, nor was a renal plasma threshold recorded. Plasma concentrations and urinary excretion rates correlated for gastrin-17 and progastrin fragment-(1-35) (r = 0.94 and 0.97, P < 0.001), whereas the excretion of glycine-extended gastrin diminished with increasing plasma concentrations. We conclude that renal excretion of progastrin products is negligible compared with renal metabolism and that renal handling of the peptides depends on their molecular structure. Hence, the kidneys exhibited a higher excretion of NH2-terminal progastrin fragments than of carboxyamidated and especially glycine-extended gastrins.

Topics: Biotransformation; Gastrins; Glomerular Filtration Rate; Humans; Infusions, Intravenous; Kidney; Metabolic Clearance Rate; Peptide Fragments; Protein Precursors; Radioimmunoassay; Reference Values; Regression Analysis; Time Factors

Vertebrate gastrointestinal hormones were tested on their ability to liberate digestive enzymes from the crustacean midgut gland. CCK-8 (desulfated form), gastrin, bombesin, secretin, and substance P were detected to release enzymes. Maximal concentrations observed were 5 nM CCK for protease release, 1 nM gastrin for protease and 100 nM for amylase release, 100 nM bombesin for protease release, 10 nM secretin for amylase and protease release, and 100 nM substance P for protease release. Unlike in vertebrates, glucagon was unable to stimulate enzyme release in crustaceans, this also applies to the counterpart insulin. These results may support the assumption that Crustacea possess endogenous factors resembling the above mentioned vertebrate hormones, at least in such a way that the appropriate receptors have the capacity to accept these hormones.

Topics: Amylases; Animals; Bombesin; Crustacea; Digestive System; Endopeptidases; Gastrins; Gastrointestinal Hormones; Glucagon; Insulin; Secretin; Sincalide; Substance P; Vertebrates

To clarify the impact of the classic gastrin/CCK-B receptor on the growth of benign and malignant colonic cells, two permanent cell lines expressing this receptor have been established. The conditionally immortalized nonmalignant colonic cell line YAMC and the colonic carcinoma cell line SW 403 were stably transfected with a plasmid encoding the gastrin/CCK-B receptor (GR), or with plasmid alone (V). Expression of the gastrin/CCK-B receptor in the transfected YAMC-GR and SW 403-GR cells was demonstrated by gastrin binding experiments. The YAMC-GR cell line did not respond mitogenically to pentagastrin or gastrin(17) in vitro and was not tumorigenic. The SW 403-GR cell line was stimulated by gastrin(17) in vitro, but the growth patterns of SW 403-GR and SW 403-V were the same in nude mice with cells injected either subcutaneously or into the spleen. These results provide further evidence that the gastrin/CCK-B receptor is not responsible for gastrin-stimulated growth in colonic tumors.

Topics: Animals; Cell Division; Cell Line, Transformed; Colon; Gastrins; Humans; Mice; Mice, Nude; Mitogens; Neoplasm Transplantation; Pentagastrin; Receptors, Cholecystokinin; Skin Neoplasms; Splenic Neoplasms; Transfection; Tumor Cells, Cultured

ECL cells are numerous in the rat stomach. They produce and store histamine and chromogranin-A (CGA)-derived peptides such as pancreastatin and respond to gastrin with secretion of these products. Numerous electron-lucent vesicles of varying size and a few small, dense-cored granules are found in the cytoplasm. Using confocal and electron microscopy, we examined these organelles and their metamorphosis as they underwent intracellular transport from the Golgi area to the cell periphery. ECL-cell histamine was found to occur in both cytosol and secretory vesicles. Histidine decarboxylase, the histamine-forming enzyme, was in the cytosol, while pancreastatin (and possibly other peptide products) was confined to the dense cores of granules and secretory vesicles. Dense-cored granules and small, clear microvesicles were more numerous in the Golgi area than in the docking zone, i.e. close to the plasma membrane. Secretory vesicles were numerous in both Golgi area and docking zone, where they were sometimes seen to be attached to the plasma membrane. Upon acute gastrin stimulation, histamine was mobilized and the compartment size (volume density) of secretory vesicles in the docking zone was decreased, while the compartment size of microvesicles was increased. Based on these findings, we propose the following life cycle of secretory organelles in ECL cells: small, electron-lucent microvesicles (pro-granules) bud off the trans Golgi network, carrying proteins and secretory peptide precursors (such as CGA and an anticipated prohormone). They are transformed into dense-cored granules (approximate profile diameter 100 nm) while still in the trans Golgi area. Pro-granules and granules accumulate histamine, which leads to their metamorphosis into dense-cored secretory vesicles. In the Golgi area the secretory vesicles have an approximate profile diameter of 150 nm. By the time they reach their destination in the docking zone, their profile diameter is between 200 and 500 nm. Exocytosis is coupled with endocytosis (membrane retrieval), and microvesicles in the docking zone are likely to represent membrane retrieval vesicles (endocytotic vesicles).

Topics: Animals; Biological Transport; Cell Membrane; Chromogranin A; Cytoplasmic Granules; Enzyme Inhibitors; Fasting; Gastric Mucosa; Gastrins; Golgi Apparatus; Histamine; Histamine Release; Histidine Decarboxylase; Male; Microscopy, Confocal; Microscopy, Immunoelectron; Omeprazole; Pancreatic Hormones; Postprandial Period; Proton Pump Inhibitors; Rats; Rats, Sprague-Dawley; Vacuoles

An immunological role for eosinophils has been well established. However, roles for eosinophils in the physiological functions of the organs they populate are little explored.. Fixed, frozen, then vibratomed sections of rat stomach were exposed to biotinylated 1-17 gastrin (bG17), biotinylated gastrin-releasing peptide (bGRP), biotinylated neuromedin C (bNC), biotinylated vasoactive intestinal peptide (bVIP), and biotinylated substance P (bSP). Binding sites were identified using an avidin-biotin-glucose oxidase complex and tetranitroblue tetrazolium staining.. bG17, bGRP, and bNC all bound to cells in the lamina propria and to a lesser extent in the submucosa. Neither bVIP nor bSP bound to cells in these sections. Stained cells were identified as eosinophils in the light microscope on the basis of their distribution and staining properties using the Luna stain for eosinophils and in the transmission electron microscope (TEM) on the basis of a light/TEM matching process. Plastic sections viewed in the light microscope showed that stain was localized to a granular component in the cytoplasm of the eosinophils. No other cell type, specifically neither mast cells nor plasma cells, stained. G17 competed for the bG17 binding site better than did NC. A competition study in which polyglutamic acid failed to compete with bG17 for the binding site, and the observation that bG17, bGRP, and bNC did not bind to other positively charged sites (e.g., collagen, red blood corpuscles), demonstrated that binding was not due to nonspecific electrostatic interactions alone. Binding of bG17 to a CCK(B)/gastrin-type receptor was ruled out when specific receptor antagonists failed to block binding.. The particulate nature of the binding site suggests a secretory substance. If so, eosinophils might use that substance to destroy, neutralize, or control the activity of peptide hormones bound to it in the extracellular space.

Topics: Animals; Binding, Competitive; Biotinylation; Bombesin; Coloring Agents; Cytoplasmic Granules; Eosinophils; Frozen Sections; Gastric Mucosa; Gastrins; Microscopy, Electron; Neuropeptides; Peptide Fragments; Rats; Rats, Sprague-Dawley; Substance P; Tissue Fixation; Vasoactive Intestinal Peptide

CCK and gastrin stimulate somatostatin (SOM) secretion and thus modulate their direct effects on the parietal cell. Although SOM is stored in D cells of the fundus and antrum, the nature of the cell type differs, and it is not known whether both regions respond to the stimulatory effects of CCK and gastrin. The objectives of the present study were to determine the separate effects of CCK and gastrin on fundic and antral SOM secretion and to assess the type of receptor involved, using CCK-A (L-364,718) and CCK-B/gastrin (L-365,260) receptor antagonists. Changes in SOM were measured in plasma collected from cannulas draining blood from the fundus (gastric vein) and antrum (gastroepiploic vein) in anesthetized sheep. Both CCK and gastrin significantly stimulated SOM from the fundus and antrum. Sulfated CCK-8 (CCK-8S) increased SOM secretion from the fundus and antrum through interaction with both type A and B receptors. In contrast to CCK-8S, sulfated gastrin-17 (G-17S) stimulated SOM from the fundus via the type B receptor alone, whereas in the antrum G-17S stimulated SOM secretion independent of the A and B receptors. Histamine mediated, at least in part, the SOM-stimulatory effects; an H2-receptor antagonist blocked CCK-stimulated SOM secretion in both the fundus and antrum and reduced gastrin-stimulated SOM secretion in the fundus. The present study demonstrates regionally distinct regulatory mechanisms for gastric SOM secretion by CCK and gastrin.

Topics: Anesthesia; Animals; Cholecystokinin; Chromatography, High Pressure Liquid; Gastric Fundus; Gastrins; Molecular Conformation; Pyloric Antrum; Receptors, Cholecystokinin; Sheep; Sincalide; Somatostatin

Human astrocytic tumors grow into the normal brain parenchyma either as localized tumors, or as highly diffuse neoplasms. The diffuse phenotype relates to a specific sub-type of neoplastic astrocytes with a high motility and invasion capacity. Motility features refer to locomotion while invasion features refer to protease secretion. Our data reveal that several peptides belonging to the gastrin/cholecystokinin peptide class are able to significantly (and in certain cases very significantly) modify the level of tumor growth (at the level of cell proliferation and/or cell death), of motility and of invasion in various experimental models of human astrocytic tumors. We are synthesizing various gastrin/cholecystokinin-related peptides in order to develop clinical applications with which we want to inhibit astrocytic tumor growth, individual neoplastic astrocytic motility and the invasion of the normal brain parenchyma.

Topics: Animals; Astrocytoma; Biomarkers, Tumor; Brain Neoplasms; Disease Models, Animal; Drug Evaluation, Preclinical; Gastrins; Humans; Mice; Sincalide

Renal handling of postprandial and intravenously administered gastrin was investigated in anaesthetised pigs. The fractional extraction of postprandial carboxyamidated and glycine-extended gastrin in the kidneys was 0.21 +/- 0.01 and 0.16 +/- 0.02, but the respective urinary clearance comprised only 0.57 +/- 0.03 and 0.44 +/- 0.05% of the GFR (P < 0.02). The respective total body clearance of carboxyamidated and glycine-extended gastrin-17 (gastrin-17 and gastrin-17Gly) during continuous infusion was 22.9 +/- 1.5 and 19.6 +/- 1.4 mL kg-1 min-1 (NS), and the renal fractional extraction of the peptides was 0.31 +/- 0.03 and 0.29 +/- 0.05, respectively. The kidneys accounted for 8% of total body clearance of gastrin-17. Renal filtration rate of gastrin-17 exceeded renal extraction rate (9.739 +/- 0.487 vs. 6.407 +/- 0.321 pmol min-1). Urinary clearance of gastrin-17 and gastrin-17Gly amounted only 0.91 +/- 0.16 and 0.13 +/- 0.03%, respectively, of the GFR (P < 0.01), but urinary excretion rate correlated with the filtered amount of the peptides (r = 0.93, P < 0.01). Neither was a renal plasma threshold recorded nor was a Tm value for tubular uptake or degradation of gastrin achieved in spite of supraphysiological plasma levels of the peptides. The results indicate that filtered gastrin is almost completely removed in the renal tubules, primary by metabolism although part of the absorbed peptides may be returned to the circulation in intact form. The process for uptake or metabolism has a high capacity but varies with the molecular form of gastrin.

Topics: Animals; Biological Transport; Chromatography, Gel; Gastrins; Glomerular Filtration Rate; Hormones; Kidney Tubules; Radioimmunoassay; Swine

Proper function of the protein tyrosine phosphatase CD45 is required for the positive regulation of the activity of src tyrosine kinases p56lck and p59fyn which participate in T-cell receptor and CD4 receptor signalling. In this study, the effect of HIV-1 infection on the function of CD45-associated tyrosine phosphatase activity in the H9 T-cell line has been investigated with respect to CD3 and CD4 ligation. A significant reduction in CD45-associated phosphatase activity was observed following CD3 + CD4 ligation in virally infected cells, whereas CD45 activity was not compromised following CD3 receptor ligation. Dysfunctional CD45 activity in infected cells was not attributable to reduced receptor surface expression induced by HIV-1, since CD4, CD3 and CD45 expression levels were found to be intact. Defective CD45 activity correlated with inhibted downstream signalling events as evidenced by reduced CD4-associated tyrosine kinase activity and inhibition of PLC-gamma1. Impaired CD45 function is likely to play a critical role in the inhibition of CD3/CD4 signalling thereby contributing to HIV-1 pathogenesis.

Topics: Amino Acid Sequence; CD3 Complex; CD4 Antigens; Cell Line; Culture Media, Serum-Free; Gastrins; HIV Core Protein p24; HIV-1; Humans; Leukocyte Common Antigens; Molecular Sequence Data; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Receptor Cross-Talk; Signal Transduction; Substrate Specificity

We report here the cloning and characterization of a 5'-end alternatively spliced human cholecystokinin-B (CCK-B) receptor mRNA. The 5'-end of this CCK-B receptor transcript (termed CCK-BRtx) consisted of exon Ia, present in the ordinary full-length CCK-B receptor mRNA (CCK-BRwt), and exon Ib, present in a previously described 5'-end alternatively spliced CCK-B receptor mRNA (CCK-BRt). A short open reading frame preceded the AUG translation initiation codon of the CCK-BRtx. Transfection of COS-7 cells with the CCK-BRtx or CCK-BRt cDNAs did not lead to the appearance of peptidergic and non-peptidergic binding sites. Cell free in vitro translation yielded proteins of approximately 44 kDa (CCK-B receptor) and 40 kDa (CCK-BRt receptor) whereas no 40 kDa product was detected from the cloned CCK-BRtx cDNA. Instead, a protein product of approximately 9 kDa was visualized, the size corresponding to the predicted protein encoded by the short open reading frame. The alternatively spliced CCK-B receptor transcripts were concomitantly expressed with the ordinary full-length CCK-B receptor mRNA in the brain, pancreas, and stomach. The possibility that such transcripts are translated in vivo into truncated CCK-B receptors is discussed.

Topics: Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Benzodiazepinones; Binding, Competitive; Cholecystokinin; Cloning, Molecular; COS Cells; Gastrins; Humans; Molecular Sequence Data; Phenylurea Compounds; Protein Binding; Protein Biosynthesis; Receptors, Cholecystokinin; RNA, Messenger; Sequence Analysis, DNA; Transfection

The mechanism of regulation of mucus production in the gastric mucosa remains unclear. Recently, we established a gastric surface mucous cell line GSM06, which produces periodic acid-Shiff (PAS)-positive glycoconjugate (mucus) layers on the cell surface, from transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. In this study, GSM06 cells were examined for its production of PAS-positive glycoconjugate layers to acid secretagogues and growth factors. The cells were cultured at nonpermissive temperature (39 degrees C) for 3-18 days and stained with PAS. Insulin (1-30 microg/ml; 0.29-8.6 microM) time- and dose-dependently increased production of glycoconjugates on the cell surface. When glycoconjugate layers produced by stimulation of insulin (3-30 microg/ml; 0.86-8.6 microM) were removed from the cell surface of GSM06 cells by a mild trypsin treatment, PAS-positive materials were remarkably decreased (day 18). In addition, morphological findings indicate that a high concentration of insulin (30 microg/ml; 8.6 microM) produced thick PAS-positive glycoconjugate layers just like normal gastric surface mucosa on the cell surface on day 18. In contrast, histamine (0.1-100 microM), carbachol (0.1-100 microM), gastrin-17 (0.1-100 nM), epidermal growth factor (0.01-10 ng/ ml; 1.7-1,700 pM), transforming growth factor-alpha (0.01-10 ng/ml; 1.8-1,800 pM), and fetal bovine serum (1-10%) did not increase glycoconjugate production. These findings suggest that insulin is a stimulator of glycoconjugate production, and stimulates production of glycoconjugate layers on the cell surface in the gastric surface mucous cell line GSM06.

Topics: Animals; Carbachol; Cattle; Cell Line; Cell Membrane; Dose-Response Relationship, Drug; Epidermal Growth Factor; Gastric Mucosa; Gastrins; Glycoconjugates; Histamine; Hypoglycemic Agents; Insulin; Mice; Mice, Inbred C57BL; Nicotinic Agonists; Serum Albumin, Bovine; Stimulation, Chemical; Transforming Growth Factor alpha

Gastrin is an important stimulator of gastric lipase secretion in man. In advanced pancreatic insufficiency gastric lipases might compensate for the lack of pancreatic lipases, but the role of gastrin in such compensation remains to be evaluated. The aim of this study was to examine the effect of gastrin on the gastric lipase secretion in patients with pancreatic insufficiency.. Eight patients with pancreatic insufficiency secondary to alcohol abuse were studied, and six healthy subjects volunteered as controls for the study. All volunteers received identical doses of intravenous gastrin-17 (10, 30, and 60 pmol/kg/h). The gastric content was measured, using a nasogastric tube for aspiration, and the amount and activity of gastric lipase output were determined. Plasma concentrations of gastrin, secretin, and cholecystokinin were measured by radioimmunoassays.. The increased plasma levels of gastrin were accompanied by a dose-dependent increase in the amount and activity of gastric lipase in controls, but in the patients the response was almost abolished.. Gastrin in postprandial concentrations does not influence the secretion of gastric lipase in patients with pancreatic insufficiency due to chronic pancreatitis.

Topics: Adult; Case-Control Studies; Cholecystokinin; Exocrine Pancreatic Insufficiency; Female; Gastric Mucosa; Gastrins; Hormones; Humans; Lipase; Male; Middle Aged; Pancreatitis, Alcoholic; Secretin

Exogenous cholecystokinin (CCK) or exposure of the stomach to the mild irritant 25% ethanol can prevent gastric injury. Ingestion of ethanol also elicits the release of CCK as well as gastrin, which is structurally similar to CCK. This study was undertaken in conscious rats to examine the gastroprotective actions of gastrin and to assess the effect of CCK-gastrin receptor blockade on adaptive cytoprotection with ethanol as the mild irritant. Intravenous (1-25 pmol/kg) administration of gastrin-17 dose dependently increased gastric mucosal blood flow (laser Doppler) and reduced gastric injury caused by 1 ml of orally administered acidified ethanol (150 mM HCl-50% ethanol). Similar gastroprotection was achieved with the gastrin secretagogue 5% peptone (1 ml orogastrically). The gastroprotective capabilities of gastrin-17 were attenuated by the type B CCK (gastrin) receptor antagonist L-365,260 (12.5-25 mg/kg i.p.) and by capsaicin desensitization (125 mg/kg s.c.). CCK octapeptide (5 nmol/kg i.v.)-induced protection was reversed by the type A CCK receptor antagonist MK-329 (1 mg/kg i.p.). Neither receptor antagonist, alone or in combination, reversed the protective effects of the mild irritant 25% ethanol (1 ml orogastrically). Thus, whereas gastrin may play a role in gastric mucosal defense, neither CCK nor gastrin appears to participate in the phenomenon of adaptive cytoprotection.

Topics: Acids; Adaptation, Physiological; Animals; Ethanol; Female; Gastric Mucosa; Gastrins; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Stomach Diseases; Time Factors

1. Cholecystokinin (CCK) and gastrin both stimulate gastric somatostatin (SOM) secretion in vitro and thus have the potential to modulate their direct effects on the parietal cell. However, the relative potencies and the mechanisms of action of CCK and gastrin on SOM secretion in vivo have not been determined. 2. The objectives of the present study were to compare the in vivo potencies of the sulphated(s) and non-sulphated (ns) forms of gastrin heptadecapeptide (G-17) and CCK octapeptide (CCK-8) on SOM secretion, and to determine the nature of the receptors involved by repeating the studies in the presence of the CCK-A and CCK-B/gastrin receptor antagonists L-364,718 and L-365,260, respectively. All experiments were performed in the chronically cannulated sheep. 3. Dose-response experiments revealed the following potencies for SOM secretion: G-17s = CCK-8s > G-17 ns >> CCK-8ns. However, based on the plasma levels achieved and a higher metabolic clearance rate (MCR) for CCK, CCK-8s was the most potent. 4. Both the CCK-A and CCK-B/gastrin receptor antagonists suppressed CCK-8s-stimulated SOM output. In contrast, G-17s-stimulated SOM output was inhibited by only the CCK-B/gastrin receptor antagonist. 5. Both receptor antagonists increased basal plasma gastrin and CCK levels. 6. The predominant circulating SOM molecular form after both gastrin and CCK stimulation was SOM-14. 7. In conclusion, the sulphated forms of CCK and gastrin are more potent than the non-sulphated forms. Despite sharing a common biologically active carboxy terminus, CCK stimulates SOM secretion by both the CCK-A and CCK-B/gastrin receptors, while gastrin acts via the CCK-B/gastrin receptor alone. These findings explain in part why CCK is a net inhibitor of gastric acid secretion in vivo.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Chromatography, High Pressure Liquid; Devazepide; Drug Interactions; Gastric Mucosa; Gastrins; Hormone Antagonists; Infusions, Intravenous; Phenylurea Compounds; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Sheep; Sincalide; Somatostatin

We investigated if hypergastrinemia exerted any influence on the proliferation of gastroduodenal epithelium during the healing of ulcers in rats. A mucosal ulcer was induced in the corpus region of the stomach in three groups of rats, which were then given vehicle, omeprazole (400 mumol/kg/day), or gastrin-17 (60 nmol/kg/day) for three or six days. A fourth group of unoperated rats served as controls. One hour before killing, [3H]thymidine was injected. The ulcer margin and corresponding control tissues were excised and processed for light microscopic determination of epithelial labeling index (LI), mitotic index, and apoptotic index. LI was also determined in other parts of the gastroduodenal mucosa. Three and six days after the ulcer operation, the LI in the vehicle-treated ulcer rats was significantly increased in the ulcer margin and in the duodenum, in comparison with the intact controls. In the ulcer margin, the mitotic index was significantly increased, in parallel with the LI; the apoptotic index remained at the control level. The LI in the ulcer margin was increased further after administration of omeprazole or gastrin-17, which elevated the plasma gastrin levels by 5-15 times. It is concluded that hypergastrinemia may increase cell proliferation in the ulcer margin, which may accelerate the rate of healing.

Topics: Animals; Anti-Ulcer Agents; Apoptosis; Autoradiography; Cell Count; Cell Division; Duodenum; Epithelium; Female; Gastric Mucosa; Gastrins; Hormones; Immunohistochemistry; Intestinal Mucosa; Mitotic Index; Omeprazole; Rats; Rats, Sprague-Dawley; Stomach Ulcer

Cholecystokinin-8 placed in the gallbladder lumen causes gallbladder contraction by a neurally mediated, tetrodotoxin-sensitive mechanism. We wished to determine whether other cholecystokinin-like peptides in the gallbladder lumen cause contraction and whether this response is inhibited by cholecystokinin-receptor antagonists. In this study, we measured gallbladder contraction induced by cholecystokinin-like peptides or by hepatic bile placed in the gallbladder lumen. Isolated gallbladders were suspended in an organ bath while luminal hormones were infused. Gallbladder contraction was measured by continuous monitoring of luminal pressure. Cholecystokinin-8, cholecystokinin-5, and gastrin-17 caused dose-related gallbladder contraction with similar potency when placed in the lumen. Each stimulated 70-80% maximal contraction at a luminal concentration of 10(-6) M. Cholecystokinin-receptor antagonists CR1409 and loxiglumide partially inhibited contraction caused by luminal cholecystokinin-8. Bile from fed animals, but not from fasted animals, stimulated gallbladder contraction to 36 +/- 4% of maximal when placed in the gallbladder lumen. We conclude that cholecystokinin and gastrin peptides in the gallbladder lumen cause contraction. This may be mediated through receptors of the cholecystokinin-B type, possibly on intrinsic nerves. Bile from fed animals also contains substances that stimulate gallbladder contraction when bile is placed in the gallbladder lumen. These findings suggest intrinsic nerves participate in the postprandial gallbladder response to cholecystokinin.

Topics: Animals; Bile; Cholecystokinin; Female; Gallbladder; Gastrins; Guinea Pigs; Hormone Antagonists; In Vitro Techniques; Muscle Contraction; Pentagastrin; Proglumide; Receptors, Cholecystokinin; Sincalide

We compared the responses of rat stomach ornithine decarboxylase (ODC) and histidine decarboxylase (HDC) to food intake, oral treatment with antisecretagogues, NaHCO3, and hypertonic NaCl, antrectomy, intravenous infusion of gastrin-17, the selective cholecystokinin (CCK)-B/gastrin receptor antagonist L-365,260, and the somatostatin analogue RC-160. The serum gastrin concentration and oxyntic mucosal ODC and HDC activities were higher in freely fed rats than in fasted rats. Food intake in fasted rats raised the serum gastrin concentration and the ODC and HDC activities. Ranitidine, omeprazole, and NaHCO3 raised the serum gastrin concentration and activated ODC and HDC. Hypertonic NaCl raised the ODC activity 200-fold, whereas circulating gastrin and HDC activity were increased only moderately. Infusion of gastrin-17 activated HDC but not ODC. L-365,260 prevented the activation of HDC but not of ODC in response to food intake and treatment with omeprazole, NaHCO3, or hypertonic NaCl. Antrectomy prevented the food- and omeprazole-evoked rise in oxyntic mucosal HDC activity but not the rise in ODC activity. RC-160 suppressed HDC activity after food intake and treatment with omeprazole, NaHCO3, or NaCl. In contrast, RC-160 suppressed omeprazole- and NaHCO3-evoked ODC activation but not that evoked by food intake or NaCl. The results support the view that HDC in the oxyntic mucosa is activated by gastrin and suppressed by somatostatin. The induction of ODC is not mediated by gastrin; ODC activation appears to be related to acid inhibition per se or to mucosal maintenance and repair; somatostatin, or rather the lack of it, might contribute to the induction of ODC after acid blockade. The mechanism behind the activation of rat stomach ODC seems to differ depending on the type of stimulus.

Topics: Analgesics; Animals; Benzodiazepinones; Cholecystokinin; Duodenum; Eating; Enzyme Activation; Fasting; Gastrectomy; Gastric Mucosa; Gastrins; Histidine Decarboxylase; Infusions, Intravenous; Kinetics; Male; Omeprazole; Ornithine Decarboxylase; Phenylurea Compounds; Pyloric Antrum; Ranitidine; Rats; Rats, Sprague-Dawley; Saline Solution, Hypertonic; Sodium Bicarbonate; Somatostatin; Time Factors

The purpose of this study was to examine whether an intermediate form of amidated gastrin, glycine-extended gastrin (Gly-G), can stimulate gastric acid secretion in conscious rats prepared with gastric fistulas. Intravenous administration of Gly-G (20 nmol.kg-1.h-1) alone for 2 h did not stimulate gastric acid secretion; however, administration of Gly-G (20 nmol.kg-1.h-1) in combination with a bolus administration of gastrin (9.5 nmol/kg) potentiated acid secretion significantly. Gastric acid secretion in response to gastrin alone and gastrin plus Gly-G (2 nmol.kg-1.h-1) was 109.1 +/- 21.6 and 170.1 +/- 27.7 mueq.kg-1.h-1, respectively (P < 0.05). Gastric acid secretion in response to gastrin alone and gastrin plus Gly-G (20 nmol.kg-1.h-1) was 84.8 +/- 17.5 and 164.1 +/- 29.3 mueq.kg-1.h-1, respectively (P < 0.05). Intravenous administration of Gly-G (20 nmol.kg-1.h-1) failed to increase histamine (1 mg/kg)-stimulated acid output. These results demonstrate that Gly-G can selectively potentiate the stimulatory effect of gastrin on acid secretion in rats and that the unprocessed form of gastrin, Gly-G, can exert a biological effect in the stomach.

Topics: Animals; Drug Synergism; Gastric Acid; Gastrins; Histamine; Hormones; Injections, Intravenous; Male; Rats; Rats, Inbred F344

To determine whether human liver cells respond to gastrin peptides by reducing their secretion of triacylglycerols, as recently observed in rat hepatocytes.. Cells of the human hepatoblastoma cell line Hep G2 were incubated with pentagastrin and heptadeca gastrin, followed by lipid analysis of media and cells.. Cultivation of cells; analyses of triacylglycerols, cholesterol and protein; statistical analysis.. As the secretion of triacylglycerols in Hep G2 cells incubated with basal medium (Eagle's minimum essential medium with non-essential amino acids, penicillin, streptomycin and glutamine) is only about 20% of the triacylglycerol secretion reported for human liver cells, the possibility of detecting statistically significant effects of gastrin peptides on lipid secretion is reduced compared to the situation in normal hepatocytes. However, by a combined addition of 0.1 mmol/l albumin-bound oleate, 10 mmol/l sodium butyrate and 0.1 mg/ml dextran sulphate to the basal medium, the triacylglycerol secretion in Hep G2 cells was found to be more than twice as high as in cells incubated with basal medium alone. With this supplemented medium a biphasic concentration-dependent statistically significant inhibitory effect of both pentagastrin and heptadeca gastrin on triacylglycerol secretion in Hep G2 cells was demonstrated.. These results indicate that gastrin peptides may play a role in the regulation of lipoprotein secretion in human liver cells.

Topics: Culture Media; Gastrins; Hormones; Humans; Liver; Liver Neoplasms; Pentagastrin; Triglycerides; Tumor Cells, Cultured

The effect in vitro of gastrin-17 and gastrin-34 was studied at concentrations from 10(-12) to 10(-6) M on several functions of resting peritoneal macrophages from BALB/c mice: adherence to substrate, mobility (spontaneous and directed by chemical gradient or chemotaxis), and ingestion of inert particles (latex beads) or cells (Candida albicans). Both gastrins, at concentrations from 10(-10) to 10(-8) M, inhibited significantly all functions studied with the exception of adherence, which was increased. A dose-response relationship was observed, with a maximum inhibition of macrophage functions found at 10(-9) M. These peptides induced in murine macrophages a significant increase of cAMP levels at 60 and 120 s. Adenosine, an adenylate cyclase inhibitor, significantly increased the ingestion of latex beads, whereas the combined presence of adenosine and either G-17 or G-34 produced similar values to those of control samples without adenosine or gastrin. These results suggest that gastrin is a negative modulator of several macrophage functions, and that the inhibition of these activities is carried out through an increase of intracellular cAMP levels.

Topics: Adenosine; Animals; Cell Adhesion; Cell Migration Inhibition; Cyclic AMP; Female; Gastrins; Leukocyte Adherence Inhibition Test; Macrophages, Peritoneal; Male; Mice; Mice, Inbred BALB C; Phagocytosis; Protein Precursors

Gastrin stimulates uptake of Ca(2)+ into bone and causes transient hypocalcemia, possibly by releasing a peptide hormone from enterochromaffin-like (ECL) cells, which are histamine- and peptidehormone-producing cells in the acid-producing part of the stomach. However, if ECL cells secrete a calciotropic hormone, it is to be expected that their activity is affected by the serum Ca(2)+ concentration.. Food-deprived male rats were infused with human (Leu)15-gastrin-17 and/or ethylenediamine-tetraacetic acid and CaCl(2). The blood Ca(2)+ level was monitored throughout the experiments (3 h), and the serum concentrations of gastrin, parathyroid hormone, and calcitonin were measured at death. The activity of the ECL cells was assessed by measuring the histidine decarboxylase (HDC) activity.. Gastrin produced the expected increase in HDC activity, but neither hyper- nor hypo-calcemia affected the RDC activity of either hypo- or hyper-gastrinemic rats.. Perturbations in blood Ca(2)+ do not seem to affect ECL cells, which is at odds with the view that ECL cells harbor a calciotropic hormone.

Topics: Animals; Calcitonin; Calcium; Calcium Chloride; Edetic Acid; Enterochromaffin Cells; Enzyme Activation; Gastric Mucosa; Gastrins; Histidine Decarboxylase; Hormones; Male; Parathyroid Hormone; Radioimmunoassay; Rats; Rats, Sprague-Dawley

The stimulatory effect of exogenous bombesin and its related mammalian peptides on gastric acid secretion and gastrin release has been examined in detail, while the regulatory role of endogenously released bombesin-like peptides is largely unknown. Accordingly we have determined the effect of a specific bombesin receptor antagonist during vagal stimulation of gastric acid secretion and gastrin release. In anesthetized rats electrical stimulation of the vagal nerves (10 V, 10 Hz, 1 ms) significantly increased plasma gastrin levels by 82 +/- 11 pg/20 min (P < 0.01) and gastric acid output by 99.4 +/- 9.9 mueq/20 min (P < 0.01). Intravenous infusion of the specific bombesin receptor antagonist D-Phe6-BN(6-13)OMe (400 nmol/kg/h) significantly reduced vagally induced increase of plasma gastrin levels by 70% to 29 +/- 8 pg/20 min (P < 0.05 vs control) and vagally stimulated gastric acid output by 40% to 57.4 +/- 10.6 mueq/20 min (P < 0.05 vs control). To demonstrate that the residual gastrin and acid response is due to non-bombesinergic mechanisms and not to an inadequate dose of the receptor antagonist, the latter was tested against gastrin-releasing peptide (GRP) at the maximally effective concentration of 300 pmol/kg/h, which resulted in an even 50% higher increase of plasma gastrin levels compared to vagal stimulation. The dose of the antagonist employed (400 nmol/kg/h) was sufficient to abolish GRP-induced stimulation of gastrin and gastric acid secretion. Previously it has been postulated that endogenous bombesin-peptides can stimulate acid secretion via gastrin-independent mechanisms. To investigate this possibility further the effect of the antagonist was examined on vagally induced acid secretion while gastrin levels were restored to the range of the respective control experiments. In presence of the antagonist the infusion of gastrin-17 (15 pmol/kg/h) in addition to vagal stimulation elevated plasma gastrin to levels not different from those during vagal stimulation alone. With identical plasma gastrin levels the bombesin receptor antagonist had no effect on vagally stimulated acid secretion (86.3 +/- 10.7 mueq/20 min vs 99.4 +/- 9.9 mueq/20 min in the controls; n.s.). In conclusion, the present data demonstrate for the first time that in rats in vivo endogenous bombesin peptides contribute to vagal stimulation of gastrin release and gastric acid secretion. Furthermore, endogenous bombesin-peptides exert their action on parietal cell function via an i

Topics: Animals; Bombesin; Electric Stimulation; Gastric Acid; Gastric Mucosa; Gastrin-Releasing Peptide; Gastrins; Hormones; Infusions, Intravenous; Male; Peptide Fragments; Peptides; Rats; Rats, Wistar; Receptors, Bombesin; Time Factors; Vagus Nerve

In rats, changes in gastric nerve fibers containing gastrin-releasing peptide (GRP) in cysteamine-induced duodenal ulcer were investigated in relation to the dynamics of gastrin-producing cells (G-cells). Marked increases in gastric acid secretion and serum gastrin level were observed from 2 h after the administration of cysteamine. The number of G-cells was significantly decreased from 2 h after the injection of cysteamine. Two and 4 h after the administration of cysteamine, the G-cells showed ultrastructural changes characterized by a markedly decreased number of secretory granules. Circulating GRP levels were significantly elevated from 2 h after the administration of cysteamine. In the control group given vehicle only, nerve fibers showing immunoreaction for GRP formed a fine network in the gastric wall and were densely distributed in the oxyntic mucosa, located close to capillaries and demonstrated varicosities that contained either small clear vesicles or GRP-immunopositive vesicles with large cores. Eight h after the administration of cysteamine, there was depleted GRP immunoreactivity, evidenced by a markedly decreased number of vesicles, with large electron-dense cores, in the oxyntic mucosa. These findings suggest that, in cysteamine-induced duodenal ulcer, alterations in gastric nerve fibers containing GRP may be related to hypergastrinemia.

Topics: Animals; Cell Count; Cysteamine; Duodenal Ulcer; Follow-Up Studies; Gastric Acid; Gastric Mucosa; Gastrin-Releasing Peptide; Gastrins; Immunohistochemistry; Male; Microscopy, Immunoelectron; Nerve Fibers; Peptides; Radiation-Protective Agents; Radioimmunoassay; Rats; Rats, Wistar; Stomach

It has been shown recently that the two largest alpha-carboxyamidated progastrin products are gastrin-71 and gastrin-52. Human gastrin-52 has now been synthesized, and the effect on gastric acid secretion and elimination from plasma was examined and compared with gastrin-17 in 12 normal subjects. The peptides were infused separately in four consecutive doses; the maximum response of gastrin-17 and gastrin-52 was 25.2 +/- 2.8 and 22.2 +/- 2.8 mmol H+/50 min, respectively (P < 0.01). This difference in efficacy was presumably related to nonequilibrium of gastrin-52 between plasma and receptor. The elimination of gastrin-17 was monoexponential with a half-life of 4.7 +/- 0.3 min; clearance and apparent volume of distribution were 16.7 +/- 1.5 ml.kg-1.min-1 and 106.0 +/- 9.2 ml/kg, respectively. The elimination of gastrin-52 was biexponential, the half-lives were 4.9 +/- 0.7 and 49.9 +/- 4.2 min, and clearance and apparent volume of distribution were 1.9 +/- 0.2 ml.kg-1.min-1 and 106.3 +/- 10.1 ml/kg, respectively. Gel chromatography of plasma samples drawn during infusion of gastrin-52 revealed that most of the immunoreactivity eluted in the position of the intact peptide. Small peaks in the positions of gastrin-34 and the NH2-terminal pentapeptide fragment of gastrin-52 indicate that a minor part of gastrin-52 is degraded to smaller peptides in vivo. It is concluded that gastrin-52 is bioactive with an efficacy close to or similar to that of gastrin-17. A minor fraction of gastrin-52 undergoes postsecretory cleavage either in plasma or after capillary transit.

Topics: Adult; Chromatography, Gel; Dose-Response Relationship, Drug; Female; Gastric Acid; Gastrins; Humans; Male; Middle Aged; Osmolar Concentration; Protein Precursors; Radioimmunoassay

Stimulation of gastric acid secretion by secretagogues was measured in developing rats by in vivo and in vitro techniques. Basal acid outputs in vivo were very low in 8- and 14-day-old rats compared with those in 20- and 30-day-old rats. In 20-day-old rats, all secretagogues increased acid output in vivo, whereas only carbachol, pentagastrin, and sulfated cholecystokinin octapeptide (CCK-8S) were active in 14-day-old rats. In contrast, basal acid output in vitro and stimulation by secretagogues did not differ significantly with age. CCK-8S-stimulated acid output in vitro in 14-day-old rats was blocked by L-365,260, L-364,718, tetrodotoxin, and atropine, but not by hexamethonium, whereas gastrin-stimulated acid output was blocked only by L-365,260. Furthermore, acid output in vivo was elevated three- to fourfold by subcutaneous naloxone-methiodide or L-364,718, but not by L-365,260, in 14-day-old rats; none of these antagonists produced an effect in 20-day-old rats. These studies show that low basal gastric acid output in neonatal rats is caused by tonic inhibitory regulation by endogenous regulatory peptides.

Topics: Animals; Animals, Newborn; Gastric Acid; Gastrins; Narcotic Antagonists; Peptides; Rats; Rats, Sprague-Dawley; Sincalide; Stimulation, Chemical

Certain gut peptides exert gastroprotective effects. However, the underlying mechanism is not fully understood. This study examines the contribution of afferent neurons, calcitonin gene-related peptide, and nitric oxide to the protection conferred by gastrin 17 in the rat stomach.. Gastroprotection by gastrin 17 against ethanol-induced gross and histological damage was studied after capsaicin-induced defunctionalization of afferent neurons, pretreatment with the calcitonin gene-related peptide receptor antagonist human calcitonin gene-related peptide8-37, anti-calcitonin gene-related peptide antibodies, and the NO synthase inhibitor NG-nitro-L-arginine.. Gastrin 17 (1-25 pmol/kg) dose-dependently prevented mucosal damage caused by ethanol. Protection was inhibited by functional ablation of afferent neurons or pretreatment with human calcitonin gene-related peptide8-37 (50% inhibitory dose, 86 pmol.kg-1.min-1), anticalcitonin gene-related peptide antibodies, or NG-nitro-L-arginine (50% inhibitory dose, 1 mg/kg). L-Arginine but not D-arginine reversed the effect of NG-nitro-L-arginine. Effects on gross damage were paralleled by histology. Protective doses of gastrin 17 increased gastric mucosal blood flow and, in addition, elevated plasma gastrin concentrations to the same extent as intragastric peptone perfusion.. Gastrin 17 has potent gastroprotective activity that involves afferent neurons, calcitonin gene-related peptide, and NO.

Topics: Amino Acid Oxidoreductases; Animals; Arginine; Calcitonin Gene-Related Peptide; Capsaicin; Ethanol; Gastric Mucosa; Gastrins; Male; Neurons, Afferent; Nitric Oxide; Nitric Oxide Synthase; Nitroarginine; Rats; Rats, Wistar; Regional Blood Flow; Stomach

We examined the effects of gastrin and histamine on rat gastric H+/K(+)-ATPase, the enzyme responsible for H+ secretion, gene expression in vivo. Gastrin 17 (G 17) or histamine dihydrochloride (histamine) was continuously infused through the femoral vein of anesthetized rats. Gastric H+/K(+)-ATPase mRNA levels were measured using northern blot analysis. Infusion of G 17 and histamine increased the H+/K(+)-ATPase mRNA level significantly compared with basal control level or vehicle control level (P < 0.01). However, pretreatment with famotidine, a potent histamine-2 (H2)-receptor antagonist, inhibited the increase of rat gastric H+/K(+)-ATPase mRNA following G 17 and histamine infusion. These findings indicate that both histamine and G 17 increase expression of H+/K(+)-ATPase mRNA by activating H2 receptor on the parietal cell.

Topics: Actins; Animals; Blotting, Northern; Famotidine; Gastrins; Gene Expression; H(+)-K(+)-Exchanging ATPase; Histamine; Histamine H2 Antagonists; Hormones; Infusions, Intravenous; Male; Parietal Cells, Gastric; Premedication; Rats; Rats, Wistar; Receptors, Histamine H2; RNA, Messenger

The effect of gastrin on the enterochromaffin-like cells in the rat stomach is mediated by cholecystokinin (CCK)-B receptors and manifested as activation of histidine decarboxylase (HDC). The dipeptoids PD 136450, PD 135158, and PD 134308 are thought to be selective CCK-B receptor antagonists. The effects of the dipeptoids and of gastrin-17 and sulfated CCK-8 on rat stomach HDC activity were examined.. Drugs were infused intravenously or subcutaneously to fasted rats, and the HDC activity was determined.. The dipeptoids activated HDC with maximal responses (50%-60% of the maximal response to gastrin) at 1 mumol.kg-1.h-1. Rat gastrin-17 activated HDC maximally at 3 nmol.kg-1.h-1, and sulfated CCK-8 produced maximal response at 20 nmol.kg-1.h-1. The CCK-B receptor antagonist L-365,260 inhibited the HDC activation induced by gastrin, sulfated CCK-8, or the dipeptoids. The dipeptoids did not inhibit the gastrin-induced HDC activation.. Gastrin, sulfated CCK-8, and the dipeptoids activated rat stomach HDC. L-365,260 but not devazepide inhibited the HDC activation. Thus, the dipeptoids, which failed to inhibit the gastrin-induced HDC activation, act as CCK-B receptor agonists and not as antagonists. It is important to recognize this to ensure appropriate interpretation of data obtained with these drugs.

Topics: Animals; Benzodiazepinones; Devazepide; Enzyme Activation; Gastrins; Histidine Decarboxylase; Indoles; Ligands; Male; Meglumine; Phenethylamines; Phenylurea Compounds; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Sincalide; Stomach

The putative role of gastrin for the regulation of esophageal motility is a matter of debate. Accordingly it was the aim of this study a) to examine if physiological postprandial plasma levels of human gastrin-17 (hG-17) can affect esophageal motility, especially the pressure of the lower esophageal sphincter (LESP), and b) to assess the contribution of augmented acid secretion during gastrin infusion. In a first series of experiments postprandial plasma gastrin levels were determined in 8 healthy volunteers following the ingestion of a mixed meal. Gastrin rose from a baseline of 21 +/- 2 pg/ml to 67 +/- 8 pg/ml and returned almost to basal levels within 120 minutes. In a second experimental series the effect of i.v. synthetic human gastrin-17 (hG-17) was studied in 17 volunteers. At a lower dose of 0.75 ng/kg/min hG-17 increased plasma gastrin to 62 +/- 7 pg/ml while a higher dose of 1.5 ng/kg min elicited a supraphysiological increase to 119 +/- 11 pg/ml. Infusion of hG-17 caused a significant increase of the LESP from 19.0 to 25.8 mmHg (p < 0.05, low dose) and from 18.5 mmHg to 23.3 mmHg (p < 0.05, high dose) when compared to the effect of i.v. saline. To exclude effects of augmented acid secretion during hG-17 infusion the experiments were repeated after complete blockade of acid secretion with famotidine 40 mg i.v. After famotidine pretreatment hG-17 caused a similar increase of LESP from 20.1 to 25.9 mmHg (low dose) and from 19.9 to 24.1 mmHg (high dose).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Dose-Response Relationship, Drug; Esophagogastric Junction; Esophagus; Famotidine; Female; Gastric Acid; Gastrins; Histamine H2 Antagonists; Hormones; Humans; Infusions, Intravenous; Male; Peristalsis

1. The cardiovascular actions of cholecystokinin and related peptides were investigated in the pithed rat. The receptors and the mechanisms involved in these experiments were characterized. 2. Sulphated cholecystokinin octapeptide (sCCK-8, 0.1-100 nmol kg-1, i.v.) elicited a dose-dependent bradycardia and increase in mean arterial blood pressure. Neither gastrin-17 nor pentagastrin had any effect at concentrations up to 100 nmol kg-1. 3. Both the pressor response and bradycardia elicited by sCCK-8 were reduced by the selective CCKA receptor antagonists, devazepide (0.5-50 nmol kg-1) and lorglumide (1-7 mumol kg-1). The selective CCKB receptor antagonists, CI-988 (1 mumol kg-1) and L-365,260 (15 mumol kg-1) did not inhibit the effects of sCCK-8. 4. The pressor response induced with sCCK-8 was reduced by treatment with either phentolamine (3 mumol kg-1) or guanethidine (2 mumol kg-1) and was unaffected by treatment with propranolol, atropine or hexamethonium. The pressor response also persisted following bilateral adrenalectomy. 5. The bradycardia induced with sCCK-8 was unaffected by treatment with phentolamine, propranolol, guanethidine, atropine, hexamethonium or bilateral adrenalectomy. 6. The tetrapeptide of cholecystokinin (CCK-4) elicited a dose-dependent pressor response but did not induce bradycardia. The pressor response was unaffected by devazepide (50 nmol kg-1), L-365260 (15 mumol kg-1) or phentolamine (3 mumol kg-1). 7. In the pithed rat, sCCK-8 acted via CCKA receptors to increase arterial blood pressure indirectly, at least in part, through activation of alpha-adrenoceptors. The observed bradycardia was also mediated byCCKA receptors but possibly through a direct action on the heart.

Topics: Adrenalectomy; Adrenergic Agents; Animals; Benzodiazepinones; Blood Pressure; Bradycardia; Cholecystokinin; Decerebrate State; Devazepide; Dose-Response Relationship, Drug; Gastrins; Guanethidine; Heart Rate; Hormone Antagonists; Hormones; Hypertension; Indoles; Male; Meglumine; Pentagastrin; Phentolamine; Proglumide; Rats; Receptors, Cholecystokinin; Sincalide; Tetragastrin

Gastrin has a potent influence on gastric acid secretion and mucosal growth but its role in mucosal integrity has been little studied. This study investigated in rats whether gastrin protects the gastric mucosa against the damage by 100% ethanol and what are the possible mechanisms of this protection. Exogenous gastrin-17 (0.6-5.0 pmol/kg) injected subcutaneously (s.c.) reduced dose dependently ethanol-induced mucosal damage and the dose decreasing the ethanol lesions by 50% was about 1.8 pmol/kg. The protection afforded by gastrin-17 was accompanied by a dose-dependent increase in gastric blood flow and these effects were almost completely abolished by the pretreatment with specific CCKB (L-365,260) but not CCKA receptor antagonist (loxiglumide). Endogenous gastrin released by intragastric (i.g.) peptone meal or s.c. injection of gastrin-releasing peptide prevented the formation of acute ethanol-induced lesions and these effects were also abolished by the pretreatment with L-365,260 but not by loxiglumide. The inhibition of nitric oxide (NO) synthase, by NG-nitro-L-arginine methyl ester almost completely eliminated both the protective and hyperemic effects of gastrin-17 and the addition of L-arginine (but not D-arginine) to NG-nitro-L-arginine-methyl ester restored, in part, these effects of gastrin-17. Deactivation of sensory nerves with capsaicin did not influence the protective or hyperemic effects of gastrin-17. We conclude that both exogenous and endogenous gastrin exert its protective activity against ethanol damage of gastric mucosa and this effect is mediated through the interaction with specific CCKB receptors and arginine-NO pathway, but does not involve sensory nerves.

Topics: Animals; Aspirin; Capsaicin; Dinoprostone; Dose-Response Relationship, Drug; Ethanol; Gastric Acid; Gastric Mucosa; Gastrin-Releasing Peptide; Gastrins; Male; Neurons, Afferent; Nitric Oxide; Peptides; Peptones; Rats; Rats, Wistar; Stomach Diseases

Neural discharge in the hypothalamic paraventricular nucleus (PVN) was examined after gastrin-17 injection into the carotid artery in anesthetized rats. Neural discharge was increased by gastrin-17 injection into the carotid artery close to the cranium, and the response due to the gastrin was dose-dependent. No discharge response was seen when gastrin was injected into the jugular vein. These results suggest that gastrin circulating in the arterial blood can penetrate the blood brain barrier, and modulate neural PVN activity which is responsible for gastric acid secretion.

Topics: Animals; Carotid Arteries; Gastrins; Injections, Intra-Arterial; Male; Membrane Potentials; Paraventricular Hypothalamic Nucleus; Rats; Rats, Wistar

The neutralising ability of rabbit anti-gastrin-17 (G17) antiserum raised by Gastrimmune, an immunogen constructed of the N-terminal portion of human G17 conjugated to diptheria toxoid (DT), was evaluated. The anti-serum (denoted anti-G17: DT) was shown to displace 125[I] G17 from the gastrin receptors on AR42J cells. The therapeutic effect of the rabbit anti-G17:DT anti-serum was evaluated on a freshly derived human colorectal cancer cell line, AP5, which was shown to express both gastrin receptors and gastrin immunoreactivity as assessed by immunocytochemistry. Rabbit anti-G17:DT anti-serum was shown to block basal in vitro growth of AP5 cells when used at an antigen binding capacity of 3.75 x 10(-9) M. The same dilution of anti-serum completely reversed growth stimulated by human G17 at concentrations of 1 x 10(-10) and 1 x 10(-9) M but did not inhibit growth at 1 x 10(-8) M G17. When AP5 was grown as a xenograft in nude mice, the sensitivity to the proliferative effect of human G17 was maintained. In addition, the basal growth of AP5 xenografts was significantly reduced by i.v. infusion of rabbit anti-G17:DT anti-serum when compared to treatment with rabbit anti:DT control anti-serum. Thus anti-G17:DT antibodies raised by Gastrimmune may be of clinical value in gastrin-sensitive tumours.

Topics: 3T3 Cells; Animals; Antibody Formation; Cell Division; Cell Line; Colorectal Neoplasms; Diphtheria Toxoid; Fasting; Gastrins; Humans; Immunotherapy; Immunotoxins; Iodine Radioisotopes; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Pancreas; Rabbits; Rats; Transplantation, Heterologous; Tumor Cells, Cultured

Functional studies suggest that guinea pig chief cells have both cholecystokinin-A (CCK-A) and CCK-B receptors (CCK-A-R and CCK-B-R, respectively). However, all efforts to directly characterize the specific CCK-A-R using binding have been unsuccessful. Recent studies describe specific CCK-A-R agonists such as A-71378 ([desamino-Nle28,31-(N-methyl)Asp32]CCK heptapeptide]. In the present study, [D-Tyr-Gly]A-71378 was synthesized, which has > 300-fold selectivity for CCK-A-R and can be iodinated. [D-Tyr-Gly]A-71378 was equipotent to A-71378 in stimulating pepsinogen release from purified guinea pig chief cells. Binding of 125I-labeled [D-Tyr-Gly]A-71378 was saturable and specific. Potencies for inhibiting binding were as follows: [D-Tyr-Gly]A-71378 = A-71378 = 4x CCK octapeptide (CCK-8) > 1,000x des(SO4)-CCK-8, gastrin. In contrast, for 125I-gastrin binding they were CCK-8 > gastrin-17-I > des(SO4)-CCK-8 >> A-71378 or [D-Tyr-Gly]A-71378. Binding of [D-Tyr-Gly]A-71378 was best fitted by a two-site model. In contrast, 125I-gastrin binding was fitted with a single-site model. For inhibiting binding of 125I-[D-Tyr-Gly]A-71378, the CCK antagonists had relative affinities of L-364,718 >> L-365,260, and the reverse was true with 125I-gastrin. Correlation of binding with changes in biological activity suggested low-affinity CCK-A-R were mediating these changes. These results demonstrate directly for the first time that guinea pig chief cells possess CCK-A-R and CCK-B-R. The pharmacology of these CCK-A-R resembles those on other tissues. This novel, highly selective CCK-A ligand should be useful because it will identify CCK-A-R when they make up as little as 0.2% of the total CCK receptor number.

Topics: Animals; Benzodiazepinones; Devazepide; Gastric Mucosa; Gastrins; Guinea Pigs; Ligands; Male; Oligopeptides; Pancreas; Pepsinogens; Phenylurea Compounds; Receptors, Cholecystokinin; Sincalide; Stomach

Gastric acid outputs were examined after gastrin-17 (gastrin) injection into either side of the hypothalamic paraventricular nucleus (PVN) or both sides of the PVN in bilaterally adrenalectomized rats. The acid output increased when 40 pM gastrin was unilaterally injected (10 s, 500 nl) into the PVN through a 28-gauge stainless steel tube. The acid output was also increased when 80 pM gastrin was iontophoretically injected (2 min, -50 nA) into the PVN through a glass tube. An additive increase in the acid output was elicited when an effective concentration of gastrin was simultaneously injected into both sides of the PVN. It was also noted that there was a significant increase in acid output when an ineffective concentration of gastrin was simultaneously injected into both sides of the PVN. Almost the same magnitude of acid response due to PVN gastrin was reproduced in normoglycemia, but it was diminished in hyperglycemia. These results suggest that PVN neurons sensitive to gastrin form a neural circuit in both sides of the nucleus, and the circuit acts to potentiate the stimulation of gastric acid which is dependent on the glycemic condition.

Topics: Animals; Brain Mapping; Gastric Acid; Gastrins; Glucose; Male; Paraventricular Hypothalamic Nucleus; Rats; Rats, Wistar

While the proliferative effects of gastrin in the gastric fundus are well established, there is a considerable degree of confusion regarding the role of gastrin on the growth of the small intestine and colon. The hypothesis that gastrin is trophic throughout the gut was tested by giving three doses of pentagastrin and one of gastrin 17 to rats maintained by total parenteral nutrition (TPN). The rats were fed intravenously for one week, with the various peptides added to the TPN diet. The number of vincristine arrested metaphases per gland or crypt was then scored to determine the proliferative state. Both gastrin 17 and pentagastrin were found to be trophic in the gastric fundus, but not to the gastric antrum. A proliferative response was also seen in the duodenum, but with little evidence of a dose response element. No effect on small bowel weight was seen, and no proliferative effect was noted in the mid small bowel, thus the duodenal effect could be attributed to a local action of increased acid output on the duodenum, not a general role throughout the small intestine. No proliferative effects of pentagastrin or gastrin were seen in the colon. It is therefore concluded that the trophic role of gastrin is restricted to the gastric fundus and the proximal duodenum.

Topics: Animals; Colon; Dose-Response Relationship, Drug; Gastric Fundus; Gastrins; Hormones; Intestine, Small; Male; Mitosis; Organ Size; Pentagastrin; Rats; Rats, Wistar; Stomach

The purpose of this study was to determine the effect of the gastrin receptor antagonist, CR2093, on basal and gastrin-stimulated growth of primary human colorectal adenocarcinomas and to relate this to gastrin receptor expression. Tumour cells, derived from surgical specimens by enzymatic disaggregation, were grown on matrices of type I collagen and irradiated fibroblasts. Gastrin receptor expression was measured by using a mouse monoclonal antibody directed against the gastrin receptor and an avidin-biotin immunocytochemical method. Increased growth in the presence of gastrin-17 (used at physiological concentrations and as assessed by [3H] thymidine uptake) was shown in 16/34 (47%) tumours. CR2093 significantly reversed this stimulated growth (P < 0.05, one way analysis of variance) in 9/16 (56.3%) of the tumours and inhibited the basal growth of 11/34 (32.4%). Basal growth inhibition was reversed by gastrin-17 in 82% (9/11) of tumours. Gastrin receptor expression was widespread, but was not related to the degree of growth response to gastrin, and there was no significant correlation between intensity of receptor expression and inhibition of basal growth by CR2093. In conclusion, both gastrin-stimulated and basal growth of primary human colorectal can be inhibited by gastrin receptor antagonism, but gastrin receptor expression does not predict the sensitivity of tumours to (i) the proliferative effects of gastrin or (ii) the inhibitory effects of a gastrin receptor antagonist on basal growth. Antigastrin agents may have clinical value in the treatment of gastrin-sensitive colorectal tumours, and gastrin receptor expression may be related to endogenous gastrin production by colorectal tumour cells.

Topics: Amino Acids; Cell Division; Colorectal Neoplasms; Gastrins; Hormone Antagonists; Hormones; Humans; Immunoenzyme Techniques; Receptors, Cholecystokinin; Thymidine; Tumor Cells, Cultured

1. Cholecystokinin octapeptide (CCK-8) and gastrin-17 augment gastric mucosal blood flow in the rat. The present study examined whether the gastric vasodilator effect of these peptides is mediated by CCKA or CCKB receptors. 2. Intravenous injection of CAM-1481 (1 mg kg-1), a dipeptoid antagonist of CCKA receptors, or CAM-1028, a dipeptoid CCKB receptor antagonist (1 mg kg-1), had no effect on basal gastric mucosal blood flow as determined by the clearance of hydrogen in urethane-anaesthetized rats. 3. Intravenous infusion of CCK-8 or gastrin-17 (8-200 pmol min-1) increased gastric mucosal blood flow in a dose-dependent fashion. The CCKB receptor antagonist, CAM-1028, significantly attenuated the hyperaemic response to CCK-8 and gastrin-17 whereas the CCKA receptor antagonist, CAM-1481, did not antagonize CCK-8 but caused a slight attenuation of the vasodilator response to gastrin-17. 4. The selectivity of the two antagonists was proved by the findings that CAM-1028, but not CAM-1481, inhibited gastric acid secretion evoked by CCK-8 or gastrin-17 (CCKB receptor assay) while CAM-1481, but not CAM-1028, inhibited the CCK-8-induced contraction of guinea-pig isolated gall bladder strips (CCKA receptor assay). 5. These data show that the actions of CCK-8 and gastrin-17 to increase mucosal blood flow in the rat stomach are primarily mediated by CCKB receptors.

Topics: Animals; Cholecystokinin; Dipeptides; Female; Gallbladder; Gastric Acidity Determination; Gastric Mucosa; Gastrins; Guinea Pigs; Hyperemia; In Vitro Techniques; Indoles; Meglumine; Muscle Contraction; Muscle, Smooth; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Regional Blood Flow; Vasodilation

Intact and antrectomized female rats were treated with the potent proton pump inhibitor, E3810 (daily 40 mg/kg weight, s.c.) for 4 weeks. Plasma gastrin concentration and urinary excretion of N-terminal big gastrin increased until day 14 and persisted at a high level in intact rats treated with E3810, but did not increase in antrectomized rats. Urinary excretion of histamine increased progressively and reached 7 times the control value following 4 weeks of treatment with E3810 in intact rats, but not in antrectomized rats. At the termination of the treatment, the endocrine cell density in the oxyntic mucosa of intact rats had increased by 85% with increased histamine content and elevated histidine decarboxylase activity, while antrectomized rats showed a low histamine level and low histidine decarboxylase activity. Administration of gastrin-17 I (10 micrograms/kg weight, sc) itself caused a significant increase in urinary excretion of histamine, which was inhibited by the specific gastrin receptor antagonist, L-365,260. These results suggests that the massive urinary excretion of histamine caused by the treatment with E3810 reflects gastrin-induced mobilization of gastric histamine and that neither E3810 itself nor E3810-induced luminal pH elevation has direct effects on mobilization of oxyntic mucosal histamine.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Adenosine Triphosphatases; Animals; Benzimidazoles; Cell Count; Enzyme Inhibitors; Female; Gastric Mucosa; Gastrins; Histamine; Histamine Release; Histidine Decarboxylase; Hormones; Injections, Subcutaneous; Omeprazole; Parietal Cells, Gastric; Protein Precursors; Pyloric Antrum; Rabeprazole; Random Allocation; Rats; Rats, Sprague-Dawley

Sulfated gastrin-17 elutes by gel chromatography significantly earlier after incubation in human serum (KD: 0.48) than when added to buffer (KD: 0.62). Also, the elution of non-sulfated gastrin-17 changes after serum incubation although to a lesser extent (KD: 0.68 vs. 0.74). In contrast neither the N-terminal 1-13 nor the sulfated C-terminal hexapeptide fragment of gastrin-17 change elution positions after serum incubation. The earlier elution is concentration dependent. The results suggest that displaced elution of sulfated gastrin-17 may constitute part of the abundance of gastrin-34-like material in normal human serum. Hence, present concepts of gastrin heterogeneity in serum seem to require re-evaluation.

Topics: Chromatography, Gel; Gastrins; Humans; Sulfates

Gastric cancer remains a major cause of mortality and will remain so for the lifetime of current clinicians. Many cancers are diagnosed at a stage when current therapy cannot provide the hope of cure. A method for early detection of gastric cancer which can be widely applied is needed. The serum levels of pepsinogen A and gastrin-17 have been shown to vary in the presence of pathologic conditions of the gastric mucosa and may provide such a tool.. Serum samples were obtained from 432 patients undergoing endoscopy for undiagnosed dyspepsia. The levels of pepsinogen I and gastrin-17 were estimated by radioimmunoassay and compared with the final diagnosis. Discriminant analysis was performed to assess the value of the peptides predicting the presence of gastric cancer and the high-risk mucosal changes.. Abnormal levels of gastrin-17 or pepsinogen A were found in 60% of patients with gastric cancer and 60% of those with one of the high-risk mucosal changes, the latter figure rising to 75% when the changes were in the upper third of the stomach. Discriminant analysis showed the log of gastrin-17 and log of pepsinogen A to be the best predictors of the high-risk mucosal changes, gastric cancer, and benign disease.. These results confirm gastrin-17 and pepsinogen A as markers of pathologic gastric conditions and suggest that these peptides are potential screening tools worthy of further assessment.

Topics: Adult; Biomarkers; Dyspepsia; Gastric Mucosa; Gastrins; Gastroscopy; Humans; Mass Screening; Pepsinogens; Radioimmunoassay; Sensitivity and Specificity; Stomach Neoplasms

Peptide alpha amidation is required to produce some hormones, such as gastrin, from their glycine-extended precursors. This terminal posttranslational processing reaction is thought to be essential for the biological activation of many peptide hormones; only amidated gastrin exerts a physiological effect that results in gastric acid secretion. However, both amidated gastrin and glycine-extended gastrin stimulate proliferation of exocrine pancreatic cell line AR4-2J through selective receptors for the substrate and the product, respectively, of peptide alpha amidation. Thus, the amidation reaction may function as a determinant of the specific biological actions of products derived from prohormones.

Topics: Benzodiazepinones; Binding Sites; Cell Division; Gastrins; Humans; Indoles; Meglumine; Octreotide; Ornithine Decarboxylase; Phenylurea Compounds; Receptors, Cholecystokinin; Tumor Cells, Cultured

To understand the short-term and long-term effects of the eradication of Helicobacter pylori on serum pepsinogen I, gastrin, and insulin concentration, we studied 53 patients with endoscopically proven duodenal ulceration and H. pylori infection.. All patients received a 2-wk course of colloidal bismuth subcitrate, amoxycillin, and metronidazole, and endoscopy was performed at 1.5, 3, 6, and 12 months after entry. H. pylori status was assessed by a urease test and histology.. Among 43 patients in whom H. pylori was eradicated throughout the follow-up year, the mean basal pepsinogen I was 108 ng/ml at pretreatment, decreasing significantly to 85, 77, 80, and 75 ng/ml at 1.5, 3, 6, and 12 months, respectively, at posttreatment. The basal gastrin was 100 pg/ml at pretreatment and fell significantly to 72, 64, 65, and 59 pg/ml, respectively, posttreatment. Of the four patients in whom the H. pylori was not eradicated, there was no significant change in the median basal pepsinogen I and gastrin concentration. Among the six patients in whom the H. pylori was again detectable within the follow-up year, the fallen serum concentration of pepsinogen I and gastrin returned to the pretreatment level. There was no significant change of basal insulin concentration after triple therapy in either the successfully eradicated or failed group.. We conclude that H. pylori is the leading and direct cause of higher serum concentration of pepsinogen I and gastrin in duodenal ulcer patients.

Topics: Amoxicillin; Anti-Ulcer Agents; Bismuth; Drug Therapy, Combination; Duodenal Ulcer; Female; Follow-Up Studies; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Insulin; Male; Metronidazole; Middle Aged; Organometallic Compounds; Pepsinogens; Time Factors

Gastrin is a trophic factor for some human colon cancer cells. However, the signal-transduction pathways by which gastrin regulates growth are still unknown. We examined the effect of synthetic human gastrin-17 (G-17) on signal-transduction pathways and cell growth using 4 different human colon cancer cell lines (LoVo, COLO 320, HT-29, and HCT116). G-17 stimulated the production of cyclic AMP in LoVo, COLO 320, and HCT116 cells, while G-17 stimulated phosphatidylinositol hydrolysis and mobilization of intracellular calcium in HT-29 cells. The growth-regulatory effect of G-17 on these colon cancer cells (stimulatory on LoVo, COLO 320, and HT-29 cells; inhibitory on HCT116 cells) was well correlated with the effect of G-17 on the signal-transduction pathway in each cell line. We further examined the effect of a selective cholecystokinin-B type receptor antagonist, JMV 320, on G-17-induced signal-transduction pathways and G-17-regulated growth. In each cell line, the effect of JMV 320 on G-17-induced signal-transduction pathways was well correlated with that on G-17-regulated growth. G-17 appears to regulate, at least to some extent, growth of human colon cancer cells through gastrin receptor-linked signal-transduction pathways that are cell-specific.

Topics: Calcium; Cell Division; Cell Line; Colonic Neoplasms; Cyclic AMP; Dose-Response Relationship, Drug; Gastrins; Hormones; Humans; Hydrolysis; Kinetics; Phosphatidylinositols; Signal Transduction; Time Factors; Tumor Cells, Cultured

Several studies examined in vivo and in vitro biologic activity of the human gallbladder in response to cholecystokinin (CCK). However, few studies have demonstrated directly the interaction of CCK with receptors on the human gallbladder, which is responsible for this biologic activity.. To characterize CCK receptors on human gallbladder tissue, gallbladders were removed from human donor grafts that were being used for liver transplantation. The gallbladders were rapidly frozen and sectioned for measurement of binding of 125I-Bolton-Hunter-labeled-CCK-8 and were cut into strips for in vitro bioassay.. Binding of 125I-BH-CCK-8 to human gallbladder was saturable, specific, and dependent on time, pH, and temperature. The binding was inhibited only by cholecystokinin-related peptides including CCK-8 (IC50 10 +/- 1.0 nmol/L) (mean +/- SD), des(SO3) CCK-8 (IC50 0.9 +/- 0.2 mumol/L), and gastrin-17-I (IC50 9.0 +/- 2.0 mumol/L) or specific CCK receptor antagonist L-364,718. Computer analysis of binding of 125I-BH-CCK-8 to gallbladder tissue showed a single class of binding sites with high affinity for CCK-8. Autoradiography localized binding of 125I-BH-CCK-8 only to the smooth muscle layer of the gallbladder. In the bioassay des(SO3) CCK-8 (EC50 1.2 +/- 0.7 mumol/L) and gastrin-17-I (EC50 4.5 +/- 2.4 mumol/L) were 150- and 563-fold less potent than CCK-8 (EC50 8.0 +/- 2.2 nmol/L). The relative potencies of CCK agonists for inhibiting binding of 125I-BH-CCK-8 agreed closely with their relative potencies for causing gallbladder contraction. The dose-response curve for CCK-8 alone to induce gallbladder contraction was not significantly different from those caused by CCK-8 plus 1 mumol/L tetrodotoxin or 1 mumol/L atropine.. These results characterized the CCK receptors on smooth muscle of human gallbladder as sulfate dependent and causing gallbladder contraction.

Topics: Autoradiography; Benzodiazepinones; Binding Sites; Carbachol; Devazepide; Dose-Response Relationship, Drug; Gallbladder; Gastrins; Hormones; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Iodine Radioisotopes; Muscle Contraction; Muscle, Smooth; Receptors, Cholecystokinin; Reference Values; Secretin; Serotonin; Sincalide; Substance P; Temperature; Vasoactive Intestinal Peptide

1. In adult sheep and in lambs, over 95% of gastrin in the abomasal antrum was G17 with small amounts of G34 and lesser amounts of Component I. 2. Low gastrin concentration in the proximal duodenum was associated with a reduced percentage of G17. 3. The proportion of G34 increased progressively down the duodenum from a mean of 7% proximally to 47% in the most distal segment, and correlated negatively in any segment with the gastrin content. 4. In both the antrum and proximal duodenum, 60-70% of the G17 was in the sulphated form. 5. The gastroepiploic venous serum contained less G17 and more G34 than the tissues and up to 19% G14.

Topics: Aging; Animals; Chromatography, Gel; Chromatography, Ion Exchange; Duodenum; Gastrins; Intestinal Mucosa; Protein Precursors; Pyloric Antrum; Radioimmunoassay; Sheep; Sulfates

The nature and developmental profile of pancreatic gastrin and somatostatin were determined in the ovine fetus, a model considered relevant to human development. Gastrin and somatostatin peptide and mRNA were examined in the pancreas of fetal sheep at 80, 105, 125 and 140 days gestation (term: 145 days), 15-day-old lambs and adult sheep. Highest concentrations of gastrin (both amidated and the glycine-extended precursor) were observed in the lamb pancreas with gastrin mRNA levels highest at 140 days gestation. Amidated gastrin was present almost entirely as sulphated gastrin-17 while glycine-extended gastrin was mostly present as a high molecular weight form. Only glycine-extended gastrin was detected in the adult pancreas, indicating attenuated processing in mature adult pancreas. Up to 140 days gestation, gastrin mRNA correlated better with glycine-extended gastrin than with the amidated form, suggesting that amidation was a rate-limiting factor in the production of bioactive gastrin. Somatostatin mRNA and peptide reached a higher concentration and peaked before that of gastrin. Gastrin is a normal product of the fetal and adult pancreas although, when compared to the antrum, the levels are low and the processing to amidated forms is substantially reduced. Unlike in the stomach, the developmental profile of pancreatic gastrin and somatostatin does not appear to be linked.

Topics: Amino Acid Sequence; Animals; Base Sequence; Gastrins; Gene Expression Regulation; Gestational Age; Molecular Sequence Data; Pancreas; Protein Precursors; Protein Processing, Post-Translational; RNA, Messenger; Sheep; Somatostatin

With the availability of selective gastrin/CCKB (L365,260) and CCKA (L364,718) receptor antagonists the present study was designed to investigate the role of gastrin and cholecystokinin (CCK) receptors in meal-stimulated gastric acid secretion. Gastric acid output was measured by continuous intragastric titration in conscious rats. Vehicle (dimethylsulfoxide/saline, 3:1), L365,260 (3 or 9 mg/kg), or L364,718 (1 mg/kg) was given by i.v. bolus injection. Basal acid output was strongly inhibited by both doses of L365,260 while L364,718 had no effect. Intragastric peptone (4%, w/v) increased acid secretion 40-65% of the response to a maximal dose (2.5 nmol/kg per h) of gastrin-17. L365,260 completely abolished gastrin-17 stimulated acid secretion and partially inhibited peptone-induced acid secretion. Blockade of CCKA receptors by L364,718 did not affect peptone-stimulated acid output. This study demonstrates that gastrin/CCKB receptors are important in regulating basal acid secretion in the conscious rat while CCKA receptors do not appear to influence basal or peptone-stimulated gastric acid secretion. Blockade of gastrin/CCKB receptors partially inhibits intragastric meal-stimulated acid secretion indicating that the gastrin/CCKB receptor has a physiological role as mediator of food-stimulated acid secretory response in conscious rats.

Topics: Animals; Benzodiazepinones; Cholecystokinin; Devazepide; Eating; Gastric Acid; Gastrins; Hormones; Injections, Intravenous; Male; Peptones; Phenylurea Compounds; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin

In this investigation we studied the influence of two gastrin fragments, pentagastrin and nonsulfated heptadecagastrin, and two cholecystokinin fragments, sulfated and desulfated cholecystokinin 26-33, on intracellular and secreted triacylglycerol in isolated hepatocyte cultures. Both gastrin fragments inhibited triacylglycerol release in a biphasic manner, exhibiting maximal effect at 0.1 nmol/L (nonsulfated heptadecagastrin) and 0.3 nmol/L (pentagastrin). At these concentrations triacylglycerol secretion was 42% (nonsulfated heptadecagastrin, p < 0.001) and 62% (pentagastrin, p < 0.001) lower than in cells untreated with gastrin. Sulfated cholecystokinin 26-33 caused a 35% decrease in triacylglycerol secretion at 0.1 nmol/L (p < 0.01), and desulfated cholecystokinin 26-33 caused a 53% decrease at 0.2 nmol/L (p < 0.001). In all experiments, the hormone-induced decrease in triacylglycerol secretion was accompanied by an increase in intracellular triacylglycerol content. The cholecystokinin-A receptor antagonist L-364, 718 did not affect the decrease in triacylglycerol secretion induced by 0.3 nmol/L pentagastrin, whereas the cholecystokinin-B receptor antagonist L-365, 260 inhibited the pentagastrin effect at concentrations above 50 nmol/L. These results suggest that gastrin, cholecystokinin or some other gastrinlike hormone (or all three) may play a previously unrecognized regulatory role with respect to hepatic very low density lipoprotein secretion.

Topics: Animals; Benzodiazepinones; Cells, Cultured; Depression, Chemical; Devazepide; Gastrins; Liver; Male; Pentagastrin; Peptide Fragments; Phenylurea Compounds; Rats; Rats, Sprague-Dawley; Receptors, Cholecystokinin; Sincalide; Triglycerides

Isolated gastric glands from rabbit were used to characterize the functional cholecystokinin (CCK)-like peptide receptors that mediate pepsinogen secretion. Pepsinogen secretion was stimulated by both CCK octapeptide sulfate (CCK-8) and A-71378, a selective CCK-A-type receptor agonist, with similar mean effective doses (1.0 and 0.8 nM, respectively). Compared with CCK-8, gastrin-17 (G-17-I) showed reduced potency and only partial efficacy for stimulation of pepsinogen secretion while inhibiting the maximal CCK-8-stimulated response. The nonpeptide inhibitors, asperlicin and L-364,718, inhibited pepsinogen secretion with identical pA2 values for antagonism of both CCK and gastrin, indicating that both peptides interact with the same functional receptor. Specific binding of [3H]CCK-8 to isolated chief cell membranes was displaced fully by both CCK and gastrin, indicating full receptor occupancy by both peptides. A novel synthetic peptide analogue, pseudogastrin [(Glu)5-Ala-Tyr-Nle-Gly-Trp-Nle-Asp-Phe-NH2], was used to investigate the structural basis for the lower potency and efficacy of G-17-I. The potency of CCK and gastrin analogues for pepsinogen secretion was found to be dependent on both sulfation of a tyrosine residue and the position of the tyrosine residue relative to the COOH-terminal phenylalanine amide. The efficacy appears to be determined partially by the extended NH2-terminal sequence of G-17-I. The results of the present study are interpreted to show that pepsinogen secretion is mediated by a CCK-A-type receptor and gastrin acts at the same receptor as a partial agonist.

Topics: Amino Acid Sequence; Animals; Benzodiazepinones; Cell Membrane; Cholecystokinin; Devazepide; Gastric Mucosa; Gastrins; Hormones; In Vitro Techniques; Kinetics; Molecular Sequence Data; Oligopeptides; Pepsinogens; Rabbits; Receptors, Cholecystokinin; Sequence Homology, Amino Acid; Sincalide

Helicobacter pylori infection increases the serum concentration of gastrin, and this may be one of the mechanisms by which it predisposes to duodenal ulceration. Different forms of circulating gastrin were studied both basally and postprandially in 13 duodenal ulcer patients before and one month after eradication of H pylori. Three antisera that are specific for particular regions of the gastrin molecules were used. Gel chromatography indicated that > 90% of the circulating gastrin consisted of gastrin (G) 17 and G34 both before and after eradicating the infection. The basal median total immunoreactive gastrin concentration fell from 26 pmol/l (range 11-43) to 19 pmol/l (8-39) (p < 0.05), entirely because of a fall in G17 from 6 pmol/l (< 2.4-25) to < 2.4 pmol/l (< 2.4-23) (p < 0.001). The median (range) basal G34 values were similar before (15 pmol (2-36)) and after (10 pmol (2-30)) eradication. The median total immunoreactive gastrin concentration determined 20 minutes postprandially fell from 59 pmol/l (38-114) to 33 pmol/l (19-88) (p < 0.005), and again this was entirely the result of a fall in G17 from 43 pmol/l (9-95) to 17 pmol/l (< 2.4-52) (p < 0.001). The median postprandial G34 values were similar before (13 pmol/l, range 6-42) and after (15 pmol/l, range 6-30) eradication. Eating stimulated a noticeable rise in G17 but little change in G34, both in the presence and absence of H pylori. The finding that H pylori infection selectively increases G17 explains why the infection causes mainly postprandial hypergastrinaemia. G17 is increased selectively because H pylori predominantly affects the antral mucosa which is the main source of G17 whereas G34 is mainly duodenal in origin. This study also indicates that the increased concentration of gastrin in H pylori infection is the result of an increase in one of the main biologically active forms of the hormone.

Topics: Adult; Duodenal Ulcer; Eating; Female; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Protein Precursors

The effect of ulcer healing with eradication of Helicobacter pylori (H pylori) on gastric function was investigated in nine patients with duodenal ulcer disease. One month after eradication there were significant reductions in both basal plasma gastrin concentration, from a median (range) of 19 (1-22) to 6 (2-15) pmol/l (p < 0.05), and of basal acid secretion from 8.3 (2.4-24) to 2.6 (1.4-8.1) mM H+/h, (p < 0.01). The peak acid secretion rate was unchanged from 37 (16-59) to 37 (21-59) mM H+/h. After treatment there was no change in the parietal cell sensitivity to stepped infusions of gastrin heptadecapeptide: the median concentration of gastrin required for 50% of maximal acid secretion (EC50) was 41 (14.8-126) before and 33 (23-125) pmol/l after eradication of H pylori. The metabolic clearance rate of gastrin was also unaffected by the eradication of H pylori. Thus eradication of H pylori infection from patients with active duodenal ulcers is accompanied by falls in both basal gastrin release and basal acid secretion without a change in the parietal cell sensitivity to gastrin. Cyclical changes in H pylori infection may cause the variations in basal acid secretion that are seen in duodenal ulcer disease.

Topics: Acute Disease; Adult; Aged; Bismuth; Drug Therapy, Combination; Duodenal Ulcer; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Male; Metronidazole; Middle Aged; Organometallic Compounds; Parietal Cells, Gastric; Tetracycline

1. Half-life (1.7 +/- 0.1 min), distribution volume (146 +/- 12 ml/kg) and metabolic clearance rate (28 +/- 1 ml/kg/min) of little gastrin (G17) in neonatal pigs (N = 6; 3-12 days old) were significantly different from those in grower-pigs (N = 4; 161-170 days old) (2.4 +/- 0.1 min; 58 +/- 2 ml/kg; 7.9 +/- 0.3 ml/kg/min, respectively). 2. Half-life (33 +/- 4 min) and distribution volume (265 +/- 33 ml/kg) of big gastrin (G34) in neonatal pigs were greater but not significantly different from those in grower-pigs (24 +/- 2 min; 217 +/- 20 ml/kg, respectively). 3. Half-life of G17 in liver extracts from pigs 2-90 days old (40.4 +/- 4.2 min) was significantly longer than in kidney extracts (22.0 +/- 1.7 min). Half-lives of G34 in liver and kidney extracts from pigs 10-90 days old (78 +/- 6; 74 +/- 4 min, respectively) were significantly shorter than the corresponding values for 2-day-old pigs (134 +/- 3; 149 +/- 9 min, respectively). 4. Since G34 is the major circulating form of gastrin in neonatal pigs the relative longer half-life of G34 to G17 in these animals may contribute to the higher circulating gastrin concentration compared with that in older animals.

Topics: Animals; Animals, Newborn; Female; Gastrins; Kinetics; Male; Protein Precursors; Swine

To determine the relative contributions of gastrin, histamine, and cholinergic stimulation to the gastric phase of acid secretion, peptone-stimulated acid output was measured in urethan-anesthetized pylorus-ligated rats after intravenous administration of gastrin monoclonal antibody, cimetidine, and atropine. Intragastric peptone stimulated acid secretion four-fold over basal, which was associated with a significant increase in plasma gastrin levels. Gastrin immunoneutralization and simultaneous H2- and muscarinic-receptor blockade demonstrated that approximately 40% of peptone-stimulated acid output as attributed to endogenous gastrin through a histamine-dependent pathway, whereas 20% of acid output was accounted for by a cholinergic component. Another 10% of titratable acid was omeprazole-insensitive and presumably due to intragastric digestion of peptone. Therefore, approximately 30% residual acid output in response to peptone could not be accounted for by known acid stimulatory mechanisms. In rats given somatostatin monoclonal antibody to block the tonic inhibitory effect of endogenous somatostatin, residual acid output was a similar fraction of meal-stimulated acid output. In contrast, gastric distension induced by intragastric instillation of saline stimulated acid secretion to 1.5-fold over basal. Although 60% of distension-induced acid secretion could be inhibited by either H2 blockade or gastrin immunoneutralization, acid output returned to basal levels after simultaneous muscarinic blockade. These results indicate that gastrin, through a histaminergic pathway, is the principal mediator of meal-stimulated acid secretion in anesthetized rats. Approximately 30% of acid output was due to other unidentified mechanisms, such as chemical secretagogues, a direct effect of amino acids, or novel peptides.

Topics: Acetylcholine; Animals; Antibodies, Monoclonal; Bethanechol; Bethanechol Compounds; Gastric Acid; Gastrins; Histamine; Male; Omeprazole; Rats; Rats, Inbred Strains; Somatostatin

Topics: Animals; Cholecystokinin; Gastric Acid; Gastric Mucosa; Gastrins; Histamine Release; Parietal Cells, Gastric; Rats; Receptors, Cholecystokinin

Gastrin was given to rats by continuous subcutaneous infusion through implanted osmotic minipumps in doses covering a wide range of the dose response relationship for gastrin with regard to the trophic effect on the enterochromaffin like cells of the oxyntic mucosa. Thirty five rats were divided into five groups (each of seven rats), one group receiving a control solution of 1% albumin, the others receiving gastrin in 1% albumin at doses of 2.5, 5, 10, and 15 micrograms/kg/h, respectively. The plasma gastrin concentrations in the various groups increased in the same order of magnitude as expected from the gastrin doses given. Gastrin induced a dose dependent increase in enterochromaffin like cell density, oxyntic mucosal histamine concentration and histidine decarboxylase activity up to the dose of 5 micrograms/kg/h, where the increase levelled off. Hence, the dose response relationship for the trophic effect of gastrin on the enterochromaffin like cells seems to follow a polynomial rather than a linear function. These findings may also contribute to the understanding of the trophic effect of gastrin on enterochromaffin like cells in man with conditions associated with hypergastrinaemia.

Topics: Animals; Cell Count; Dose-Response Relationship, Drug; Enterochromaffin Cells; Female; Gastric Mucosa; Gastrins; Histamine; Histidine Decarboxylase; Hormones; Rats; Rats, Sprague-Dawley; Stomach

The aim of this study was to determine the cholecystokinin (CCK) receptor subtype involved in the direct myogenic effect of CCK on pig ileum. Smooth muscle cells were dispersed from pig ileum circular muscle layer and incubated in the presence of various concentrations of CCK agonists and antagonists. Contraction was assessed by measuring the length of 50 cells and expressed as the percentage decrease in cell length from control. Maximal contraction varied between 19% +/- 3% (gastrin II, 10 nmol/L) and 26% +/- 3% [CCK octapeptide (CCK-8), 10 nmol/L]. EC50 for CCK tetrapeptide (CCK-4) was the same than for pentagastrin (30 pmol/L), which were more potent than CCK-8 (100 pmol/L) and unsulfated gastrin 17 (100 pmol/L), which in turn were more potent than unsulfated CCK heptapeptide (CCK-7; 300 pmol/L) and sulfated gastrin II (300 pmol/L). The maximal contraction induced by synthetic analogs of CCK was 22% +/- 1% for 1 nmol/L JMV 170 and 23% +/- 1% for 10 nmol/L JMV 180. EC50 was 10 pmol/L for JMV 170 and 800 pmol/L for JMV 180. Contraction induced by 10 nmol/L CCK was inhibited as follows: L 365,260 half maximal inhibition (IC50) = 1 nmol/L greater than L 364,718 (IC50 = 90 nmol/L) greater than proglumide (IC50 = 1 mumol/L). Contraction induced by 10 nmol/L unsulfated gastrin 17 was inhibited as follows: L 365,260 (IC50 = 1 pmol/L) greater than L 364,718 (IC50 = 60 nmol/L) greater than proglumide (IC50 = 4 mumol/L). Removal of Ca2+ from the extracellular medium did not alter the contraction induced by CCK-8 (10 nmol/L) but impaired the contraction induced by unsulfated gastrin 17 (10 nmol/L) -56% in Ca(2+)-free medium, -77% in Ca(2+)-free medium plus 2 mmol/L EGTA, and -70% in the presence of 1 mumol/L nifedipine. These results show that the CCK receptor of pig ileum smooth muscle cells is closely similar to the B receptor and is not dependent on an influx of extracellular Ca2+ to induce cell contraction. By contrast, gastrin could act through a specific receptor subtype, the "gastrin receptor," triggering a Ca2+ influx into the cell to induce cell contraction.

Topics: Animals; Calcium; Cholecystokinin; Dose-Response Relationship, Drug; Gastrins; Ileum; In Vitro Techniques; Male; Muscle Contraction; Pentagastrin; Peptide Fragments; Proglumide; Receptors, Cholecystokinin; Sincalide; Swine; Tetragastrin

The ability of gastrin, histamine, and carbachol to stimulate acid secretion by direct action on gastric parietal cells is well established but the role of intracellular Ca2+ concentration ([Ca2+]i) in mediating these effects is the subject of some controversy. To examine this issue further, secretagogue-mediated changes in [Ca2+]i in single isolated canine gastric parietal cells were examined by microspectrofluorometry of fura-2-loaded cells. Resting [Ca2+]i in single parietal cells was 63 +/- 6 (SE) nM. Carbachol, 10(-5) M, induced a maximum elevation in [Ca2+]i with an initial transient rise of 178 +/- 24 (SE) nM, which was maintained in the absence of extracellular Ca2+ and a sustained plateau of 112 +/- 20 (SE) nM, which was abolished by removal of extracellular Ca2+. Both effects were reversed by the muscarinic receptor antagonist atropine. Gastrin (10(-9)-10(-7) M) also induced a bimodal rise in [Ca2+]i with a maximal initial transient rise of 206 +/- 14 nM and a sustained plateau of 94 +/- 9 nM. Both components of the [Ca2+]i response to gastrin were reversed by the gastrin specific antagonist L 365260. Lower concentrations of gastrin (10(-10) M) induced repetitive transient increases (oscillations) in cytosolic Ca2+. The amplitude of the first spike was less than 50% of the transient rise in [Ca2+]i stimulated by 10(-8) M gastrin. The oscillations occurred at a rate of 0.9/min, gradually decreasing in amplitude within 15 min of secretagogue administration. Histamine (10(-4) M) led to a minimal rise in [Ca2+]i (less than 5% of control) in less than 10% of the canine parietal cells tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Benzodiazepinones; Calcium; Carbachol; Cytosol; Dogs; Dose-Response Relationship, Drug; Gastrins; Histamine; In Vitro Techniques; Kinetics; Parietal Cells, Gastric; Phenylurea Compounds; Rabbits; Signal Transduction; Species Specificity; Spectrometry, Fluorescence

Gastrin is known as a trophic factor for some stomach and colorectal cancer cells; however, the roles of gastrin receptors and the intracellular signal transduction pathways by which gastrin regulates cell growth are still unknown. The authors examined the effect of synthetic human gastrin-17 on growth of human stomach cancer cells (the parent line, AGS-P, and two different clones, AGS-10 and AGS-12), which were established (and have been maintained) in our laboratory. Gastrin stimulated growth of AGS-P and AGS-10 cells, which have gastrin receptors, in a dose-dependent fashion. A highly selective gastrin receptor antagonist, JMV 320, inhibited the growth-stimulatory effect of gastrin on AGS-P cells in a dose-dependent fashion. Concentrations of gastrin (10(-8) to 10(-6) M), which stimulated growth of AGS-P cells, did not affect either cyclic adenosine monophosphate production or phosphatidylinositol hydrolysis. Gastrin (10(-11) to 10(-5) M) mobilized calcium from the intracellular organelles to increases intracellular calcium level in AGS-P cells. The AGS-12 clone has no gastrin receptors, and gastrin did not affect growth or mobilization of intracellular calcium in these cells. Our findings indicate that gastrin stimulates growth of AGS cells through a mechanism that involves binding to specific gastrin receptors that are linked to the system for mobilization of intracellular calcium.

Topics: Amino Acid Sequence; Calcium; Gastrins; Hormones; Humans; In Vitro Techniques; Molecular Sequence Data; Receptors, Cholecystokinin; Sincalide; Stomach Neoplasms; Tumor Cells, Cultured

To explore the mechanisms of the effects of sucralfate on the stomach, we investigated the action of sucrose octasulfate (SOS), a constituent of sucralfate, on the function of canine gastric parietal cells and somatostatin cells and in the isolated perfused intact rat stomach. Somatostatin cells from the canine gastric fundus were isolated by EDTA-collagenase dispersion and counterflow elutriation, and somatostatin-like immunoreactivity (SLI) release in response to SOS was measured by radioimmunoassay. Similar methods were used to isolate gastric parietal cells, in which gastric acid secretion was measured by uptake of a radiolabeled weak base, [14C]aminopyrine. SLI release by the intact rat stomach was examined in an isolated vascularly perfused rat stomach model. SOS, either alone or co-administered with epinephrine or gastrin heptadecapeptide (G17), dose-dependently stimulated SLI release by isolated canine fundic D-cells. At the highest doses, SOS potentiated the effect of epinephrine but not G17. Similarly, SOS potentiated the stimulating effect of dibutyryl cyclic adenosine 3',5'-monophosphate (DBcAMP), but not 12-O-tetradecanoylphorbol 13-acetate (TPA). The effect of SOS on SLI release could be inhibited by octreotide, a somatostatin analogue. SOS did not alter acid secretion by cultured canine parietal cells either in the basal state or when coadministered with acid secretagogues. In isolated perfused rat stomach studies, SOS produced a significant (60% greater than basal) increase in SLI secretion. There was a similar effect when SOS was perfused against a background of isoproterenol. SOS stimulates SLI release from gastric somatostatin cells and from the isolated perfused stomach but has no direct effect on gastric parietal cells. These actions of SOS may mediate in part the apparent ability of sucralfate to enhance gastric mucosal defense.

Topics: Aminopyrine; Animals; Bucladesine; Dose-Response Relationship, Drug; Drug Synergism; Epinephrine; Gastric Fundus; Gastrins; Isoproterenol; Male; Octreotide; Parietal Cells, Gastric; Peptides; Radioimmunoassay; Rats; Rats, Inbred Strains; Somatostatin; Sucrose; Tetradecanoylphorbol Acetate

The regulation of gastric somatostatin is linked to changes in gastric acidity, with a number of studies showing a good correlation between somatostatin secretion and gastrin-stimulated luminal acidity. However, gastrin may also have direct effects on somatostatin secretion independent of the concurrent acid status. We have examined the relative contribution of gastrin itself vs. gastric acid on the increase in somatostatin secretion observed after gastrin administration. Pentagastrin administered to conscious sheep for 2 h caused a 10- to 12-fold increase in both portal venous and peripheral jugular venous plasma somatostatin levels. This was associated with a decrease in gastric pH from 3.5 to 1.7. When the sheep were pretreated with the proton pump inhibitor omeprazole to prevent any change in gastric acidity, pentagastrin caused a similar increase in plasma somatostatin. The increase in somatostatin could also be produced by gastrin-17 infusions. Thus, these studies demonstrate that in the conscious animal gastrin can stimulate somatostatin independent of changes in gastric acidity. It is proposed that there is a negative feedback between somatostatin and gastrin, which may modulate the acid secretory response to gastrin.

Topics: Animals; Chromatography, High Pressure Liquid; Female; Gastric Acid; Gastrins; Infusions, Intravenous; Jugular Veins; Omeprazole; Pentagastrin; Portal Vein; Sheep; Somatostatin

Gastrin 17-I was infused into conscious rats equipped with jugular and portal vein catheters and with a pyloric gastric drainage tube to achieve serum concentrations slightly higher than those found during intragastrically instilled peptone solutions. I.v. injected rabbit gastrin antiserum abolished gastrin 17-I-stimulated gastric acid secretion in these animals. Gastrin immunoneutralization reduced peptone-stimulated gastric acid secretion by approximately 37% during the entire 30-min period of stimulation. Peptone-stimulated gastric acid secretion was only significantly (P less than 0.05) inhibited in the third 10-min period, but not in the first or second 10-min periods of stimulation. This study demonstrates that the late but not the initial period of peptone-stimulated gastric acid secretion is regulated by circulating gastrin in rats.

Topics: Animals; Gastric Acid; Gastrins; Immune Sera; Male; Peptones; Rats; Rats, Inbred Strains

The effects of age on basal, meal-stimulated, and human gastrin-17-stimulated gastric acid secretion rates and serum pepsinogen concentrations were evaluated in 41 healthy men and women. Older subjects (ages 44-71 years; mean, 57 years) had higher mean basal, meal-stimulated, and gastrin-17-stimulated acid secretory rates and basal serum pepsinogen I and II concentrations than younger subjects (ages 23-42 years; mean, 33 years). Age-related differences in acid secretion were especially prominent in men, and age-related differences in serum pepsinogen I and II concentrations were more prominent in women. Higher gastric acid secretion rates in older subjects could not be explained by body size (height, weight, body surface area, or fat-free body mass) or by the higher incidence of infection with Helicobacter pylori. Using a multivariate linear regression model, age had an independent positive effect on acid secretion, and H. pylori infection had an independent negative effect. It was concluded that aging is associated with an increase in gastric acid secretion in humans, especially in men, while infection with H. pylori is associated with lower acid secretion rates.

Topics: Adult; Aged; Aging; Female; Food; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Hormones; Humans; Male; Middle Aged; Pepsinogens; Regression Analysis

The effects of gastrin (G-17), proglumide (a gastrin receptor antagonist), and enprostil (a synthetic analog of prostaglandin E2) used alone or in association were studied in colonic cancer Prob and Regb cell growth. The Prob (progressive in BD IX rats) and Regb (regressive) cell lines were cloned from a single chemically-induced rat colonic cancer. After a serum-free period corresponding to one doubling cell time, cells were incubated with 100 to 1,200 pM G-17, 40 or 80 mM proglumide, and 2.5 to 5 micrograms/ml enprostil for 8 h. Cell growth was measured 48 h later by colorimetric MTT assay. Two and four hundred pM G-17 gave a growth stimulation of 17.4 percent and 31 percent for Prob cells respectively or 35.5 percent and 49 percent for Regb cells. Growth stimulation was found to be statistically different (P less than 0.01) for Prob and Regb cells. Proglumide partially inhibited this growth stimulation whereas enprostil inhibited in totally. These results suggest that growth of some colonic cancer cell lines may be G-17 dependent. However the intensity of cell-growth stimulation depends on the level of cell malignancy or differentiation in a single tumor.

Topics: Adenocarcinoma; Animals; Colonic Neoplasms; Dimethylhydrazines; Drug Combinations; Enprostil; Gastrins; Proglumide; Rats; Stimulation, Chemical; Tumor Cells, Cultured

An organ-culture system has been used to investigate the effect of certain gastrointestinal peptides on the morphology and cell proliferation of explants of azoxymethane (AOM)-treated colonic mucosa. Our aim was to ascertain whether such factors play a direct part in the maintenance of hyperplastic changes in the large intestine. Explants of AOM-treated colonic mucosa from 15 animals were maintained in a serum-free medium in the presence of either gastrin-17 (250 pg/ml and 250 ng/ml), peptide YY (80 pmol/l and 160 pmol/l) epidermal growth factor (EGF) (10 ng/ml and 100 ng/ml) or the C-terminal fragment of glucagon-37 (30 pmol/l) for a period of up to 7 days. Other explants (controls) received fresh medium only each day. After 1, 2, 3, 5 and 7 days of culture both experimental and control explants received vincristine (4 micrograms/ml) for 3 h prior to fixation. The proportion of vincristine-arrested metaphases within the explants was determined together with crypt length. Neither gastrin nor peptide YY was found to influence cell division at either concentration. Despite an initial inhibitory effect, both concentrations of EGF exerted a trophic effect which increased with time. The glucagon-37 fragment caused an immediate increase in proliferation which then declined as time progressed. None of these factors, however, were able to maintain the hyperplastic changes seen in the pre-culture samples of AOM-treated mucosae.

Topics: Animals; Azoxymethane; Cell Division; Epidermal Growth Factor; Gastrins; Gastrointestinal Hormones; Gastrointestinal Neoplasms; Glucagon-Like Peptides; Hormones; Intestinal Mucosa; Male; Mitotic Index; Organ Culture Techniques; Peptide YY; Peptides; Rats; Rats, Inbred Strains

Prolonged achlorhydria leads to hypergastrinemia which must be matched by increased gastrin production. The extent to which the balance between synthesis and storage or secretion is shifted in achlorhydria remains uncertain. In the present study, rats were treated for 14 days with the hydrogen-potassium-stimulated ATPase inhibitor omeprazole, and the effects on plasma and tissue gastrin concentrations and on the abundance of gastrin messenger RNA were examined. To calculate the fractional release rates of gastrin, the metabolic clearance rate of synthetic unsulfated rat heptadeca peptide gastrin in anesthetized rats was also measured. Treatment with omeprazole for 14 days led to a profound hypergastrinemia, a twofold increase in antral gastrin stores, and a tenfold increase in messenger RNA. Calculations based on the metabolic clearance rate for rat heptadecapeptide gastrin suggested that in control rats, about 0.08% of stored gastrin was released per minute compared with about 0.4% in omeprazole-treated rats. No evidence was observed to suggest that changes in the efficiency of conversion of Gly-extended gastrins to amidated peptides were of any significance in accounting for the increased production of amidated gastrin. The increased gastrin synthesis in achlorhydria is therefore attributable to increased messenger RNA levels; most of the increase in gastrin production is directly secreted as changes in the stores of gastrin appear to be of lesser importance.

Topics: Animals; Female; Gastric Acid; Gastric Mucosa; Gastrins; Omeprazole; Pyloric Antrum; Rats; RNA, Messenger

Duplex ultrasound was used to investigate superior mesenteric artery haemodynamics in humans in order to determine the physiological importance of postprandial blood concentrations of cholecystokinin octapeptide (CCK8), gastrin 17, secretin, and glucagon and to study whether a nervous cholinergic reflex mechanism has a role in the postprandial mesenteric blood flow response. Duplex parameters of vessel diameter, mean velocity, and flow volume were determined serially in the basal state and after stimulation. Changes were compared with baseline values. Superior mesenteric artery parameters were significantly increased over baseline values after a liquid test meal, but ingestion of saline did not cause any changes. Hormones infused simultaneously at postprandial concentrations did not change mesenteric blood flow. When they were infused at pharmacological doses, however, a significant increase in flow parameters was observed. Pretreatment with atropine significantly (p less than 0.05) reduced the mesenteric blood flow response to meal stimulation (57%). These data suggest that the four hormones tested are not of quantitative importance in regulating postprandial superior mesenteric artery blood flow. A cholinergic nervous reflex, however, participates in the control of food induced mesenteric artery flow changes.

Topics: Adult; Atropine; Blood Flow Velocity; Blood Volume; Food; Gastrins; Glucagon; Hormones; Humans; Male; Mesenteric Arteries; Parasympathetic Nervous System; Reflex; Secretin; Sincalide; Ultrasonography

The mechanism of hyperplasia of gastrin-producing cells (G-cells) in the rat antral mucosa after truncal vagotomy was studied using double immunostaining for bromodeoxyuridine (BrdU) and little gastrin (G17). With single labeling of BrdU, a few G-cells (less than 1%) showed positive immunostaining for BrdU in the nucleus throughout the experimental period in both vagotomized rats and those given a sham operation. The labeled cells in both groups demonstrated a linear increase of BrdU labeling in an identical number of cells for each experimental time-point. The labeling index of the G-cells increased rapidly from day 2 to day 6 and attained a maximum level of 44.0% on day 10 in the vagotomized group after cumulative labeling. Even in this group, however, many G-cells showed no BrdU immunoreactivity throughout the experimental period. These cells did not replicate during the experimental period, but showed an intense reaction product for G17 in their cytoplasm after vagotomy. The present study indicates that the most important factor involved in G-cell hyperplasia observed after truncal vagotomy is the activation of pre-existing G-cells to synthesize and release hormone, together with the rapid maturation of progenitor cells to mature G-cells.

Topics: Animals; Bromodeoxyuridine; Gastric Mucosa; Gastrins; Immunologic Techniques; Male; Rats; Rats, Inbred Strains; Staining and Labeling; Vagotomy

The enterochromaffinlike cells in the rat stomach are rich in histamine and are thought to be under the influence of gastrin. The effect of sustained endogenous and exogenous hypergastrinemia on the activity and proliferation rate of the enterochromaffinlike cells was studied by determining the histidine decarboxylase activity and histamine concentration and by combining histamine immunocytochemistry and autoradiography after in vivo labeling with [3H]thymidine. The proliferation rate of the stem cells in the oxyntic mucosal progenitor zone was also studied. Exogenous hypergastrinemia was induced by infusion of rat gastrin-17 (60 nmol.kg-1.day-1). Endogenous hypergastrinemia was induced by inhibition of gastric acid secretion with omeprazole (80 mumol.kg-1.day-1) or ranitidine (1200 mumol.kg-1.day-1). The effect of omeprazole was also studied in antrectomized rats. In intact rats, all treatments resulted in elevated plasma gastrin levels and were accompanied by an increase in the histidine decarboxylase activity and the histamine content of the oxyntic mucosa. This resulted in an increase in the enterochromaffinlike cell proliferation rate, leading to enterochromaffinlike cell hyperplasia. The number of labeled stem cells was increased, but this effect was not as pronounced as in the enterochromaffinlike cells. In antrectomized rats, the inhibition of acid secretion by omeprazole did not result in elevated plasma gastrin or in an increase in the activity or number of enterochromaffinlike cells, indicating that omeprazole per se had no effect on these cells. These data support the view that gastrin stimulates the proliferation rate of both enterochromaffinlike cells and stem cells. Gastrin also stimulates the activity of the enterochromaffinlike cells.

Topics: Animals; Cell Division; Chromaffin System; Enterochromaffin Cells; Female; Gastric Mucosa; Gastrins; Histamine; Histidine Decarboxylase; Hormones; Omeprazole; Pyloric Antrum; Ranitidine; Rats; Rats, Inbred Strains; Somatostatin; Stem Cells

We investigated the relationship between gastrin and somatostatin, and catecholamine concentrations in the cord blood of newborn infants. We also measured the levels of the two peptides during the first postnatal hours in the infants and furthermore characterized their molecular pattern. Twenty-two healthy infants who had been born at term were studied. Blood samples were collected from the umbilical cord and from the infants 0.5 h and 3.5 h after delivery. Peptides were measured with radioimmunoassay and further characterized by HPLC. Catecholamines were analysed by HPLC. We found that gastrin and somatostatin concentration in the umbilical cord blood was 106 +/- 40 pmol/l and 29 +/- 17 pmol/l, respectively. A significant relationship between the concentrations of somatostatin and noradrenaline in cord blood was found, (r = 0.7, n = 11, P less than 0.01). No such relation was found for gastrin. No change occurred in gastrin concentrations postnatally. Somatostatin concentration in the blood collected from the infant 0.5 h and 3.5 h after delivery was 19 +/- 11 pmol/l and 16 +/- 7 pmol/l, respectively. These concentrations were significantly lower (P less than 0.01) compared to the level measured in cord blood. Circulating gastrin was found to correspond to non-sulphated gastrin-34 and somatostatin to both somatostatin-28 and somatostatin-14. The proportion of somatostatin-28 was 30-40% and of somatostatin-14, 60-70%. We conclude that the somatostatin level, but not the gastrin level is influenced by the degree of fetal stress during labour, as evidenced by the relationship with noradrenaline. The gastrin level remained unchanged during the 3.5 h following delivery, whereas the somatostatin level decreased significantly during the same time.

Topics: Adult; Catecholamines; Chromatography, High Pressure Liquid; Dopamine; Epinephrine; Female; Fetal Blood; Gastrins; Humans; Hydrogen-Ion Concentration; Infant, Newborn; Labor, Obstetric; Male; Norepinephrine; Pregnancy; Protein Precursors; Radioimmunoassay; Somatostatin; Somatostatin-28

Functional gastrin-containing tumor cells were maintained for up to 8 wk without fibroblastoid cell overgrowth. Short-term cultures consisted mainly of colonies composed of small polygonal cells, 70%-90% of which stained positive for immunoreactive gastrin. Cultures exhibited limited growth but viability remained high for 2-3 wk. Culture medium contained component I, and gastrin 34, 17, and 14. With time the major C-terminal gastrin species in medium changed from gastrin 17 at 3 days to gastrin 34 at 5 wk. Extracts of cultured cells contained gastrin 34, 17, and 14; gastrin 17 was the major form detected at all times. Ultrastructurally, cultured tumor cells retained morphological integrity for several weeks; however, with time changes in the appearance of the secretory granules accompanied by evidence of cellular retrodifferentiation were gradually observed. Secretin, gastrin-releasing peptide, 8-bromoadenosine 3':5'-cyclic monophosphate, and phorbol, 12-myristate, 13-acetate stimulated the release of gastrin from cultured cells in a time-dependent fashion. Secretin, bombesin, gastrin-releasing peptide, L-tryptophan, and ethylamine stimulated gastrin release in a dose-dependent fashion. Somatostatin 14 inhibited secretin, bombesin, and gastrin-releasing peptide stimulated gastrin release but did not alter basal release. Cultured cells demonstrated de novo gastrin synthesis, evidenced by their ability to incorporate radiolabeled amino acids into immunoadsorbable gastrinlike material. Primary cultures of gastrin-containing tumor cells free from stromal contamination offer unique advantages for studies of factors that regulate the synthesis and secretion of gastrin and may prove of potential value for studies on cell differentiation and growth.

Topics: Culture Media; Gastrinoma; Gastrins; Humans; Immunoenzyme Techniques; Pancreatic Neoplasms; Protein Precursors; Time Factors; Tumor Cells, Cultured

This report describes the trophic effects of exogenous gastrin on the digestive tract and pancreas and the effect on the density of enterochromaffinlike cells in the oxyntic mucosa of the stomach. Female rats were given 1.2 or 2.4 nmol/kg.h of synthetic human [Leu15]-gastrin-17 for 28 days (via osmotic minipumps implanted subcutaneously). As a result, measurable plasma gastrin increased from about 230 pg/ml in the controls to about 500 and 800 pg/ml in the low- and high-dose groups, respectively. The trophic effects of gastrin were reflected in increased stomach weight and oxyntic mucosal mass. Gastrin also increased the enterochromaffinlike cell density and associated parameters (histamine concentration and histidine decarboxylase activity) but was without demonstrable effects on other parts of the digestive tract and pancreas. The results show that continuous infusion of exogenous gastrin for 28 days induces trophic changes similar to those seen after a period of hypergastrinemia induced by treatment with effective inhibitors of acid secretion.

Topics: Animals; Cell Count; Digestive System; Female; Gastric Mucosa; Gastrins; Hormones; Pancreas; Parietal Cells, Gastric; Rats; Rats, Inbred Strains

Injections of picomolar quantities of gastrin-17 into the hypothalamic paraventricular nucleus increased gastric acid output in anesthetized rats. The response was dose-dependent, and it was blocked by atropin and by vagotomy. The same doses, injected intravenously, intraventriculary or into sites far from the nucleus, did not increase the output. Cholecystokinin-8 injected into the nucleus had no effect on the acid output.

Topics: Animals; Dose-Response Relationship, Drug; Gastric Acid; Gastrins; Male; Paraventricular Hypothalamic Nucleus; Rats; Rats, Inbred Strains; Vagus Nerve

An acute challenge with gastrin-17 enhanced the uptake of 45Ca into sternum and several long bones in rats by about 10-30%; gastrectomy prevented this effect. Long-term treatment with (Leu15)-gastrin-17 (continuous infusion via osmotic minipumps for 4 weeks) enhanced the uptake of 45Ca into bone (examplified by radius and sternum) by 18-26% (tested on the last day of the infusion). Surgical removal of the acid-producing part of the stomach (fundectomy) or treatment with the anti-ulcer drugs, ranitidine (a histamine H2-receptor antagonist administered by continuous infusion) or omeprazole (an H+/K(+)-ATPase inhibitor administered daily by gastric tube for 4 weeks), induced sustained hypergastrinemia (through loss of acid feedback inhibition of gastrin release). The ranitidine- and omeprazole-evoked hypergastrinemia was associated with 32-62% enhancement of bone 45Ca uptake but the hypergastrinemia of fundectomized rats was not. Gastrectomy abolished the effect of omeprazole. We suggest that exogenous and endogenous gastrin influences calcium uptake into bone indirectly by releasing a calciotropic hormone (gastrocalcin) from the acid-producing part of the stomach. The bone ash weight was reduced by gastrectomy or fundectomy (4 weeks), but neither ranitidine nor omeprazole-evoked hypergastrinemia (4 weeks) raised the bone ash weight. The stimulated calcium uptake into bone of hypergastrinemic rats treated with ranitidine or omeprazole was associated with a 22-32% increase in the density of osteoclasts in the tibia. This finding is in line with the hypothesis that long-lasting hypergastrocalcinemia produces accelerated turn-over of bone rather than increased bone calcium content.

Topics: Animals; Bone and Bones; Calcium; Female; Gastrectomy; Gastrins; Kinetics; Male; Omeprazole; Radioimmunoassay; Radius; Ranitidine; Rats; Rats, Inbred Strains; Sternum; Time Factors

Topics: Ganglioneuroma; Gastrins; Humans; Hypothalamic Neoplasms

Smooth muscle cells isolated from the longitudinal muscle layer of guinea pig ileum were used to determine the presence and type of cholecystokinin/gastrin receptor mediating contraction. This was accomplished with a series of cholecystokinin and gastrin agonists (CCK-8, des(SO3)CCK-8, gastrin-17, des(SO3)gastrin-17 and pentagastrin) and antagonists (glutaramic acid derivatives CR 1392, CR 1409, CR 1505 and proglumide). The order of potency of agonists based on EC50 values derived from concentration-response curves was: CCK-8 greater than des(SO3)CCK-8 greater than gastrin-17 greater than des(SO3)gastrin-17. The inhibitory dissociation constant (Ki) for the antagonist CR 1505 derived from Schild plots was the same whether sulfated CCK-8 or desulfated gastrin-17 was used as agonist (4.47 +/- 0.76 versus 4.68 +/- 0.78 nM). Pentagastrin acted as a partial agonist and inhibited partially the response to CCK-8. The Ki values determined for all antagonists with pentagastrin as agonist were similar to those with CCK-8 as agonist. The order of potency of agonists and the independence of Ki values from the type of agonist used implied that CCK and gastrin interact with one receptor type; the receptor is more sensitive to CCK-8 but is minimally influenced by sulfation of the tyrosine residue. In this respect, the receptor appears to be distinct from the CCK receptor on gallbladder muscle cells and pancreatic acinar cells.

Topics: Animals; Cholecystokinin; Dose-Response Relationship, Drug; Gallbladder; Gastrins; Guinea Pigs; Hormones; Intestinal Mucosa; Intestines; Muscle, Smooth; Pancreas; Pentagastrin; Proglumide; Receptors, Cholecystokinin

Patients with Addisonian pernicious anaemia are alleged to generate antibodies directed against the gastrin receptor. We purified IgG from 15 patients with pernicious anaemia and 15 healthy controls in an effort to show attenuation of gastrin specific binding in vitro and inhibition of gastrin stimulated acid secretion in vivo. Binding of the IgG fraction was determined in a radioreceptor assay utilising the rat pancreatic carcinoma cell line AR42J which expresses high affinity gastrin binding sites (Kd = 5 x 10(-10)). In comparison with control serum, there was no significant displacement (p = 0.10) of human gastrin-17 binding by pernicious anemia samples at either 0.3 mg protein/ml (control (mean (SEM)) 1489 (131) cpm; patients 1858 (174) cpm) or 3 mg protein/ml (control 1930 (110); patients 2195 (107) cpm). The effect of intravenous and intragastric IgG on acid secretion in the anaesthetised rat was determined over a 60 minute period after stimulation with 1 microgram/kg human gastrin-17. A bolus injection of IgG (60-200 mg/kg) had no significant effect (p = 0.50) on gastrin stimulated acid output (29.21 (1.28) mumol H+/h) compared with control (27.48 (4.70) mumol H+/h). Similarly, instillation of 800 mg/kg IgG directly into the stomach for 90 minutes also failed to influence gastrin stimulated acid output (29.69 (3.22) mumol H+/h). Thus, we have been unable to confirm previous reports of an IgG from patients with pernicious anaemia capable of blocking gastrin receptor binding or gastrin stimulated acid secretion.

Topics: Adult; Aged; Anemia, Pernicious; Animals; Female; Gastric Acid; Gastric Mucosa; Gastrins; Hormones; Humans; Immunoglobulin G; Middle Aged; Radioligand Assay; Rats; Receptors, Cholecystokinin

To assess the physiologic significance of tyrosine o-sulfation of gastrin in humans, the gastric acid stimulatory potencies of sulfated and non-sulfated human gastrin-17 were compared in six normal young subjects. Sulfated and non-sulfated forms of synthetic human gastrin-17 were infused intravenously in doses from 12.7 to 478 pmol/kg/h. Similar acid secretory responses were observed. The calculated maximal acid response for sulfated gastrin-17 was 35.7 +/- 4.3 mmol/h, and that for non-sulfated gastrin-17 was 39.8 +/- 7.5 mmol/h (mean +/- SEM, NS). The 50% effective dose of sulfated gastrin-17 was 22.2 +/- 6.7 pmol/kg/h, whereas it was 29.3 +/- 5.8 pmol/kg/h for non-sulfated gastrin-17 (NS). Finally, the 50% effective concentration of gastrin in serum was 34.7 +/- 5.0 pmol sulfated gastrin-17/l and 42.5 +/- 11.8 pmol non-sulfated gastrin-17/l (NS). The results show that tyrosine o-sulfation is without significant influence on the gastric acid secretory potency of gastrin in man. Moreover, the results also suggest that sulfated and non-sulfated gastrin-17 in man have similar rates of metabolism.

Topics: Adult; Female; Gastric Acid; Gastrins; Hormones; Humans; Infusions, Intravenous; Male; Secretory Rate; Somatomedins; Sulfates; Tyrosine

The aim of the present investigation was to study how bombesin, gastrin-17, cholecystokinin-8 (CCK-8) and electrical vagal stimulation influence the release of gastrin and somatostatin into the gastric lumen. Bombesin (3 and 30 nmol kg-1 h-1), gastrin-17 and CCK-8 (10 nmol kg-1h-1) were infused i.v. and vagal stimulations at 5 V, 2 ms, 5 Hz were performed in anaesthetized rats, in which the stomach was perfused with a dextran solution (pH approximately 6 or approximately 1.5). pH, gastrin and somatostatin levels were measured in the perfusate after having passed the stomach. In addition, blood samples were drawn from the jugular vein in the experiments in which bombesin was infused. Gastrin and somatostatin levels were determined with radioimmunoassay, and gastrin- and somatostatin-like immunoreactivity will be referred to as gastrin and somatostatin below. Infusion of bombesin, 3 and 30 nmol kg-1 h-1, did not influence acid secretion as evidenced by an unchanged intraluminal pH. Nor was the intraluminal secretion of gastrin or somatostatin influenced by bombesin, whereas plasma gastrin and somatostatin levels were significantly increased at the higher dose. In contrast, infusion of CCK-8 and gastrin-17 (10 nmol kg-1 h-1), as well as electrical vagal stimulation, significantly decreased the pH and increased the somatostatin levels in the perfusate. Vagal activation in addition increased the gastrin levels. The present results, demonstrating that bombesin influences plasma and perfusate levels of gastrin and somatostatin differently, indicate that intraluminal and intravascular gastrin and somatostatin release may be separately regulated.

Topics: Animals; Bombesin; Cholecystokinin; Electric Stimulation; Gastrins; Infusions, Intravenous; Male; Pyloric Antrum; Rats; Rats, Inbred Strains; Somatostatin; Vagus Nerve

We developed a monoclonal antibody, 28.2, that binds specifically to the amidated carboxyl terminal region common to gastrin and cholecystokinin. This immunoglobulin G1 antibody has high affinity (ID50 = 30-70 pM for gastrin and cholecystokinin peptides), binds labeled gastrin similarly at 37 degrees C and 4 degrees C, and shows minimal inhibition of binding in the presence of 40% canine serum. Antibody 28.2 was used to carry out in vivo immunoneutralization studies in 8 dogs previously prepared with chronic gastric fistulas. Preliminary studies revealed that a single intravenous dose of 0.75 mg of partially purified immunoglobulin G of monoclonal antibody 28.2 completely inhibited the acid stimulatory effect of exogenous gastrin-17 given intravenously at 200 pmol/kg.h, a physiologic dose, and inhibited by 70% the acid response to a supraphysiologic dose, 800 pmol/kg.h. The same dose of antibody decreased the acid secretory response obtained during distention of the stomach with 300 ml of 5.8% glucose solution by 98% and decreased the response to distention with 300 ml of 8% peptone solution by 68%. A 10-fold higher dose of antibody decreased the acid response to peptone by 96%. The gastrin antibody had no effect on the acid response to exogenous histamine. A control antibody, specific for the biologically inactive glycine-extended gastrin/cholecystokinin peptapeptide region, had no significant effect on gastric acid secretion stimulated by gastrin or by gastric distention with nutrients. These studies indicate that circulating gastrin is of major importance in the gastric phase of gastric acid stimulation caused by distention of the stomach with nutrients.

Topics: Animals; Antibodies, Monoclonal; Dogs; Gastric Acid; Gastrins; Glucose; Histamine; Hormones; Isotonic Solutions; Neutralization Tests; Peptones

For a selective covalent linkage of muramyl-peptides with human-little-gastrin the maleimide-thiol reaction principle was adopted. For this purpose thiol-functionalized muramyl-peptide derivatives, i.e. N-acetyl-muramyl-alanyl-D-isoglutaminyl-cysteamine and N-acetyl-muramyl-alanyl-D-isoglutaminyl-N epsilon-palmitoyl-lysyl-cysteamine, were reacted with N alpha-maleoyl-beta-alanyl-[15-methoxinine]-human-little-g ast rin-I-[2-17]. The resulting gastrin conjugates were used in immunization experiments on rabbits and mice. Unexpectedly, these gastrin derivatives proved to be poorly immunogenic despite the built-in immunoadjuvanticity. The titers of the antipeptide antibodies as well as of the unspecific immunoglobulins were in the range of those of the control group.

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Adjuvants, Immunologic; Animals; Enzyme-Linked Immunosorbent Assay; Gastrins; Humans; Immune Sera; Immunization; Immunoglobulin G; Immunoglobulin M; Mice; Mice, Inbred BALB C; Rabbits

The aim of the present study was to investigate how infusion of gastrin-17 and oxytocin affects plasma levels of insulin, glucagon and glucose in order to elucidate how the two hormones contribute to metabolic changes seen in situations where they are released, e.g. feeding and suckling during lactation. Thus, gastrin-17 (0.5 and 2.0 nmol kg-1 h-1) and oxytocin (0.11 and 1.1 nmol kg-1 h-1) were infused separately or simultaneously into conscious dogs. Both gastrin-17 and oxytocin induced significant, dose-dependent increases in insulin levels. An additive effect on insulin levels was obtained when gastrin-17 and oxytocin were infused simultaneously. Glucagon levels were not affected by gastrin-17 whereas infusion of 1.1 nmol kg-1 h-1 of oxytocin was followed by a significant increase. In contrast to a slight transient increase in the glucose level induced by oxytocin, infusion of gastrin-17 caused a sustained period of hypoglycaemia. Thus, infusion of gastrin-17 and oxytocin, respectively, gave rise to different ratios between circulating concentrations of insulin and glucagon reflected in different effects on the glucose level. The gastrin-induced hypoglycaemia could reflect that gastrin, via a release of insulin, promotes storing of glucose, e.g. in connection with feeding. That infusion of oxytocin caused a parallel increase in insulin and glucagon levels together with a slight increase in the glucose level could imply that oxytocin favours mobilization of glucose, e.g. during lactation.

Topics: Animals; Blood Glucose; Dogs; Dose-Response Relationship, Drug; Drug Interactions; Female; Gastrins; Glucagon; Insulin; Male; Oxytocin

A new specific method for determination of cholecystokinin, CCK-8, and CCK-33, 39 in rat plasma is described. Plasma CCK radioimmunoassay (RIA) is difficult, because of cross-reactivity with gastrin. In the rat, problems because of difficulties in separating gastrin from CCK by high performance liquid chromatography (HPLC) exist. These were solved by enzyme digestion of gastrin before HPLC separation of molecular variants of CCK from gastrin fragments. Cholecystokinin immunoreactive forms in the HPLC fractions were determined by an antibody, which recognises the carboxyl terminus of CCK and gastrin. Fasting concentrations of small (CCK-8) and large (CCK-33, 39) molecular forms of CCK averaged 1.9 (0.3) pM and were raised to 13.4 (3.8) pM in rats fed ad libitum. Cholecystokinin in lactating rats rose two-fold after suckling, compared with 2.8 fold in response to feeding. The basal ratio between CCK-8 and CCK-33, 39 was approximately 1:1, but increased in favour of CCK-8 after feeding and in response to suckling. Gastrin like immunoreactivity measured in unextracted plasma was found to rise after feeding, but was unchanged in response to suckling.

Topics: Animals; Cholecystokinin; Chromatography, High Pressure Liquid; Eating; Female; Gastric Mucosa; Gastrins; Intestinal Mucosa; Lactation; Methods; Pregnancy; Protein Precursors; Radioimmunoassay; Rats; Rats, Inbred Strains; Serine Endopeptidases; Sincalide

Two colorectal (HT29, LoVo) and one gastric (MKN45) human tumour cell lines were examined for their in vitro trophic response to human gastrin-17. MKN45 and HT29 responded by increased 75Se selenomethionine uptake to exogenous gastrin (139 +/- 5.5% and 123 +/- 3% of control values respectively) whereas LoVo showed no significant response to this hormone. When these same cell lines were grown as xenografts in nude mice, similar responses were seen to exogenously administered human gastrin-17 (10 micrograms mouse-1 day-1, subcutaneous injection). MKN45 xenografts showed a greater response to continuously administered gastrin (osmotic mini-pumps, (10 micrograms mouse-1 day-1) when compared to the same dose given via a subcutaneous bolus injection. The hormone-treated xenografts had a two-fold increase in tumour cross-sectional area and growth rate when compared to saline-treated controls. Dose-response studies revealed that 0.4 micrograms gastrin mouse-1 day-1 appeared to be the minimally effective dose. As gastric and colorectal tumour cells show a trophic response to gastrin, antagonists of the gastrin receptor may prevent this effect causing tumour stasis. The gastric tumour cell line, MKN45, is gastrin-responsive and would be an ideal model for screening potent receptor antagonists.

Topics: Adenocarcinoma; Animals; Cell Division; Cell Line; Colorectal Neoplasms; Gastrins; Hormones; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Stomach Neoplasms; Tumor Cells, Cultured

Tissue pieces of a metastatic human gastrinoma (ultrastructural Type II) were successfully transplanted to the anterior eye-chamber of rats immunosuppressed with Cyclosporin A. Immunocytochemical investigation of the transplants showed evidence for preserved endocrine activity of tumour cells with immunoreactivity towards the C-terminal of the gastrin/cholecystokinin molecule. Studies of gastric acid secretion in tumour-bearing rats and sham-operated controls with chronic gastric fistulas showed that the basal acid output did not differ between the groups during 3 weeks of study. However, the stimulated gastric acid secretion decreased after 5 days in both groups to remain significantly depressed throughout the study, an effect probably due to Cyclosporin A treatment of the groups. The concentration of immunoreactive gastrin in plasma from rats with tumours in oculo was 5 times higher than in sham-operated rats. Gastrin-34 was the major immunoreactive component in both patient serum and rat plasma. An immunoreactive fraction corresponding to component I was found in the patient serum, but not in the rat plasma, although present in the chamber fluid. Components corresponding to gastrin-17 were found both in the patient serum and in the rat plasma. The chromatographic pattern of the tumour was similar to that in rat chamber fluid. The dominating component corresponded to gastrin-17, while gastrin-34 represented the quantitatively smaller component. Gastrin-34 was, however, relatively more abundant in the tumour extract than in the chamber fluid. The study also indicates that a gastrin-producing tumour transplanted in oculo in immunosuppressed rats may increase the rat plasma concentration of the same molecular forms of gastrin as seen in the clinical situation.

Topics: Adolescent; Animals; Anterior Chamber; Chromatography, Gel; Female; Gastric Acid; Gastrinoma; Gastrins; Humans; Immunosuppression Therapy; Male; Microscopy, Electron; Neoplasm Transplantation; Pancreatic Neoplasms; Protein Precursors; Radioimmunoassay; Rats; Rats, Inbred Strains

The specific binding of 125I-labeled gastrin-17 was studied in samples of human gastric mucosa, duodenal mucosa, colonic mucosa or pancreatic tissue obtained surgically. With regard to gastric fundic mucosa, the criteria for receptor binding were studied, and saturability, high affinity, tissue specificity and hormone specificity were demonstrated. The dissociation constant for gastric fundic mucosa was 1.6 X 10(-9)M, and the binding capacity was 15 fmol/mg protein. Tissue specificity studies revealed a high degree of gastrin receptor binding in human gastric fundic mucosa, duodenal mucosa and pancreas, whereas antral mucosa and colonic mucosa demonstrated a low degree of binding.

Topics: Binding Sites; Gastric Mucosa; Gastrins; Hormones; Humans; Intestinal Mucosa; Iodine Radioisotopes; Pancreas; Receptors, Cholecystokinin

Gastrin 17 (G17) is a potent stimulant of gastric acid secretion in vivo. In this study, the effects of G17 and some related peptides on intracellular free Ca2+ in isolated pig parietal cells were studied. Both G17 and the synthetic peptide pentagastrin increased intracellular free Ca2+ in a dose-dependent manner over the concentration range 10(-9) to 10(-6) M, suggesting a specific action. The EC50 values were 3 X 10(-8) M for G17 and 8 X 10(-8) M for pentagastrin. The N-terminal tridecapeptide of G17 [(1-13)G17] did not have any effect on intracellular free Ca2+, nor was it able to inhibit the action of G17. A glycine-extended gastrin [(5-17)G17-Gly)] elicited a small but significant increase in intracellular free Ca2+ although only at 10(-6) M. This increase was approximately 20% of that obtained with a similar concentration of G17. Sequential incubations with (5-17)G17-Gly and G17 showed that both peptides increased the intracellular free Ca2+ through the same mechanisms.

Topics: Animals; Calcium; Cell Separation; Cytosol; Extracellular Space; Gastrins; Parietal Cells, Gastric; Pentagastrin; Swine

Gastric acid secretion in response to a protein meal and to exogenously administered synthetic human gastrin 17-I was measured in patients with Barrett's esophagus, patients with uncomplicated gastroesophageal reflux, and normal age- and sex-matched controls. Acid secretion, both basally and in response to gastrin 17-I, was significantly greater in patients with Barrett's esophagus compared to normal individuals without reflux. Basal gastrin levels and meal-stimulated levels of the hormone were similar among all three groups. Sensitivity to gastrin, expressed as the concentration causing half-maximal acid secretion, was also similar among the study groups. It is speculated that elevated basal acid production in Barrett's esophagus may contribute to the pathogenesis of the disorder.

Topics: Barrett Esophagus; Chronic Disease; Cimetidine; Female; Gastric Acid; Gastric Acidity Determination; Gastrins; Gastroesophageal Reflux; Humans; Male; Middle Aged; Monitoring, Physiologic; N-Methylscopolamine; Parasympatholytics; Scopolamine Derivatives

When changing from bovine serum albumin to dextran T70 as colloid without adjusting the total calcium concentration in the vascular perfusate of the totally isolated vascularly perfused rat stomach, we noticed a drastic fall in gastrin-stimulated acid secretion. In the present study the effect of the two colloids on ionized calcium in the vascular perfusate as well as the effect on acid secretion and vascular histamine release were studied. There was no difference in gastrin-stimulated acid secretion or vascular histamine release between the two colloids after adjusting the total calcium concentrations so that ionized calcium was similar. Whereas baseline acid secretion showed no marked dependency of ionized calcium within the range tested (0.73-1.54 mmol l-1, gastrin-stimulated acid secretion was highly dependent on ionized calcium being reduced at the higher concentration of Ca2+. Histamine stimulated acid secretion, on the other hand, was virtually unaffected by the concentration of ionized calcium in the same range. Like gastrin-stimulated acid secretion, gastrin-stimulated histamine release was inhibited at higher Ca2+ concentrations. Thus, elevated Ca2+ concentrations seemed to reduce gastrin-stimulated acid secretion by inhibiting vascular histamine release.

Topics: Animals; Calcium; Colloids; Gastric Acid; Gastrins; Histamine; Histamine Release; Humans; Male; Perfusion; Rats; Rats, Inbred Strains; Stomach

Big gastrin comprising 34 amino acid residues (G34) consists of an N-terminal pentadecapeptide linked via two lysine residues to a C-terminal heptadecapeptide identical with little gastrin (G17). Both G17 and G34 have now been established as the principal active forms of gastrin. In this study, release of G34 N-terminal peptide fragment of methacholine and porcine gastrin releasing peptide (pGRP) stimulation in isolated rat stomach perfusion system was investigated by radioimmunoassay with use of an antiserum specific to the N-terminal portion of G34. G34 N-terminal immunoreactivity (IR-G34-N) was detected in rat stomach and proximal duodenum, and the highest concentration was found in extract of the antral mucosa. The concentration of IR-G34-N was constantly lower than that of IR-G17. By gel-filtration study, IR-G34-N in antral mucosa extract was attributed mostly to the G34 N-terminal pentadecapeptide-like component, and the concentration of G34 was about one tenth of G17. Methacholine 10(-8)-10(-3) M produced a biphasic dose-dependent release of IR-G34-N from the vascularly perfused isolated rat stomach. The maximal release was shown by 10(-5) M of methacholine. The release was concomitant with that of IR-G17 during methacholine stimulation. Stimulation of pGRP (14-27) (10(-7) M) produced a monophasic release of IR-G34-N from the vascularly perfused isolated rat stomach. The release was concomitant with that of G17 during the stimulation. The integrated IR-G34-N release was not stoichiometric with that of IR-G17, and IR-G34-N was constantly low. Gel-filtration of the perfusate from rat stomach revealed the presence of the G34 N-terminal pentadecapeptide-like component as a sole major component. The present results demonstrate that post-translational processing of the gastrin precursor in the rat antrum did not necessarily produce G34, which is further converted in the tissue to G17-related peptide(s) and that the G34 N-terminal fragment formed in the G34 conversion is stored and released concomitantly with G17-related peptide(s).

Topics: Animals; Dose-Response Relationship, Drug; Duodenum; Gastric Mucosa; Gastrin-Releasing Peptide; Gastrins; In Vitro Techniques; Male; Methacholine Chloride; Methacholine Compounds; Peptides; Perfusion; Protein Precursors; Pyloric Antrum; Radioimmunoassay; Rats; Rats, Inbred Strains

The purpose of this investigation is to examine the metabolism and inactivation of human and porcine gastrin 17 (nonsulfated) (G-17) and cholecystokinin octapeptide (sulfated) (CCK-8) by gastric endopeptidase 24.11. Endopeptidase 24.11 was isolated by immunoaffinity chromatography using a monoclonal antibody to the kidney enzyme. Peptides were incubated with endopeptidase 24.11. The digests were either fractionated by reverse-phase high-pressure liquid chromatography and the products identified by amino acid analysis or they were used for bioassays. Digests of human gastrin were assayed for stimulation of acid secretion in the anesthetized rat, and cholecystokinin digests were assayed for the stimulation of amylase secretion from isolated rat pancreatic acini. Human G-17 was degraded by cleavage of the Trp4-Leu5,Ala11-Tyr12,Gly13-Trp14,Trp14 -Met15, and Asp16-Phe17-NH2 bonds, and the fragments (1-16), (1-13), (1-11), (1-4), (5-11), (5-13), (12-13), (12-14), (14-16), and (17-NH2) were identified. Porcine G-17 was degraded by hydrolysis of the Ala11-Tyr12,Gly13-Trp14, and Asp16-Phe17-NH2 bonds producing (1-16), (1-13), (1-11), (12-13), (14-16), and (17-NH2) fragments. CCK-8 was degraded by hydrolysis of the Gly4-Trp5 and Asp7-Phe8-NH2 bonds, and the fragments (1-7), (1-4), (5-7), (5-8), and (8-NH2) were identified. There was a progressive decline in the biological activity with incubation time.

Topics: Amino Acid Sequence; Animals; Gastrins; In Vitro Techniques; Molecular Sequence Data; Neprilysin; Sincalide; Stomach; Swine

The purpose of this study was to characterize the effects of aging on gastric acid secretion and on serum and antral concentrations of gastrin in rats. Young and old Fischer 344 rats were prepared with gastric fistulas. Twenty-four hours after surgery, graded doses of human synthetic gastrin-17 (SHG-17) (2, 5, 10, 20, and 40 micrograms/kg) were given intravenously in random order. Gastric secretions were collected for gastric acid measurement before and at 15-min intervals after each dose of gastrin. In a separate study, blood was collected and the stomachs were removed for antral gastrin extraction from fed young and old rats. Serum and antral gastrin was measured by radioimmunoassay. The basal and gastrin-stimulated acid secretions were significantly decreased in aged rats compared to the young rats. The basal acid output was 0.4 +/- 0.2 microeq/15 min in the aged rats and 1.5 +/- 0.5 microeq/15 min in the young. The maximal acid output stimulated by gastrin was 11.1 +/- 1.8 microeq/15 min in the aged rats and 24.2 +/- 2.8 microeq/15 min in the young. Both serum and antral concentrations of gastrin were significantly decreased in aged rats. Serum gastrin concentration was 114.8 +/- 7.4 pg/ml in the aged rats and 192.0 +/- 14.4 pg/ml in the young. Antral gastrin concentration was 3.9 +/- 0.5 micrograms/g tissue in the aged rats, which was significantly less than the concentration in the young (6.5 +/- 0.4 micrograms/g tissue). Antral gastrin content did not change with aging.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aging; Animals; Gastric Acid; Gastric Fistula; Gastrins; Hormones; Male; Pyloric Antrum; Rats; Rats, Inbred F344

Topics: Coma; Digestive System Diseases; Gastrins; Humans; Protein Precursors

The nature of xenopsin immunoreactivity in mammalian antral G-cells has been reassessed. Xenopsin immunostaining was most intense in human antral G-cells, present in those of the dog and pig and not detected in guinea pig or rat tissues. Rigorous specificity controls for ionic binding of immunoglobulins to antral G-cell granules indicated that this mechanism was not responsible for xenopsin immunostaining. Preincubation of the xenopsin antiserum with xenopsin, human gastrin 1-13 and gastrin 2-17 completely abolished immunostaining at similar molar concentrations. Gastrin 34 was ineffective at much higher concentrations. These results infer that xenopsin-immunoreactivity in antral G-cells resides in the N-terminal region of gastrin 17. Examination of the primary structures of xenopsin and the N-terminal regions of some mammalian gastrins reveals a hitherto unrecognized homology.

Topics: Amino Acid Sequence; Animals; Dogs; Gastric Mucosa; Gastrins; Guinea Pigs; Hormones; Humans; Immunohistochemistry; Molecular Sequence Data; Oligopeptides; Peptides; Rats; Swine; Xenopus Proteins

The effect on gastric acid secretion of two gastrin 17-related peptides without the carboxyamide, i.e., the glycine-extended 5-17 fragment and the 1-13 fragment of human gastrin 17, was examined in normal subjects. Acid secretion was stimulated by an intravenous infusion of 21 pmol/kg.h of gastrin 17 or by intragastric instillation of peptone; gastric acid output during simultaneous infusion of 325 pmol/kg.h of the glycine-extended 5-17 fragment or 319 pmol/kg.h of the 1-13 fragment was then compared with acid output during infusion of saline. Neither the glycine-extended 5-17 fragment nor the 1-13 fragment of gastrin 17 influenced gastric acid secretion. By gel and ion-exchange chromatography of serum drawn during infusion, the infused peptide was recovered at the position of the intact synthetic peptide. The disappearance curve of circulating glycine-extended gastrin could be described by two components with half-lives of 3.6 and 48 min. As the glycine-extended fragment was stable in serum or plasma in vitro for 1 h at 37 degrees C, the rapid elimination observed in vivo cannot be ascribed to circulating plasma enzymes.

Topics: Adult; Chromatography, Gel; Chromatography, Ion Exchange; Female; Gastric Acid; Gastrins; Glycine; Hormones; Humans; Male; Middle Aged; Radioimmunoassay

The hormone gastrin stimulates acid secretion by gastric parietal cells and acts as a growth factor for the gastric mucosa. Gastrin receptors with dissociation constants of approximately 0.5 nM have been detected on isolated gastric parietal cells, and on some cell lines derived from colon carcinomas. We now report that gastrin is also bound by five cell lines derived from human gastric carcinomas, but that the affinities of these lines for gastrin range from 0.2 to 1.3 microM. Cholecystokinin8 binds to the cell line Okajima with an affinity similar to gastrin17, while shorter gastrin analogues bind with reduced affinity. Binding of gastrin is unaffected by acetylcholine, histamine, or a number of other hormones with the exception of insulin which inhibits binding with an IC50 value of 0.5 microM. The ability to bind gastrin with affinities in the microM range appears to be a property widespread among other tumor cell lines.

Topics: Animals; Binding, Competitive; Cell Line; Dogs; Gastrins; Hormones; Humans; Kinetics; Neoplasms; Parietal Cells, Gastric; Receptors, Cholecystokinin; Stomach Neoplasms

Gastrin gene expression exhibits a complex pattern of tissue-specific expression during the neonatal development of the gastrointestinal tract and pancreas. In the rat fetus, the pancreas is the major site of gastrin expression; very little gastrin is found in the antrum which is the major site of adult expression. Pancreatic gastrin mRNA is identical to the antral species having the same transcriptional initiation site. The post-translational processing of the pancreatic gastrin peptide, however, differs in being fully tyrosine sulfated, and thus it resembles gastrin's homologue, cholecystokinin. Pancreatic gastrin is maximally expressed during late fetal gestation before the marked rise in somatostatin, insulin, and glucagon mRNA levels which occurs during the last 4 days of gestation. After birth, gastrin mRNA levels rapidly disappear as the other islet mRNAs achieve stable maximal levels. Unlike the pancreas, gastrin gene expression in the duodenum and antrum is similar to the development profiles of somatostatin and glucagon gene expression. In the duodenum, however, expression of cholecystokinin differs from the common developmental pattern in being expressed only after birth. Thus, pancreatic gastrin gene expression shows a reciprocal relationship to the developmental expression of cholecystokinin in the duodenum.

Topics: Amino Acid Sequence; Animals; Autoradiography; Digestive System; Electrophoresis, Polyacrylamide Gel; Gastrins; Gene Expression Regulation; Pancreas; Rats; RNA, Messenger

Subcutaneous injections of gastrin-17, cholecystokinin-39, cholecystokinin-8 (sulfated and non-sulfated forms), cholecystokinin-4 or pentagastrin induced hypocalcemia in rats. The hypocalcemia was associated with calcitonin release for pentagastrin and the cholecystokinins but not for gastrin-17, even at very high doses. Permanent hypergastrinemia, induced by surgical removal of the acid-producing part of the stomach (fundectomy) or by treatment with high doses of omeprazole, a blocker of acid secretion, was not accompanied by elevated plasma calcitonin. Long-lasting hypergastrinemia is known to cause hyperplasia of gastrin-sensitive endocrine cells in the rat stomach while hypogastrinemia does the reverse. In antrectomized rats, having low serum gastrin, and in fundectomized rats, having high serum gastrin, the serum calcitonin concentration, the thyroid calcitonin content and the number of C-cells remained as in sham-operated controls two months after the operations. We conclude that neither exogenous nor endogenous gastrin stimulates calcitonin secretion in the rat and that long-standing hypo- or hypergastrinemia is without effect on the number of thyroid C-cells. Our results, however, do not exclude the possibility that the cholecystokinins might act as calcitonin secretagogues in the rat although such a role remains to be established.

Topics: Animals; Calcitonin; Cholecystokinin; Gastrins; Kinetics; Male; Pentagastrin; Peptide Fragments; Rats; Reference Values; Thyroid Gland

The degradation of human unsulfated heptadecapeptide gastrin (G-17) by human kidney endopeptidase 24.11 has been studied in vitro, and some of the products of degradation have been identified in plasma after in vivo infusion of G-17. The enzyme cleaved G-17 at four peptide bonds: Trp4Leu5, Ala11Tyr12, Gly13Trp14, and Asp16Phe17. The cleavage at Gly-Trp was rapid and 1-13 G-17 was an important intermediate. All the products of cleavage of synthetic 1-13 G-17 were also found after degradation of intact G-17. When normal human volunteers received infusions of G-17, there appeared in their blood peptides with the properties of 1-11, 1-13, 1-16, and 5-17 G-17 on the basis of immunochemical and high-performance liquid chromatographic properties. These observations provide evidence that endopeptidase 24.11 is involved in gastrin metabolism in humans, and may be responsible for the generation of G-17 fragments in the peripheral circulation.

Topics: Gastrins; Humans; In Vitro Techniques; Metalloendopeptidases; Neprilysin

The effect of the H2 agonist impromidine, gastrin 1-17 (G1-17), pentagastrin, and the M1 agonist McN-A-343 on pepsin secretion in the acid-inhibited totally isolated, vascularly perfused rat stomach was studied. Omeprazole produced a 97-98% inhibition of stimulated acid outputs. Base-line pepsin output after omeprazole was 712 +/- 278 micrograms/h (mean +/- SEM) and, after stimulation with impromidine, 1528 +/- 164 micrograms/h; G1-17, 1520 +/- 180 micrograms/h; and pentagastrin, 2063 +/- 605 micrograms/h. Output after McN-A-343 was 534 +/- 69 micrograms/h. Pepsin secretion after impromidine, G1-17, and pentagastrin was significantly (p less than 0.01) higher than base-line output. McN-A-343 had no significant effect on pepsin output in this model. Pepsin secretion after impromidine, G1-17, and pentagastrin was considerably lower than found in the same model with uninhibited acid output. This could be caused by decreased tubular 'washout' after acid inhibition, and, accordingly, no conclusions can be drawn as to the possible stimulatory effect of acid on pepsin secretion. However, the present study indicates that pepsin secretion can be stimulated directly by impromidine and (penta)gastrin without concomitant acidification of the gastric glands.

Topics: (4-(m-Chlorophenylcarbamoyloxy)-2-butynyl)trimethylammonium Chloride; Animals; Gastric Acid; Gastrins; Imidazoles; Impromidine; Male; Omeprazole; Pentagastrin; Pepsin A; Perfusion; Rats; Rats, Inbred Strains; Stomach

Increasing doses of gastrin 1-17 (G1-17) were administered to totally isolated, vascularly perfused rat stomachs prestimulated with the phosphodiesterase inhibitor isobutyl methylxanthine (IMX). Vascular and luminal histamine outputs and luminal acid output were monitored at short intervals. G1-17 induced an immediate histamine release to the vascular perfusate, preceding the increase in acid secretion by approximately 10 min. Vascular histamine output increased from a base line (IMX only) of 4.0 +/- 0.4 to a maximum of 34.5 +/- 7.3 nmol/60 min (mean +/- SEM) after 1040 pM G1-17, and acid output from 8.0 +/- 2.8 to 61.5 +/- 7.0 mumol/60 min after 520 pM G1-17. Acid output was correlated to vascular histamine release (r = 0.64, p less than 0.001). Gastrin produced a histamine release giving gastric venous concentrations of the same magnitude as the concentration of histamine necessary to induce a comparable acid response. Histamine release to the lumen, on the other hand, paralleled the acid secretion in time, suggesting it to be a passive phenomenon secondary to acid secretion. Thus, the present study for the first time shows that gastrin induces vascular histamine release of such a magnitude that this substance could be the mediator of the gastrin effect on acid secretion.

Topics: Animals; Dose-Response Relationship, Drug; Gastric Acid; Gastrins; Histamine Release; In Vitro Techniques; Male; Perfusion; Radioimmunoassay; Rats; Rats, Inbred Strains; Stomach

Iso-1-cytochrome c contains in penultimate position of its sequence a cysteine residue which in analogy to the known tertiary structures of cytochromes c should be exposed on the surface of the protein. Its selective reaction with N alpha-maleoyl-beta-alanyl-human-little-gastrin-I-[2-17] led to a well characterized and homogeneous gastrin conjugate to be used as immunogen in rabbits. The antisera raised by this procedure exhibited a degree of specificity for the hormone gastrin parallel to that of the gastrin receptor. This is clearly documented by comparison of the immune crossreactivities of gastrin-peptides of increasing chain length and of fragments corresponding to various regions of the hormone molecule with their biological activity. The immune response provoked in the animals by the use of an homogeneous immunogen was found to be highly reproducible in terms of specificity of the antigastrin antibodies.

Topics: Binding, Competitive; Cytochrome c Group; Cytochromes c; Enzyme-Linked Immunosorbent Assay; Gastrins; Haptens; Humans; Macromolecular Substances; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Spectrophotometry, Ultraviolet

Hydrolysis of heptadecapeptide gastrin (G-17) by endopeptidase 24.11 (EC 3.4.24.11) was studied in vivo and in vitro in the pig. Ion exchange chromatography and radioimmunoassay with three region-specific antisera were used to identify the products of porcine G-17 degradation. Incubation of antral extracts with pure endopeptidase 24.11 resulted in a substantial loss of intact G-17: 80% C-terminal immunoreactivity was lost in 60 min. This hydrolysis was completely inhibited by phosphoramidon, which is a specific inhibitor of endopeptidase 24.11. In antral extracts G-17 accounted for greater than 95% of total C-terminal immunoreactivity, compared with less than 60% C-terminal immunoreactivity in the gastric venous outflow; shorter C-terminal forms comprised the major part of the remaining immunoreactivity. After infusion of phosphoramidon, the concentration of intact G-17 was increased, and there was a corresponding reduction in the concentration of other C-terminal immunoreactive fragments. We conclude that endopeptidase 24.11 degrades G-17 in vitro and in vivo and may be responsible for the generation of C-terminal fragments from G-17 after secretion from the porcine antral mucosa.

Topics: Animals; Chemical Phenomena; Chemistry; Endopeptidases; Female; Gastrins; Glycopeptides; Hydrolysis; Male; Neprilysin; Peptide Fragments; Protease Inhibitors; Pyloric Antrum; Swine; Tissue Extracts; Veins

The fluorogenic chymotrypsin substrate N alpha-(4-carboxybutyryl)-L-phenylalanine (4-methyl-7-coumaryl)amide was converted to a thiol-containing compound via its condensation at the carboxyl function with cystamine followed by reduction of the resulting disulfide compound to a cysteamine derivative. By subsequent reaction of the thiol group with N alpha-maleoyl-beta-alanyl-human-little-gastrin-I-[2-17] a fluorogenic substrate-labeled gastrin, fully immunoreactive against antigastrin antisera, was obtained. This tracer was then applied for developing a fluorescence immunoassay based on separation of bound and free tracer followed by chymotryptic digestion of the fluorogenic substrate in the supernatant. The fluorescence intensity of the extracted fluorophore i.e., 7-amino-4-methyl-coumarin, was found to monitor gastrin concentrations in a reproducible manner. With the model peptide hormone human little-gastrin-I the sensitivity of this alternative immunoassay procedure was well documented.

Topics: Amino Acids; Binding, Competitive; Chymotrypsin; Fluorescent Antibody Technique; Gastrins; Humans; Hydrolysis; Immunoenzyme Techniques

We have shown that structurally well-defined homogeneous maleoyl-peptides are synthetically accessible. These anchor-modified peptide derivatives allow their selective covalent linkage to thiol-containing proteins via the maleimide-thiol procedure. Correspondingly mercaptosuccinylated horseradish peroxidase was reacted with N alpha-maleoyl-beta-alanyl-human-little gastrin-I-[2-17] to produce the gastrin/peroxidase conjugate in good yields at 1:1 stoichiometry. The conjugate exhibited full enzymatic activity and identical binding affinity to antigastrin antisera as the parent gastrin. This approach proved to be well suited for the preparation of enzyme labeled peptide factors as tracers for immunoassays.

Topics: Enzyme-Linked Immunosorbent Assay; Gastrins; Horseradish Peroxidase; Humans; Immunoassay; Immunoenzyme Techniques; Immunoglobulin G; Peroxidases; Spectrophotometry, Ultraviolet; Sulfhydryl Compounds

Six patients were studied with pituitary adenomas and elevated concentrations of gastrin similar to those found in cases of benign antral gastrinoma syndrome. Chromatography of the serum using Sephadex-G50 revealed different molecular forms of gastrin according to the type of adenomas. In those cases of acromegaly and gonadotrophinoma, gastrin-34 and unsulphated gastrins constitute the predominant forms. In contrast, in cases of Cushing's disease, gastrin-17, sulphated as well as non-sulphated were the predominant types; the chromatographic pattern was similar to that observed in two patients with antral gastrinoma syndrome who acted as controls. These findings demonstrate that pituitary adenomas might secrete gastrin. Taking into account that gastrin-34 and unsulphated gastrins were the predominant forms in cases of acromegaly, gonadotrophinoma and non-functioning adenoma, it is assumed that those molecular forms are mainly produced in the anterior lobe of the hypophysis. Conversely, gastrin-17 was the principal molecular form in cases of Cushing's disease confirming the close relationship of the synthesis of gastrin and corticotrophin peptides. The cases with Cushing's disease exhibited a serum gastrin pattern similar to that observed in the two cases with antral syndrome in which the predominant immunoreactive form of gastrin in gastrin-17 exhibiting a degree of sulphation corresponding to that of antral gastrin. It is concluded that the circulating excess of gastrin originated in the pituitary tumour tissue and the molecular form varied with the type of pituitary adenoma.

Topics: Adenoma; Adult; Chromatography, Gel; Female; Gastrins; Humans; Male; Middle Aged; Pituitary Hormones; Pituitary Hormones, Anterior; Pituitary Neoplasms; Protein Precursors

125I-[Nle15]-gastrin17 prepared by the iodogen method can be separated by reversed-phase high performance liquid chromatography into two peaks, both of which elute after [Nle15]-gastrin17. Direct determination of the specific activities of the two derivatives by microbore reversed-phase HPLC indicated that they were the mono- and di-iodinated species. In contrast the two peaks obtained with [Met15]-gastrin17 iodinated under the same conditions eluted earlier, relative to the appropriate gastrin17 standard, than the [Nle15]-gastrin derivatives. Treatment of either peak with 0.75 M dithiothreitol at 56 degrees C or 95 degrees C resulted in progressive conversion to compounds migrating in relative positions similar to the 125I-[Nle15]-gastrin17 derivatives. Direct determination of the specific activity of the earlier eluting [Met15]-gastrin17 derivative before reduction indicated that it was the mono-iodinated species. It thus appears likely that iodination of [Met15]-gastrin17 by the iodogen method results predominantly in the formation of mono- and di-125I-[Met sulphoxide15]-gastrin17. To avoid problems arising from oxidation of the methionine residue of gastrin during iodination, the use of 125I-[Nle15]-gastrin17 in binding studies is therefore recommended.

Topics: Chromatography, High Pressure Liquid; Gastrins; Iodine Radioisotopes

The purpose of these experiments was to determine the contribution of gastrin to the acid secretory response to eating in healthy human subjects. To simulate the gastric and intestinal phases of eating, a meal was homogenized and then infused into the stomach through a nasogastric tube. At the same time, the cephalic phase of acid secretion was activated by sham feeding. With this simulated meal, mean serum gastrin concentration increased from a basal value of 43 +/- 9 pg/ml to an average postprandial gastrin concentration over 2 h of 121 +/- 25 pg/ml. Gastrin release after this simulated meal was similar to gastrin release after a normally eaten meal in the same 12 subjects. Gastric acid secretion in response to the simulated meal, which was measured by in vivo intragastric titration, averaged 24.2 +/- 2.4 mmol/h. To determine how much of this postprandial acid secretion could be attributed to gastrin, gastrin 17 I was infused intravenously in the same subjects on a separate day and acid secretion and serum gastrin concentrations were measured. By relating serum gastrin concentration during gastrin 17 infusion to concomitant acid secretion, we determined that an average postprandial serum gastrin concentration of 121 pg/ml could result in an acid secretion rate of 21.5 mmol/h, 89% of the actual acid secreted after the simulated meal in these subjects. However, in individual subjects, the amount of gastrin released after a meal could produce as little as 51% or as much as 162% of actual postprandial acid secretion. Thus, in individual human subjects the contribution of gastrin to acid secretion after a meal is variable.

Topics: Adult; Feeding Behavior; Female; Gastric Acid; Gastrins; Hormones; Humans; Infusions, Intravenous; Intubation, Gastrointestinal; Male; Middle Aged; Time Factors

We calculated gastric HCO3- and H+ secretion, as well as nonparietal and parietal volume secretion, in 15 duodenal ulcer patients who had previously undergone successful proximal gastric vagotomy, 15 unoperated duodenal ulcer patients, and 15 normal control subjects. Basal HCO3- secretion was not significantly altered after vagotomy, while basal H+ secretion, parietal volume and nonparietal volume secretion were reduced significantly. Intravenous gastrin-17 infusion reduced gastric HCO3- secretion by approximately 50% in both unoperated ulcer patients and normal subjects (P less than 0.05). Gastrin-17 infusion did not inhibit gastric HCO3- secretion after vagotomy. In fact, mean gastric HCO3- secretion increased to a nearly significant extent in response to gastrin (P = 0.06). These findings indicate that gastrin inhibits gastric HCO3- secretion in humans and that the gastrin-induced reduction in gastric HCO3- secretion is dependent upon intact vagal innervation to the oxyntic mucosa.

Topics: Bicarbonates; Depression, Chemical; Duodenal Ulcer; Female; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Male; Middle Aged; Secretory Rate; Vagotomy, Proximal Gastric

Monoiodinated gastrin was produced by a gentle Iodo-gen method, followed by gel and ion-exchange chromatography. During storage this tracer has previously been found to retain its immunological activity, whereas its specific binding to rat gastric fundic plasma membranes decreased rapidly. To examine whether the loss of specific binding could be reflected in loss of biological activity, we examined the tracer at regular intervals for immunoreactivity by binding to an antibody directed against the C-terminal bioactive site of the gastrin molecule; for biological activity in the totally isolated, vascularly perfused rat stomach concomitantly stimulated with a phosphodiesterase inhibitor; for specific binding ('receptor binding') to a rat gastric fundic plasma membrane fraction; and for fragmentation and intramolecular changes by fast protein liquid chromatography (FPLC). Biological activity and 'specific' binding showed a parallel decrease to zero during 4 weeks of storage, whereas the immunoreactivity was retained much longer. There was no apparent fragmentation of the gastrin molecule during the 1st month after preparation as evaluated by FPLC. This study accordingly shows that both biological activity and specific binding to a gastric fundic plasma membrane fraction of 125I-gastrin are lost before detectable loss in immunoreactivity and before FPLC-detectable fragmentation of the molecule. Thus, during the early storage period subtle changes in the 125I-gastrin molecule must take place. Since the specific binding is so closely correlated to biological activity, it suggests that the binding actually represents true receptor binding.

Topics: Animals; Biological Assay; Cell Membrane; Chromatography, Gel; Chromatography, Liquid; Drug Storage; Gastric Fundus; Gastric Mucosa; Gastrins; Humans; Iodine Radioisotopes; Radioimmunoassay; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin; Time Factors

Serum gastrin concentrations were measured using antisera with specificity for the carboxyl and amino terminus of gastrin-17 in 50 healthy subjects and 18 patients with active duodenal ulcer disease (DU). The amino terminal of gastrin-17 immunoreactivity was significantly higher in DU patients than in healthy subjects. NH2-terminus of gastrin-17 immunopurified material from serum of DU patients was subjected to Sephadex G50 column chromatography and eluates were monitored by an additional antiserum EG10 that recognizes COOH-terminally extended gastrin. Besides the NH2 terminal tridecapeptide of gastrin-17, COOH-terminally extended progastrin was found. This may reflect abnormal processing of gastrin in patients with active duodenal ulcer disease.

Topics: Adolescent; Adult; Aged; Amino Acid Sequence; Duodenal Ulcer; Female; Gastrins; Humans; Immune Sera; Male; Middle Aged; Protein Precursors

The role of gastrin as a regulator of exocrine pancreatic secretion has not been proven adequately. In the present study we therefore compared the relative molar potencies of sulfated and unsulfated gastrin 17 with structurally related CCK peptides (synthetic CCK-8 and natural porcine CCK-33) in stimulating exocrine pancreatic secretion in conscious dogs. Dose response curves were constructed for pancreatic and gastric acid secretion. Plasma gastrin levels after exogenous gastrin 17-I and -II were compared with postprandial gastrin concentrations (meal: ground beef 20 g/kg body wt). The molar potency estimates calculated with synthetic CCK8 as standard (potency = 1.00) for pancreatic protein secretion were natural porcine 50% pure CCK-33 1.60, gastrin 17-I 0.12, and gastrin 17-II 0.16. All four peptides induced a dose-dependent increase in pancreatic bicarbonate output. However, the blood concentrations needed to stimulate pancreatic secretion were above the postprandial gastrin levels. Our data indicate that both gastrin 17 peptides are not physiological regulators of pancreatic enzyme secretion in dogs.

Topics: Animals; Cholecystokinin; Dogs; Female; Gastric Acid; Gastric Juice; Gastrins; Kinetics; Pancreatic Juice; Sincalide

Molecular heterogeneity between cholecystokinin (CCK) present in humans and that present in the pig has been proposed. We recently demonstrated that CCK-8 exists in humans in form identical to the porcine peptide. The aims of this work were to evaluate the presence in human plasma of CCK forms larger than CCK-8 and to compare them with the well-characterized porcine forms. Antiserum (no. 4899) was raised in a New Zealand white rabbit immunized with porcine CCK-33 that had specificity for the 7 to 21 region of that peptide and that recognized molecules present in human plasma. To characterize these, postprandial human plasma was applied to an immunoaffinity column generated with this antiserum. Adsorbed peptides were eluted, concentrated on an octadecylsilane cartridge, separated by reversed-phase HPLC and gel filtration chromatography, and screened by cross-reacting and specific CCK and gastrin radioimmunoassays and CCK bioassay by quantification of amylase release by rat pancreatic acini. Two peptides were consistently identified that possessed CCK-like but not gastrin-specific immunoreactivity and CCK-like biological activity. These appeared to be similar in size to CCK-33 and intermediate in size between CCK-33 and CCK-8. Though analogous to porcine CCK based on antibody cross-reactivity and biological activity, the human peptides were heterogeneous from the porcine peptides based on differing chromatographic behavior.

Topics: Amylases; Animals; Antibody Specificity; Cholecystokinin; Chromatography, Gel; Chromatography, High Pressure Liquid; Eating; Female; Gastrins; Humans; Male; Molecular Weight; Peptide Fragments; Radioimmunoassay; Rats; Receptors, Cholecystokinin; Sincalide; Swine

Forty-six patients with the gastrinoma syndrome were divided into 2 categories: 1) benign sporadic gastrinoma (n = 30), and 2) gastrinoma with metastases to liver (n = 16). Thirteen of the 46 patients had multiple endocrine neoplasia type I syndrome. Serum gastrin levels in patients fasted overnight were determined by RIA using antisera directed toward the NH2- and COOH-terminals of heptadecapeptide gastrin (G17) and the NH2-terminus of the triacontatetrapeptide (G34). These results were compared with findings in 50 normal subjects. In the normal subjects, the mean COOH-terminal gastrin-17 level was higher [65 +/- 8 (+/- SEM) pg/ml] than the NH2-terminal gastrin-17 level (11 +/- 0.2 pg/ml) and lower than the NH2-terminal gastrin-34 level (134 +/- 20 pg/ml). The levels of NH2-terminal gastrin-17 were higher in patients with metastatic disease than in those with benign gastrinoma, whereas the COOH-terminal gastrin-17 and the NH2-terminal gastrin-34 levels were similarly high in both groups. The mean ratio of NH2-terminal gastrin-17 to COOH-terminal gastrin-17 was less than 1 in normal subjects (0.22 +/- 0.02) and benign gastrinoma patients (0.2 +/- 0.04), and it was 2.2 +/- 0.41 in the patients with metastatic gastrinoma. An NH2 to COOH gastrin-17 ratio greater than 1 was found in 13 of 16 patients with metastatic gastrinoma, but in none of the patients with benign gastrinoma or normal subjects. Similar results were found in multiple endocrine neoplasia type I patients with benign and metastatic disease. A high NH2 to COOH gastrin-17 ratio is suggestive of metastatic gastrinoma. In 4 patients with metastatic gastrinoma, the NH2 to COOH gastrin-17 ratio fell in parallel with the response to chemotherapy.

Topics: Chromatography, Gel; Gastrins; Humans; Liver Neoplasms; Multiple Endocrine Neoplasia; Protein Precursors; Radioimmunoassay; Zollinger-Ellison Syndrome

To determine if gastrin in hyperparathyroid glands is true gastrin or artifact and to determine the frequency of gastrin in parathyroid glands, 20 parathyroid glands from 11 patients with hyperparathyroidism but without MEA were extracted and analyzed for gastrin. The parathyroid glands from 4 out of 11 patients had measurable gastrin immunoreactivity (10.7 + 6 pg/mg tissue). Column separation chromatography confirmed that this was true gastrin (40% G-34; 50% G-17). Immunohistochemistry with ABC (avidin biotin complex) immunoperoxidase confirmed the presence of gastrin in cytoplasmic vesicles in scattered parathyroid cells. True gastrin does exist in some cells in some patients with hyperparathyroidism.

Topics: Adenoma; APUD Cells; Gastrins; Humans; Hyperparathyroidism; Hyperplasia; Immunoenzyme Techniques; Parathyroid Glands; Parathyroid Neoplasms; Protein Precursors; Radioimmunoassay

Binding of 125I-gastrin to the 270-30,000 g fraction from homogenized rat oxyntic mucosa was studied. 'Specific' binding was calculated by subtracting the binding at excess cold gastrin from the binding with labelled gastrin (250 pM) only. At 30 degrees C specific binding rose rapidly to a short-lived maximum before falling gradually, whereas at 15 degrees C and 0 degree C specific binding rose gradually to a higher plateau level. The reduced binding at 30 degrees C could be caused by degradation of either the tracer or the binding site or by a combination of these two events. Degradation of 125I-gastrin was evaluated by trichloroacetic acid (TCA) precipitation, fast protein liquid chromatography, and binding to a gastrin antibody (immunoreactivity). The effect of incubation on the binding site was evaluated by preincubation of the homogenate fraction before adding gastrin. In separate studies, the proteolytic activity of the homogenate fraction was studied by TCA precipitation of radioactive casein. Different enzyme inhibitors tested were virtually ineffective in preventing gastrin and casein degradation. Only lowering the incubation temperature to 15 degrees C or lower could prevent this degradation. The reduced and transient binding of 125I-gastrin at 30 degrees C most probably reflects tracer degradation. Accordingly, the gastrin binding experiments were performed at 15 degrees C. Only homogenates from the oxyntic area of the stomach bound 125I-gastrin specifically and with a Kd of 0.8 nM (Scatchard analysis). However, micromolar concentrations of unlabelled gastrin were required to inhibit half maximal binding of the tracer. The tracer binding was unaffected by secretin, slightly reduced by a CCK-9 analogue, and more markedly reduced by pentagastrin.

Topics: Animals; Cell Membrane; Chromatography, Gel; Gastric Mucosa; Gastrins; Iodine Radioisotopes; Male; Peptide Hydrolases; Rats; Rats, Inbred Strains; Receptors, Cell Surface; Receptors, Cholecystokinin; Temperature; Trichloroacetic Acid

Several studies have suggested that gastrointestinal peptides can produce trophic changes in the small intestine epithelium. In a previous study utilizing a rat fetal intestine transplant model, we reported that chronic, continuous, systemic administration of gastrin-17 increased carbohydrate absorption 2.5-fold and protein absorption 1.3-fold. The present study was designed to evaluate the effect of chronic luminal perfusion of gastrin on substrate absorption in rat mature small intestine. A 10-cm segment of mid small intestine was isolated with both ends brought out as abdominal wall stomas (creating a Thiry-Vella loop) and bowel continuity was established by end-to-end anastomosis. After a 1-week recovery, the tips of two catheters were positioned at approximately 3 and 6 cm from the proximal end of the isolated small intestine segment. A 14-day continuous luminal perfusion was accomplished by connecting the other ends of the catheters to subcutaneously placed osmotic pumps filled to deliver saline (control; N = 10) or gastrin-17 (13.5 nM/kg/day; N = 7). At the completion of the luminal perfusion, intestinal absorption was determined with labeled substrates [14C]galactose and [14C]glycine) using a closed, recirculation technique. Absorption (microM/cm2 small intestine) of galactose in the control animals was 1.44 +/- 0.18 and for the gastrin infused rats, it was 6.56 +/- 0.46. Glycine absorption was 1.63 +/- 0.31 for the control group and 7.83 +/- 0.62 for the gastrin infused group. Thus, in this rat model, intraluminal gastrin infusion was capable of increasing carbohydrate (galactose) absorption 456% (P less than 0.01) and protein (glycine) absorption 480% (P less than 0.01). These data represent the first demonstration that intraluminal gastrin can influence small intestine mucosal function by enhancing substrate absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Galactose; Gastrins; Glycine; Hormones; Intestinal Absorption; Intestine, Small; Perfusion; Rats

Serum gastrin concentrations and gastric acid secretion were measured during intravenous infusion of gastrin heptadecapeptide (G-17) (0, 7, 22.1, 70, 221, and 700 pmol/kg X h) in 15 duodenal ulcer patients and 15 healthy controls. Ulcer patients developed higher serum gastrin concentrations during G-17 infusion due to nearly twofold slower clearance of gastrin (8.8 vs. 15.7 ml/kg X min; P less than 0.01). Despite slower clearance of G-17, ulcer patients had plasma elimination half-times for G-17 similar to controls (6.0 vs. 6.1 min, respectively). Thus, calculated volume of distribution for G-17 was lower in ulcer patients than controls (78.5 vs. 140.7 ml/kg; P less than 0.025). For any serum gastrin during gastrin-17 infusion, acid secretion (millimoles per hour) was higher in ulcer patients than in controls. However, when acid secretion was expressed as a percentage of peak acid output to G-17 (to correct for differences in parietal cell mass), curves relating acid secretion to serum gastrin were identical in ulcer patients and controls.

Topics: Adult; Duodenal Ulcer; Female; Gastric Acid; Gastrins; Half-Life; Humans; Kinetics; Male; Metabolic Clearance Rate; Middle Aged

A bioassay sensitive to gastrin (G 1-17) in physiological concentrations and suitable for testing of biological activity of minor amounts of radioiodinated gastrin is reported. G 1-17 was iodinated by a gentle Iodo-gen method and purified to high specific activity (1900 Ci/mmol). Totally isolated vascularly perfused rat stomachs were prepared and stimulated by graded amounts of G 1-17. Gastrin 'dose'-dependently increased the acid output from 5.7 +/- 1.0 mueq/40 min (basal) to a maximum of 58.8 +/- 10.0 mueq/40 min at a concentration of 520 pmol/l in the vascular perfusate. The lowest G 1-17 concentration that significantly increased the acid output from the basal value was 65 pmol/l, corresponding to a dose of 17.5 ng/stomach-hour. 125I-G 1-17 also increased the acid output significantly at this threshold dose. The amount of lactic acid enzymatically determined in the luminal perfusate was negligible, indicating a true parietal cell stimulation. Accordingly, a very sensitive bioassay for gastrin, suitable for testing of biological activity of G 1-17 and 125I-G, is described. Significant acid responses were obtained with physiological concentrations of gastrin, requiring less than 100 ng of hormone and labelled hormone, respectively, to show biological activity.

Topics: Animals; Biological Assay; Gastric Acid; Gastrins; In Vitro Techniques; Iodine Radioisotopes; Lactates; Lactic Acid; Male; Models, Biological; Perfusion; Rats; Rats, Inbred Strains; Stomach

The trophic effects of the hormone gastrin-17 were examined on a human colon cancer cell line. LoVo cells were obtained from the American Type Culture Collection and grown in minimal essential medium in the presence of 10% bovine fetal serum. To demonstrate the trophic effect of gastrin, synchronization was necessary. The effect of gastrin was optimal after 26-h exposure to 0.6 mM thymidine. In the presence of serum the optimal dose of gastrin for stimulation of DNA synthesis was 7.2 X 10(-10) M. Under these conditions gastrin caused a 220% increase in [3H]thymidine incorporation. In the absence of serum the optimal dose of gastrin (3.6 X 10(-9) M) increased DNA synthesis approximately 200%. Twenty-four hours after gastrin treatment (1.8 X 10(-10) M gastrin 17) cell numbers increased 50.8% compared with control. At 48 h this increase was maintained at 44%. Maximum stimulation by gastrin occurred 7-8 h after release from synchronization and exposure to gastrin. This corresponded to the S phase of the cell cycle. Significant stimulation occurred a second time at 22-24 h, presumably during the second S phase in a still synchronous or partially synchronous cell population. These data demonstrate that physiological concentrations of gastrin-17 can stimulate the growth of a human cancer cell line and that some degree of synchronization may be necessary to demonstrate similar effects in other cell lines. Such cell lines may provide a source of rapidly growing cells in which the mechanisms of the trophic effect of gastrin can be examined.

Topics: Adenocarcinoma; Blood; Cell Division; Cell Line; Colonic Neoplasms; Culture Media; DNA; Gastrins; Humans

To improve intestinal function in children with short bowel syndrome, our laboratory has focused on identifying substances, which may enhance the function of small intestine epithelium. Previous studies have demonstrated that gastrin appeared to exert a trophic effect on the gastrointestinal tract. We chose to evaluate the influence of chronic, systemic, and luminal administration of gastrin-17 on substrate absorption in both fetal and mature rat small intestine. Transplanted fetal small intestine, mature small intestine in situ, and isolated mature small intestine segments were the surgical preparations used. Saline (control) or gastrin-17 (13.5 nmol/kg/d) was administered continuously for 14 days either systemically or luminally using osmotic pumps. The response to the saline or gastrin-17 infusions was determined by measuring absorption of radiolabeled substrates (14-C-galactose and 14-C-glycine). Following transplantation of fetal small intestine to a syngeneic host, galactose absorption rose 250% (P less than .01) and glycine absorption rose 130% (P less than .05) when compared with controls (N = 10). The response of mature jejunum and ileum following systemic gastrin infusion was a mild to moderate rise in galactose and glycine absorption, although statistical significance was not achieved. However, following luminal gastrin infusion into mature small intestine segments, there was a 4.54 fold rise in galactose absorption (P less than .01) and a 4.79 fold rise in glycine absorption (P less than .01) when compared with controls. These data suggest that gastrin can enhance substrate absorption in rat fetal and mature small intestine and that luminal perfusion appears to induce the greatest response.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Fetus; Galactose; Gastrins; Glycine; Hormones; Intestinal Absorption; Intestine, Small; Rats; Rats, Inbred F344

We have compared the binding of cholecystokinin (CCK) antibodies with different sequence-specificities to Bolton-Hunter labeled CCK-33 (125I-BH-CCK-33), CCK-8 (125I-BH-CCK-8) and chloramine-T iodinated gastrin-17 (125I-gastrin-17). The antibody binding was expressed as the final antiserum dilution ('titer') and the effective equilibrium constant of the binding (Ko eff). Antibodies specific for the C- or the N-terminal sequence of CCK-8 all bound well to 125I-BH-CCK-8. In contrast, some of the antibodies directed against the common C-terminus of CCK and gastrin displayed remarkably low binding of 125I-gastrin-17 or 125I-BH-CCK-33, whereas all antisera specific for the N-terminal or midsequence of CCK-33 bound 125I-BH-CCK-33 well. The lower binding of 125I-BH-CCK-33 to some C-terminal antibodies raised against gastrin may be due to a C-terminal conformation of CCK-33 different from that of gastrin. In accord with the high specific radioactivity of 125I-BH-CCK-8, the best sensitivity of CCK radioimmunoassays was obtained with the CCK-8 tracer.

Topics: Amino Acid Sequence; Antibody Specificity; Cholecystokinin; Cross Reactions; Epitopes; Gastrins; Radioimmunoassay; Sincalide

Previous studies indicated that gastrin-17 (G-17) and the octapeptide of colecystokinin (CCK-8) were equally potent in their interaction with receptors for 125I-[Leu15]G-17 on isolated canine parietal cells. These findings were inconsistent with the poor efficacy of CCK-8 compared with G-17 as stimuli of acid secretion in dogs. The present study examines the effects of G-17 and CCK-8 on the release of somatostatinlike immunoreactivity (SLI) from a fraction of small canine fundic mucosal cells separated by elutriation and placed in short-term culture. CCK-8 was considerably more potent and more effective than G-17 as a stimulant of SLI release from these cultured cells. CCK-8 was slightly more potent than G-17 in inhibiting 125I-[Leu15]G-17 binding to receptors in the same elutriator fraction. Our present findings support the hypothesis that the poor efficacy of CCK compared with G-17 as a stimulant of acid secretion may reflect pronounced activation of somatostatin-mediated acid-inhibitory mechanisms by CCK-8. The present data indicate that differences in affinity between CCK-8 and G-17 at the 125I[Leu15]G-17 receptor probably do not account for the greater efficacy of CCK-8; the receptor or cell activation mechanisms underlying this greater efficacy of CCK-8 on SLI release remain to be elucidated.

Topics: Animals; Cells, Cultured; Dogs; Epinephrine; Gastric Fundus; Gastric Mucosa; Gastrins; Sincalide; Somatostatin; Time Factors

Gastric acid and pepsin secretion and serum gastrin concentrations were measured in nine patients with uncomplicated duodenal ulcer (DU) and 10 normal controls in the fasting state and in response to graded doses of bombesin, a tetradecapeptide gastrin releaser, and, for reference, synthetic gastrin G-17. Serum gastrin with bombesin stimulation was significantly greater in duodenal ulcer (maximum 467 pg/ml) than in controls (153 pg/ml), while in seven of the DU group tested gastrin levels after a meal were not different from that seen in five of the normal controls. Gastric acid concentrations and outputs were greater in duodenal ulcer with both stimuli. Secretory responses were then related to serum gastrin levels; despite increasing gastrin levels with bombesin stimulation, peak outputs achieved with bombesin were only 50% of G-17 maximum in normals and up to 90% of maximum in duodenal ulcer. Up to the point of peak response to bombesin, acid and pepsin outputs were the same with exogenous and endogenous gastrin, ie, bombesin acted only via G-17. Furthermore, in direct comparison of duodenal ulcer and normals with G-17 infusion, acid and pepsin outputs related to serum gastrin were congruent up to 75% of duodenal ulcer maximum, at which point normals reached their maximum level. These data have shown that duodenal ulcer patients are not more sensitive to either exogenous or endogenous gastrin; we have also shown regulatory defects in duodenal ulcer patients not previously described: an exaggerated release of gastrin with bombesin stimulation, and a defective inhibition of acid and pepsin secretion with higher doses of bombesin.

Topics: Adult; Bombesin; Dose-Response Relationship, Drug; Duodenal Ulcer; Female; Gastric Acid; Gastrins; Hormones; Humans; Male; Pepsin A; Stimulation, Chemical

Similar maximal rates of gastric acid secretion are achieved with histamine and gastrin stimulation in human, dog, or cat, but gastrin produces higher rates than histamine in the rat. Gastric acid secretion was measured in seven nonsedated, alert, chaired rhesus monkeys (Macaca mulatta). Dose-response studies were performed using intravenous histamine or tetragastrin. These studies showed histamine to be a much more efficacious and more potent stimulant of gastric acid secretion than tetragastrin in the monkey. Both histamine and tetragastrin had similar potency and efficacy in the dog, while tetragastrin, pentagastrin, and hog heptadecapeptide were similarly less active than histamine in the monkey. Background carbachol (4 micrograms/kg/hr) did not affect the histamine or tetragastrin dose-response curves. Histamine stimulation with background tetragastrin (64 micrograms/kg/hr) did not produce a dose-response curve statistically different from histamine alone. Tetragastrin stimulation with background histamine (60 micrograms/kg/hr) increased the tetragastrin dose-response curve, with a probable additive effect. We conclude that the rhesus monkey differs from cat, dog, and man in that gastrin and its analogs are not able to stimulate maximal acid secretion to the level achieved by histamine.

Topics: Animals; Carbachol; Dose-Response Relationship, Drug; Gastric Acid; Gastrins; Histamine; Macaca mulatta; Pentagastrin; Swine; Tetragastrin; Time Factors

The sulfation of gastrin in serum, antrum and duodenum was studied in 22 normo- and 20 hypergastrinemic patients. The ratio between gastrin-17 and gastrin-34 was measured in antrum and duodenum. The degree of sulfation was reduced in the antrum of hypergastrinemic patients (35.3 +/- 1.3%, mean +/- SEM) compared with 48.0 +/- 2.1% in normo-gastrinemic patients (p less than 0.001). The degree of sulfation in serum and duodenum was similar to that of the antral gastrins in all patients. The percentage of gastrin-34 in antrum was increased (7.3 +/- 0.7%) in hypergastrinemic compared with 4.9 +/- 0.3% in normogastrinemic patients (p less than 0.01). In the duodenum the percentage of gastrin-34 was similar in normo- and hypergastrinemia. When classified according to clinical diagnosis, sulfation of antral gastrin was normal in duodenal ulcer (47.6 +/- 4.5%) but decreased in gastric ulcer (36.7 +/- 1.6%, p less than 0.01) and pernicious anemia (31.3 +/- 1.9%, p less than 0.001) compared with 48.2 +/- 2.2% in control patients. In pernicious anemia a larger proportion of antral gastrins occurred as gastrin-34 (8.2 +/- 0.9%) compared with 4.8 +/- 0.4% in control patients (p less than 0.01). Our study suggests that both sulfation and proteolytic processing of the gastrin precursor is diminished in hypergastrinemia of antral origin.

Topics: Anemia, Pernicious; Duodenal Ulcer; Gastrins; Gastritis; Gastritis, Atrophic; Humans; Protein Precursors; Pyloric Antrum; Radioimmunoassay; Stomach Ulcer; Sulfuric Acids

In 68 patients with chronic renal failure (CRF), 15 patients with duodenal ulcer and 15 normal subjects, basal plasma gastrin levels and basal and stimulated gastric acid secretion were measured. Two antisera were used: antiserum R2702 with specificity for human G34 and its N-terminal fragments [G34] and antiserum 2604 with specificity for the four main components of gastrin (total gastrin). Basal gastrin concentrations of both total gastrin and G34-like immunoreactivity (G34LI) were significantly higher in the CRF patients than in the other two groups, irrespective of dialysis. Total gastrin levels were not correlated with serum creatinine levels. Total gastrin levels were significantly decreased during hemodialysis, but G34LI levels showed no significant change. A small amount of total gastrin was detected in the dialysate by antiserum 2604. As to the postprandial gastrin release, in the first 30 min, the pattern of response in the patients with CRF was similar to that of the normal subjects, but the peak value was attained later, and the response was more rather prolonged. Gastric analysis showed a low basal acid out put and impaired acid secretion in response to secretagogue. It is concluded that (1) one of the predominant circulating forms of gastrin in CRF is G34LI, and (2) the hypergastrinemia in the CRF patients is probably due to reduced removal of gastrin by kidneys, increased gastrin production by impairment of the negative acid feedback mechanism induced by parietal cell dysfunction or reduced parietal cell sensitivity to gastrin by atrophic gastritis.

Topics: Achlorhydria; Adult; Endoscopy; Female; Food; Gastric Acid; Gastrins; Humans; Kidney Failure, Chronic; Male; Middle Aged; Protein Precursors; Renal Dialysis

We determined total gastrin and pepsinogen I in frozen serum samples from 175 overnight-fasted women 54 years old, and from 81 overnight-fasted women 60 years old, who took part in a population study in 1968-69. We also assayed samples from some of these women, who participated in clinical follow-up studies in 1974-75 and 1980-81: all of the women in the initial group whose serum gastrin concentration exceeded the 85th centile value and, as a reference group, a randomized subsample of women whose initial serum gastrin concentration was less than the 80th centile. Samples with total gastrin concentration greater than 400 ng/L were also assayed for gastrin-17 and gastrin-34. We found that: a pronounced increase of serum gastrin persisted throughout the study period for most of these postmenopausal women, indicating that conversion of type A gastritis (antrum-sparing) to pan-gastritis is uncommon; unexplained high concentrations of pepsinogen I in relation to the reference interval for young and middle-aged adults, as well as in relation to serum gastrin, were common; and the gastrin-17/gastrin-34 ratio is not correlated with the outcome of pronounced hypergastrinemia.

Topics: Achlorhydria; Fasting; Female; Follow-Up Studies; Food; Gastrins; Gastritis; Humans; Longitudinal Studies; Middle Aged; Pepsinogens; Sweden

The metabolism and action on basal and gastrin 17 (G-17)-stimulated acid secretion of the N-terminal 1-13 sequence of G-17 was studied in human volunteers. Basal acid secretion was not changed by infusion of 1-13 G-17 in doses of 75-1000 pmol X kg-1 X h-1 which gave plasma concentrations of N-terminal G-17 immunoreactivity of 150-2020 pmol X L-1. In addition the acid response to G-17 in a dose that stimulated about 50% maximal acid output was not influenced by 1-13 G-17 (75 and 1000 pmol X kg-1 X h-1). The mean half-time for disappearance of N-terminal immunoreactivity after stopping infusion of 1-13 G-17 was 9.8 +/- 0.5 min. Gel filtration indicated a single peak of N-terminal immunoreactivity in plasma during infusion of 1-13 G-17. Ion exchange chromatography on diethylaminoethyl cellulose, however, revealed two peaks of immunoreactivity. One corresponded to 1-13 G-17, the other eluted earlier. In samples taken after stopping the infusion, the variant predominated. On high-pressure liquid chromatography the variant was resolved into a major component, which had a retention time less than 1-13 G-17, and two minor components. The variants were not produced by incubation of 1-13 G-17 with plasma in vitro. It is concluded that 1-13 G-17 is converted in the circulation to new forms with longer half-lives. Because plasma enzymes cannot account for the formation of these variants, it is possible that enzymes present on cell walls, for example, on capillaries, may be responsible.

Topics: Adult; Amino Acid Sequence; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Iodine Radioisotopes; Male; Peptide Chain Termination, Translational; Radioimmunoassay

The fasting concentrations of total gastrin and gastrin-17 (G-17) were similar in healthy volunteers and in asymptomatic patients with gastric ulcers or duodenal ulcers. However, the fasting serum concentration of gastrin-34 (G-34) was higher in patients with gastric ulcers than in normal subjects, in whom it was higher than in patients with duodenal ulcers. In response to food, the increases in G-17, G-34, and total gastrin were greater in ulcer patients than in healthy subjects. Cimetidine administration was associated with further increases in G-17, G-34, and total gastrin in normal subjects and gastric ulcer patients after meals. The ratio G-17/G-34 was similar in placebo-treated normal subjects and placebo-treated patients with gastric or duodenal ulcers. Cimetidine produced an increase in G-17/G-34 in placebo-treated normal subjects and placebo-treated patients with gastric or duodenal ulcers, but the ratio G-17/G-34 was greater in patients with gastric ulcers than in normal subjects. These results indicate that: differences in serum gastrin concentrations between patient groups, treatment regimens, and time of day are better detected by measuring G-17 and G-34 rather than total gastrin; there are differences in fasting and food-stimulated gastrin concentrations between normal subjects and patients with gastric or duodenal ulcers; the fasting concentration of G-34 is higher than G-17 in normal subjects and patients with gastric ulcers but not in patients with duodenal ulcers; food increases G-17 in all subjects but G-34 only in subjects with gastric ulcers; cimetidine increases the fasting concentration of total gastrin in normal subjects and patients with gastric ulcers and increases G-17 and G-34 in normal subjects; cimetidine increases the ratio G-17/G-34 in normal subjects and patients with gastric ulcers, but decreases G-17/G-34 in patients with duodenal ulcers. It is proposed: that measurements of total gastrin concentration should be replaced by measurements of G-17 and G-34 and that such measurements of G-17 and G-34 indicate differences in serum gastrin concentrations between normal subjects and those with peptic ulcers and between those with gastric versus duodenal ulcers. The role of altered gastrin metabolism in the pathogenesis of ulcers needs to be established.

Topics: Cimetidine; Duodenal Ulcer; Eating; Gastrins; Humans; Protein Precursors; Stomach Ulcer; Time Factors

Gastrin- 17 (G-17) and gastrin-34-like immunoreactivities of human gastrinoma cells were investigated at light and electron microscope level using N-terminally directed antisera. The procedure includes (a) the 24 hr/immunoperoxidase staining of Bouin-fixed paraffin embedded tissues, (b) the immunoelectron microscopic labelling of aldehyde-fixed Epon-embedded tissues according to the immunogold technique. On light microscopy, a variable number of tumor cells stained for G-34. In contrast, G-17 immunoreactivity was very low or undetectable in the tumor material, although it was easily detected in endocrine cells of similarly processed human pyloric mucosa. On electron microscopy, most of the tumor cell granules belonging to the round compact or dense-cored type exhibited a variable labelling for G-34, whereas the vacuolar/floccular type remained unlabelled. In contrast, the labelling for G-17 occurred over most of the tumor cell granules, whether compact or floccular. Dense granules of varying size and shape, previously shown to store C-terminal gastrin immunoreactivity, were only faintly labelled by the two antisera. When compared to the labelling pattern of human pyloric G-cells, the predominance of round dense granules with G-34 and G-17 immunoreactivity in gastrinoma cells suggests an incomplete or defective post-translational processing of the precursor peptide.

Topics: Colloids; Gastrins; Gold; Humans; Immune Sera; Immunoassay; Immunoglobulin G; Microscopy; Microscopy, Electron; Protein Precursors; Zollinger-Ellison Syndrome

Topics: Duodenal Ulcer; Gastrins; Humans; Radioimmunoassay

The cellular localization of gastrin receptors was studied using dispersed canine fundic mucosal cells. In previous studies 125I-[Leu15]gastrin-17 (125I-[Leu15]G-17) binding was found to parietal cells, but gastrin binding was also found in the small-cell elutriator fractions (SCEF). In the present study a density gradient was used to further separate the SCEF and the distribution of 125I-[Leu15]G-17 binding correlated with cellular content of somatostatinlike immunoreactivity (SLI). In contrast, 125I-[Leu15]G-17 binding was inversely correlated with the histamine content of the fractions. 125I-[Leu15]G-17 binding to the SCEF was rapid and reversible. Total binding was 0.29 +/- 0.02 fmol/10(6) cells (mean +/- SE, n = 15); excess unlabeled G-17 inhibited 85% of this binding. G-17, [Leu15]G-17, and 127I-[Leu15]G-17 were equipotent in inhibiting 125I-[Leu15]G-17 binding and stimulating SLI secretion from the SCEF placed in short-term culture, whereas 127I-G-17 had a low potency for both effects. Proglumide, known to inhibit cholecystokinin binding to pancreatic acinar cell receptors, also inhibited 125I-[Leu15]G-17 binding to the SCEF and inhibited G-17 stimulated SLI release. We conclude that in the canine fundic mucosa gastrin interacts with receptor sites on parietal cells and somatostatin cells but probably not on fundic mucosal histamine-containing cells. These receptor sites for gastrin may activate counterbalancing mechanisms regulating the secretion of acid.

Topics: Animals; Cell Separation; Centrifugation, Density Gradient; Dogs; Gastric Fundus; Gastric Mucosa; Gastrins; Homeostasis; Receptors, Cell Surface; Receptors, Cholecystokinin; Statistics as Topic; Time Factors

Passage of neuropeptides from the cerebrospinal fluid to circulation depends upon cisternal pressure. When cisternal collecting pressure was kept at -20 cm, plasma levels of gastrin-17 and somatostatin-14 remained at basal values despite perfusion of high doses of the peptides into the cerebro-ventricular system. Progressive reduction of this pressure above -15 cm results in a progressive rise of the peripheral concentration of the peptides. Discrimination between central and peripheral action of centrally administered neuropeptides is, therefore, possible.

Topics: Animals; Gastrins; Intracranial Pressure; Rabbits; Somatostatin

The receptors in the fundic mucosa that mediate gastrin stimulation of acid secretion have been studied. Synthetic human gastrin-17-I (G17) with a leucine substitution in the 15th position ( [Leu15]-G17) was iodinated by chloramine T; high saturable binding was found to enzyme-dispersed canine fundic mucosal cells. 127I-[Leu15]-G17, but not 127I-G17, retained binding potency and biological activity comparable with uniodinated G17. Fundic mucosal cells were separated by size by using an elutriator rotor, and specific 125I-[Leu-15]-G17 binding in the larger cell fractions was highly correlated with the distribution of parietal cells. There was, however, specific gastrin binding in the small cell fractions, not accounted for by parietal cells. Using sequential elutriation and stepwise density gradients, highly enriched parietal and chief cell fractions were prepared; 125I-[Leu15]-G17 binding correlated positively with the parietal cell (r = 0.98) and negatively with chief cell content (r = -0.96). In fractions enriched to 45-65% parietal cells, specific 125I-[Leu15]-G17 binding was rapid, reaching a steady state at 37 degrees C within 30 min. Dissociation was also rapid, with the rate similar after 100-fold dilution or dilution plus excess pentagastrin. At a tracer concentration from 10 to 30 pM, saturable binding was 7.8 +/- 0.8% per 10(6) cells (mean +/- SE) and binding in the presence of excess pentagastrin accounted for 11% of total binding. G17 and carboxyl terminal octapeptide of cholecystokinin (26-33) were equipotent in displacing tracer binding and in stimulating parietal cell function ( [14C]aminopyrine accumulation), whereas the tetrapeptide of gastrin (14-17) had a much lower potency. Proglumide inhibited gastrin binding and selectively inhibited gastrin stimulation of parietal cell function. Canine parietal cells have specific receptors for gastrin that mediate stimulation of parietal cell function. Gastrin receptors were undetectable on chief cells, and yet present on another smaller mucosal cell(s).

Topics: Aminopyrine; Animals; Dogs; Gastrins; In Vitro Techniques; Iodine Radioisotopes; Mast Cells; Parietal Cells, Gastric; Receptors, Cell Surface; Receptors, Cholecystokinin

The effect of intravenous administration of gastrin-releasing peptide ( GRP ) on serum gastrin and insulin levels was studied in ad libitum fed and 24-h fasted rats. Administration of GRP (55 micrograms/kg body weight) caused a significant (P less than 0.05) elevation in serum gastrin levels at 10, 30, 60, and 120 min in the rats fed ad libitum, whereas in the fasted rats, gastrin levels rose significantly only at 10 min. GRP did not cause insulin release in fasted rats, but in the fed rats, it led to a significant elevation in serum insulin levels at 10 and 30 min, in comparison to controls. GRP appears to have an insulinotropic action in addition to a gastrin-releasing effect.

Topics: Animals; Drug Interactions; Eating; Fasting; Gastrin-Releasing Peptide; Gastrins; Insulin; Insulin Secretion; Male; Peptides; Rats

The concentrations of gastrins containing the active C-terminal tetrapeptide amide (mainly gastrin-34 and gastrin-17) and the N-terminal tridecapeptide fragment of gastrin-17 were measured in antral and duodenal biopsy specimens. The antral concentration of the N-terminal gastrin fragment was much higher in patients with active duodenal ulcer (33.4 +/- 6.8 nmol g-1, mean +/- SEM, n = 15) than in controls (5.6 +/- 2.9 nmol g-1, n = 10), patients with gastric ulcer (5.6 +/- 1.8 nmol g-1, n = 10) or patients with pernicious anaemia (7.7 +/- 2.5 nmol g-1, n = 6). No differences were found between the groups regarding gastrin-34 and gastrin-17 concentrations. In duodenal extracts, the N- and C-terminal gastrin concentrations were similar in all groups of patients. These data suggest that the posttranslational processing of antral gastrin is abnormal in patients with active duodenal ulcer disease.

Topics: Adult; Aged; Anemia, Pernicious; Chromatography, Gel; Duodenal Ulcer; Female; Gastrins; Hormones; Humans; Male; Middle Aged; Protein Precursors; Pyloric Antrum; Radioimmunoassay; Stomach Ulcer

The gastric-acid secretory potency of gastrin peptides was investigated in vivo, in conscious cats prepared with gastric fistula, and in vitro, with kitten isolated gastric mucosae. The influence of peptide length on potency was investigated by comparing synthetic human gastrin heptadecapeptide, non-sulphate (shG17ns) with a synthetic gastrin butyloxycarbonyl hexapeptide (G6ns), and the influence of sulphation by comparison of G6ns with its sister sulphated peptide (G6s). When exogenous doses were compared, shG17ns was the most potent peptide (mean exogenous dose for half-maximal stimulation (EDe50) : 0.33 nmol kg-1 h-1), and was 15.8 times more potent than G6ns (EDe50:5.14 nmol kg-1 h-1). This potency ratio was reduced to 9.4 when circulating immunoreactive concentrations of the two peptides were compared (mean circulating concentration for half-maximal stimulation (EDc50) : shG17ns, 201 pM; G6ns, 1890 pM). The greater potency ratio when exogenous doses were compared was due to the greater metabolic clearance rate (m.c.r.) of the shorter gastrin (m.c.r.: shG17ns, 37 ml kg-1 min-1; G6ns, 121 ml kg-1 min-1). In vitro, shG17ns (mean concentration for half-maximal stimulation (EC50) : 1.99 nM) was 2.8 times more potent than G6ns (EC50: 5.57 nM). Sulphation of the hexapeptide increased its potency 3.6-fold when exogenous doses were compared (EDe50 G6s: 1.42 nmol kg-1 h-1). The greater potency of the sulphated peptide appeared to be due to its lower m.c.r. (20 ml kg-1 min-1), and was eliminated when circulating concentrations were compared; potency ratio G6ns: G6s, 1.1. We conclude that the increased potency of short gastrin peptides observed upon sulphation is likely to be due to increased resistance to metabolic clearance. Part of the increased potency observed with increasing peptide length can also be explained by increased resistance to clearance, but the small potency difference in vitro may reflect greater affinity for gastrin receptors.

Topics: Animals; Cats; Chemical Phenomena; Chemistry; Female; Gastric Acid; Gastric Mucosa; Gastrins; Half-Life; In Vitro Techniques; Male; Metabolic Clearance Rate; Peptides; Structure-Activity Relationship; Sulfuric Acids

The metabolism and some biological properties of the N-terminal 1-17 sequence of human big gastrin (G-34) were studied during infusion in 5 human volunteers. Radioimmunoassay of the 1-17 fragment in plasma indicated rapid clearance (t1/2, 2.4 min). In doses of 75-1000 pmol X kg-1 X h-1, 1-17 G-34 did not, however, influence basal acid output or G-17-stimulated acid output. Gel filtration of plasma samples taken during the infusion indicated the presence of the 1-17 fragment of G-34, together with three other immunoreactive species. Two of these correspond to N-terminal G-34 immunoreactive forms previously found in human peripheral circulation. A fourth immunoreactive component that eluted late on Sephadex G50 was identified for the first time. This component also occurred in fasting human plasma, where it was the only detectable form of N-terminal G-34 immunoreactivity; its concentration increased during infusion of 1-17 G-34. The identification of this fragment and its concentrations in human circulation after feeding deserves further study. Because the fragments of 1-17 G-34 do not occur in antral extracts, and are not produced when G-34 or its N-terminal fragments are incubated in plasma in vitro, they are presumed to be generated from the 1-17 sequence by the action of peptidases found on capillary walls. The elucidation of the mechanisms involved is essential for an understanding of the metabolic pathways of gastrin.

Topics: Adult; Chromatography, Gel; Gastric Acid; Gastrins; Humans; Male; Peptide Fragments; Protein Precursors; Trypsin

A dose response study of the effect on gastric acid secretion of synthetic human gastrin-17 in doses of 50,200, and 500 ng/kg/h was performed in eight healthy volunteers and in eight patients with duodenal ulcer. The study was repeated on a separate day during intravenous infusion of calcium gluconate (0.1 mmol Ca2+/kg/h). In healthy subjects the acid response to the combined infusion of synthetic human gastrin and calcium did not significantly exceed the response to synthetic human gastrin alone, in contrast with patients with duodenal ulcer in whom the combined infusion did significantly improve acid output compared with infusion of synthetic human gastrin alone. The dose of synthetic human gastrin required for half maximal acid response (D50) was reduced in both groups but significantly more in patients with duodenal ulcer. No difference in serum gastrin concentrations or in serum calcium concentrations were found. It is hypothesised that extracellular calcium plays a role in gastrin stimulated acid secretion in man and that patients with duodenal ulcer are more sensitive to this calcium dependent mechanism than non-duodenal ulcer subjects.

Topics: Adult; Calcium Gluconate; Dose-Response Relationship, Drug; Duodenal Ulcer; Female; Gastric Acid; Gastrins; Gluconates; Hormones; Humans; Male; Middle Aged

A comparison was made between use of isotonic 0.15 M sodium chloride and 5.8 g/100 ml glucose solutions for measurement of gastric acid secretion by intragastric titration in normal and ulcer subjects. Glucose distention did not cause significantly different acid secretion than saline distention in either group. The total amounts of glucose entering the duodenum over the 3.5-hr study period were 99 g in normal subjects and 122 g in ulcer subjects. In normal subjects, circulating gastrin-related acid secretion curves were not significantly different during endogenous peptone and exogenous G-17 stimulation using either the glucose or the saline meals. This finding provides evidence that glucose meals of this size do not alter sensitivity to gastrin. With glucose meals, inhibition of gastric emptying caused retention of a sufficient volume in the stomach to permit accurate continuous intragastric titration. Saline meals caused pronounced diarrhea which was not seen after glucose meals. Glucose distention intragastric titration allows reliable comparisons of endogenously and exogenously stimulated gastric acid secretion without serious side effects and is especially suitable for studying acid secretion in duodenal ulcer subjects.

Topics: Adult; Aged; Duodenal Ulcer; Evaluation Studies as Topic; Food; Gastric Acid; Gastric Acidity Determination; Gastric Emptying; Gastrins; Glucose; Humans; Infusions, Parenteral; Male; Middle Aged; Peptones; Sodium Chloride; Time Factors

To identify the role of the block of glutamic acid residues characteristic for the gastrin molecule, a series of shortened peptides related to the human little-gastrin-I sequence were synthesized. The biological activities of these gastrin peptides strongly suggest in the pentaglutamic acid sequence a specific information for a pronounced amplification of the hormonal activity.

Topics: Amino Acid Sequence; Animals; Chemical Phenomena; Chemistry; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Gastric Acid; Gastrins; Glutamates; Humans; Peptide Fragments; Rats; Rats, Inbred Strains; Structure-Activity Relationship

A newly synthesized human big gastrin (G34) that was prepared according to the revised structure and that contained less than 3% oxidized methionine residues was compared with synthetic human little gastrin (G17) for acid-stimulating activity and clearance in human subjects. Prolonged infusions of each type of gastrin revealed that the time required to approach stable plasma concentrations was much longer for G34 than for G17. The time course of plasma gastrin concentration could be described by one-compartment models with half-lives of 44 min for G34 and 8 min for G17. After rapid intravenous infusion, G34 produced a much larger total acid response than did an equimolar dose of G17, and the responses were directly proportional to the integrated plasma gastrin increments. During the third hour of prolonged intravenous infusions of G34 and G17, the exogenous dosage of G34 required to produce the same blood concentration of gastrin was only one-fourth that of G17. Equivalent blood concentrations of G34 and G17 were associated with similar rates of acid secretion. These results suggest that G34 is more potent than has been thought, that it has an activity similar to that of G17 and that it must not be ignored in estimating total acid-stimulating activity of circulating gastrins. The measurement of total carboxyl-terminal immunoreactive gastrin can produce a good estimate of total acid-stimulating activity.

Topics: Adult; Aged; Duodenal Ulcer; Gastric Acid; Gastrins; Humans; Injections, Intravenous; Male; Middle Aged; Protein Precursors; Radioimmunoassay

The degradation of porcine and human gastrin-34, -17, and -14 in the isolated pig liver was investigated in 13 perfusion experiments. The concentrations of gastrins in the perfusate were measured by radioimmunoassay, and the molecular nature was determined by gel chromatography. Gastrin-34 was neither eliminated nor converted to other molecular forms, whereas gastrin-17 and -14 were both degraded in the liver, gastrin-17 being degraded to measurable smaller forms during the process. It is suggested that the liver plays an important part in the regulation of circulating gastrins.

Topics: Animals; Chromatography, Gel; Gastrins; Liver; Molecular Conformation; Perfusion; Protein Precursors; Radioimmunoassay; Swine

In the present paper pharmacological properties studied on the gastrointestinal tract of two new alkylaminoalkylphenylbenzisothiazole derivatives, 4-dimethylamino-2-phenyl-2-(1,2-benzisothiazole-3-yl)butyramide (PM2) and N,N-dimethyl-3-phenyl-3-(1,2-benzisothiazole-3-yl)propylamine (PM3) have been reported. Both drugs showed antispasmodic effects on gastroduodenal junction of the anaesthetized rat stimulated by Caerulein, according to previous results obtained on guinea-pig isolated ileum. On this substrate they were different in the potency being PM3 more active than PM2. On the contrary, the hypersecretion induced by Histamine or Gastrin-17 in rat perfused stomach was potentiated by PM2 and inhibited by PM3. Similar effects were observed on guinea-pig "in vitro" stomach preparation where PM2 and Papaverine were ineffective in modifying Histamine dose-response curves and PM3 reduced significantly maximal peak effects of Histamine, behaving as a non-competitive antagonist. The significant differences observed on gastric secretion but not on other substrates, from compounds structural analysis, appear scarcely justified and seem to us important to be further investigated.

Topics: Animals; Ceruletide; Digestive System; Dose-Response Relationship, Drug; Drug Synergism; Gastric Mucosa; Gastrins; Guinea Pigs; Histamine; Papaverine; Rats; Thiazoles

In order to study some of the molecular events during the hepatic passage of gastrin, we perfused sulfated natural porcine gastrin (G17 II) through isolated pig livers. The disappearance half time of G17 II was about 20-30 min when the starting gastrin concentrations were greater than 100 pM; lower concentrations were reduced with half times of 40-100 min. Synthetic human leu-32 (G34) was not eliminated. The use of region-specific antibodies to gastrin indicated that degradation was more effective at the N-terminus of gastrin. Whereas Sephadex chromatography revealed no change of the molecular size, SDS-polyacrylamide gel electrophoresis showed the presence of smaller immunoreactive fragments of gastrin in addition to immunoreactive fragments of gastrin of the heptadecapeptide size. These findings indicate that the isolated porcine liver degrades porcine G17 to smaller fragments.

Topics: Animals; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Gastrins; Humans; Liver; Protein Precursors; Swine

Sequence determination of peptides blocked by amino-terminal pyrrolidone carboxylic acid (PCA) has in the past been hampered by the lack of a reliable and efficient method for removing this residue. We report here a rapid, efficient enzymatic method for removal of PCA. Reversed-phase high-performance liquid chromatography is used to monitor the reaction and to separate unblocked peptide from the reaction product. The method allows direct sequence analysis of newly purified PCA blocked peptides, eliminating the need for complicated enzymatic digestions and chromatography to determine the amino-terminal residue. Only a few micrograms of peptide are required instead of the several milligrams needed in the past.

Topics: Amino Acids; Bombesin; Chemical Phenomena; Chemistry; Chromatography, High Pressure Liquid; Gastrins; Humans; Peptides; Protein Precursors; Pyroglutamyl-Peptidase I; Pyrrolidinones; Pyrrolidonecarboxylic Acid

Topics: Gastrins; Humans; Protein Precursors; Radioimmunoassay; Reagent Kits, Diagnostic; Zollinger-Ellison Syndrome

Histamine accumulated in the ligated vagus nerve of the rat, both above and below the ligature; maximum accumulation was after 4 h. The finding is suggestive of axonal flow. Further evidence for histamine in peripheral nerves was obtained in experiments showing that the guinea-pig gut wall could be labelled with [3H]histamine. The experiments were carried out with isolated strips of stomach wall and taenia coli. Electrical stimulation released [3H]histamine from these specimens. The release could be blocked by Ca2+-free medium or by tetrodotoxin. The release was unaffected by vagal denervation or chemical sympathectomy (6-hydroxydopamine) but prevented by reserpinization. Gastrin-17 and cholecystokinin-39 released radioactivity by a tetrodotoxin-sensitive mechanism. The possible existence of a gastrin/cholecystokinin-sensitive neuronal pool of histamine in the gut wall offers a new perspective on the postulated role of histamine as a physiological stimulant of gastric acid secretion and might explain why H2-receptor antagonists block gastrin-stimulated acid secretion.

Topics: Animals; Cholecystokinin; Colon; Electric Stimulation; Gastrins; Guinea Pigs; Histamine; Neurons; Peptide Fragments; Stomach; Synaptic Transmission; Vagus Nerve

To quantitate bombesin stimulation of gastric acid and pepsin via release of gastrin, five gastric fistula dogs were given graded doses (60-1,250 pmol X kg-1 X h-1) of bombesin tetradecapeptide and 40-2,000 pmol X kg-1 X h-1 of synthetic gastrin-17 (G-17). Acid and pepsin output and serum gastrin were proportional to the dose of stimulant. The half-maximal dose of bombesin for gastrin release was 200 pmol X kg-1 X h-1. Bombesin-stimulated acid secretion related to serum gastrin concentrations was congruent with the G-17 curve, but with a maximum of only 62% of the G-17 maximum before declining by 27% despite higher serum gastrin levels. This suggested that bombesin stimulates acid secretion only via gastrin release and inhibits at higher doses by releasing another inhibitory peptide, most likely somatostatin, which is also released by bombesin. The same mechanism could apply to supramaximal inhibition of acid and pepsin seen with high doses of G-17. Because the pepsin curve related to serum gastrin was to the left of the G-17 curve, we concluded that another secretagogue released by bombesin acts synergistically with gastrin on pepsin secretion. Therefore, bombesin stimulates gastric secretion through gastrin release, but its effects are modified by peptides coreleased to a) increase pepsin output at low doses and b) limit the output of acid and pepsin to 50-60% of the G-17 maximum.

Topics: Animals; Bombesin; Dogs; Gastric Juice; Gastrins; Half-Life; Hydrogen-Ion Concentration; Kinetics; Pepsin A; Peptides

Tyrosine phosphorylation seems to be a key event in the control of cellular growth. Several viral transforming proteins, including the src protein of Rous sarcoma virus, the p120 protein of Abelson leukaemia virus and the middle T antigen of polyoma virus, are phosphorylated by associated tyrosine kinases. The levels of kinase activity correlate with the transforming efficiency of the virus. The receptors for epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and insulin are also phosphorylated by associated tyrosine kinase activities, which are stimulated by EGF, PDGF and insulin, respectively. The EGF-stimulated kinase and the src protein share similar substrate specificity for tyrosines immediately C-terminal to a sequence of acidic amino acids. Such a sequence is also found adjacent to the phosphotyrosine of middle T antigen, and in the homologous region of the hormone gastrin, adjacent to a tyrosine which is sulphated in approximately half the gastrin isolated from gastric mucosa. Reports that gastrin acts as a growth factor for cells of the gastrointestinal tract suggested that phosphorylation of this tyrosine might be physiologically more relevant than sulphation. We report here that synthetic human gastrin 17 is phosphorylated by the EGF-stimulated tyrosine kinase of A431 cell membranes. The Km values of 53-87 and 223-547 microM obtained in the presence and absence of EGF, respectively, are the lowest reported so far for this enzyme.

Topics: Carcinoma, Squamous Cell; Cell Line; Cell Membrane; Chromatography, High Pressure Liquid; Epidermal Growth Factor; Gastrins; Humans; Phosphorylation; Protein Kinases; Protein-Tyrosine Kinases

After a meal the serum concentrations of the N-terminal tridecapeptide-like fragment of gastrin-17, (1-13)G-17, increased markedly in patients with active duodenal ulcer, but less so in healthy subjects. Consequently the synthetic (1-13)G-17 was infused intravenously in doses that resulted in concentrations similar to those measured in duodenal ulcer patients in order to examine whether the N-terminal fragment influences gastric acid secretion. Doses of 125 and 400 pmol (1-13)G-17/kg per h inhibited the meal-stimulated acid secretion by 36% (P less than 0.05) and 66% (P less than 0.05) respectively. The release of endogenous C-terminal gastrin immunoreactivity was not influenced. The infusion of (1-13)G-17 also inhibited the acid response to exogenous gastrin-34, gastrin-17 and Peptavlon, but not to gastrin-4. The results suggest that the N-terminal gastrin-17 fragment--although devoid of the hitherto considered only active site of gastrin--plays a significant role in the regulation of the gastric acid secretion in patients with active duodenal ulcer.

Topics: Adult; Binding Sites; Depression, Chemical; Duodenal Ulcer; Fasting; Female; Food; Gastric Acid; Gastrins; Humans; Male; Middle Aged; Peptide Fragments

The metabolism of the NH2-terminal tridecapeptide fragment of gastrin-17 (1-13)G-17) was examined in normal subjects and duodenal ulcer patients. A dose of 65 pmol synthetic human (1-13)G-17/kg/h was infused intravenously for 90 min. After cessation of infusion the disappearance curve was similar in the two groups. The mean half-life, volume of distribution, and clearance rate were, for normal and duodenal ulcer subjects, 6.3 and 6.3 min, 100 and 93 ml/kg, and 11.0 and 10.2 ml/kg/h, respectively. The gastric acidity decreased during the infusion in duodenal ulcer patients (54 +/- 11 to 40 +/- 10 meq/l (p less than 0.02] but not in normal subjects. The results suggest that the increased serum concentrations of the NH2-terminal fragment of gastrin-17 in duodenal ulcer patients are not caused by a decreased metabolism of (1-13)G-17. Moreover, the data show that (1-13)G-17 reduces gastric acid secretion.

Topics: Adult; Duodenal Ulcer; Female; Gastric Acid; Gastrins; Humans; Injections, Intravenous; Male; Middle Aged; Peptide Fragments

The concentration of the NH2-terminal fragment of gastrin-17 in serum was determined by radioimmunochemistry. Two antisera were used, one specific for the COOH-terminus and the other for the NH2-terminus of gastrin-17. The NH2-terminal gastrin-17 immunoreactivity in unfractionated serum correlated well with the amount of fragment found after gel filtration of the same sera (p less than 0.001). In healthy subjects (no. = 100), the NH2- and COOH-terminal gastrin immunoreactivity was 8 +/- 1 and 20 +/- 1 pmol/l (mean +/- SEM), respectively. In patients with acute duodenal ulcer (no. = 30) and acute gastritis (no. = 10) the NH2-terminal immunoreactivity was fourfold increased compared with in healthy subjects (p less than 0.001), whereas the COOH-terminal was identical, the NH2- and COOH-terminal concentrations being 33 +/- 7 and 22 +/- 2 pmol/l in duodenal ulcer and 35 +/- 6 and 21 +/- 1 pmol/l in acute gastritis. Other groups of patients had NH2- and COOH-terminal gastrin concentrations in serum similar to those measured in healthy subjects. The results suggest that gastrin cells process gastrin-17 abnormally during the acute phase of duodenal ulcer and gastritis.

Topics: Acute Disease; Adolescent; Adult; Aged; Amino Acid Sequence; Chromatography, Gel; Duodenal Ulcer; Female; Gastrins; Gastritis; Humans; Male; Middle Aged; Peptide Fragments; Radioimmunoassay

A radioimmunochemical procedure which distinguishes sulfated from non-sulfated gastrins has been developed. Two antisera raised against synthetic non-sulfated human hexadecapeptide gastrin were used. No. 2604 binds sulfated and non-sulfated gastrins with equimolar potency, whereas No. 2605 reacts poorly with sulfated gastrin (ID50 for non-sulfated gastrin: ID50 for sulfated gastrin = 0.06). Both antisera bind gastrins of different molecular length with equimolar potency using monoiodinated human gastrin-17 as tracer. The method was validated by fractionating gastrins in serum and in tissue extracts, and by recovery experiments. We found that Component I of gastrin--like the smaller gastrin components--was present in both, sulfated and non-sulfated form. In serum from normal fasting subjects the concentration of non-sulfated gastrin was 12.5 +/- 0.8 pmol/l (mean +/- SEM) with a total range of 0-44 pmol/l and the corresponding values for sulfated gastrin were 7.5 +/- 0.5 pmol/l (range 0-20 pmol/l). Sulfated gastrin accounted for more than half of the gastrins in only 21% of normal subjects. There was a parallel rise and fall in sulfated and non-sulfated gastrins after a meal and after stimulation with adrenaline.

Topics: Animals; Eating; Epinephrine; Gastrins; Humans; Pyloric Antrum; Radioimmunoassay; Sulfuric Acids; Swine; Zollinger-Ellison Syndrome

We compared serum gastrin concentrations and gastric acid secretion basally and in response to a mixed meal in age-matched women and men. Women had significantly higher basal serum gastrin concentrations (P < 0.01) and two- to threefold higher food-stimulated serum gastrin concentrations (P < 0.001) than men. Basal and food-stimulated serum gastrin concentrations in women did not fluctuate significantly during the menstrual cycle. Sex-related differences in food-stimulated serum gastrin concentrations were not due to differences in antral pH because pH after the meal in women and men had been kept constant at 5.0 by in vivo intragastric titration with sodium bicarbonate. Studies using an antibody that reacts only with potent gastrin heptadecapeptide species (G-17-I and II) indicated that women also had threefold higher serum G-17 concentrations after the meal than men (P < 0.005). Elevated serum G-17 concentrations after the meal in women were due to increased release of G-17 rather than slower clearance of G-17 from the circulation.Despite elevated serum gastrin concentrations in response to food, women secreted approximately the same amount of acid relative to their maximal secretory capacity as men. Furthermore, during exogenous G-17 infusion, which led to identical serum gastrin concentrations in women and men, the dose-response curve for acid secretion in women was shifted significantly to the right of the G-17 dose-response curve in men (P < 0.02). The dose of G-17 that stimulated half of peak acid secretion was two to three times higher in women than in men, reflecting significantly reduced sensitivity of parietal cells to gastrin in women (P < 0.05). Our studies suggest that, compared with men, women release greater amounts of gastrin but are at the same time less sensitive to stimulation of acid secretion by gastrin.

Topics: Adult; Eating; Female; Gastric Acid; Gastrins; Humans; Male; Middle Aged; Secretory Rate; Sex Factors

Human little gastrin-I is known to exhibit a high tendency to air-oxidation of its methionine-15 residue to the corresponding S-oxide derivative, with concomitant loss of biological activity. Since its leucine-15 analog, even if fully biologically active, differs significantly from the parent hormone in the immunological properties, the norleucine-15 and methoxinine-15 analogues were synthetized. For the required comparative analyses new syntheses of human little gastrin-I and of its leucine-15 analog were additionally elaborated. Upon an optimized condensation of the fragments, followed by the deprotection step, partition chromatography as well as preparative high-performance liquid chromatography led to the desired gastrins in satisfactory yields and high degree of purity as judged by the expected and known side products.

Topics: Amino Acid Sequence; Chemical Phenomena; Chemistry; Chromatography, High Pressure Liquid; Gastrins; Homoserine; Hormones; Humans; Magnetic Resonance Spectroscopy

The hepatic uptake of unlabeled synthetic human gastrin I (1-17) was determined in four unanesthetized patients who did not have hepatic or gastroduodenal disease. The hormone was given by brief infusion and at rates producing concentrations of immunoreactive gastrin within the physiologic range. We estimated the first-pass fractional hepatic uptake by comparing the results after a portal and a peripheral infusion in each patient. It was -0.01 +/- 0.14 (mean +/- SD), demonstrating lack of hepatic uptake of gastrin I (1-17) in humans.

Topics: Colonic Neoplasms; Gastrins; Half-Life; Humans; Kinetics; Liver; Middle Aged

Dibutyryl cyclic GMP has been reported to interact with antisera specific for C-terminal tetrapeptide amide common for cholecystokinin (CCK) and gastrin. Moreover, cyclic nucleotides elute by gel chromatography in the same position as the free CCK/gastrin tetrapeptide. Therefore, we have examined the reactivity of 25 mononucleotides with eight CCK and gastrin antisera. The results show that the nucleotides all bind poorly to the antisera (nucleotide concentration required greater than 1 mM). Hence, endogenous cyclic nucleotides, which are present in biological extracts in pM to nM concentrations, do not interfere with immunochemical CCK or gastrin measurements. The antisera displayed highly individual patterns of reactivity without preferential binding of di- or monobutyryl cyclic nucleotides (AMP, GMP or IMP). Thus, the present results do not support the idea of structural resemblance between the C-terminus of CCK/gastrin peptides and butyryl derivatives of cyclic GMP. Enzymatic treatment of the antral tetrapeptide-like immunoreactivity showed that nucleotides do not contribute to this material, which appears exclusively peptidergic.

Topics: Animals; Cholecystokinin; Gastrins; Hormones; Humans; Immune Sera; Peptide Fragments; Radioimmunoassay; Ribonucleotides; Structure-Activity Relationship; Swine

Smooth muscle cells were isolated from the stomach of the guinea pig, and the kinetics, stoichiometry, and specificity of contraction in response to the C-terminal octapeptides of cholecystokinin (CCK-OP), gastrin-17, and acetylcholine were examined. All three agonists elicited dose-dependent peak contraction that did not depend on the presence of extra-cellular calcium. The potencies of CCK-OP and gastrin-17 were equal (D50, 10(-11) M) and 10 times greater than the potency of acetylcholine (D50, 10(-10) M). A combination of low doses of acetylcholine and CCK-OP was synergistic; however, its effect did not exceed the maximal responses to either agonists alone or to high extracellular concentrations of calcium. The specificity of the receptors was established by the use of atropine and the two CCK-receptor antagonists dibutyryl cGMP and proglumide. The span of the dose-response curves was wide, suggesting the existence of receptor heterogeneity. It is concluded that gastric smooth muscle cells of the guinea pig possess distinct, high-affinity receptors for CCK-gastrin and acetylcholine; the receptors mediate contraction that is not immediately dependent on the presence of extracellular calcium.

Topics: Animals; Cholecystokinin; Dose-Response Relationship, Drug; Gastrins; Guinea Pigs; Hormones; In Vitro Techniques; Kinetics; Male; Muscle Contraction; Muscle, Smooth; Peptide Fragments; Receptors, Cell Surface; Sincalide; Stomach

Acid and pepsin secretion was stimulated by graded doses of synthetic human gastrin I (G-17-I) and pentagastrin (G-5) in six conscious gastric fistula dogs, three with intact vagi and three with fundic vagotomy. Metabolic clearance rate of G-17 was 15.2 ml.kg-1.min-1 and volume of distribution was 15.8%. Gastrin levels decayed in two slopes: t1/2 of 6.8 min and 25-35 min, respectively. These were compared with other published data. Vmax was higher in intact stomachs and at doses or blood levels of gastrin about three to four times smaller. G-17 was almost four times more potent (molar basis) than G-5. Responses were log linearly related to G-17 dose and to serum G-17 during infusion (incremental) and after stopping infusion (decremental). Normalized decremental curves were congruent in all dogs but displaced fivefold (625 vs. 130 pmol/l) to the right at midpoint. Vagotomy changed only association (incremental) kinetics (Km = 352 pmol/l). The previously undescribed difference between blood concentration-effect relationship during drug administration and withdrawal may be important in situations in which blood levels are used as therapeutic guide.

Topics: Animals; Dogs; Dose-Response Relationship, Drug; Gastric Acid; Gastric Juice; Gastrins; Kinetics; Pentagastrin; Pepsin A; Stomach; Vagotomy

Topics: Animals; Biological Assay; Carbonic Anhydrases; Gastric Mucosa; Gastrins; Guinea Pigs; Hormones; Humans; In Vitro Techniques; Male; Pyloric Antrum; Stomach

Topics: Animals; Chromatography, Gel; Dogs; Gastric Mucosa; Gastrins; Hormones; In Vitro Techniques; Metabolic Clearance Rate; Peptide Fragments; Protein Precursors; Pyloric Antrum; Radioimmunoassay

Topics: Chromatography, Affinity; Chromatography, Gel; Duodenal Ulcer; Duodenum; Gastrectomy; Gastrins; Humans; Protein Precursors; Pyloric Antrum; Radioimmunoassay

Topics: Chromatography, Ion Exchange; Gastrins; Humans; Liver Neoplasms; Prognosis; Radioimmunoassay; Zollinger-Ellison Syndrome

The effect on gastric acid secretion and the elimination of a commercially available synthetic human gastrin analogue (15-Leucine Synthetic Human Gastrin I, 15-LSG) were studied in six healthy human subjects. On a molar basis acid secretory efficacy was approximately four times greater than pentagastrin and secretory potency ten times greater. Elimination of 15-LSG was bi-exponential, with half-lives of 5.2 +/- 0.8 and 25.9 +/- 7.0 min. Metabolic clearance rate was 6.9 +/- 0.4 ml/kg-min and volume of distribution 52 ml/kg.

Topics: Adult; Female; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Male; Metabolic Clearance Rate; Middle Aged; Reference Values; Secretory Rate

Topics: Animals; Colon; DNA; Duodenum; Gastrins; Ileum; Intestinal Mucosa; Jejunum; Male; Rats; RNA

Topics: Amino Acid Sequence; Animals; Carbonic Anhydrases; Cholecystokinin; Enzyme Activation; Female; Gastrins; Guinea Pigs; Hormones; Humans; In Vitro Techniques; Pentagastrin; Peptide Fragments; Peptides; Rats; Sincalide; Stomach

Topics: Animals; Cholecystokinin; Diazepam; Dose-Response Relationship, Drug; Exploratory Behavior; Feeding Behavior; Female; Gastrins; Male; Mice; Mice, Inbred Strains; Peptide Fragments; Sincalide

Synthetic human non-sulphated gastrin heptadecapeptide (little gastrin) and tetradecapeptide (minigastrin) are equipotent stimulants of gastric acid and pepsin secretions in the conscious cat. This supports the thesis that minigastrin is a major physiologically active, circulating form of the hormone in the cat. It is estimated that little gastrin and minigastrin contribute equally to the gastric acid response to a protein meal in the cat.

Topics: Animals; Cats; Gastric Juice; Gastrins; Hormones; Humans; Pepsin A; Stimulation, Chemical

Frog skin was mounted in an Ussing chamber and the actions of caerulein, gastrin, pentagastrin, and secretin on the active transport of sodium were studied using the short-circuit current method. All polypeptides exerted their effect when placed in the solution bathing the outside surface of the skin. The response was a transient dose-related increase in the transepithelial electrical potential difference and in the short-circuit current. Analysis of the response indicated that at submaximal doses the effect was due to an increase in the rate of entry of sodium through the outer barrier to active sodium transport. At supramaximal doses the passive permeability of the skin was also increased. Th ED50 concentrations of the hormones were: caerulein, 50 pM; gastrin, 53 pM; pentagastrin, 440 pM; and secretin, 30 pM. It is argued that the large quantity of caerulein or caerulein-like peptides stored in the skin may be required either to control the entry of sodium when the amphibian is undergoing maximum stress in a freshwater environment, or that it may have a protective function for the amphibian as it could elicit a noxious hypersecretion in the gastrointestinal tract of the predator together with a marked hypotension.

Topics: Animals; Biological Transport, Active; Ceruletide; Dose-Response Relationship, Drug; Gastrins; Membrane Potentials; Pentagastrin; Rana pipiens; Secretin; Skin; Sodium

The heptadecapeptide form of rat gastrin was purified by a combination of DEAE cellulose, Sephadex G50 affinity, and high performance liquid chromatography. An amino terminal pyroglutamyl blocking group was removed by incubation with PCA peptidase. Amino acid analysis before and after the unblocking reaction revealed the presence of one additional residue of arginine and proline compared with porcine gastrin. Microsequencing analysis of the unblocked peptide revealed that the sequence of the remaining hexadecapeptide was RPPMEEEEEAYGWMDF. The corresponding sequence of porcine gastrin is GPWMEEEEEAYGWMDF amide. The presence of carboxyl-terminal amide group in rat gastrin is strongly supported by complete immunoreactivity with antibodies specific for amidated C-terminal sequences of mammalian gastrins. The Arg and Pro substitutions in the amino terminal region can explain poor crossreactivity of rat gastrin with antibodies specific for the amino-terminal portion of porcine or human gastrin and its more basic chromatography pattern on ion exchange resins.

Topics: Amino Acid Sequence; Amino Acids; Animals; Chromatography, Affinity; Chromatography, DEAE-Cellulose; Chromatography, Gel; Chromatography, High Pressure Liquid; Gastric Mucosa; Gastrins; Humans; Pyloric Antrum; Rats; Rats, Inbred Strains; Swine

Studies were performed in six men to determine the relationship between serum gastrin concentration and gastric function during exogenous and endogenous stimulation of gastrin release. When the intragastric pH was maintained at 5.0, there were dose-related increases in gastric acid secretion with increasing serum gastrin concentrations produced either by stepwise increasing doses of intravenous gastrin or bombesin, or by intragastric perfusion with peptone. When intragastric pH was maintained at 2.5, or when intravenous atropine was given hourly, sensitivity to both exogenous and endogenously released gastrin were similarly decreased. Gastric emptying was inhibited in a dose-dependent manner by both bombesin and peptone but not by exogenous gastrin. These results suggest that bombesin and peptone stimulate gastric acid secretion through release of circulating gastrin but inhibit gastric emptying by another mechanism.

Topics: Adult; Aged; Bombesin; Dose-Response Relationship, Drug; Gastric Acid; Gastric Emptying; Gastrins; Humans; Hydrogen-Ion Concentration; Kinetics; Male; Middle Aged; Peptides; Peptones

Twenty-four male albino rats were given daily intraperitoneal injections of vasoactive intestinal polypeptide (VIP), motilin, human gastrin I (1-17) or the diluent control vehicle at a dose of 100 micrograms/kg for four consecutive days and food intake, water intake, body weight, and running wheel activity were determined every 24 hours. Animals injected with motilin or human gastrin I (1-17) exhibited decreased food intake relative to those injected with VIP or diluent, which did not differ from each other, although food intake increased reliably over days. The mean water consumption followed the same pattern as that of food intake. As expected from the above results, VIP produced weight gains as compared with rats injected with motilin or gastrin but not reliably more than after diluent. A reliable effect of trials for weight gain was the greatest on day three. Running wheel activity was not affected by injections of human gastrin I (1-17), motilin, or diluent but was reliably decreased by VIP. No significant differences existed across days. Although the results indicate that GI peptides may affect behavior when injected systemically and that like other peptides they have multiple effects, caution is urged in the interpretation of behavioral results at this time.

Topics: Animals; Behavior, Animal; Body Weight; Drinking; Eating; Gastrins; Gastrointestinal Hormones; Male; Motilin; Motor Activity; Rats; Rats, Inbred Strains; Vasoactive Intestinal Peptide

Human gastrin I heptadecapeptide, infused intravenously to healthy volunteers in a dose of 0.5 micrograms/kg/hr, caused a prompt, significant reduction in gastric potential difference (decrease of mucosal negativity), with the peak change at 6 min. This decline in potential difference occurred at a time when the serum gastrin level was between 24 and 83 pg/ml; at the same time, scanning electron microscopic examination of fractographs of parietal cells demonstrated marked increase in canalicular membrane area. This study shows that the decrease in potential difference after gastrin occurs with serum gastrin levels which are in the physiologic range.

Topics: Action Potentials; Adult; Depression, Chemical; Female; Gastric Mucosa; Gastrins; Hormones; Humans; Hydrogen-Ion Concentration; Infusions, Parenteral; Male; Microscopy, Electron, Scanning

An intravenous bolus of pentagastrin significantly increased the amplitude and duration of oesophageal body contractions in seven patients with diffuse oesophageal spasm (DES) when compared with five normal subjects (P greater than 0.05). In order to determine whether this stimulation also occurred at physiological gastrin concentrations, the effect of an intravenous infusion of gastrin heptadecapeptide (G17), 25 pmol/kg-h, on oesophageal contractions was studied in DES patients. G17 had no significant effect on the amplitude and duration of oesophageal contractions compared with a saline control. This dose of G17 was near the D50 for gastric acid secretion and produced a rise in serum gastrin concentration comparable with a meal. G17 infusions at doses of 100 and 200 pmol/kg-h increased the amplitude and duration of oesophageal contractions, but the corresponding serum gastrin concentrations were higher than postprandial levels. Thus, endogenous fluctuations in serum gastrin heptadecapeptide, alone, are unlikely to alter oesophageal contractions in DES patients.

Topics: Adult; Aged; Dose-Response Relationship, Drug; Esophageal Diseases; Esophagus; Female; Gastrins; Humans; Infusions, Parenteral; Male; Middle Aged; Muscle Contraction; Pentagastrin; Spasm