gastrins and Disease-Models--Animal

Neuroendocrine tumors (NETs) were initially identified as a separate entity in the early 1900s as a unique malignancy that secretes bioactive amines. GI-NETs are the most frequent type and represent a unique subset of NETs, because at least 75% of these tumors represent gastrin stimulation of the enterochromaffin-like cell located in the body of the stomach. The purpose of this review is to understand the specific role of gastrin in the generation of Gastric NETs (G-NETs).. We review here the origin of enterochromaffin cells gut and the role of hypergastrinemia in gastric enteroendocrine tumorigenesis. We describe generation of the first genetically engineered mouse model of gastrin-driven G-NETs that mimics the human phenotype. The common mechanism observed in both the hypergastrinemic mouse model and human carcinoids is translocation of the cyclin-dependent inhibitor p27

Topics: Animals; Carcinoid Tumor; Cyclin-Dependent Kinase Inhibitor p27; Cytoplasm; Disease Models, Animal; Enterochromaffin-like Cells; Gastrins; Humans; Mice; Neuroendocrine Tumors; Phenotype; Receptor, Cholecystokinin B; Stomach Neoplasms

Gastric cancer is the third leading cause of cancer-related mortality worldwide. This is in part due to the asymptomatic nature of the disease, which often results in late-stage diagnosis, at which point there are limited treatment options. Even when treated successfully, gastric cancer patients have a high risk of tumor recurrence and acquired drug resistance. It is vital to gain a better understanding of the molecular mechanisms underlying gastric cancer pathogenesis to facilitate the design of new-targeted therapies that may improve patient survival. A number of chemically and genetically engineered mouse models of gastric cancer have provided significant insight into the contribution of genetic and environmental factors to disease onset and progression. This review outlines the strengths and limitations of current mouse models of gastric cancer and their relevance to the pre-clinical development of new therapeutics.

Topics: Animals; Disease Models, Animal; Gastrins; Helicobacter felis; Helicobacter Infections; Helicobacter pylori; Methylnitrosourea; Mice, Inbred Strains; Mice, Transgenic; Molecular Targeted Therapy; Stomach Neoplasms

Gastrin controls gastric acid secretion and mucosal cell growth, especially of enterochromaffin-like cells, via gastrin/cholecystokinin-2 receptor (CCK

Topics: Animals; Antineoplastic Agents; Benzodiazepinones; Disease Models, Animal; Drug Design; Gastric Acid; Gastrins; Humans; Neuroendocrine Tumors; Pancreatic Neoplasms; Phenylurea Compounds; Receptor, Cholecystokinin B; Stomach Neoplasms

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Studying menin and its complex interrelationship with gastrin may provide insight into tumor biology at the clinical level and in terms of basic cell biology (eg, the role of the epigenome in neuroendocrine cell proliferation), and lead to potential consideration of other targets that are known candidates for molecular-based therapies in other adenocarcinomas.

Topics: Animals; Carcinoid Tumor; Disease Models, Animal; Gastrins; Humans; Stomach Neoplasms

Patients with chronic hypergastrinemia due to chronic atrophic gastritis or gastrinomas have an increased risk of developing gastric malignancy, and it has been questioned whether also patients with hypergastrinemia caused by long-term use of acid inhibiting drugs are at risk. Gastric carcinogenesis in humans is affected by numerous factors and progresses slowly over years. When using animal models with the possibility of intervention, a complex process can be dissected by studying the role of hypergastrinemia in carcinogenesis within a relatively short period of time. We have reviewed findings from relevant models where gastric changes in animal models of long-term hypergastrinemia have been investigated. In all species where long-term hypergastrinemia has been induced, there is an increased risk of gastric malignancy. There is evidence that hypergastrinemia is a common causative factor in carcinogenesis in the oxyntic mucosa, while other cofactors may vary in the different models.

Topics: Animals; Disease Models, Animal; Gastrins; Mice; Rats; Stomach Neoplasms

Topics: Animals; Disease Models, Animal; Gastrins; Gastrointestinal Diseases; Gastrointestinal Neoplasms; Humans; Pancreas; Peptic Ulcer; Protein Precursors

Gastric hypoacidity and hypergastrinaemia are seen in several conditions associated with an increased risk of gastric malignancy. Hypoacidity and hypergastrinaemia are closely related and their long-term effects are difficult to study separately in patients. Studies using animal models can provide valuable information about risk factors and mechanisms in gastric cancer development as the models allow a high degree of intervention when introducing or eliminating factors possibly affecting carcinogenesis. In this report, we briefly review findings from relevant animal studies on this topic. Animal models of gastric hypoacidity and hypergastrinaemia provide evidence hypergastrinaemia is a common causative factor in many otherwise diverse settings. In all species where sufficient hypoacidity and hypergastrinaemia have been induced, a proportion of the animals develop malignant lesions in the gastric oxyntic mucosa.

Topics: Achlorhydria; Animals; Cell Proliferation; Cell Transformation, Neoplastic; Disease Models, Animal; Enterochromaffin-like Cells; Gastric Acid; Gastric Mucosa; Gastrins; Humans; Receptor, Cholecystokinin B; Risk Assessment; Risk Factors; Stomach; Stomach Neoplasms

Our understanding of the function and etiology of various gastric diseases has exponentially expanded over the past 40 years. In particular, several animal models had been devised and used for screening of anti-ulcer drugs and elucidation of pathogenesis. This review describes how water-immersion stress ulcer model, Helicobacter pylori ulcer model, and acetic acid ulcer models were established in experimental animals. In recent years, genetically modified mice allowed rapid accumulation of very important findings. H(2)-receptor knockout mice revealed to exhibit Menetrier's disease-like gastric mucosal changes. Gastrin-transgenic mice infected with H. pylori revealed to develop gastric cancer. The hypothesis for the origin of parietal cells was provided.

Topics: Acetates; Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis, Hypertrophic; Helicobacter Infections; Helicobacter pylori; Humans; Immersion; Mice; Mice, Knockout; Mice, Transgenic; Rats; Receptors, Histamine H2; Stomach Ulcer; Stress, Physiological

Helicobacter pylori infection has been found to decrease the expression of antral somatostatin and to increase the release of the acid-stimulating hormone gastrin. The reversal of these changes in gut hormones by the eradication of H. pylori, and in-vivo and in-vitro studies in animals either infected with H. pylori or exposed to H. pylori-related materials may support the somatostatin-gastrin link theory in the pathophysiology of H. pylori infection. The following mechanisms have been proposed to explain the H. pylori infection-associated changes in gut hormones; (1) ammonia produced by H. pylori and monochloramine, (2) effect on somatostatin receptor subtype-2, (3) action of lipopolysaccharide from H. pylori on somatostatin receptor, (4) inflammatory cells and mediators, and (5) bacterial strain diversity. H. pylori infection can alter gastric acid secretion in both directions. The elevated acid secretion in patients with duodenal ulcer is decreased by H. pylori eradication, and is accompanied by the normalization of gut hormones in patients whose H. pylori-induced gastritis is limited to the antrum with hyperacidity. Corpus gastritis and the subsequent development of mucosal atrophy induced by H. pylori result in decreased acid secretion, although the mechanism underlying H. pylori-induced atrophy in some subjects remains unclear. Hypoacidity enhances corpus atrophy and increases gastrin secretion, mediated via a physiological suppression of somatostatin release, features that are also observed in H. pylori infection. Therefore, the capacity of acid secretion and distribution of gastritis or atrophy should be taken into consideration when we discuss the affect of H. pylori on gut hormones.

Topics: Animals; Disease Models, Animal; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen-Ion Concentration; Somatostatin

Gastrin is the principal hormonal inducer of gastric acid secretion. Chronic hypergastrinemia, leading to hypersecretion of gastric acid and increased proliferation of parietal and enterochromaffin-like (ECL) cells, has been well described. In contrast, the physiological consequences of chronic gastrin deficiency had been poorly understood until the recent genetic engineering of mouse mutants containing a gastrin gene deletion by homologous recombination in embryonic stem cells. This themes article describes the consequences of constitutive gastrin deficiency on the development and physiology of the stomach. A lack of gastrin disrupts basal gastric acid secretion and renders the acid secretory system unresponsive to acute histaminergic, cholinergic, and gastrinergic stimulation. The defect in acid secretion is greater than would have been predicted from previous studies in which gastrin action was acutely blocked. Cellular changes include thinning of the gastric mucosa in the gastrin-deficient mice, with a reduction in parietal cells and reduced expression of markers of parietal and ECL cell-differentiated functions. The results suggest that gastrin is required for the functional maturation of the acid-secretory system.

Topics: Animals; Disease Models, Animal; Gastric Acid; Gastric Mucosa; Gastrins; Gene Deletion; Genetic Engineering; Mice; Mice, Knockout; Stomach

Drug-induced achlorhydria in experimental animals results in excessive hypergastrinaemia, ECL-cell hyperplasia and ECL-cell carcinoidosis. However, these events have not been observed in long-term studies in patients receiving proton pump inhibitors. Serum gastrin levels increase only modestly during acute and long-term treatment. It is concluded that monitoring of serum gastrin levels and of fundic ECL cells is of no clinical relevance even during long-term therapy with proton pump inhibitors. The clinically available proton pump inhibitors such as pantoprazole, omeprazole and lansoprazole are well tolerated, with a low incidence of side-effects. Minor and serious side-effects classified as possibly related to proton pump therapy have been described in up to 2.5% of patients. This is the same order of magnitude as that found in patients treated with H2-receptor blockers and in placebo-treated controls. In most cases, therefore, the observed side-effects are unrelated to the intake of proton pump inhibitors. Minor adverse events include headache, diarrhoea, dizziness, pruritus and rash. Proton pump inhibitors are metabolized mainly in the liver via the cytochrome P450 system and interactions with drugs metabolized by the same system are possible. Evidence is becoming available which suggests that pantoprazole may have less potential to interact with the cytochrome P450 system than the other proton pump inhibitors. In the case of diazepam metabolism, pantoprazole had the least effect on prolongation of the diazepam effect. This may well be an advantage in the clinical use of the drug.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Animals; Benzimidazoles; Cytochrome P-450 Enzyme System; Disease Models, Animal; Drug Interactions; Enterochromaffin Cells; Gastrins; Humans; Lansoprazole; Omeprazole; Pantoprazole; Peptic Ulcer; Proton Pump Inhibitors; Sulfoxides

In hormone-producing tumors such as the carcinoids, overproduction of certain hormones may activate proto-oncogenes. Hormones, or growth factors, thus can be of importance for growth regulation. Information is presented on some growth factors and their receptors in this respect and on the involvement of gastrin and its receptor on tumor development in the experimental Mastomys model. The relevance of differential expression of cell adhesion molecules in endocrine tumors is discussed also.

Topics: Animals; Carcinoid Tumor; Cell Adhesion Molecules; Disease Models, Animal; Gastrins; Gastrointestinal Neoplasms; Growth Substances; Humans; Muridae

The patient with gastric ulcer (GU) has abnormal reflux of bile-containing duodenal contents into the stomach. Antral gastritis is prominently associated with GU and is more extensive with severe reflux and with ulcer chronicity and probably when bile salts are accompanied by other constituents of duodenal fluids. Smoking is significantly associated with GU, and it produces reflux in normal subjects and in patients with duodenal ulcer, which in turn is commonly associated with GU. Reflux has not been shown to precede either the gastritis or the gastric ulcer and probably persists despite ulcer healing. The pyloric spincter in the patient with GU probably contracts subnormally to endogenous or exogenous secretin or CCK. This can be explained by associated hypergastrinemia since antral acidification improves the response. Because the pylorus may be usually open, abnormal reflux may be related as much or more to disturbances of other gastroduodenal functions known to control the movement of chyme through what may be a relatively passive pyloric zone. Speculation from animal models implicates bile reflux in aspirin-induced and shock-related gastric ulceration and assigns to bile a possible explanation, in part at least, for the apparent therapeutic efficacy of a carbenoxalone derivative and an antipepsin agent. Similar speculation warrants a search in the patient with GU for abnormalities of gastroduodenal peristalsis-related electric activity and for impaired release of secretin, possibly from antral cells of production. Possible abnormal purinergic inhibition of the gastric fundus and pylorus also warrants further study.

Topics: Animals; Bile; Cholecystokinin; Disease Models, Animal; Duodenum; Gastric Mucosa; Gastrins; Gastritis; Gastroesophageal Reflux; Humans; Pyloric Antrum; Pylorus; Secretin; Stomach Ulcer

In patients with autoimmune atrophic gastritis and achlorhydria, hypergastrinemia is associated with the development of type 1 gastric neuroendocrine tumors (gNETs). Twelve months of treatment with netazepide (YF476), an antagonist of the cholecystokinin B receptor (CCKBR or CCK2R), eradicated some type 1 gNETs in patients. We investigated the mechanisms by which netazepide induced gNET regression using gene expression profiling.. We obtained serum samples and gastric corpus biopsy specimens from 8 patients with hypergastrinemia and type 1 gNETs enrolled in a phase 2 trial of netazepide. Control samples were obtained from 10 patients without gastric cancer. We used amplified and biotinylated sense-strand DNA targets from total RNA and Affymetrix (Thermofisher Scientific, UK) Human Gene 2.0 ST microarrays to identify differentially expressed genes in stomach tissues from patients with type 1 gNETs before, during, and after netazepide treatment. Findings were validated in a human AGS. Levels of pappalysin 2 (PAPPA2) messenger RNA were reduced significantly in gNET tissues from patients receiving netazepide therapy compared with tissues collected before therapy. PAPPA2 is a metalloproteinase that increases the bioavailability of insulin-like growth factor (IGF) by cleaving IGF binding proteins (IGFBPs). PAPPA2 expression was increased in the gastric corpus of patients with type 1 gNETs, and immunohistochemistry showed localization in the same vicinity as CCK2R-expressing enterochromaffin-like cells. Up-regulation of PAPPA2 also was found in the stomachs of INS-GAS mice. Gastrin increased PAPPA2 expression with time and in a dose-dependent manner in gastric AGS. In an analysis of human gNETS and mice, we found that gastrin up-regulates the expression of gastric PAPPA2. Increased PAPPA2 alters IGF bioavailability, cell migration, and tissue remodeling, which are involved in type 1 gNET development. These effects are inhibited by netazepide.

Topics: Animals; Benzodiazepines; Benzodiazepinones; Cell Line, Tumor; Disease Models, Animal; Gastric Mucosa; Gastrins; Gene Knockdown Techniques; Humans; Mice; Mice, Transgenic; Neuroendocrine Tumors; Organoids; Phenylurea Compounds; Pregnancy-Associated Plasma Protein-A; Primary Cell Culture; Receptor, Cholecystokinin B; Stomach Neoplasms; Treatment Outcome

It is known that increased gastrin concentration is negatively correlated with cardiovascular mortality, and plasma gastrin levels are increased in patients after myocardial infarction (MI). However, whether gastrin can play a protective role in MI remains unknown.. Adult C57BL/6 mice were subjected to ligation of the left anterior descending coronary artery (LAD) and subcutaneous infusion of gastrin (120 μg/Kg body weight/day, 100 μL in the pump) for 28 days after MI. Plasma gastrin concentrations were measured through an ELISA detection kit. Mice were analyzed by echocardiography after surgery. CD31 and VEGF expression were quantified using immunofluorescence staining or/and western blot to assess the angiogenesis in peri-infarct myocardium. Capillary-like tube formation and cell migration assays were performed to detect gastrin-induced angiogenesis.. We found that gastrin administration significantly ameliorated MI-induced cardiac dysfunction and reduced fibrosis at 28 days in post-MI hearts. Additionally, gastrin treatment significantly decreased cardiomyocyte apoptosis and increased angiogenesis in the infarct border zone without influencing cardiomyocyte proliferation. In vitro results revealed that gastrin up-regulated the PI3K/Akt/vascular endothelial growth factor (VEGF) signaling pathway and promoted migration and tube formation of human coronary artery endothelial cells (HCAECs). Cholecystokinin 2 receptor (CCK. Our data revealed that gastrin promoted angiogenesis and improved cardiac function in post-MI mice, highlighting its potential as a therapeutic target candidate.

Topics: Animals; Apoptosis; Biomarkers; Cardiotonic Agents; Disease Management; Disease Models, Animal; Disease Susceptibility; Echocardiography; Echocardiography, Three-Dimensional; Gastrins; Heart Function Tests; Immunohistochemistry; Male; Mice; Myocardial Infarction; Myocytes, Cardiac; Neovascularization, Physiologic; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Vascular Endothelial Growth Factor A

Enterochromaffin-like (ECL) cells in the stomach express gastrin/cholecystokinin 2 receptor CCK2R and are known to expand under hypergastrinemia, but whether this results from expansion of existing ECL cells or increased production from progenitors has not been clarified.. We used mice with green fluorescent protein fluorescent reporter expression in ECL cells (histidine decarboxylase [Hdc]-green fluorescent protein), as well as Cck2r- and Hdc-driven Tamoxifen inducible recombinase Cre (Cck2r-CreERT2, Hdc-CreERT2) mice combined with Rosa26Sor-tdTomato (R26-tdTomato) mice, and studied their expression and cell fate in the gastric corpus by using models of hypergastrinemia (gastrin infusion, omeprazole treatment).. Hdc-GFP marked the majority of ECL cells, located in the lower third of the gastric glands. Hypergastrinemia led to expansion of ECL cells that was not restricted to the gland base, and promoted cellular proliferation (Ki67) in the gastric isthmus but not in basal ECL cells. Cck2r-CreERT2 mice marked most ECL cells, as well as scattered cell types located higher up in the glands, whose number was increased during hypergastrinemia. Cck2r-CreERT2. We show here that hypergastrinemia induces ECL cell hyperplasia that is derived primarily from CCK2R

Topics: Animals; Disease Models, Animal; Enterochromaffin-like Cells; Gastric Mucosa; Gastrins; Humans; Hyperplasia; MAP Kinase Signaling System; Mice; Receptor, Cholecystokinin B; Stem Cells

An account is given of the process by which the Primary Hyperacidity pathogenesis of Pyloric Stenosis of Infancy (PS) evolved. The initial discovery that fasting gastrins were high at birth and continued to rise within the first 4 days was the starting point. Since acidity was also rising at the same time it was proposed that the usual negative feed-back between gastrin and stomach acidity was not mature in the first few weeks of life. The gastrin model for producing PS in puppy dogs was a further incentive to believe that relatively high gastrins, and secondary high acidity would thereby repeatedly cause sphincter contraction and lead to hypertrophy. When gastrin was found to be normal in PS babies we considered and accepted, the less complicated hypothesis that a Primary Inherited Hyperacidity itself was the driving force. Such a theory explained nearly all the clinical features. When we further considered the expected consequences of an initially ineffective negative feed -back and its later maturation, the known peak acidity in neonatal development was explained. This phenomenon also provided an explanation for the remaining previously unexplained time sensitive features of the condition.

Topics: Animals; Disease Models, Animal; Dogs; Fasting; Gastrins; Humans; Hypertrophy; Infant; Pyloric Stenosis

To investigate the effect of Poria and effective constituents on gastrointestinal injury animals in the area of the side effects which caused by Rhubarb. Mice were administered i.g. with Rhubarb until the induction of diarrhea followed by gastrointestinal injury. The gastrointestinal injured mice were treated with high, medium and low doses of poria water extract and it's subfractions for 5 days. All indexes were determined to evaluate the action of poria in the pair treatment. The results showed that the higher dose of poria water decoction was discovered to be the most effective dose to treat gastrointestinal injury induced by rhubarb. Body weight, thymus and spleen indexes, the small intestinal propulsion rate and D-xylose absorption in mice with diarrhea and intestinal injury were analyzed to reveal the significant difference with the model group (P<0.01). EAF (Ethyl Acetate Fraction), PEF (Petroleum Ether Fraction) and CPF (Crude Polysaccharide Fraction) not only increase the levels of AMS, GAS and VIP significantly but also ameliorate diarrhea and intestinal injury situation compared with the model group (P<0.01). EAF, PEF and CPF were the most effective components to alleviate diarrhea and gastrointestinal injury induced by rhubarb.

Topics: Amylases; Animals; Colon; Defecation; Diarrhea; Disease Models, Animal; Female; Gastrins; Gastrointestinal Agents; Intestine, Small; Male; Mice; Rheum; Vasoactive Intestinal Peptide; Wolfiporia; Xylose

Pain is associated with negative emotions such as anxiety, but the underlying neurocircuitry and modulators of the association of pain and anxiety remain unclear. The neuropeptide cholecystokinin (CCK) has both pronociceptive and anxiogenic properties, so we explored the role of CCK in anxiety and nociception in the central amygdala (CeA), a key area in control of emotions and descending pain pathways. Local infusion of CCK into the CeA of control rats increased anxiety, as measured in the light-dark box test, but had no effect on mechanical sensitivity. By contrast, intra-CeA CCK infusion 4 days after Complete Freund's Adjuvant (CFA) injection into the hindpaw resulted in analgesia, but also in loss of its anxiogenic capacity. Inflammatory conditions induced changes in the CeA CCK signaling system with an increase of CCK immunoreactivity and a decrease in CCK1, but not CCK2, receptor mRNA. In CFA rats, patch-clamp experiments revealed that CCK infusion increased CeA neuron excitability. It also partially blocked the discharge of wide dynamic range neurons in the dorsal spinal cord. These effects of CCK on CeA and spinal neurons in CFA rats were mimicked by the specific CCK2 receptor agonist, gastrin. This analgesic effect was likely mediated by identified CeA neurons projecting to the periaqueductal gray matter that express CCK receptors. Together, our data demonstrate that intra-CeA CCK infusion activated a descending CCK2 receptor-dependent pathway that inhibited spinal neuron discharge. Thus, persistent pain induces a functional switch to a newly identified analgesic capacity of CCK in the amygdala, indicating central emotion-related circuit controls pain transmission in spinal cord.

Topics: Amygdala; Animals; Cholecystokinin; Dark Adaptation; Disease Models, Animal; Exploratory Behavior; Freund's Adjuvant; Gastrins; Glutamate Decarboxylase; Inflammation; Male; Neurons; Nociception; Pain; Pain Threshold; Periaqueductal Gray; Rats; Rats, Sprague-Dawley; Receptor, Cholecystokinin B; Signal Transduction; Sincalide; Tetragastrin

Sleeve gastrectomy with ileal transposition has been shown to be superior to sleeve gastrectomy alone for promoting weight loss in rat and porcine models. The absence of a mouse model for this procedure has impeded efforts to understand the molecular physiology underlying its efficacy. This study demonstrates the long-term survivability of sleeve gastrectomy with ileal transposition in mice.. In this study of technical feasibility, a sleeve gastrectomy with ileal transposition (SGIT), sleeve gastrectomy (SG), or sham surgery (SH) was performed on 7- to 8-week-old C57Bl/6J mice (n = 8 for each). To evaluate long-term survivability, mice were placed on an obesogenic diet and weighed weekly for 10 weeks. The intestinal identity of the transposed segment was assessed with gene expression analysis of duodenal-, jejunal-, and ileal-specific hormones using quantitative polymerase chain reaction.. Overall, SGIT better prevented weight gain than the SG or sham procedures (10-week post-operative weight: SH 45.3 ± 1.0 g, SG 41.25 ± 1.6 g, SGIT 35.4 ± 0.8 g). Gene expression pattern analysis of three markers of intestinal identity (gastrin, cholecystokinin, and peptide YY) suggests that the ileal identity of the transposed segment is maintained 10 weeks after transposition.. We demonstrate for the first time a reproducible mouse model of sleeve gastrectomy with ileal transposition. Future studies utilizing this model will expand our understanding of the molecular pathways through which the hindgut regulates satiety.

Topics: Animals; Biomarkers; Blood Glucose; Cholecystokinin; Disease Models, Animal; Feasibility Studies; Gastrectomy; Gastrins; Gene Expression; Ileum; Mice, Inbred C57BL; Peptide YY; Random Allocation; RNA; Weight Loss

BACKGROUND This study investigated the effect and mechanism of notoginsenoside R1 (NGR1) on chronic atrophic gastritis (CAG) in a rat model. MATERIAL AND METHODS To perform our investigation, a rat model of CAG was established, and then rats were treated with various doses of NGR1. After treatment, hematoxylin-eosin (HE) staining was used for histopathological observation and further scoring. Enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of gastrointestinal hormones, inflammatory factors, gastric mucosal destruction factors, and gastric mucosal-protective factors. Gene and protein expressions were measured using quantitative real-time PCR and Western blot assay, respectively. RESULTS Results indicated that NGR1 relieved rat CAG. NGR1 treatment significantly increased the levels of gastrin (GAS) and somatostatin (SS) and reduced motilin (MTL) in the serum of CAG rats. The serum levels of interleukin (IL)-1β and IL-6 were significantly reduced by NGR1 treatment in CAG rats in a dose-dependent manner. Additionally, the increased levels of prostaglandin (PG)E2, nitric oxide synthase (NOS), and endothelin (ET) in CAG rats were significantly decreased by NGR1 administration. Moreover, the decreased level of secretory IgA (sIgA) and glutathione (GSH) in rats caused by MNNG was notably increased by NGR1 treatment. No significant changes were found in glutathione disulfide (GSSG) secretion. Finally, we found that the increased Bcl-2 expression and reduced Bax expression in the stomach tissues of rats caused by MNNG were eliminated by NGR1 treatment. CONCLUSIONS NGR1 exerts a protective effect on CAG, and it is a multi-target, multi-linked, comprehensive process.

Topics: Animals; Chronic Disease; Disease Models, Animal; Female; Gastric Mucosa; Gastrins; Gastritis, Atrophic; Ginsenosides; Male; Rats; Rats, Sprague-Dawley; Signal Transduction; Somatostatin

Topics: Administration, Oral; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Gastrins; Gene Knockout Techniques; Humans; Injections, Intraperitoneal; Mice; Parietal Cells, Gastric; Stomach Diseases; Tamoxifen

To test the hypothesis that activated extracellular signal-regulated kinase (ERK) regulates P65-miR23a/27a/24 axis in gastric cancer (GC) and the ERK-P65-miR23a/27a/24 axis plays an important role in the development of GC, and to evaluate the role of gastrin in GC progression and ERK-P65-miR23a/27a/24 axis.. The component levels of the ERK-P65-miR23a/27a/24 axis in four fresh GC tissues, 101 paraffin-embedded GC tissues and four GC cell lines were determined by Western blotting, immunohistochemistry (IHC) or qRT-PCR. The effects of gastrin on GC were first evaluated by measuring gastrin serum levels in 30 healthy and 70 GC patients and performing a correlation analysis between gastrin levels and survival time in 27 GC patients after eight years of follow-up, then evaluated on GC cell lines, GC cell xenograft models, and patient-derived xenografts (PDX) mouse models. The roles of ERK-P65-miR23a/27a/24 axis in GC progression and in the effects of gastrin on GC were examined.. ERK- P65-miR23a/27a/24 axis was proved to be present in GC cells. The levels of components of ERK-P65-miR23a/27a/24 axis were decreased in GC tissue samples and PGC cells. The decreased levels of components of ERK-P65-miR23a/27a/24 axis were associated with poor prognosis of GC, and ERK-P65-miR23a/27a/24 axis played a suppressive role in GC progression. Low blood gastrin was correlated with poor prognosis of the GC patients and decreased expression of p-ERK and p-P65 in GC tissues. Gastrin inhibited proliferation of poorly-differentiated GC (PGC) cells through activating the ERK-P65-miR23a/27a/24 axis. Gastrin inhibited GC growth and enhanced the suppression of GC by cisplatin in mice or PGC cell culture models through activating the ERK-P65-miR23a/27a/24 axis or its components.. ERK-P65-miR23a/27a/24 axis is down-regulated, leading to excess GC growth and poor prognosis of GC. Low gastrin promoted excess GC growth and contributed to the poor prognosis of the GC patients by down-regulating ERK-P65-miR23a/27a/24 axis. Gastrin inhibits gastric cancer growth through activating the ERK-P65-miR23a/27a/24 axis.

Topics: Animals; Cell Line, Tumor; Cisplatin; Disease Models, Animal; Disease Progression; Extracellular Signal-Regulated MAP Kinases; Female; Gastrins; Gene Expression; Gene Expression Regulation, Neoplastic; Genes, Reporter; Heterografts; Humans; Mice; MicroRNAs; RNA Interference; Signal Transduction; Stomach Neoplasms; Transcription Factor RelA

The incidence of esophageal adenocarcinoma (EAC) is increasing, but factors contributing to malignant progression of its precursor lesion, Barrett's esophagus (BE), have not been defined. Hypergastrinemia caused by long-term use of proton pump inhibitors (PPIs), has been suggested as one possible risk factor. The gastrin receptor, CCK2R, is expressed in the cardia and upregulated in BE, suggesting the involvement of the gastrin-CCK2R pathway in progression. In the L2-IL-1β mouse model, Barrett's-like esophagus arises from the gastric cardia. Therefore, we aimed to analyze the effect of hypergastrinemia on CCK2R+ progenitor cells in L2-IL-1β mice.. L2-IL-1β mice were mated with hypergastrinemic (INS-GAS) mice or treated with PPIs to examine the effect of hypergastrinemia in BE progression. CCK2R-CreERT crossed with L2-IL-1β mice were used to analyze the lineage progenitor potential of CCK2R+ cells. Cardia glands were cultured in vitro, and the effect of gastrin treatment analyzed. L2-IL-1β mice were treated with a CCK2R antagonist YF476 as a potential chemopreventive drug.. Hypergastrinemia resulted in increased proliferation and expansion of Barrett's-like esophagus. Lineage tracing experiments revealed that CCK2R+ cells are long-lived progenitors that can give rise to such lesions under chronic inflammation. Gastrin stimulated organoid growth in cardia culture, while CCK2R inhibition prevented Barrett's-like esophagus and dysplasia.. Our data suggest a progression model for BE to EAC in which CCK2R+ progenitor cells, stimulated by hypergastrinemia, proliferate to give rise to metaplasia and dysplasia. Hypergastrinemia can result from PPI use, and the effects of hypergastrinemia in human BE should be studied further.

Topics: Animals; Barrett Esophagus; Biomarkers; Disease Models, Animal; Disease Progression; Gastrins; Gene Expression Regulation; Hyperglycemia; Immunohistochemistry; Metaplasia; Mice; Mice, Transgenic; Myoblasts, Cardiac; Phenotype; Receptor, Cholecystokinin B

The pharmacological effects of glutinous rice (GR) and GR amylopectin (GRA) on the gastrointestine were investigated in rhubarb-induced spleen deficiency rats by determining the levels of gastrointestinal hormones such as the peptides serum gastrin, amylase motilin, and somatostatin. GR and GRA were given by gavage at various doses of GR (7.5, 15, and 30 g per kg body weight) and GRA (3.8, 7.6, and 15 g per kg body weight) every day for 4 weeks, respectively. The results indicated that the final body weight of rats in the highest-dose GR (GRH) group and all the GRA groups significantly (P < 0.05) increased (7.2-12.1%) compared with the model control (MC) group. All the GR and GRA treated groups had significantly (P < 0.05) higher gastrin contents (32.8-51.2%), motilin levels (13.8-39.2%), and amylase contents (22.5-39.4%) and the GRH and highest-dose GRA (GRAH) groups had significantly (P < 0.05) lower somatostatin contents compared with the MC group. Meanwhile, the somatostatin contents were negatively correlated with the motilin levels (r = -0.964, P < 0.01) and amylase contents (r = -0.981, P < 0.01). The GRAH treatment group had the highest final body weight, gastrin contents, motilin levels, and amylase contents and the lowest somatostatin contents, which demonstrated that GRA might play the most important role in the spleen-regulating activities of GR.

Topics: Amylopectin; Animals; Body Weight; Disease Models, Animal; Dose-Response Relationship, Drug; Gastrins; Male; Motilin; Oryza; Plant Extracts; Rats; Rheum; Somatostatin; Spleen

Intestinal ischemia-reperfusion (I/R) injury is a devastating complication when the blood supply is reflowed in ischemic organs. Gastrin has critical function in regulating acid secretion, proliferation, and differentiation in the gastric mucosa. We aimed to determine whether gastrin has an effect on intestinal I/R damage. Intestinal I/R injury was induced by 60-min occlusion of the superior mesenteric artery followed by 60-min reperfusion, and the rats were induced to be hypergastrinemic by pretreated with omeprazole or directly injected with gastrin. Some hypergastrinemic rats were injected with cholecystokinin-2 (CCK-2) receptor antagonist prior to I/R operation. After the animal surgery, the intestine was collected for histological analysis. Isolated intestinal epithelial cells or crypts were harvested for RNA and protein analysis. CCK-2 receptor expression, intestinal mucosal damage, cell apoptosis, and apoptotic protein caspase-3 activity were measured. We found that high gastrin in serum significantly reduced intestinal hemorrhage, alleviated extensive epithelial disruption, decreased disintegration of lamina propria, downregulated myeloperoxidase activity, tumor necrosis factor-α, and caspase-3 activity, and lead to low mortality in response to I/R injury. On the contrary, CCK-2 receptor antagonist L365260 could markedly impair intestinal protection by gastrin on intestinal I/R. Severe edema of mucosal villi with severe intestinal crypt injury and numerous intestinal villi disintegrated were observed again in the hypergastrinemic rats with L365260. The survival in the hypergastrinemic rats after intestinal I/R injury was shortened by L365260. Finally, gastrin could remarkably upregulated intestinal CCK-2 receptor expression. Our data suggest that gastrin by omeprazole remarkably attenuated I/R induced intestinal injury by enhancing CCK-2 receptor expression and gastrin could be a potential mitigator for intestinal I/R damage in the clinical setting.

Topics: Animals; Benzodiazepinones; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Gastrins; Intestinal Diseases; Male; Phenylurea Compounds; Porins; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptor, Cholecystokinin B; Reperfusion Injury

To investigate the mechanisms and effects of sphincter of Oddi (SO) motility on cholesterol gallbladder stone formation in guinea pigs.. Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group (n = 10) and the cholesterol gallstone group (n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor (CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR (qRT-PCR) and serum vasoactive intestinal peptide (VIP), gastrin, and cholecystokinin octapeptide (CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation.. The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups.. A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction.

Topics: Animals; Cholesterol; Disease Models, Animal; Electromyography; Enzyme-Linked Immunosorbent Assay; Gallstones; Gastrins; Guinea Pigs; Manometry; Muscle, Smooth; Real-Time Polymerase Chain Reaction; Receptor, Cholecystokinin A; Sincalide; Sphincter of Oddi; Sphincter of Oddi Dysfunction; Vasoactive Intestinal Peptide

By whole exome sequencing, we recently identified a missense mutation (p.R703C) in the human ATP4a gene, which encodes the proton pump responsible for gastric acidification. This mutation causes an aggressive familial type I gastric neuroendocrine tumor in homozygous individuals. Affected individuals show an early onset of the disease, characterized by gastric hypoacidity, hypergastrinemia, iron-deficiency anemia, gastric intestinal metaplasia and, in one case, an associated gastric adenocarcinoma. Total gastrectomy was performed as the definitive treatment in all affected individuals. We now describe the generation and characterization of a knockin mouse model for the ATP4a(R703C) mutation to better understand the tumorigenesis process. Homozygous mice recapitulated most of the phenotypical alterations that were observed in human individuals, strongly suggesting that this mutation is the primary alteration responsible for disease development. Homozygous mice developed premalignant condition with severe hyperplasia, dysplasia and glandular metaplasia in the stomach. Interestingly, gastric acidification in homozygous mice, induced by treatment with 3% HCl acid in the drinking water, prevented (if treated from birth) or partially reverted (if treated during adulthood) the development of glandular metaplasia and dysplasia in the stomach and partially rescued the abnormal biochemical parameters. We therefore suggest that, in this model, achlorhydria contributes to tumorigenesis to a greater extent than hypergastrinemia. Furthermore, our mouse model represents a unique and novel tool for studying the pathologies associated with disturbances in gastric acid secretion.

Topics: Anemia; Animals; Disease Models, Animal; Gastric Acid; Gastrins; Gene Knock-In Techniques; H(+)-K(+)-Exchanging ATPase; Homozygote; Humans; Hydrochloric Acid; Hyperplasia; Mice, Inbred C57BL; Mice, Mutant Strains; Mutation; Neuroendocrine Tumors; Phenotype; Stomach; Stomach Neoplasms

A novel strain of Lactobacillus johnsonii No. 1088 was isolated from the gastric juice of a healthy Japanese male volunteer, and characterized for its effectiveness in the stomach environment. Lactobacillus johnsonii No. 1088 was found to have the strongest acid resistance among several lactobacilli examined (>10% of cells survived at pH 1.0 after 2 h), and such a high acid resistance property was a specific characteristic of this strain of L. johnsonii. When cultured with various virulent bacteria, L. johnsonii No. 1088 inhibited the growth of Helicobacter pylori, Escherichia coli O-157, Salmonella Typhimurium, and Clostridium difficile, in which case its effectiveness was more potent than that of a type strain of L. johnsonii, JCM2012. In addition to its effect in vitro, L. johnsonii No. 1088 inhibited the growth of H. pylori in human intestinal microbiota-associated mice in both its live and lyophilized forms. Moreover, L. johnsonii No. 1088 suppressed gastric acid secretion in mice via decreasing the number of gastrin-positive cells in the stomach. These results taken together suggest that L. johnsonii No. 1088 is a unique lactobacillus having properties beneficial for supporting H. pylori eradication by triple therapy including the use of a proton pump inhibitor (PPI) and also for prophylaxis of gastroesophageal reflux disease possibly caused after H. pylori eradication as a side effect of PPI.

Topics: Animals; Antibiosis; Disease Models, Animal; Gastric Acid; Gastrins; Gastrointestinal Microbiome; Helicobacter Infections; Helicobacter pylori; Humans; Lactobacillus; Mice; Proton Pump Inhibitors

Shuidouchi (Natto) is a fermented soy product showing in vivo gastric injury preventive effects. The treatment effects of Shuidouchi fermented in different vessels on HCl/ethanol-induced gastric mucosal injury mice through their antioxidant effect was determined. Shuidouchi contained isoflavones (daidzein and genistein), and GVFS (glass vessel fermented Shuidouchi) had the highest isoflavone levels among Shuidouchi samples fermented in different vessels. After treatment with GVFS, the gastric mucosal injury was reduced as compared to the control mice. The gastric secretion volume (0.47 mL) and pH of gastric juice (3.1) of GVFS treated gastric mucosal injury mice were close to those of ranitidine-treated mice and normal mice. Shuidouchi could decrease serum motilin (MTL), gastrin (Gas) level and increase somatostatin (SS), vasoactive intestinal peptide (VIP) level, and GVFS showed the strongest effects. GVFS showed lower IL-6, IL-12, TNF-α and IFN-γ cytokine levels than other vessel fermented Shuidouchi samples, and these levels were higher than those of ranitidine-treated mice and normal mice. GVFS also had higher superoxide dismutase (SOD), nitric oxide (NO) and malonaldehyde (MDA) contents in gastric tissues than other Shuidouchi samples. Shuidouchi could raise IκB-α, EGF, EGFR, nNOS, eNOS, Mn-SOD, Gu/Zn-SOD, CAT mRNA expressions and reduce NF-κB, COX-2, iNOS expressions as compared to the control mice. GVFS showed the best treatment effects for gastric mucosal injuries, suggesting that glass vessels could be used for Shuidouchi fermentation in functional food manufacturing.

Topics: Animals; Biological Products; Biomarkers; Cytokines; Disease Models, Animal; Fermentation; Gastric Juice; Gastric Mucosa; Gastrins; Gene Expression; Glycine max; Hydrogen-Ion Concentration; Isoflavones; Malondialdehyde; Mice; Motilin; Nitric Oxide; RNA, Messenger; Somatostatin; Superoxide Dismutase; Vasoactive Intestinal Peptide

To investigate roles of sphincter of Oddi (SO) motility played in pigment gallbladder stone formation in model of guinea pigs.. Thirty-four adult male Hartley guinea pigs were divided randomly into two groups: the control group and pigment stone group. The pigment stone group was divided into 4 subgroups with 6 guinea pigs each according to time of sacrifice, and were fed a pigment lithogenic diet and sacrificed after 3, 6, 9 and 12 wk. SO manometry and recording of myoelectric activity of the guinea pigs were obtained by multifunctional physiograph at each stage. Serum vasoactive intestinal peptide (VIP), gastrin and cholecystokinin octapeptide (CCK-8) were detected at each stage in the process of pigment gallbladder stone formation by enzyme-linked immunosorbent assay.. The incidence of pigment gallstone formation was 0%, 0%, 16.7% and 66.7% in the 3-, 6-, 9- and 12-wk group, respectively. The frequency of myoelectric activity decreased in the 3-wk group. The amplitude of myoelectric activity had a tendency to decrease but not significantly. The frequency of the SO decreased significantly in the 9-wk group. The SO basal pressure and common bile duct pressure increased in the 12-wk group (25.19 ± 7.77 mmHg vs 40.56 ± 11.81 mmHg, 22.35 ± 7.60 mmHg vs 38.51 ± 11.57 mmHg, P < 0.05). Serum VIP was significantly elevated in the 6- and 12-wk groups and serum CCK-8 was decreased significantly in the 12-wk group.. Pigment gallstone-causing diet may induce SO dysfunction. The tension of the SO increased. The disturbance in SO motility may play a role in pigment gallstone formation, and changes in serum VIP and CCK-8 may be important causes of SO dysfunction.

Topics: Animals; Cholestasis; Disease Models, Animal; Gallstones; Gastrins; Guinea Pigs; Male; Manometry; Membrane Potentials; Pressure; Sincalide; Sphincter of Oddi; Time Factors; Vasoactive Intestinal Peptide

Loss of expression of Sonic Hedgehog (Shh) from parietal cells results in hypergastrinemia in mice, accompanied by increased expression of Indian Hedgehog (Ihh) and hyperproliferation of surface mucous cells. We investigated whether hypergastrinemia induces gastric epithelial proliferation by activating Ihh signaling in mice.. We studied mice with parietal cell-specific deletion of Shh (PC-Shh(KO)) and hypergastrinemia, crossed with gastrin-deficient (GKO) mice (PC-Shh(KO)/GKO). When mice were 3-4 months old, gastric tissues were collected and analyzed by histology, for incorporation of bromodeoxyuridine, and for expression of the surface mucous cell marker Ulex europaeus. PC-Shh(KO)/GKO mice were given gastrin infusions for 7 days; gastric surface epithelium was collected and expression of Ihh was quantified by laser capture microdissection followed by quantitative reverse transcriptase polymerase chain reaction. Mouse stomach-derived organoids were incubated with or without inhibitors of WNT (DKK1) or Smoothened (vismodegib) and then cocultured with immortalized stomach mesenchymal cells, to assess proliferative responses to gastrin.. Gastric tissues from PC-Shh(KO)/GKO mice with hypergastrinemia had an expanded surface pit epithelium, indicated by a significant increase in numbers of bromodeoxyuridine- and Ulex europaeus-positive cells, but there was no evidence for hyperproliferation. Gastrin infusion of PC PC-Shh(KO)/GKO mice increased expression of Ihh and proliferation within the surface epithelium compared with mice given infusions of saline. In gastric organoids cocultured with immortalized stomach mesenchymal cells, antagonists of WNT and Smoothened inhibited gastrin-induced proliferation and WNT activity. Activity of WNT in media collected from immortalized stomach mesenchymal cells correlated with increased expression of glioma-associated oncogene homolog 1, and was inhibited by DKK1 or vismodegib.. Ihh signaling mediates gastrin-induced proliferation of epithelial cells in stomachs of adult mice.

Topics: Animals; Cell Line; Cell Proliferation; Coculture Techniques; Disease Models, Animal; Epithelial Cells; Gastric Mucosa; Gastrins; Hedgehog Proteins; Infusions, Parenteral; Intercellular Signaling Peptides and Proteins; Kruppel-Like Transcription Factors; Mice; Mice, Inbred C57BL; Mice, Knockout; Organoids; Receptors, G-Protein-Coupled; Smoothened Receptor; Stomach Diseases; Time Factors; Wnt Signaling Pathway; Zinc Finger Protein GLI1

The aim of the present study was to perform immunohistochemical and ultrastructural analysis of gastrin-, synaptophysin (SY)- and atrial natriuretic peptide (ANP)-positive cells in the pylorus of "two kidney, one clip" (2K1C) renovascular hypertension model in rats.. In order to identify neuroendocrine (NE) cells, immunohistochemical reactions were performed with the use of specific antibodies against gastrin, SY and ANP. Gastric NE cells were also examined using an electron microscope.. The present study revealed a twofold increase in the number of gastrin- and SY-positive cells and a significant decrease in the number of ANP-immunoreactive (IR) cells in the pyloric mucosa of 2K1C rats. Test results obtained with an electron microscope confirmed a change in the activity of the stomach endocrine cells of hypertensive rats.. Immunohistochemical and ultrastructural investigations demonstrated the impact of renovascular hypertension on the neuroendocrine system in the rat stomach. The changes in the total number and ultrastructure of DNES cells proved their undeniable role in the modulation of gastric dysfunction, as a consequence of deregulation of homeostasis-maintaining systems.

Topics: Animals; Atrial Natriuretic Factor; Biomarkers; Disease Models, Animal; Enteroendocrine Cells; Gastric Mucosa; Gastrins; Hypertension, Renovascular; Male; Pylorus; Rats, Wistar; Synaptophysin

The natural immunomodulator lactoferrin is known to possess anti-inflammatory effects. However, there have been no studies examining the mode of action of lactoferrin in protecting the esophageal mucosa against damage. We investigated the effect of lactoferrin on gastric acid secretion and in protecting against acute acid reflux-induced esophagitis in rats.. Male Wistar rats aged 8 weeks, weighing 210-240 g, were used for all the experiments. A gastric perfusion system was installed using the method of Ghosh et al. Lactoferrin was administered once via the caudate vein, starting 24 hours before an acute acid reflux (treatment mode), or saline (control). Statistical comparison of the parameters between the two test conditions was performed.. No significant differences in basal or stimulated gastric acid secretion, or in the serum gastrin level were observed between the two test conditions. Esophageal damage was attenuated by lactoferrin in a dose-dependent manner, as reflected by the improvement in the esophageal tissue weight and macroscopic scores. Significant reductions in the histological scores, myeloperoxidase activity and the levels of proinflammatory cytokines, tumor necrosis factor-α and interleukin-1β were also observed following lactoferrin administration.. We concluded that lactoferrin exerts a protective effect against acute acid reflux-induced esophageal damage in rats.

Topics: Animals; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Esophagus; Gastric Acid; Gastric Mucosa; Gastrins; Gastroesophageal Reflux; Inflammation Mediators; Injections, Intravenous; Lactoferrin; Male; Mucous Membrane; Protective Agents; Rats, Wistar

The stomach is innervated by the vagal nerve. Several studies have demonstrated that the vagal nerve has a trophic effect on the rat oxyntic mucosa and that the trophic effect of hypergastrinemia is dependent on intact vagal innervation. The effect of vagal denervation on gastric carcinogenesis has been examined in Mastomys natalensis and hypergastrinemic transgenic INS-GAS mice, with no effect of unilateral vagotomy in Mastomys but an anti-carcinogenic effect in INS-GAS mice. A proportion of female Japanese cotton rats develop spontaneous hypergastrinemia and ECL cell derived gastric carcinomas. In the current study we have examined the effects of unilateral anterior subdiaphragmatic vagotomy on gastric carcinogenesis. Female Japanese cotton rats were operated with unilateral anterior vagotomy or sham-operation at age 2 months and were terminated at age 10 months. Ten of fifteen animals operated by anterior vagotomy and 11 of 16 sham-operated developed hypergastrinemia. Vagotomy did not affect intragastric pH or serum gastrin. When comparing the anterior and posterior sides of the stomachs, vagotomy did not affect the occurrence of dysplasia or carcinoma development in the oxyntic mucosa. However, vagotomy resulted in lower stomach weight and reduced oxyntic mucosal thickness on the anterior side. Vagotomy also resulted in a reduction in volume density of chromogranin A positive cells in the oxyntic mucosa. In conclusion, vagotomy reduced the trophic effects of hypergastrinemia on the ECL cell and oxyntic mucosa, but did not prevent gastric carcinogenesis in female Japanese cotton rats. The effects of vagotomy on gastric carcinogenesis in animal models are conflicting and further studies in patients should be done to clarify the clinically significant effects of vagotomy.

Topics: Animals; Carcinogenesis; Chromogranin A; Disease Models, Animal; Enterochromaffin-like Cells; Female; Gastric Mucosa; Gastrins; Hydrogen-Ion Concentration; Sigmodontinae; Stomach Neoplasms; Vagotomy, Truncal

This study was conducted to evaluate gastric acid secretion in acute renal failure, highlighting the roles of renal mass and gastrin hormone. Acute uremic rats were divided into bilateral nephrectomized and bilateral ureteric obstruction groups. Gastric juice was collected for 2 h and analyzed for volume, free acidity, total acidity, and total acid output. Plasma levels of creatinine, urea, and gastrin were also determined. Bilateral nephrectomized and bilateral ureteric obstruction groups showed a significant increase in levels of free acidity, total acidity, and plasma gastrin. Compared with the ureteric obstruction group, nephrectomized rats showed a significant increase in gastric juice volume, total acid output, and plasma gastrin levels. Following pentagastrin stimulation, gastric juice volume, total acid output, free acidity, and total acidity were increased in the bilateral nephrectomy and ureteric obstruction groups compared with the respective control groups. The free and total acidity and total acid output also increased compared with the respective non-stimulated groups. Plasma creatinine and urea levels were significantly positively correlated with plasma gastrin, free acidity, and total acidity. Creatinine was positively correlated with total acid output, and gastrin was positively correlated with total acidity. In conclusion, acute renal failure promotes gastric acid hypersecretion that could potentially be attributed to high levels of gastrin hormone and uremic state per se.

Topics: Acute Kidney Injury; Animals; Creatinine; Disease Models, Animal; Gastric Acid; Gastric Acidity Determination; Gastric Juice; Gastric Mucosa; Gastrins; Male; Nephrectomy; Pentagastrin; Rats; Rats, Wistar; Time Factors; Urea; Uremia; Ureteral Obstruction

To establish a rat model mimicking human bile reflux for studying the pathological effects of chronic bile reflux.. The duodenum of Sprague-Dawley rats was transected below the opening of the common bile duct, and a gastrojejunostomy was performed at the greater curvature of the forestomach. After the rats demonstrated bile reflux for 1 year, we studied the pathological features of the glandular stomach and forestomach mucosa. We also studied the effect of bile reflux on gastrin expression in the glandular stomach mucosa by using immunohistochemistry.. Chronic bile reflux caused significant hyperplasia and expansion of gastric glands in the glandular stomach. Dysplasia and cancer formation also developed, but the incidence was significantly lower than that reported in the literature. Intestinal metaplasia and ulceration in the glandular stomach were also rare. In the forestomach, the squamous epithelium showed significant hyperplasia and keratinization along with keratin pearls and keratocysts. Intestinal metaplasia was rare and no tumorigenesis was observed. Chronic bile reflux significantly increased gastrin expression in the glandular stomach mucosa.. When simulating the physiological bile reflux pathway, chronic bile reflux caused hyperplasia and expansion of gastric glands in the glandular stomach and squamous epithelial hyperplasia and keratinization in the forestomach.

Topics: Animals; Bile Reflux; Chronic Disease; Disease Models, Animal; Duodenum; Gastric Bypass; Gastric Mucosa; Gastrins; Hyperplasia; Male; Rats; Rats, Sprague-Dawley

To be able to evaluate new radiopharmaceuticals and optimize diagnostic and therapeutic procedures, relevant animal models are required. The aim of this study was to evaluate the medullary thyroid carcinoma GOT2 animal model by analyzing the biodistribution of 177Lu-octreotate and 111In-minigastrin (MG0). BALB/c nude mice, subcutaneously transplanted with GOT2, were intravenously injected with either 177Lu-octreotate or 111In-MG0, with or without excess of unlabeled human minigastrin simultaneously with 111In-MG0. Animals were sacrificed 1-7 days after injection in the 177Lu-octreotate study and 1 h after injection of 111In-MG0. The activity concentrations in organs and tissues were determined and mean absorbed doses from 177Lu were calculated. There was a specific tumor uptake of either 177Lu-octreotate or 111In-MG0. 177Lu-octreotate samples showed high activity concentrations in tissues expressing somatostatin receptors (SSTR). For both radiopharmaceuticals the highest activity concentrations were found in the kidneys. Compared to results from similar studies in mice with another MTC cell line (TT) the biodistribution was favorable (higher tumor uptake) for the GOT2 model, while compared to other animal models expressing SSTR, the tumor uptake of 177Lu-octreotate was modest. In conclusion, the GOT2 animal model is a valuable model for evaluation and optimization of diagnostic and therapeutic procedures using radiolabeled somatostatin, CCK2 and gastrin analogues prior to clinical studies.

Topics: Animals; Carcinoma, Neuroendocrine; Cell Line, Tumor; Disease Models, Animal; Female; Gastrins; Humans; Indium Radioisotopes; Mice; Mice, Nude; Octreotide; Radionuclide Imaging; Radiopharmaceuticals; Thyroid Neoplasms; Tissue Distribution; Transplantation, Heterologous

The present study was designed to evaluate the anti-ulcerogenic properties of an alkaloid chromane, rohitukine from Dysoxylum binectariferum. Anti-ulcer potential of rohitukine was assessed in cold restrained, pyloric ligated and ethanol induced ulcers in rats. In addition, rohitukine was tested in vitro for H(+) K(+)-ATPase inhibitory activity in gastric microsomes. Moreover, we studied the role of rohitukine on the cytosolic concentration of Ca(2+) in parietal cell-enriched cell suspension in order to ascertain its mechanism of action. Cytoprotective activity was evaluated through PGE(2) level. Rohitukine significantly attenuated the ulcers in cold restraint ulcer (CRU) model in a dose-related manner. Moreover, it significantly lowered the free acidity and pepsin activity in pyloric ligated rats while improved the depleted level of mucin. Furthermore, rohitukine significantly reversed the cold restrained-induced increase in gastrin level. Our in vitro study revealed that rohitukine moderately inhibited the microsomal H(+) K(+)-ATPase activity with respect to positive control omeprazole. Furthermore, rohitukine potently antagonized the gastrin-elicited increase in cytosolic Ca(2+) level in parietal cell-enriched suspension. In ethanol-induced gastric lesions in rats, rohitukine significantly inhibited the formation of erosions and increased PGE(2) content showing more potency than reference drug sucralfate. Our results thus suggest that rohitukine possess significant anti-ulcer and anti-gastrinic activity in rats. It is likely that gastro-protective influences of rohitukine are dependent partly on its acid-lowering potential and partly on cytoprotective property. The acid-reducing effect of rohitukine might be attributed to its lowering effect on gastrin production and/or antagonism of gastrin-evoked functional responses of parietal cells. Thus, rohitukine represent a useful agent in the treatment of peptic ulcer disease.

Topics: Animals; Anti-Ulcer Agents; Antineoplastic Agents; Calcium; Chromones; Cold Temperature; Disease Models, Animal; Ethanol; Gastrins; H(+)-K(+)-Exchanging ATPase; Ligation; Meliaceae; Microsomes; Piperidines; Plant Bark; Proton Pump Inhibitors; Pylorus; Rats; Rats, Sprague-Dawley; Restraint, Physical; Stomach Ulcer; Stress, Physiological

Previous studies have suggested that dietary folic acid (FA) can protect against certain types of cancers. However, the findings have varied, and the mechanisms by which FA exerts chemopreventive effects remain to be clarified. We examined the effects of FA supplementation on DNA methylation, gene expression, and gastric dysplasia in a transgenic mouse model that is etiologically and histologically well matched with human gastric cancers.. Hypergastrinemic mice infected with Helicobacter felis were studied at multiple stages of gastric dysplasia and early cancer with FA supplementation initiated both at weaning and later in life. Global DNA methylation was assessed by a methylation sensitive cytosine incorporation assay, bisulfite pyrosequencing of B1 repetitive elements, and immunohistochemistry with anti-5-methylcytosine. We also profiled gene expression in the same tissues.. We found a decrease in global DNA methylation and tissue folate and an increase in serum homocysteine with progression of gastric dysplasia. FA supplementation prevented this loss of global DNA methylation and markedly reduced gastric dysplasia and mucosal inflammation. FA protected against the loss of global DNA methylation both in the dysplastic gastric epithelial cells and in gastric stromal myofibroblasts. In addition, FA supplementation had an anti-inflammatory effect, as indicated by expression profiling and immunohistochemistry for lymphocyte markers.. We conclude that FA supplementation is chemopreventive in this model of Helicobacter-associated gastric cancer. The beneficial effect of FA is likely due to its ability to prevent global loss of methylation and suppress inflammation.

Topics: Animals; Anti-Inflammatory Agents; Anticarcinogenic Agents; Disease Models, Animal; DNA Methylation; Folic Acid; Gastric Mucosa; Gastrins; Gastritis; Gene Expression Profiling; Gene Expression Regulation; Helicobacter felis; Helicobacter Infections; Homocysteine; Immunohistochemistry; Lymphocytes; Male; Mice; Mice, Transgenic; Myofibroblasts; Stomach; Stomach Neoplasms; Stromal Cells; Up-Regulation

Nonsteroidal anti-inflammatory drugs (NSAIDs) are valuable agents; however, their use has been limited by their association with mucosal damage in the upper gastrointestinal tract. NSAIDs inhibit cyclooxygenase and consequently block the synthesis of prostaglandins, which have cytoprotective effects in gastric mucosa; these effects on prostaglandins have been thought to be major cause of NSAID-induced ulceration. However, studies indicate that additional NSAID-related mechanisms are involved in formation of gastric lesions. Here, we used a toxicoproteomic approach to understand cellular processes that are affected by NSAIDs in mouse stomach tissue during ulcer formation. We used fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS)-which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry-in this proteomic analysis of pyrolic stomach from control and diclofenac (Dic)-treated mice. FD-LC-MS/MS results were highly sensitive; 10 differentially expressed proteins were identified, and all 10 were more highly expressed in Dic-treated mice than in control mice. Specifically, expression levels of 78 kDa glucose-regulated protein (GRP78), heat shock protein beta-1 (HSP27), and gastrin were more than 3-fold higher in Dic-treated mice than in control mice. This study represents a first step to ascertain the precise actors of early NSAID-induced ulceration.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Chromatography, Liquid; Cyclooxygenase Inhibitors; Diclofenac; Disease Models, Animal; Endoplasmic Reticulum Chaperone BiP; Fluorescent Dyes; Gastric Mucosa; Gastrins; Heat-Shock Proteins; HSP27 Heat-Shock Proteins; Male; Mice; Mice, Inbred C57BL; Proteomics; Stomach Ulcer; Tandem Mass Spectrometry

Transgenic mice overexpressing human progastrin (hGAS) show colonic crypt hyper-proliferation and elevated susceptibility to colon carcinogenesis. We aimed to investigate effects of p53 mutation on colon carcinogenesis in hGAS mice. We show that introducing a p53 gene mutation further increases progastrin dependent BrdU labeling and results in markedly elevated number of aberrant crypt foci (ACF) and colonic tumors. We demonstrate that hGAS/Lgr5-GFP mice have higher number of Lgr5+ colonic stem cells per crypt when compared to Lgr5-GFP mice indicating that progastrin changes crypt biology through increased stem cell numbers and additional p53 mutation leads to more aggressive phenotype in this murine colon cancer model.

Topics: Aberrant Crypt Foci; Animals; Azoxymethane; Carcinogens; Cell Proliferation; Cell Transformation, Neoplastic; Colonic Neoplasms; Disease Models, Animal; Female; Gastrins; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Protein Precursors; Tumor Suppressor Protein p53

Cysteamine is a reducing aminothiol used for inducing duodenal ulcer through mechanisms of oxidative stress related to thiol-derived H(2)O(2) reaction. Cochinchina momordica saponins have been suggested to be protective against various gastric diseases based on their cytoprotective and anti-inflammatory mechanisms. This study was aimed to document the preventive effects of Cochinchina momordica seed extract against cysteamine-induced duodenal ulcer as well as the elucidation of its pharmacological mechanisms.. Cochinchina momordica seed extract (50, 100, 200 mg/kg) was administrated intragastrically before cysteamine administration, after which the incidence of the duodenal ulcer, ulcer size, serum gastrin level, and the ratio of reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG) as well as biochemical and molecular measurements of cytoplasmic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), 5-lipoxygenase and the expression of proinflammatory genes including IL-1β, IL-6, COX-2 were measured in rat model. Additional experiments of electron spin resonance measurement and the changes of glutathione were performed.. Cochinchina momordica seed extract effectively prevented cysteamine-induced duodenal ulcer in a dose-dependent manner as reflected with significant decreases in either duodenal ulcerogenesis or perforation accompanied with significantly decreased in serum gastrin in addition to inflammatory mediators including cPLA(2), COX-2, and 5-lipoxygenase. Cochinchina momordica seed extract induced the expression of γ-glutamylcysteine synthetase (γ-GCS)-related glutathione synthesis as well as significantly reduced the expression of cPLA(2). Cochinchina momordica seed extract preserved reduced glutathione through increased expressions of γ-GCS.. Cochinchina momordica seed extracts exerted significantly protective effect against cysteamine-induced duodenal ulcer by either cPLA2 inhibition or glutathione preservation.

Topics: Animals; Anti-Ulcer Agents; Antioxidants; Arachidonate 5-Lipoxygenase; Cell Line; Cyclooxygenase 2; Cysteamine; Disease Models, Animal; Dose-Response Relationship, Drug; Duodenal Ulcer; Duodenum; Enzyme Activation; Enzyme Activators; Gastrins; Glutamate-Cysteine Ligase; Glutathione; Inflammation Mediators; Intestinal Mucosa; Lipoxygenase Inhibitors; Male; Momordica; Oxidation-Reduction; Oxidative Stress; Phospholipases A2, Cytosolic; Plant Extracts; Rats; Rats, Sprague-Dawley; Seeds; Time Factors

Type 1 diabetes (T1D) results from an autoimmune destruction of insulin-producing β cells. Currently, islet transplantation is the only curative therapy for late-stage T1D, but the beneficial effect is limited in its duration, even under chronic immunosuppression, because of the chronic graft rejection mediated by both auto- and alloimmunity. Clinical islet transplantation is also restricted by a severe shortage of donor islets. Induction of mixed chimerism reverses autoimmunity, eliminates insulitis, and reverses new-onset but not late-stage disease in the nonobese diabetic (NOD) mouse model of T1D. Administration of gastrin and epidermal growth factor (EGF) also reverses new-onset but not late-stage T1D in this animal model. Here, we showed that combination therapy of induced mixed chimerism under a radiation-free nontoxic anti-CD3/CD8 conditioning regimen and administration of gastrin/EGF augments both β cell neogenesis and replication, resulting in reversal of late-stage T1D in NOD mice. If successfully translated into humans, this combination therapy could replace islet transplantation as a long-term curative therapy for T1D.

Topics: Animals; Combined Modality Therapy; Diabetes Mellitus, Type 1; Disease Models, Animal; Epidermal Growth Factor; Female; Gastrins; Humans; Insulin Resistance; Insulin-Secreting Cells; Islets of Langerhans Transplantation; Mice; Mice, Inbred C57BL; Mice, Inbred NOD; Mice, SCID; Mice, Transgenic; Regeneration; Translational Research, Biomedical; Transplantation Chimera; Transplantation Conditioning

Chronic inflammation in the stomach can lead to gastric cancer. We previously reported that gastrin-deficient (Gast⁻/⁻) mice develop bacterial overgrowth, inflammatory infiltrate, increased Il-1β expression, antral hyperplasia and eventually antral tumors. Since Hedgehog (Hh) signaling is active in gastric cancers but its role in precursor lesions is poorly understood, we examined the role of inflammation and Hh signaling in antral hyperplasia. LacZ reporter mice for Sonic hedgehog (Shh), Gli1, and Gli2 expression bred onto the Gast⁻/⁻ background revealed reduced Shh and Gli1 expression in the antra compared to wild type controls (WT). Gli2 expression in the Gast⁻/⁻ corpus was unchanged. However in the hyperplastic Gast⁻/⁻ antra, Gli2 expression increased in both the mesenchyme and epithelium, whereas expression in WT mice remained exclusively mesenchymal. These observations suggested that Gli2 is differentially regulated in the hyperplastic Gast⁻/⁻ antrum versus the corpus and by a Shh ligand-independent mechanism. Moreover, the proinflammatory cytokines Il-1β and Il-11, which promote gastric epithelial proliferation, were increased in the Gast⁻/⁻ stomach along with Infγ. To test if inflammation could account for elevated epithelial Gli2 expression in the Gast⁻/⁻ antra, the human gastric cell line AGS was treated with IL-1β and was found to increase GLI2 but decrease GLI1 levels. IL-1β also repressed human GAST gene expression. Indeed, GLI2 but not GLI1 or GLI3 expression repressed gastrin luciferase reporter activity by ∼50 percent. Moreover, chromatin immunoprecipitation of GLI2 in AGS cells confirmed that GLI2 directly binds to the GAST promoter. Using a mouse model of constitutively active epithelial GLI2 expression, we found that activated GLI2 repressed Gast expression but induced Il-1β gene expression and proliferation in the gastric antrum, along with a reduction of the number of G-cells. In summary, epithelial Gli2 expression was sufficient to stimulate Il-1β expression, repress Gast gene expression and increase proliferation, leading to antral hyperplasia.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Epithelium; Female; Gastrins; Gene Expression Regulation; Hedgehog Proteins; Humans; Hyperplasia; Immunohistochemistry; Inflammation; Interleukin-1beta; Kruppel-Like Transcription Factors; Male; Mice; Mice, Knockout; Mice, Transgenic; Pyloric Antrum; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Zinc Finger Protein Gli2

Gastric mucosa is one of the most vulnerable tissues in human and animal. However, little is known about the effects of calcitonin gene-related peptide (CGRP) on gastric mucosa injuries induced by gastric ischemia reperfusion. The purpose of the present study was to investigate the protective effects and mechanism of CGRP on gastric mucosa injury after gastric ischemia reperfusion in rats. Thirty-six healthy Wistar rats were randomly divided into CGRP-treated, sham-operated, and control groups. Twelve rats were involved in each group. These groups were further divided into 24-h and 48-h subgroups. Gastric ischemia reperfusion injury (GI-RI) rat model was established by a 30-min celiac artery occlusion by an artery clamp, followed by 24 h or 48 h of reperfusion. CGRP (1 μg/ml) at the dose of 3 μg/kg was given intraperiloneally (IP) at the beginning of reperfusion for rats in CGRP-treated group. Saline as vehicle (3 ml/kg body weight), IP, was administered at the beginning of reperfusion for rats in control group. Sham-operated animals were subjected to an operation without GI-RI. Twenty-four hours or 48 h after operation, the samples were taken out and processed for calculating stomach mucous membrane damage index according to Guth method, detecting pathological changes of gastric mucosa tissue by light microscopy and observing the expression of gastrin (Gas) and somatostatin (SST) by immunohistochemical staining. The results showed the following: (i) gastric mucosa with diffuse edema, splinter hemorrhage and erosion, numerous endothelial cells necrosis, mucosa dissociation, and infiltration of inflammatory cells were observed in both control and CGRP-treated animals, especially in the earlier period (24 h) and then gradually healing. CGRP administration could reduce the damage of gastric mucosa. The injury index of gastric mucosa was lower in CGRP-treated group as compared with that in control group (P < 0.01). (ii) Gas expression in gastric antrum mucosa was lower in CGRP-treated group than that in control group (P < 0.01). SST expression in gastric antrum mucosa was higher in CGRP-treated group than that in control group (P < 0.01). It is concluded that CGRP regulated the secretion of Gas and SST and thus alleviated the damage of gastric mucosa induced by ischemia and reperfusion. CGRP might be a potential candidate for clinical therapy on modulating gastric mucosal protection and maintaining gastric mucosal integrity after ischemia and reperfusion of t

Topics: Animals; Calcitonin Gene-Related Peptide; Disease Models, Animal; Gastric Mucosa; Gastrins; Immunohistochemistry; Male; Rats; Rats, Wistar; Reperfusion Injury; Somatostatin; Vasodilator Agents

We investigated whether corpus atrophic gastritis worsens in Mongolian gerbils (MGs) after long-term administration of proton pump inhibitor (PPI). MGs are an excellent model for studying Helicobacter pylori-related gastritis and adenocarcinoma.. MGs were separated into four groups (n =15/group); H pylori (ATCC43504) was inoculated into the OPZ(omeprazole)+Hp (H pylori) and Hp groups, a PPI (OPZ) was administered to the OPZ+Hp and OPZ groups and the control group received no treatment. MGs had access to food containing omeprazole (100 mg/kg body weight/day) for 6 months, after which their stomachs were removed and cut into nine sections (six sections in the fundus and three sections in the antrum). Corpus atrophy was evaluated by the absence of parietal cells in the six sections in the fundus. First, we calculated a percentage of the area devoid of parietal cells in each haematoxylin and eosin-stained section, and then we scored the degree of atrophy by adding the percentages of the six sections. A full score was 600.. Neutrophilic and lymphoid infiltrates were greater in the OPZ+Hp group than in the other groups. The corpus atrophy score in the OPZ+Hp group was significantly higher than that in the Hp group (p < 0.0048, Student t test). Significantly more adenocarcinomas were found in the OPZ+Hp (60%) than in the Hp (7%) group animals.. Long-term PPI administration promotes development of adenocarcinoma, which is associated with the progression of atrophic corpus gastritis in MGs infected with H pylori.

Topics: Adenocarcinoma; Animals; Body Weight; Cocarcinogenesis; Disease Models, Animal; Disease Progression; Drug Administration Schedule; Gastrins; Gastritis, Atrophic; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Metaplasia; Proton Pump Inhibitors; Stomach; Stomach Neoplasms

Mutations in TRPML1, a lysosomal Ca(2+)-permeable TRP channel, lead to mucolipidosis type IV, a neurodegenerative lysosomal storage disease. An unusual feature of mucolipidosis type IV is constitutive achlorhydria. We produced Trpml1(-/-) (null) mice to investigate the requirement for this protein in gastric acid secretion.. Trpml1-null mice were generated by gene targeting. The expression of Trpml1 and its role in acid secretion by gastric parietal cells were analyzed using biochemical, histologic, and ultrastructural approaches.. Trpml1 is expressed by parietal cells and localizes predominantly to the lysosomes; it was dynamically palmitoylated and dephosphorylated in vivo following histamine stimulation of acid secretion. Trpml1-null mice had significant impairments in basal and histamine-stimulated gastric acid secretion and markedly reduced levels of the gastric proton pump. Histologic and ultrastructural analyses revealed that Trpml1(-/-) parietal cells were enlarged, had multivesicular and multi-lamellated lysosomes, and maintained an abnormal intracellular canalicular membrane. The intralysosomal Ca(2+) content and receptor-mediated Ca(2+) signaling were, however, unaffected in Trpml1(-/-) gastric glands, indicating that Trpml1 does not function in the regulation of lysosomal Ca(2+).. Loss of Trpml1 causes reduced levels and mislocalization of the gastric proton pump and alters the secretory canaliculi, causing hypochlorhydria and hypergastrinemia. The lysosomal enlargement and defective intracellular canaliculi formation observed in Trpml1(-/-) parietal cells indicate that Trpml1 functions in the formation and trafficking of the tubulovesicles. This study provides direct evidence for the regulation of gastric acid secretion by a TRP channel; TRPML1 is an important protein in parietal cell apical membrane trafficking.

Topics: Achlorhydria; Animals; Calcium; Disease Models, Animal; Gastric Acid; Gastrins; H(+)-K(+)-Exchanging ATPase; Histamine; Hypertrophy; Lipoylation; Lysosomes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mucolipidoses; Parietal Cells, Gastric; Phosphorylation; Protein Transport; Time Factors; Transient Receptor Potential Channels; TRPM Cation Channels

Epigenetic alterations have been correlated with field cancerization in human patients, but evidence from experimental models that specific epigenetic changes can initiate cancer has been lacking. Although hormones have been associated with cancer risk, the mechanisms have not been determined. The peptide hormone gastrin exerts a suppressive effect on antral gastric carcinogenesis.. N-methyl-N-nitrosourea (MNU)-dependent gastric cancer was investigated in hypergastrinemic (INS-GAS), gastrin-deficient (GAS(-/-)), Tff1-deficient (Tff1(+/-)), and wild-type (WT) mice. Epigenetic alterations of the trefoil factor 1 (TFF1) tumor suppressor gene were evaluated in vitro and in vivo.. Human intestinal-type gastric cancers in the antrum exhibited progressive TFF1 repression and promoter hypermethylation. Mice treated with MNU exhibited a field defect characterized by widespread Tff1 repression associated with histone H3 lysine 9 methylation and H3 deacetylation at the Tff1 promoter in epithelial cells. In MNU-induced advanced cancers, DNA methylation at the Tff1 promoter was observed. Tumor induction and Tff1 repression were increased in MNU-treated mice by Helicobacter infection. Hypergastrinemia suppressed MNU-dependent tumor initiation and progression in a manner that correlated with gene silencing and epigenetic alterations of Tff1. In contrast, homozygous gastrin-deficient and heterozygous Tff1-deficient mice showed enhanced MNU-dependent field defects and cancer initiation compared with WT mice. In gastric cancer cells, gastrin stimulation partially reversed the epigenetic silencing in the TFF1 promoter.. Initiation of antral gastric cancer is associated with progressive epigenetic silencing of TFF1, which can be suppressed by the hormone gastrin.

Topics: Adult; Aged; Aged, 80 and over; Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Chromatin Assembly and Disassembly; Disease Models, Animal; DNA Methylation; Female; Gastrins; Gene Expression Regulation, Neoplastic; Gene Silencing; Helicobacter felis; Helicobacter Infections; Histones; Humans; Male; Methylnitrosourea; Mice; Mice, Knockout; Middle Aged; Neoplastic Stem Cells; Peptides; Promoter Regions, Genetic; RNA, Messenger; Stomach Neoplasms; Time Factors; Transfection; Trefoil Factor-1; Tumor Suppressor Proteins

A variety of tumors in different organs with good accessibility to near-infrared light express the cholecystokinin-2 (CCK₂)/gastrin receptor. Therefore, the applicability of fluorescence optical imaging was assessed using a novel peptide probe.. This study was approved by the regional animal committee. Our optical peptide probe (DY-minigastrin) was synthesized by coupling a hemicyanine dye to a gastrin derivative peptide (minigastrin). In vitro CCK₂/gastrin receptor identification was performed in receptor-positive HT-29 and negative A-375 cells using flow cytometry, laser scanning microscopy, and macroscopic near-infrared fluorescent (NIRF) imaging. For in vivo studies, tumor cells were implanted into mice, and DY-minigastrin in presence or absence of nonlabeled minigastrin (control of signaling specificity) was applied intravenously. Fluorescence signals in tumors and organs were recorded and statistically analyzed.. Flow cytometry, laser scanning microscopy, and in vitro macroscopic imaging of cell pellets revealed a distinct accumulation of our minigastrin probe in HT-29 cells, showing distinct probe internalization. In vivo NIRF whole-body animal imaging, again, demonstrated a clear depiction of HT-29 tumors, which was reversed by blocking with nonlabeled minigastrin. Semi-quantitative fluorescence analysis and histologic observations were in agreement with these observations. A distinct probe organ distribution was observed.. Our observations indicate that DY-minigastrin-based NIRF optical imaging of CCK₂/gastrin receptor protein is feasible. Because of its widespread occurrence in different tumor types, endoscopic, laparoscopic, and tomographic receptor imaging could be accomplished in the near future.

Topics: Animals; Disease Models, Animal; Feasibility Studies; Flow Cytometry; Gastrins; HT29 Cells; Humans; Mice; Mice, Inbred BALB C; Neoplasms; Receptor, Cholecystokinin B; RNA, Messenger

Under conditions of omeprazole-induced hypergastrinemia the activity of NOS and the concentration of NO2-, the end product of metabolism of nitric oxide were studied in salivary glands of rats. We detected an increase in NOS activity, reaching a maximum (7.61+/-0.39 Mmol [NO2-]/(g*min) at 14th day of the experiment. At 28th day following omeprazole introduction its activity was 5,76+/-0.25 Mmol [NO2-]/(g*min).

Topics: Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Male; Nitric Oxide; Nitric Oxide Synthase; Omeprazole; Rats; Rats, Wistar; Salivary Glands; Time Factors

Gastritis, an inflammation of gastric mucosa, may be due to many pathological factors and infection, such as with Helicobacter pylori. The use of experimental models of gastritis is important to evaluate the biochemical changes and study chemotherapeutic intervention. In a previous study we demonstrated an acute gastritis model induced by iodoacetamide.. Our objective in this study was to evaluate a new gastritis model induced by H. pylori infection in experimental rats in terms of certain biomarkers in serum and mucosal tissues in addition to histopathological examination.. Gastritis was induced in 20 albino Wistar rats by H. pylori isolated from antral biopsy taken from a 49-year-old male patient endoscopically diagnosed as having H. pylori infection. Another ten rats were used as controls. Serum gastrin, pepsinogen I activity, interleukin-6 (IL-6) and gastric mucosal myeloperoxidase (MPO) activity and prostaglandin E(2) (PGE(2)) were measured. Immunostaining for inducible nitric oxide synthase (iNOS), nitrotyrosine and DNA fragmentation were used to further evaluate H. pylori-induced gastritis.. Serum gastrin, IL-6, mucosal MPO activity, and PGE(2) demonstrated significant increases joined with a decreased serum pepsinogen I activity (P < 0.001). Immunohistochemistry demonstrated positive reaction for iNOS, nitrotyrosine and DNA fragmentation.. Helicobacter pylori-induced gastritis models demonstrated massive oxidative stress and pronounced injury in mucosal tissue. Since our model in rats reflected the clinical picture of H. pylori infection, it can be considered as a consistent model to study chemotherapeutic intervention for this type of gastritis.

Topics: Animals; Biomarkers; Biopsy; Dinoprostone; Disease Models, Animal; DNA Fragmentation; Female; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Interleukin-6; Male; Middle Aged; Nitric Oxide Synthase Type II; Pepsinogen A; Peroxidase; Pyloric Antrum; Rats; Rats, Wistar

The effect of the administration of a whey protein isolate (WPI) and collagen hydrolysates on ethanol-induced ulcerative lesions was studied in rats. WPI and bovine or porcine collagen hydrolysate (BCH and PCH, respectively) were given to rats by gavage. In acute experiments, (single-dose) physiological saline (10 mL/kg of body weight) was used as the negative control, and carbenoxolone (200 mg/kg of body weight) was used as a positive control. Ethanol (1 mL per 250-g rat) was also given by gavage. These treatments reduced the ulcerative lesion index (ULI) in a range of 40-77%, depending on the dosage. Some mixtures of WPI with either PCH or BCH provided results that suggested synergisms between WPI and the collagen hydrolysates. For example, WPI/BCH (in the proportion of 375:375 mg/kg of body weight) decreased ULI by 64%. The mechanism for mucosal protection involved a decrease in plasma gastrin (approximately 40%), a significant increase (50-267%) in mucus production, and a reduction in ULI (percentage) when intragastric administrations were performed after in vivo alkylation by N-ethylmaleimide. Results suggest that gastrin, sulfhydryl substances, and some mechanisms related to mucus production are all involved in gastric ulcer protection against ethanol. The collagen hydrolysates (both PCH and BCH) presented a stronger effect on mucus production; on the other hand, the effect of WPI was also dependent on sulfhydryl compounds, resulting in a more protective effect when the two proteins were administered together.

Topics: Alkylation; Animals; Anti-Ulcer Agents; Carbenoxolone; Cattle; Collagen; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Ethanol; Ethylmaleimide; Gastric Mucosa; Gastrins; Hydrolysis; Male; Milk Proteins; Mucus; Rats; Rats, Wistar; Stomach; Stomach Ulcer; Sulfhydryl Compounds; Swine; Whey Proteins

Evidences have suggested that Tectona grandis (TG) attenuates gastric mucosal injury; however its mechanism has not yet been established. The aim of present study was to evaluate the gastroprotective mechanism of ethanolic extract of TG (E-EtOH), butanolic fraction (Fr-Bu) and to identify its active constituents. Anti-ulcer activities were evaluated against cold restraint (CRU) and pyloric ligation (PL) induced gastric ulcer models and further confirmed through H(+) K(+)-ATPase inhibitory activity. Cytoprotective activity was evaluated in alcohol (AL) induced gastric ulcer model and further through PGE(2) level. E-EtOH and Fr-Bu attenuated ulcer formation in CRU. Moreover E-EtOH and Fr-Bu displayed potent anti-secretory activity as evident through reduced free acidity and pepsin activity in PL, confirmed further by in vitro inhibition of H(+) K(+)-ATPase activity. In addition cytoprotective potential of E-EtOH and Fr-Bu were apparent with protection in AL model, increased PGE(2) content and enhanced mucin level in PL. Phytochemical investigations of Fr-Bu yielded terpenoides and a phenolic glycoside, verbascoside. The anti-secretory mechanism of verbascoside mediated apparently through inhibition of H(+) K(+)-ATPase with corresponding decrease in plasma gastrin level, is novel to our finding. Gastroprotection elicited by TG might be through proton pump inhibition and consequent augmentation of the defensive mechanism.

Topics: Animals; Anti-Ulcer Agents; Cold Temperature; Dinoprostone; Disease Models, Animal; Female; Gastric Acid; Gastric Mucosa; Gastrins; Glucosides; Male; Mucins; Pepsin A; Phenols; Phytotherapy; Plant Extracts; Plant Leaves; Proton Pump Inhibitors; Rats; Rats, Sprague-Dawley; Sodium-Potassium-Exchanging ATPase; Stomach; Stomach Ulcer; Verbenaceae

Helicobacter pylori (H pylori) infection is a major risk factor in the development of distal gastric adenocarcinoma. Development of the invasive phenotype is associated with the phenomenon of epithelial:mesenchymal transition (EMT). Soluble heparin-binding epidermal growth factor (HB-EGF) has been implicated in this process. A study was undertaken to investigate the possibility that matrix metalloproteinase (MMP)-7 is upregulated in H pylori infection as a result of hypergastrinaemia, which may enhance shedding of HB-EGF and contribute towards EMT in gastric adenocarcinoma cell lines.. Three gastric epithelial cell lines (AGS, MGLVA1 and ST16) were co-cultured with the pathogenic H pylori strain 60190 and non-pathogenic strain Tx30a in an in vitro infection model. Gene expression was quantified by real-time PCR, HB-EGF shedding by ELISA and protein expression by immunofluorescence or immunohistochemistry. The INS-GAS mouse, a transgenic mouse model of gastric carcinogenesis which overexpresses amidated gastrin, was used to investigate the in vivo relationship between HB-EGF, MMP-7, gastrin and EMT.. The pathogenic strain of H pylori significantly upregulated EMT-associated genes Snail, Slug and vimentin in all three gastric cell lines to a greater degree than the non-pathogenic strain. Pathogenic H pylori also upregulated HB-EGF shedding, a factor implicated in EMT, which was partially dependent on both gastrin and MMP-7 expression. Gastrin and MMP-7 siRNAs and MMP-7 neutralising antibody significantly reduced upregulation of HB-EGF shedding in H pylori infected gastric cell lines and reduced EMT gene expression. The effect of H pylori on EMT was also reversed by gastrin siRNA. Neutralisation of gastrin in the INS-GAS mouse model reduced expression of MMP-7, HB-EGF and key EMT proteins.. The upregulation of MMP-7 by pathogenic H pylori is partially dependent on gastrin and may have a role in the development of gastric cancer, potentially through EMT, by indirectly increasing levels of soluble HB-EGF.

Topics: Animals; Cell Transformation, Neoplastic; Coculture Techniques; Disease Models, Animal; Epithelial Cells; Gastrins; Gene Expression Regulation, Neoplastic; Helicobacter Infections; Helicobacter pylori; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Matrix Metalloproteinase 7; Mesenchymal Stem Cells; Mice; Mice, Transgenic; Neoplasm Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Stomach Neoplasms; Tumor Cells, Cultured; Up-Regulation; Virulence

Gastrin has been implicated in islet growth/neogenesis, and proton pump inhibitors (PPIs) have been shown to increase endogenous gastrin levels in animals and humans. Therefore, we investigated the effect of PPIs in a model of type 2 diabetes, Psammomys obesus.. P. obesus (morning blood glucose [mBG] 16.9 +/- 0.6 mmol/l) were treated with vehicle or different doses (1-15 mg/kg) of lansoprazole for 17 days.. Treatment with lansoprazole resulted in up to ninefold dose-dependent increases in endogenous gastrin levels (p < 0.05 for 10 mg/kg lansoprazole vs vehicle). There was a significant reduction in mBG levels in all animals in the high-dose lansoprazole groups during the 17 day treatment period, whereas there was no significant improvement in mBG in animals in the vehicle groups. The mBG at end of study was 18.2 +/- 2.1, 8.7 +/- 2.2 (p < 0.01), and 6.1 +/- 2.3 (p < 0.001) mmol/l for vehicle and lansoprazole 10 and 15 mg/kg, respectively. The animals treated with 15 mg/kg lansoprazole, compared with vehicle, had a 2.3-fold increase in the intensity of insulin staining in beta cells (p=0.0002) and 50% higher beta cell mass (p=0.04).. The PPI lansoprazole had significant glucose-lowering effects in an animal model of type 2 diabetes, an effect that is most likely mediated through an increase in endogenous gastrin levels.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Analysis of Variance; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Gastrins; Gerbillinae; Hyperglycemia; Immunohistochemistry; Insulin; Insulin-Secreting Cells; Lansoprazole; Male; Proton Pump Inhibitors

Helicobacter pylori (H. pylori) infection has been linked to the development of chronic gastritis, duodenal ulcer disease, and gastric cancer. Helicobacter pylori- infected patients and animal models develop hypergastrinemia, chronic gastritis, and gastric atrophy. Since gastrin is an important regulator of gastric acid secretion and cell growth, H. pylori regulation of this hormone has been implicated in its pathogenesis.. To investigate the effect of H. pylori on gastrin gene expression in mice and of human bacterial isolates on gastrin mRNA expressed in a human cell line.. Gastrin mRNA was measured by qRT-PCR in H. pylori-infected mice. H. pylori were co-cultured with AGS cells to study regulation of human gastrin gene expression. Various MAP kinases were implicated in signal transduction from the bacteria using specific inhibitors. Gastrin reporter constructs and gel shift assays were used to map DNA responsive elements.. In addition to an increase in gastrin mRNA in H. pylori-infected mice, H. pylori induced the endogenous human gastrin gene through MAP kinase-dependent signaling but not NFκB-dependent signaling. Activation of gastrin through MAPK signaling did not require CagA or VacA virulence factors. Transfection studies demonstrated that a GC-rich motif mediated H. pylori-induction of the gastrin promoter and that the motif inducibly binds Sp1 and Sp3 transcription factors.. Direct contact of live H. pylori bacteria with human cells is sufficient to induce gastrin gene expression.

Topics: Animals; Artificial Gene Fusion; Cell Line, Tumor; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Gastrins; Gene Expression; Gene Expression Profiling; Genes, Reporter; Helicobacter Infections; Helicobacter pylori; Humans; Mice; Mice, Inbred C57BL; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

To explore the effects of the method of soothing the liver and regulating qi on expression of gastrin and somatostatin in hypothalamus and gastric antrum of functional dyspepsia model rats.. The 32 rats were randomly divided into normal group, model group, Chaihu Shugansan group and domperidone group (n = 8). The functional dyspepsia model was established by constantly squeezing their tails and mean while saline, Chaihu Shugansan decoction and domperidone suspension were administered respectively to 4 groups by gavage. The expression of gastrin and somatostatin in hypothalamus and gastric antrum of rats by immunohistochemical were detected 3 weeks later.. The expression of GAS in the hypothalamus and gastric antrum of model group were less than those of normal group (P < 0.05, P < 0.01), while the expression of SS in the hypothalamus and gastric antrum in Model group were significantly increased than those of normal group (P < 0.01). The expression of GAS and SS in gastric antrum of Chaihu Shugansan group and domperidone group were increased and decreased respectively, and the differences were significant (P < 0.05, P < 0.01). There were no obvious difference about expression of GAS, SS in the hypothalamus between domperidone group and model group. GAS expression in hypothalamus of Chaihu Shugansan group were increased than those of normal group but there was no obvious difference in SS expression in hypothalamus between Chaihu Shugansan group and model group.. The method of soothing the liver and regulating qi can increase GAS expression in central and peripheral and decrease SS expression in peripheral gastric antrum, which may be one of its therapeutic mechanisms on functional dyspepsia.

Topics: Animals; Disease Models, Animal; Drugs, Chinese Herbal; Dyspepsia; Female; Gastrins; Gene Expression Regulation; Humans; Hypothalamus; Liver; Pyloric Antrum; Qi; Random Allocation; Rats; Rats, Wistar; Somatostatin

Female Japanese cotton rats become hypoacidic and hypergastrinaemic from age 2 months and later develop gastric carcinomas in the oxyntic mucosa. Previous studies have demonstrated that carcinogenesis can be halted by a gastrin receptor antagonist and that carcinomas can be induced by a histamine-2 receptor antagonist or partial corpectomy, both of which induce hypergastrinaemia. The aim of the present study was to examine the effect of antrectomy in female cotton rats.. The animals were either antrectomized (Group 1) or sham-operated (Group 2) 2 months after detection of hypergastrinaemia and terminated 4 months after operation. A third group was antrectomized at age 2 months while still normo-acidic (Group 3) and terminated 6 months after operation.. Antrectomy after 2 months of hypergastrinaemia prevented the development of carcinoma compared with in sham-operated animals, whereas some of the animals that were antrectomized at 2 months of age also developed carcinomas. In Groups 1 and 2 as well as in animals developing carcinomas in Group 3, there was marked hyperplasia of neuroendocrine cells in the oxyntic mucosa expressing chromogranin A, vesicular monoamine transporter (VMAT)-2, ghrelin and somatostatin. Gastrin-positive cells were found adjacent to neoplastic areas in the oxyntic mucosa.. The removal of antral gastrin by antrectomy halts carcinogenesis in cotton rats, but other mechanisms may also play a role.

Topics: Animals; Carcinoma; Disease Models, Animal; Female; Gastrectomy; Gastrins; Hormones; Pyloric Antrum; Sigmodontinae; Stomach Neoplasms

This study investigates the effects of Uliveto, a bicarbonate-alkaline mineral water, in experimental models of diarrhea, constipation and colitis. Rats were allowed to drink Uliveto or oligomineral water (control) for 30 days. Diarrhea and constipation were evoked by 16,16-dimethyl-prostaglandin E(2) (dmPGE(2)) or loperamide, respectively. Colitis was induced by 2,4-dinitrobenzenesulfonic acid (DNBS) or acetic acid. Gastric emptying, small-intestinal and colonic transit were evaluated. dmPGE(2)-induced diarrhea reduced gastric emptying and increased small-intestinal and colonic transit. In this setting, Uliveto water enhanced gastric emptying, and this effect was prevented by L-365,260 (gastrin receptor antagonist). Loperamide-induced constipation reduced gastric emptying, small-intestinal and colonic transit, and these effects were prevented by Uliveto water. L-365,260 counteracted the effects of Uliveto on gastric emptying, while alosetron (serotonin 5-HT(3) receptor antagonist) blunted the effect of Uliveto on colonic transit. Gastric emptying, small-intestinal and colonic transit were reduced in DNBS-induced colitis, and Uliveto water enhanced gastric emptying and normalized small-intestinal and colonic transit. Gastric emptying, small-intestinal and colonic transit were also reduced in acetic acid-induced colitis, and Uliveto increased both gastric emptying and small-intestinal transit. In conclusion, Uliveto water exerts beneficial effects on gastrointestinal motility in the presence of bowel motor dysfunctions. The effects of Uliveto water on gastric emptying depend on gastrin-mediated mechanisms, whereas the activation of serotonergic pathways accounts for the modulation of colonic functions.

Topics: Animals; Benzodiazepinones; Bicarbonates; Colitis; Constipation; Diarrhea; Disease Models, Animal; Gastric Emptying; Gastrins; Gastrointestinal Motility; Hydrogen-Ion Concentration; Male; Mineral Waters; Phenylurea Compounds; Rats; Rats, Wistar; Receptors, Serotonin, 5-HT3

To evaluate measurements of intragastric pH with the Bravo capsule system over a prolonged time.. A Bravo capsule was placed inside the rat gastric body and pH was studied for periods up to five consecutive days. For comparison, a gastric fistula model was used. Effects of ghrelin and esomeprazole, with or without pentagastrin, on gastric pH were studied. In addition, effects of esomeprazole on plasma ghrelin, gastrin and somatostatin were analyzed.. All rats recovered after surgery. The average 24-h pH during free feeding was 2.3 +/- 0.1 (n = 20) with a variation of 18% +/- 6% over 5 d. Ghrelin, 2400 pmol/kg, t.i.d. increased pH from 1.7 +/- 0.1 to 3.1 +/- 0.3 (P < 0.01) as recorded with the Bravo system. After esomeprazole (1 mg/kg, 3 mg/kg and 5 mg/kg) there was a dose-dependent pH increase of maximally 3.4 +/- 0.1, with day-to-day variation over the entire period of 8% +/- 3%. The fistula and pH studies generated similar results. Acid inhibition with esomeprazole increased plasma ghrelin from 10 +/- 2 pmol/L to 65 +/- 26 pmol/L (P < 0.001), and somatostatin from 10 +/- 2 pmol/L to 67 +/- 18 pmol/L (P < 0.001).. pH measurements with the Bravo capsule are reliable, and comparable to those of the gastric fistula model. The Bravo system optimizes accurate intragastric pH monitoring over prolonged periods and allows both short- and long-term evaluation of effects of drugs and hormones.

Topics: Animals; Capsule Endoscopes; Capsule Endoscopy; Disease Models, Animal; Esomeprazole; Gastric Acid; Gastric Acidity Determination; Gastric Fistula; Gastric Mucosa; Gastrins; Gastrointestinal Agents; Gastrointestinal Hormones; Ghrelin; Hydrogen-Ion Concentration; Male; Monitoring, Ambulatory; Pentagastrin; Proton Pump Inhibitors; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Somatostatin; Telemetry; Time Factors

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

Oxidative stress is linked to gastric carcinogenesis because of its ability to damage DNA. Here we examined antioxidative and anti-inflammatory effects of 4-vinyl-2,6-dimethoxyphenol (canolol), a recently identified potent antioxidative compound obtained from crude canola oil, on Helicobacter (H.) pylori-induced gastritis and gastric carcinogenesis using a Mongolian gerbil model. The animals were allocated to H. pylori-infection alone (12 weeks) or H.pylori + N-methyl-N-nitrosourea (MNU) administration (52 weeks). After oral inoculation of H. pylori, they were fed for 10 and 44 weeks with or without 0.1% canolol. H. pylori-induced gastritis, 5'-bromo-2'-deoxyuridine (BrdU) labeling and scores for cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) immunohistochemistry were attenuated in the canolol-treated groups. Expression of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), COX-2 and iNOS mRNA in the gastric mucosa, and serum 8-hydroxy-2'-deoxyguanosine (8-OHdG), anti-H. pylori IgG and gastrin levels were also significantly lower in canolol-treated groups. Furthermore, the incidence of gastric adenocarcinomas was markedly reduced in the H. pylori + MNU + canolol-treated group [15.0% (6/40)] compared to the control group [39.4% (13/33)] (p < 0.05). These data indicate canolol to be effective for suppressing inflammation, gastric epithelial cell proliferation and gastric carcinogenesis in H. pylori-infected Mongolian gerbils. Interestingly, the viable H. pylori count was not changed by the canolol containing diet. Thus, the data point to the level of inflammation because of H. pylori rather than the existence of the bacteria as the determining factor. Importantly, canolol appears to suppress induction of mRNAs for inflammatory cytokines.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anti-Inflammatory Agents; Antibodies, Bacterial; Antioxidants; Biomarkers; Cell Proliferation; Cell Transformation, Neoplastic; Cyclooxygenase 2; Deoxyguanosine; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Immunoglobulin G; Immunohistochemistry; Interleukin-1beta; Nitric Oxide Synthase Type II; Oxidative Stress; Phenols; Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Tumor Necrosis Factor-alpha; Vinyl Compounds

Gastritis, an inflammatory state in gastric mucosa, can be induced experimentally in various ways. The present study considered the iodoacetamide model (Iodo). Omega-3 fatty acids (fish oil), black seed oil, and curcuminoids (natural products) in addition to omeprazole (synthetic proton-pump inhibitor) were tested. Supplementation of 0.1% iodoacetamide to drinking water of experimental rats for two consecutive weeks resulted in: (i) increased serum nitric oxide (NO) and gastrin, and decreased pepsinogen, (ii) depletion of gastric mucosal glutathione (GSH), and (iii) increased gastric mucosal lipid peroxidation (MDA), but failed to affect gastric mucosal myeloperoxidase (MPO) activity. Histological examination showed marked neutrophilic infiltration after 1 week of iodoacetamide administration and shedding of apical cell layer with pale edematous vacuolated gastric gland cells and thickening of muscularis mucosa after 2 weeks of iodoacetamide intake. Individual administration of omega-3 fatty acids 12 mg/kg, black seed oil 50 mg/kg, and curcuminoids 50 mg/kg body weight orally daily for 3 weeks decreased MDA, gastrin, and NO, and normalized mucosal GSH but failed to affect serum pepsinogen level. Combined administration of these natural products for 3 weeks normalized MPO activity, and other effects were nearly the same as with individual use. Omeprazole administration 30 mg/kg body weight orally daily for 3 weeks induced a similar response except for an observed increase in serum gastrin and pepsinogen levels.

Topics: Administration, Oral; Analysis of Variance; Animals; Curcuma; Disease Models, Animal; Fatty Acids, Omega-3; Gastric Mucosa; Gastrins; Gastritis; Iodoacetamide; Lipid Peroxidation; Male; Malondialdehyde; Nitrites; Omeprazole; Pepsinogen A; Peroxidase; Plant Extracts; Plant Oils; Rats; Rats, Wistar

The KCNQ1 gene encodes a voltage-dependent potassium ion channel, and mutations in this gene are the most common cause of congenital long QT syndrome (LQTS). In the present study, we investigated the various phenotypic characteristics of vertigo 2 Jackson (C3H/HeJCrl-Kcnq1(vtg-2J)/J) mice with a Kcnq1 mutation. Both heterozygotes (vtg-2J/+) and homozygotes (vtg-2J/vtg-2J) showed prolonged QT intervals in electrocardiograms (ECGs) compared to C3H/HeJ control (+/+) mice. Furthermore, vtg-2J/vtg-2J mice showed gastric achlorhydria associated with elevation of their serum gastrin levels. The serum corticosterone levels were also significantly increased in vtg-2J/vtg-2J mice. In addition, vtg-2J/vtg-2J mice exhibited significantly higher blood pressure. These findings indicate that the Kcnq1 mutation in vtg-2J mice alters various physiological functions in the cardiac, gastric and adrenocortical systems, and suggest that vtg-2J mice may represent a useful model for studying Kcnq1 functions.

Topics: Achlorhydria; Animals; Corticosterone; Disease Models, Animal; Electrocardiography; Female; Gastric Acid; Gastric Acidity Determination; Gastric Mucosa; Gastrins; Genotype; Hypertension; KCNQ1 Potassium Channel; Long QT Syndrome; Male; Mice; Mice, Inbred C3H; Mice, Mutant Strains; Mutation; Phenotype; Stomach

Mucolipidosis type IV (MLIV) is an autosomal recessive lysosomal storage disorder caused by mutations in the MCOLN1 gene, which encodes the 65-kDa protein mucolipin-1. The most common clinical features of patients with MLIV include severe mental retardation, delayed motor milestones, ophthalmologic abnormalities, constitutive achlorhydria, and elevated plasma gastrin levels. Here, we describe the first murine model for MLIV, which accurately replicates the phenotype of patients with MLIV. The Mcoln1(-/-) mice present with numerous dense inclusion bodies in all cell types in brain and particularly in neurons, elevated plasma gastrin, vacuolization in parietal cells, and retinal degeneration. Neurobehavioral assessments, including analysis of gait and clasping, confirm the presence of a neurological defect. Gait deficits progress to complete hind-limb paralysis and death at age ~8 mo. The Mcoln1(-/-) mice are born in Mendelian ratios, and both male and female Mcoln1(-/-) mice are fertile and can breed to produce progeny. The creation of the first murine model for human MLIV provides an excellent system for elucidating disease pathogenesis. In addition, this model provides an invaluable resource for testing treatment strategies and potential therapies aimed at preventing or ameliorating the abnormal lysosomal storage in this devastating neurological disorder.

Topics: Animals; Body Weight; Disease Models, Animal; Eye Diseases; Gastric Mucosa; Gastrins; Gene Targeting; Hindlimb; Inclusion Bodies; Longevity; Mice; Mice, Knockout; Mucolipidoses; Nervous System Diseases; Paralysis; Pyramidal Cells; Retinal Degeneration; Stomach Diseases; Survival Analysis; Transient Receptor Potential Channels; TRPM Cation Channels

The stimulation of gastric acid secretion from parietal cells involves both intracellular calcium and cAMP signaling. To understand the effect of increased cAMP on parietal cell function, we engineered transgenic mice expressing cholera toxin (Ctox), an irreversible stimulator of adenylate cyclase. The parietal cell-specific H(+),K(+)-ATPase beta-subunit promoter was used to drive expression of the cholera toxin A1 subunit (CtoxA1). Transgenic lines were established and tested for Ctox expression, acid content, plasma gastrin, tissue morphology, and cellular composition of the gastric mucosa. Four lines were generated, with Ctox-7 expressing approximately 50-fold higher Ctox than the other lines. Enhanced cAMP signaling in parietal cells was confirmed by observation of hyperphosphorylation of the protein kinase A-regulated proteins LASP-1 and CREB. Basal acid content was elevated and circulating gastrin was reduced in Ctox transgenic lines. Analysis of gastric morphology revealed a progressive cellular transformation in Ctox-7. Expanded patches of mucous neck cells were observed as early as 3 mo of age, and by 15 mo, extensive mucous cell metaplasia was observed in parallel with almost complete loss of parietal and chief cells. Detection of anti-parietal cell antibodies, inflammatory cell infiltrates, and increased expression of the Th1 cytokine IFN-gamma in Ctox-7 mice suggested that autoimmune destruction of the tissue caused atrophic gastritis. Thus constitutively high parietal cell cAMP results in high acid secretion and a compensatory reduction in circulating gastrin. High Ctox in parietal cells can also induce progressive changes in the cellular architecture of the gastric glands, corresponding to the development of anti-parietal cell antibodies and autoimmune gastritis.

Topics: Aging; Animals; Animals, Genetically Modified; Antibodies; Autoimmune Diseases; Cholera Toxin; Cyclic AMP; Disease Models, Animal; Gastric Acid; Gastrins; Gastritis; Gastritis, Atrophic; H(+)-K(+)-Exchanging ATPase; Mice; Mice, Inbred C57BL; Parietal Cells, Gastric; Promoter Regions, Genetic

Gender differences have been shown regarding the changes in the inflammatory response, gastrin secretion, and gastric acidity during Helicobacter pylori infection.. To investigate the role of estradiol and progesterone in the changes of the gastric mucosa induced by H. pylori during the early stage of infection in female gerbils.. Thirty-three adult ovariectomized female gerbils were infected with H. pylori (SS1); 7 days after infection they were treated with low and high doses of estradiol (50 and 250 microg/60 days pellet), progesterone (15 and 50 mg/60 days pellet) and vehicle. Non-ovariectomized infected gerbils were used as control. Gerbils were euthanized after 6 weeks of infection. Histologic evaluation, immunohistochemical detection of proliferation cell nuclear antigen (PCNA), gastrin, and apoptosis by terminal deoxynucleotide nick end labeling (TUNEL) assay were performed. Positive cells for PCNA, TUNEL, and gastrin were counted in 10 oriented glands per animal. Two-sided p = .05 was considered significant.. Estradiol-treated groups showed more intense and extended acute and follicular gastritis compared to the vehicle group, whereas progesterone-treated groups presented less gastritis than the other groups. Proliferation and apoptosis indexes were significantly lower in the vehicle group when compared with those of the control; both indexes were increased in the high-dose estradiol and progesterone groups as compared with those of the vehicle. Grade I nonmetaplastic atrophy was observed in the vehicle and progesterone groups. The high-dose progesterone group showed a significant reduction in the number of gastrin cells.. Estradiol and progesterone participate in the gastric mucosal response to early H. pylori infection in gerbils.

Topics: Animals; Apoptosis; Cell Proliferation; Disease Models, Animal; Estradiol; Female; Gastric Mucosa; Gastrins; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Immunohistochemistry; In Situ Nick-End Labeling; Progesterone; Proliferating Cell Nuclear Antigen

Interactions between epithelial and stromal cells are important determinants of mucosal organization, but the signaling mechanisms are understood incompletely. Matrix metalloproteinase (MMP)-7 is produced uniquely in epithelia, may act on growth factors and matrix proteins, and in the stomach is increased with Helicobacter pylori infection. We have studied the role of MMP-7 in signaling between epithelial cells and a key stromal cell type, the myofibroblast.. Immunohistochemistry and Western blotting were applied to gastric corpus biopsy specimens; primary cultures of human gastric glands and myofibroblasts were used to study the role of MMP-7 in regulating proliferation and migration of the latter, and MMP-7 substrates were identified by proteomic methods.. Increased abundance of the myofibroblast marker alpha-smooth muscle actin was identified in H. pylori-positive biopsy specimens. Media from H pylori-infected gastric epithelial cultures stimulated proliferation and migration of primary human gastric myofibroblasts and antisense oligonucleotide treatment indicated a role for MMP-7. Proteomic methods identified insulin-like growth factor binding protein (IGFBP)-5 as a substrate for MMP-7 in medium from gastric myofibroblasts. Knockdown of IGFBP-5 by small interfering RNA or immunoneutralization of IGF-II, abolished myofibroblast responses to MMP-7. Proliferation of gastric epithelial cells also was stimulated by MMP-7-treated myofibroblasts via IGF-II.. MMP-7 acts as an epithelial-derived signal increasing the bioavailability of IGF-II released from myofibroblasts. Because IGF-II acts on both stromal and epithelial cells, the findings suggest that increased MMP-7 expression contributes to redefining the niche occupied by dividing cells and leading to hyperproliferation in H pylori infection.

Topics: Animals; Biopsy, Needle; Blotting, Western; Cell Proliferation; Cells, Cultured; Disease Models, Animal; Fibroblasts; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; Male; Matrix Metalloproteinase 7; Mice; Probability; Radioimmunoassay; Sensitivity and Specificity

Gastrin deficiency and proton pump inhibitor treatment cause achlorhydria, which predisposes to disease. To elucidate the underlying molecular biology, we examined the changes in gastric gene expression in both types of achlorhydria. We also explored the associated changes in the gastric microflora and the long-term consequences of gastrin-deficient achlorhydria.. Expression profiles were generated from gastric RNA from wild-type mice, gastrin knockout (KO) mice, gastrin KO mice after 1 week of gastrin infusion, and wild-type mice treated for 1 month with a proton pump inhibitor. The results were confirmed using real-time polymerase chain reaction and immunohistochemistry. Selective media were used to characterize the gastric microflora.. The number of gastric bacteria was increased in both gastrin KO and PPI-treated mice. The expression profiles revealed activation of immune defense genes, interferon-regulated response genes, and intestinal metaplasia of the gastric mucosa. In young gastrin-deficient mice, gastrin infusions reversed the changes. Over time, the changes accumulated, became irreversible, and progressed into metaplasia and polyp development. Finally, the study showed that gastrin regulated the expression of genes encoding extracellular matrix proteins.. Independently of gastrin, achlorhydria is associated with gastric bacterial overgrowth and intestinal gene expression patterns and is associated with predisposition to disease. Gastrin is therefore essential for prevention of gastric disease, mainly through control of acid secretion but to a lesser extent also through control of gastric gene expression. The gastrin-deficient mouse serves as a useful new model for gastric metaplasia and neoplasia.

Topics: Animals; CDX2 Transcription Factor; Disease Models, Animal; DNA, Neoplasm; Female; Gastric Mucosa; Gastrins; Gastritis; Gene Expression; Homeodomain Proteins; Hormones; Immunohistochemistry; Male; Metaplasia; Mice; Mice, Inbred C57BL; Mice, Knockout; Polymerase Chain Reaction; Stomach Neoplasms; Transcription Factors

Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is highly effective for morbid obesity. However, the long-term effects in the bypassed segments are unknown. The aim of this study is to evaluate gastrin and histologic changes in bypassed segments after LRYGBP.. 10 50-kg pigs were subjected to LRYGBP. Preoperative weight and serum gastrin were compared with similar measures at 6 months postoperatively, when the pigs were euthanized. At necropsy, full-thickness gastric, duodenal, and jejunal biopsies were performed. Normal biopsies were obtained from a control group of 10 pigs.. 1 pig died at 3 months postoperatively because of an intestinal intussusception. In the remaining 9 pigs, weight increased after surgery from 52+/-2.2 kg to 55+/-1.9 kg. Serum gastrin was unchanged after surgery (mean 68.2 vs 68.3 pg/mL at 3 months and 61.7 pg/mL at 6 months). Histology showed no abnormalities from sections in all control pigs, and in 7 of the LRYGBP pigs as well. 1 LRYGBP pig was found to have hyperplastic duodenal glands, jejunal mucosa with mild chronic inflammation, and gastric mucosa with focal erosive gastritis. 1 LRYGBP pig had jejunal sections showing Peyer's patches.. LRYGBP is not associated with gastrin changes and major histologic changes in the bypassed segments, at 6 months postoperatively in the porcine model.

Topics: Anastomosis, Roux-en-Y; Animals; Disease Models, Animal; Gastric Bypass; Gastrins; Postoperative Complications; Stomach; Swine

Both gastrin and Helicobacter pylori have been shown capable of up-regulating gene expression and protein shedding of heparin-binding epidermal growth factor (HB-EGF). Furthermore, the bacteria have previously been shown to induce serum hypergastrinemia in infected individuals. The aim of this work was to assess the extent to which the ability of H. pylori to up-regulate expression of HB-EGF can be attributed to its effect on gastrin. Gastric cells, transfected with either gastrin small interfering RNA or antisense plasmid or the gastrin/cholecystokinin-2 receptor (CCK-2R), were cultured for 24 hours with H. pylori(+/-), a CCK-2R antagonist. Gene expression levels were measured using reverse transcription-PCR, whereas protein changes were measured using ELISA, Western blotting, and immunofluorescence. H. pylori induced significantly higher levels of HB-EGF gene expression and ectodomain shedding in the CCK-2R-transfected cells than the vector control (P < 0.01). Addition of the CCK-2R inhibitor significantly decreased gene and shedding up-regulation. Gastrin down-regulation reduced the effect of the bacteria on HB-EGF gene and protein expression levels. Endogenous gastrin and CCK-2R expression were also found to be significantly up-regulated in all cell lines as a result of exposure to H. pylori (P < 0.02). Gastric mucosal tissue from H. pylori-infected individuals had significantly higher CCK-2R expression levels than noninfected (P < 0.003), and in hypergastrinemic mice, there was an increase in HB-EGF-expressing cells in the gastric mucosa and colocalization of HB-EGF with CCK-2R-positive enterochromaffin-like cells. In conclusion, gastrin and the CCK-2R play significant roles in the induction of HB-EGF gene and protein expression and ectodomain shedding by H. pylori.

Topics: Adenocarcinoma; Animals; Cell Line, Tumor; Disease Models, Animal; DNA, Antisense; Enterochromaffin Cells; Epidermal Growth Factor; Gastrins; Helicobacter Infections; Helicobacter pylori; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Mice; Plasmids; Receptor, Cholecystokinin B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Stomach Neoplasms; Transfection; Up-Regulation

Hypergastrinemia in INS-GAS mice leads to accelerated carcinogenesis of the stomach, but the mechanisms have not been well defined. We investigated the possible role of gastrin-induced gastric cell apoptosis in the development of gastric cancer. We examined apoptosis and the expression of Bcl-2 family proteins in INS-GAS mice of different ages, as well as in gastrin-deficient (GAS-KO) mice after gastrin-17 (G-17) infusion. In addition, we studied the effects of the gastrin/cholecystokinin-2 (CCK-2) receptor antagonist YF476 and/or histamine H2 (H-2) receptor antagonist loxtidine on apoptosis and atrophy in INS-GAS mice with or without Helicobacter felis (H. felis) infection. INS-GAS mice had age-associated increases in Bax protein expression and decreases in Bcl-2 protein expression, along with increased glandular and epithelial cell apoptosis. At 8-week gastrin infusions in GAS-KO mice resulted in a similar pattern of altered Bax and Bcl-2 expression, followed by gastric cell apoptosis. H. felis infection of INS-GAS mice led to increased apoptosis and the development of atrophy, whereas treatment with either YF476 and/or loxtidine strongly inhibited both apoptosis and atrophy. In vitro studies with Fas-expressing RGM1 cells showed that gastrin stimulation alone directly induced apoptosis via gastrin/CCK-2 receptor and synergized with FasL stimulation. These results indicate that gastrin can induce apoptosis in gastric epithelial cells and contribute to the development of gastric carcinogenesis.

Topics: Animals; Apoptosis; Atrophy; Disease Models, Animal; Gastrins; Helicobacter felis; Helicobacter Infections; Male; Mice; Mice, Knockout; Proto-Oncogene Proteins c-bcl-2; Receptor, Cholecystokinin B; Receptors, Histamine H2; Stomach Neoplasms

The gp130(757F/F) mouse is a well-characterized and robust model of distal gastric tumorigenesis displaying many of the characteristics of human intestinal type gastric cancer. Key to the development of tumors in this model, and in many examples of human tumor development, is hyperactivation of the transcription factor STAT3. This study addressed the requirement for STAT3 activation in tumor initiation and characterized some of the genes downstream of STAT3 required for tumor development. Furthermore, the interaction among STAT3, the microbial environment, and tumorigenesis was evaluated.. The role of STAT3 in gastric tumor development was assessed in detail in gp130(757F/Y757F):STAT3(+/-) mice displaying reduced STAT3 activity. Tumor size was quantified morphologically, and the effects on endocrine cell populations, neovascularization, and inflammatory cell infiltration as well as the outcome of STAT3 activation on transcription of a number of genes relevant in growth and inflammation were quantified.. Loss of one STAT3 allele in gp130(757F/F) mice reduced the frequency and rate of tumor development because of inhibition of proliferation-induced glandular hyperplasia. There was also a concomitant reduction in the degree of inflammatory infiltration and cytokine and chemokine expression, angiogenesis, and expression of metalloproteinases and growth factors. Antimicrobial treatment of gp130(757F/F) mice slowed tumor growth coincident with reduced macrophage and neutrophil infiltration.. Activation of STAT3 and the microbial environment are pivotal for gastric tumor initiation and development in the gp130(757F/F) mouse, thus supporting the notion that STAT3 activation may play a role in human gastric cancer development.

Topics: Animals; Cell Division; Cell Movement; Cytokine Receptor gp130; Disease Models, Animal; Extracellular Matrix; Gastric Mucosa; Gastrins; Gastritis; Gene Expression Regulation, Neoplastic; Leptin; Macrophages, Peritoneal; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Neovascularization, Pathologic; Neutrophils; Phosphorylation; Pyloric Antrum; Somatostatin; STAT3 Transcription Factor; Stomach Neoplasms

Candida albicans frequently inhabits the gastrointestinal tract of humans leading to gastrointestinal candidiasis, especially following suppression of gastric acidity, but studies on the relation between this fungal infection and gastric pathology are limited due to lack of convenient animal models resembling Candida infection in humans. MATERIAL AND METHODS. We compared the effects of C. albicans and vehicle inoculation on gastric secretion and healing of gastric ulcers induced by acetic acid in rats treated with 1) ranitidine (30 mg kg(-1) day(-1) s.c.) and 2) aspirin (ASA) (60 mg kg(-1) day(-1) i.g.) with or without probiotic bacteria Lactobacillus acidophillus. At day 0 and at 4, 15 and 25 days after ulcer induction, the ulcer area, the gastric blood flow (GBF), the quantitative gastric cultures of Candida and the expression of mRNAs for pro-inflammatory cytokines IL-1beta and TNF-alpha and growth factors EGF and TGFalpha were assessed in the gastric mucosa.. Gastric acid output was reduced by over 40% soon after Candida inoculation and this effect persisted during all time intervals tested. The area of ulcers in control rats significantly decreased at day 15 and the ulcers disappeared almost completely after 25 days of their induction. In contrast, the ulcers were present until day 25 in Candida-inoculated rats followed by a fall in GBF and a rise in plasma gastrin levels, these effects being significantly attenuated by the co-treatment with Lactobacillus. Candidiasis was accompanied by up-regulation of mRNA for IL-1beta, TNF-alpha, EGF and TGFalpha and a significant increment in plasma IL-1beta and TNF-alpha levels.. 1) Persistent colonization with Candida could be achieved in rats treated with antisecretory agents or non-steroidal anti-inflammatory drugs (NSAIDs) such as ASA; 2) candidiasis reduces gastric acid secretion, while delaying ulcer healing possibly due to the impairment in GBF in the ulcer area and enhanced expression and release of IL-1beta and TNFalpha and 3) probiotic therapy could be useful in the treatment against the deleterious action of fungal infection on the healing of pre-existing gastric ulcers.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Anti-Ulcer Agents; Aspirin; Biopsy; Blood Flow Velocity; Candida albicans; Chronic Disease; Colony Count, Microbial; Cytokines; Disease Models, Animal; Electrophoresis, Agar Gel; Gastric Juice; Gastric Mucosa; Gastrins; Gene Expression Regulation; Lactobacillus acidophilus; Male; Microcirculation; Probiotics; Ranitidine; Rats; Rats, Wistar; RNA, Messenger; Stomach Ulcer

Apart from its importance as an acid secretogogue, the role of histamine as a downstream target of gastrin has not been fully explored. Previous studies have shown that the combination of hypergastrinemia and Helicobacter infection resulted in accelerated gastric cancer in mice. We used this model to examine the role of cholecystokinin 2 (CCK2)/gastrin receptor and histamine H2-receptor signaling in the development of gastric atrophy and cancer.. Male hypergastrinemic mice (INS-GAS mice) were infected with Helicobacter felis and given the CCK2/gastrin receptor antagonist YF476 and/or the histamine H2-receptor antagonist loxtidine for 3 or 6 months. In addition, mice were treated with omeprazole alone or in combination with either YF476 or loxtidine for 3 months.. Mice treated with YF476 or loxtidine alone showed partial suppression of both gastric acid secretion and progression to neoplasia. The combination of YF476 plus loxtidine treatment resulted in nearly complete inhibition of both parameters. YF476 and/or loxtidine treatment did not alter the overall level of H. felis colonization but did result in significant down-regulation of the growth factors regenerating gene I and amphiregulin. Loxtidine treatment, with or without YF476, induced a mild shift in T-helper cell polarization. In contrast, omeprazole treatment resulted in mild progression of gastric hyperplasia/dysplasia, which was ameliorated by the addition of YF476 or loxtidine.. The combination of CCK2/gastrin- and histamine H2-receptor antagonists has synergistic inhibitory effects on development of gastric atrophy and cancer in H. felis/INS-GAS mice, while the proton pump inhibitor showed no such effects. These results support an important role for the gastrin-histamine axis in Helicobacter-induced gastric carcinogenesis.

Topics: Achlorhydria; Animals; Atrophy; Benzodiazepinones; Disease Models, Animal; Gastrins; Helicobacter felis; Helicobacter Infections; Histamine H2 Antagonists; Male; Mice; Mice, Transgenic; Phenylurea Compounds; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Receptors, Histamine H2; Stomach Neoplasms; Triazoles

H+/K+-ATPase beta-subunit-deficient mice (129/Sv background) display numerous pathologies in the stomach. Expression of the mutation in BALB/cCrSlc mice results in the development of an aberrant 'mucus-rich' cell population. 'Mucus-rich' cells have been described in stomachs of mice with autoimmune gastritis, a disease mediated by CD4+ T cells. Other pathological features of autoimmune gastritis are similar to those in H+/K+ beta-deficient mice and include a mononuclear cell infiltrate in the gastric mucosa, non-functional or absent parietal cells, depletion of zymogenic cells, hypergastrinaemia, and gastric unit hypertrophy caused by immature cell hyperplasia. The present study investigates further the aberrant gastric 'mucus-rich' cell lineage and analyses the mRNA expression of mucus cell products TFF1 and TFF2. 'Mucus-rich' cells stained for both acidic and neutral mucins, and with a TFF2-specific antibody. Stomachs from both models expressed decreased TFF1 mRNA and reciprocally increased TFF2 mRNA. The involvement of gastrin in regulating trefoil mRNA expression was also investigated using gastrin-deficient mice. In contrast to previous findings, gastrin did not positively regulate TFF1 mRNA expression, but there was possible augmentation of TFF2. Additionally, a clear role for inflammation was established involving both polymorphonuclear and mononuclear cells in these models, and a link was found between mucosal hypertrophy and increased interleukin-11 (IL-11) expression.

Topics: Animals; Autoimmune Diseases; Cytokines; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Gene Expression Regulation; H(+)-K(+)-Exchanging ATPase; Hyperplasia; Hypertrophy; Interleukin-11; Mice; Mice, Inbred BALB C; Mice, Mutant Strains; Mucins; Muscle Proteins; Peptides; RNA, Messenger; Species Specificity; Trefoil Factor-1; Trefoil Factor-2

Epidemiological studies have shown that Helicobacter pylori infection with associated chronic gastritis is the main risk factor for development of gastric cancer. The aim of this study was to investigate the long-term development of H. pylori-induced gastritis in Mongolian gerbils in terms of morphology, gastrin secretion, epithelial proliferation and gene expression of pro-inflammatory cytokines.. A total of 133 gerbils were inoculated with H. pylori and 62 served as controls. The gerbils were killed at different time-points between 6 and 94 weeks after inoculation. Serum concentrations of anti-H. pylori IgG and gastrin were determined by enzyme-linked immunoabsorbent assay (ELISA) and radioimmunoassay (RIA), respectively. Epithelial proliferation was evaluated immunohistochemically after labeling with 5-bromo-2'-deoxy-uridine. Gene expression of beta-actin, interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were measured by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Histological parameters of gastritis were assessed semiquantitatively and expressed as a "gastritis score".. Serum concentrations of anti-H. pylori IgG and gastrin increased over time. Epithelial proliferation in the antrum was increased 6 weeks after inoculation, followed by increased proliferation in the corpus 32 weeks after inoculation. Gene expression of IL-1beta and TNF-alpha were increased in H. pylori-infected gerbils. Beta-actin was not a reliable endogenous control for RT-PCR. With time, gastritis expanded from the antrum to the corpus and the gastritis score increased to reach a peak 32 weeks after inoculation. Pseudopyloric metaplasia (loss of specialized cells) was a characteristic feature in the corpus mucosa. Gastric ulcers, but neither dysplasia nor carcinoma, were observed during 94 weeks of infection.. Long-term H. pylori infection in Mongolian gerbils led to progressive gastritis, glandular atrophy, hypergastrinemia, increased epithelial proliferation and elevated gene expression of pro-inflammatory cytokines.

Topics: Actins; Animals; Biomarkers; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Gastric Mucosa; Gastrins; Gastritis; Gene Expression Regulation, Bacterial; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Immunoglobulin G; Immunohistochemistry; Interleukin-1; Male; Pyloric Antrum; Radioimmunoassay; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Tumor Necrosis Factor-alpha

We examined the roles of cholecystokinin (CCK)-2 receptors in the regulation of pepsinogen secretion in the CCK-1 receptor deficient Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Pepsinogen secretion was determined in fasted acute fistula OLETF and control Long-Evans Tokusima Otsuka (LETO) rats. Pepsinogen secretion in OLETF rats under basal conditions as well as in response to CCK-8 stimulation was significantly higher than that in LETO rats. CCK-1 receptor specific agonist ARL 15849 was unable to stimulate pepsinogen secretion in OLETF rats, whereas it elicited pepsinogen secretion in LETO rats to levels similar to those obtained with equimolar CCK-8 stimulation. CCK-2 receptor antagonist reduced basal pepsinogen secretion and completely abolished CCK-8-stimulated pepsinogen output in OLETF rats, whereas in LETO rats, it reduced basal pepsinogen secretion but augmented CCK-8-stimulated pepsinogen output. CCK-1 receptor antagonist loxiglumide also greatly decreased CCK-8-stimulated pepsinogen secretion in OLETF rat, which indicates that loxiglumide is not a specific CCK-1 receptor antagonist. Intravenous infusion of somatostatin antagonist significantly increased CCK-8-stimulated pepsinogen secretion in LETO rats, whereas it had no significant influence on CCK-8-stimulated pepsinogen secretion in OLETF rats. These results indicate that CCK-8 stimulates pepsinogen secretion via CCK-2 receptors in CCK-1 receptor deficient OLETF rats and that the higher CCK-8-stimulated as well as basal pepsinogen secretion in OLETF rats might result from an elimination of tonic inhibition by somatostatin that is released from D cells through mainly CCK-1 receptors.

Topics: Animals; Disease Models, Animal; Gastrins; Male; Pepsinogen A; Probability; Rats; Rats, Inbred OLETF; Rats, Long-Evans; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Reference Values; Risk Factors; Sensitivity and Specificity; Sincalide; Somatostatin; Species Specificity; Statistics, Nonparametric

Among inbred female cotton rats (Sigmodon hispidus) 25%-50% of the animals develop spontaneous gastric carcinomas, whereas males have an incidence of less than 1%. The carcinomas are enterochromaffin-like (ECL)-cell derived. Animals with gastric carcinomas also have hypergastrinaemia and gastric hypoacidity, but the mechanism behind the hypoacidity is unknown. Carcinomas have been found in all female cotton rats with spontaneous hypergastrinaemia lasting more than 4 months, and a gastrin receptor antagonist prevents the development of carcinoma. The purpose of the present study was to investigate whether induced hypergastrinaemia in male cotton rats would also result in carcinomas.. Hypergastrinaemia was induced by partial corpectomy of male cotton rats, aiming at removal of 80%-90% of the corpus. A control group was sham-operated.. All partially corpectomized animals developed persistent hypergastrinaemia. Six months after the operation, 9 out of 13 partially corpectomized animals developed gastric cancer. In the dysplastic mucosa surrounding the tumours there was an increase in chromogranin A immunoreactive cells, where numerous cells also were stained using the Sevier-Munger technique. Tumour tissue also contained cells that were chromogranin A positive and stained by Sevier-Munger.. ECL-cell carcinomas can be induced in male cotton rats by partial corpectomy. This supports a previous statement that spontaneous carcinomas in female cotton rats are caused by gastric hypoacidity and hypergastrinaemia. In hypergastrinaemic animals, ECL-cell carcinomas develop independently of gender within a relatively short period of time, and cotton rats therefore represent an interesting model for studying gastric carcinogenesis.

Topics: Animals; Biopsy, Needle; Carcinoma; Disease Models, Animal; Enterochromaffin-like Cells; Gastrectomy; Gastrins; Hydrogen-Ion Concentration; Immunohistochemistry; Male; Probability; Rats; Sensitivity and Specificity; Sigmodontinae; Statistics, Nonparametric; Stomach Neoplasms

Helicobacter pylori is a human gastric carcinogen. Sterigmatocystin (ST), a fungus toxin, is a risk factor of gastric cancer. Cytotoxin-vacuolation toxin A (VacA) present in supernatants of H. pylori suspensions can cause gastritis and ulcer. The aim of this study was to examine the effects of H. pylori, ST and VacA in Mongolian gerbils.. Male Mongolian gerbils (n = 196) were treated with H. pylori supernatants (10 ml/1000 mg) mixed with diet or inoculated intragastrically with H. pylori alone or with ST (100 or 1000 ppb), and then killed 27 months later. Gastric tissue sections were stained with haematoxylin and eosin (H&E), periodic acid-Schiff (PAS), Alcian blue (AB, pH 2.5) and with immunostaining for PCNA and p53 expression.. In H. pylori-infected gerbils, the normal mucosa was replaced by hyperplastic epithelium. Severe gastritis, cystic dilatation of gastric glands, hyperplastic polyps and intestinal metaplasia were observed. In H. pylori + ST (1000 ppb) gerbils, intestinal metaplasia was significantly more frequent than in H. pylori alone animals. No pathological changes were observed in the H. pylori supernatant group. Osseous metaplasia was observed in the H. pylori + ST (100 ppb) group. Serum gastrin levels of the H. pylori + ST (1000 ppb) group were significantly higher than those of the other groups. PCNA labelling index and p53 index of infected gerbils were significantly higher than those of uninfected groups.. H. pylori causes gastritis, ulcer and intestinal metaplasia. ST enhances the development of intestinal metaplasia and increases gastrin levels in H. pylori-infected Mongolian gerbils.

Topics: Animals; Bacterial Proteins; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Metaplasia; Sterigmatocystin; Tumor Suppressor Protein p53

Gastrin regulates gastric acid secretion, believed to be primarily responsible for killing ingested microbes. We examined gastric killing of gavaged E. coli in gastrin-deficient mice, which have decreased gastric acid production. Additionally, the expression of intestinal genes involved in epithelial protection were analyzed: the mucus layer glycoprotein muclin, the polymeric Ig receptor, trefoil factor 3, and small proline-rich protein 2a (sprr2a). Gastric pH was 2.5 pH units greater in gastrin-deficient mice, and E. coli survival was increased greater than 20-fold at 10 min after gavage compared to control. Muclin and sprr2a gene expression were significantly increased (2.0- and 2.6-fold) in the intestine, and antibiotic treatment reversed these effects. In conclusion, reduced gastric acid secretion results in increased survival of ingested microorganisms in gastrin-deficient mice. Bacterial survival is associated with increased expression of muclin and sprr2a in the intestine, indicating that these genes play protective roles in the intestine.

Topics: Animals; Base Sequence; Cornified Envelope Proline-Rich Proteins; Disease Models, Animal; DNA, Bacterial; Escherichia coli; Female; Gastric Acid; Gastric Mucosa; Gastrins; Growth Substances; Hydrogen-Ion Concentration; Intestine, Small; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Mucins; Muscle Proteins; Neuropeptides; Peptides; Polymerase Chain Reaction; Protein Precursors; RNA, Messenger; Sensitivity and Specificity; Trefoil Factor-2; Trefoil Factor-3; Up-Regulation

Helicobacter pylori cag(+) strains and high-expression host interleukin 1beta (IL-1beta) polymorphisms augment the risk for intestinal-type gastric adenocarcinoma, a malignancy that predominates in males. We examined the effects of an H. pylori cancer-associated determinant (cagE), IL-1beta, and host gender in a transgenic hypergastrinemic (INS-GAS) murine model of gastric carcinogenesis.. Male and female INS-GAS mice infected with wild-type H. pylori, an H. pylori cagE(-) mutant, or H. felis were killed 2-24 weeks postchallenge. Gastric injury was scored from 0 to 4, and mucosal IL-1beta levels were quantified by ELISA.. Male INS-GAS mice infected with H. pylori uniformly developed atrophy, intestinal metaplasia, and dysplasia by 6 weeks and carcinoma by 24 weeks. Mucosal IL-1beta concentrations increased 12 weeks following Helicobacter challenge, but levels then decreased by 24 weeks. Inactivation of cagE delayed the progression to carcinoma, but neoplasia ultimately developed in all males infected with the H. pylori mutant. In contrast, none of the H. pylori-infected female mice developed cancer, and injury scores, but not IL-1beta levels, were significantly higher in males compared with females.. H. pylori infection induces gastric adenocarcinoma in an experimental mouse model of disease. Cancer is restricted to males and loss of cagE temporally retards but does not abrogate pathologic progression. Mucosal levels of IL-1beta increase prior to the development of gastric cancer but are not related to gender. The INS-GAS model is effective for investigating discrete host-microbial interactions that culminate in gastric cancer within the context of biologic conditions induced by H. pylori.

Topics: Adenocarcinoma; Animals; Bacterial Proteins; Disease Models, Animal; Female; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Interleukin-1; Male; Mice; Precancerous Conditions; Sex Factors; Stomach; Stomach Neoplasms

Helicobacter pylori infection of Mongolian gerbils is an established model of gastric carcinogenesis, but gastric secretory aspects of this carcinogenesis have not been studied.. The effects of single intragastric inoculation of gerbils with H. pylori strain (cagA+ vacA+, 5 x 10(6) CFU/ml) or vehicle (saline) were examined at 1, 2, 4, 6, 9, 12 and 30 weeks from inoculation. Gastric morphology, the presence of H. pylori using the rapid urease test, the density of H. pylori and 16S rRNA and the plasma gastrin and somatostatin were determined.. H. pylori was detected in gastric mucosa in all infected animals. Basal gastric acid in gerbils was reduced by about 50% after H. pylori inoculation. Early lesions seen at 4 weeks after H. pylori inoculation consisted of chronic gastritis with thickened mucosal folds, oedema, congestion and mucosal lymphocytic infiltration. Adenomatous hyperplasia with cellular atypia with increased mitotic activity and the formation of apoptotic bodies and visible erosions and ulcerations were observed at 12-30 weeks after inoculation. The atypical gastric glands were situated 'back-to-back', suggesting gastric pre-cancer. The gastric blood flow in H. pylori-infected gerbils was significantly lower than that in the controls. Six- to seven-fold increase in plasma gastrin levels combined with significant fall in gastric somatostatin contents and the intraepithelial neoplasia were noticed in gerbils at all tested periods.. H. pylori-infection in gerbils resulted in gastric pre-cancer associated with functional changes, such as suppression of gastric secretion and impairment of both gastric mucosal microcirculation and the gastrin-somatostatin link.

Topics: Animals; Cell Transformation, Neoplastic; Disease Models, Animal; Gastric Acid; Gastric Mucosa; Gastrins; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Microcirculation; Precancerous Conditions; Somatostatin; Stomach Neoplasms

Although regenerating gene (Reg) protein is reported to have a trophic effect on gastric epithelial cells, its involvement in human gastric diseases is not clear. We have recently shown that both gastrin and gastric mucosal inflammation enhance Reg gene expression in the fundic mucosa in rats. This study was designed to clarify whether Reg protein is involved in Helicobacter pylori-induced gastritis and whether Reg gene expression is linked to serum gastrin levels in this condition. Mongolian gerbils were inoculated with an H. pylori strain isolated from a gastric cancer patient. Four weeks later, some of the gerbils with H. pylori infection were eradicated by lansoprazole, amoxicillin, and clarithromycin. The time courses of changes in Reg gene expression, serum gastrin levels, gastric acidity, and histopathologic factors were examined. Four weeks after H. pylori infection, gastritis started spreading to the fundic mucosa, and gastric acidity started reducing. Serum gastrin levels and Reg mRNA expression in the fundus were significantly increased 6 weeks after infection. Reg mRNA expression in the fundus correlated significantly with both serum gastrin levels and the severity of fundic mucosal inflammation. After H. pylori eradication, serum gastrin levels and fundic mucosal inflammation were normalized, and the increase in Reg mRNA expression was abolished. The Reg gene is associated with hypergastrinemia and fundic mucosal inflammation and may be involved in H. pylori-induced gastritis.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Base Sequence; Calcium-Binding Proteins; Cell Division; Disease Models, Animal; Gastric Acidity Determination; Gastric Mucosa; Gastrins; Gastritis; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Lithostathine; Male; Molecular Sequence Data; Nerve Tissue Proteins; RNA, Messenger; Sequence Alignment; Up-Regulation

To investigate the changes of gastrin, somatostatin and motilin production in the gastric antral mucosa of rats with experimental gastric ulcer.. Rat models of gastric ulcer model were induced successfully by injection of acetic acid into the gastric antral wall of 2 groups of Wistar rats (7 in each group) that were subjected to environment of either high or normal temperature. Another 2 groups of rats (n=7) receiving normal saline injection in the same manner, along with still another 2 groups (n=7) without any treatment, all of which were kept under conditions with different temperatures accordingly, constituted the control groups. The levels of gastrin, somatostatin and motilin in the gastric antral mucosa of the rats were measured with radioimmunoassay.. In rats with gastric ulcer, the levels of gastrin and motilin in the antral mucosa increased, but in a lesser scale in rats with ulcer kept in high temperature than in normal temperature group, while that of somatostatin was reduced. The level of somatostatin declined less in the high temperature group with ulcer than in the normal temperature group with ulcer.. High temperature can affect gastrin, somatostatin and motilin production in the gastric antral mucosa of rats with gastric ulcer.

Topics: Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Male; Motilin; Pyloric Antrum; Rats; Rats, Wistar; Somatostatin; Stomach Ulcer; Temperature

Gastric carcinoids are strongly associated with chronic atrophic gastritis A, and it is suggested that hypergastrinemia plays a critical role in development of gastric carcinoids. Since Helicobacter pylori infection causes hypergastrinemia, it is held that H. pylori infection produces gastric carcinoids. We followed the histological changes of H. pylori-infected stomachs of Mongolian gerbils for a long time.. Five-week-old-male Mongolian gerbils were infected with H. pylori ATCC 43504 with cagA gene, expressing vacuolating cytotoxin. Determination of the serum gastrin and histopathological examination of the stomach at 6, 12, 18, and 24 months after H. pylori inoculation was studied and compared with uninfected animals.. In infected animals, the gastric carcinomas appeared 18 and 24 months after infection. Endocrine cell dysplasias and carcinoids with marked atrophic gastritis of the oxyntic mucosa were observed in the infected animals 24 months after H. pylori inoculation. The serum gastrin level in the infected group increased from an average of 86.2 pg/ml at the beginning of the study to an average of 498 pg/ml and 989 pg/ml at 18 and 24 months after infection, respectively. These changes in the serum gastrin levels were significant compared with uninfected controls that showed no changes.. H. pylori infection caused not only gastric carcinomas but also enterochromaffin-like cell tumors in Mongolian gerbils, due to hypergastrinemia. This model is thought to be useful to study the relationship between hypergastrinemia and gastric carcinoids.

Topics: Adenocarcinoma; Animals; Carcinoid Tumor; Disease Models, Animal; Gastric Mucosa; Gastrins; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Stomach Neoplasms

It is hypothesized that cholecystokinin stimulates acid secretion directly and indirectly by binding to CCK-2 (CCK-B/gastrin) receptors on both parietal and enterochromaffin-like cells. At the same time, however, it inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells and thereby exerts a tonic inhibition on the parietal cells. To test the validity of this hypothesis, we determined gastric acid secretion in the CCK-1 (CCK-A) receptor-deficient Otsuka Long-Evans Tokushima fatty (OLETF) rats.. Gastric acid secretion was determined in the acute fistula OLETF and the control Long-Evans Tokushima Otsuka (LETO) rats. Plasma concentrations of gastrin, CCK, somatostatin and histamine were determined by radioimmunoassay. The levels of CCK-2 receptor mRNA in the mucosa of the glandular stomach were determined by Northern blot analysis.. Pentagastrin- and CCK-8-stimulated as well as basal acid outputs in OLETF rats were significantly higher than those in LETO rats. CCK-2 receptor antagonist reduced basal acid outputs and completely suppressed CCK-8-stimulated acid secretion in both strains. CCK-8 enhanced the pentagastrin-stimulated gastric acid output in OLETF rats, but not in LETO rats. In LETO rats, CCK-1 receptor antagonist increased CCK-8-stimulated gastric acid secretions to those in OLETF rats. The level of CCK-2 receptor mRNA in the stomach in OLETF rats was 2-fold higher than that in LETO rats. In OLETF rats, plasma concentrations of CCK and histamine were higher, whereas somatostatin concentrations were lower than those in LETO rats, with no change in basal plasma gastrin concentrations.. These results in the CCK-1 receptor-deficient OLETF rats confirmed that CCK stimulates acid secretion by binding to CCK-2 receptors, but at the same time inhibits acid responses by stimulating the paracrine secretion of somatostatin from D cells in the gastric mucosa.

Topics: Animals; Cholecystokinin; Disease Models, Animal; Gastric Acid; Gastrins; Histamine; Male; Paracrine Communication; Parietal Cells, Gastric; Rats; Rats, Inbred OLETF; Receptor, Cholecystokinin A; Receptors, Cholecystokinin; Somatostatin; Somatostatin-Secreting Cells

Catechin, a polyphenol contained in tea (a cup of tea contains approximately 0.1% [w/v] catechin), has various physiological effects. The aim of this study was to investigate the mechanism of the inhibitory effect of catechin on gastric mucosal lesions.. We studied the effect of catechin on gastric mucosal lesions in rats, using a water immersion restraint (WIR) stress-induced gastric mucosal lesion model. We used crude catechin that contained 52.6% (w/w) (-)-epigallocatechin gallate and 16.7% (w/w) (-)-epicatechin gallate. The rats were randomly divided into three groups; control rats freely drank distilled water, and the remaining rats drank 0.1% (w/v) or 1% (w/v) crude catechin-containing water for 2 weeks. We measured fractional areas of hemorrhagic erosion in the gastric mucosa induced by WIR stress for 4h, compared with findings in the controls. We also employed an isolated rat stomach infusion model and measured gastrin, somatostatin, and histamine in the perfusate to endocrinologically investigate the mechanism underlying the putative protective effect of catechin.. Catechin had a significant protective effect against the gastric mucosal lesions induced by WIR stress. Catechin also significantly inhibited the release of gastrin, somatostatin, and histamine.. Catechin confers a protective effect against gastric mucosal lesions, and anti-gastric and anti-histaminergic effects may be involved in the mechanism of this effect.

Topics: Animals; Catechin; Disease Models, Animal; Gastric Mucosa; Gastrins; Male; Rats; Rats, Wistar; Somatostatin; Stomach Diseases

To investigate the relationship among gastrin, somatostatin, G and D cells in gastric ulcer and in its healing process in rats.. Fourty-nine Wistar rats were divided into 7 groups. The gastric ulcer model was induced by acetic acid successfully. The gastrin and the somatostatin in rat plasma, gastric fluid and antral tissue were measured by radioimmunoassay(RIA). G and D cells in antral mucosa were analyzed with polyclonal antibody of gastrin and somatostatin by immunohistochemical method and Quantimet 500 image analysis system.. In gastric ulcer, the level of gastrin in plasma, gastric fluid, and antral tissue increased, that of somatostatin declined, and the disorder gradually recovered to the normal level in the healing process. Immunohistochemical technique of G and D cells in antral mucosa demonstrated that the number of G cells increased and that of D cells decreased, both areas of G and D cells declined, the ratio of number and area of G/D increased in gastric ulcer, and the disorder gradually recovered in the healing process.. In gastric ulcer, the increased gastrin secreted by G cells, the declined somatostatin secreted by D cells, and the disordered G/D cell ratio can lead to gastrointestinal dysfunction.

Topics: Animals; Disease Models, Animal; Gastric Mucosa; Gastrin-Secreting Cells; Gastrins; Male; Rats; Rats, Wistar; Somatostatin; Somatostatin-Secreting Cells; Stomach Ulcer

Previous studies in our laboratory demonstrated that pancreatic carcinomas in rodents express receptors for the peptide hormone gastrin that are not present in normal adult pancreas. In view of an abundant literature suggesting that gastrin may promote growth of various gastrointestinal tissues and tumors, the effect of hypergastrinemia on the process of pancreatic carcinogenesis was evaluated.. Rats received subcutaneous injections of the pancreatic carcinogen azaserine at 19 and 26 days of age. Starting at 12 months of age, animals were randomized to treatment with the proton pump inhibitor lansoprazole or vehicle by gavage for 6 months. At autopsy, pancreatic wet weight normalized to body weight was recorded, as well as the number of benign and malignant pancreatic lesions.. Serum gastrin levels were determined by radioimmunoassay and showed a greater than two-fold increase in lansoprazole-treated animals. Pancreatic wet weight in hypergastrinemic rats was increased compared to controls (p <0.05). Premalignant lesions such as acidophilic atypical acinar cell foci, adenomas, heterogeneous phenotypic populations of nodules within nodules, and carcinoma-in-situ were not increased in the hypergastrinemic group. Likewise, there was no difference in the incidence of invasive carcinoma in hypergastrinemic animals (10%) compared to controls (5.7%).. Hypergastrinemia stimulated an increase in pancreatic weight, but did not stimulate development of premalignant lesions or progression to cancer in the azaserine model of rat pancreatic acinar cell carcinoma.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Adenoma; Animals; Anti-Ulcer Agents; Azaserine; Carcinoma in Situ; Carcinoma, Acinar Cell; Disease Models, Animal; Gastrins; Lansoprazole; Male; Omeprazole; Organ Size; Pancreas; Pancreatic Neoplasms; Precancerous Conditions; Rats; Rats, Inbred Lew

Serum hypergastrinemia promotes the growth of colorectal adenocarcinoma. Some colorectal adenomas express cholecystokinin B/gastrin receptor mRNA, and thus hypergastrinemia may increase progression through the adenoma-carcinoma sequence. This was investigated in the multiple intestinal neoplasia APC(Min-/+) mouse. Serum gastrin levels in APC(Min-/+) mice were elevated 5-6-fold by oral administration of omeprazole (75 mg/kg). Terminal tumor burden was monitored by onset of anemia. A labeling index was generated by immunohistochemical detection of bromodeoxyuridine incorporation. Serum gastrin was neutralized by antigastrin antibodies raised in situ by use of a gastrin immunogen, Gastrimmune. Hypergastrinemia resulted in reduced survival of the APC(Min-/+) mice from a median survival of 13 weeks in the controls to 10 weeks following omeprazole treatment (P < 0.00001, log-rank test). The labeling indices of adenomas from the small and large intestines of omeprazole-treated mice were increased 35 and 29%, respectively (P < 0.05 and P < 0.025, respectively). Gastrimmune immunization reversed both the survival effect and the increased proliferation resulting from serum hypergastrinemia. Hypergastrinemia may promote the progression of existing premalignant colonic lesions by increasing proliferation. Clinical investigations should determine whether this occurs in the human scenario, considering the widespread use of proton pump inhibitors.

Topics: Adenoma; Adenomatous Polyposis Coli; Adenomatous Polyposis Coli Protein; Animals; Bromodeoxyuridine; Cancer Vaccines; Colorectal Neoplasms; Cytoskeletal Proteins; Diphtheria Toxoid; Disease Models, Animal; Disease Progression; Female; Gastrins; Gene Expression Regulation; Heterozygote; Immunization; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Omeprazole; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; RNA, Messenger; Survival Rate

Gastric infection with Helicobacter pylori is associated with hypergastrinemia. Platelet activating factor (PAF) is produced in H. pylori-infected mucosa. The effects of PAF on gastrin release from cultured antral rabbit G cells were examined. Rabbit antral G-cells were obtained by collagenase-EDTA digestion and enriched by centrifugal elutriation. After 40 hr in culture, gastrin release in response to PAF was assessed. PAF stimulated gastrin release in a dose-dependent manner. A maximal release of 67% above basal was seen with PAF at 100 nM. PAF also enhanced the gastrin release stimulated by forskolin and bombesin. PAF-stimulated gastrin release was abolished by a PAF-receptor antagonist. Gastrin release stimulated by PAF was abolished by chelation of intra- or extracellular calcium or the L-type calcium channel inhibitor verapamil as well as by the protein kinase C inhibitor chelerythrine. Platelet-activating factor may contribute to the hypergastrinemia of H. pylori infection by stimulating gastrin release from G cells. PAF-stimulated gastrin release involves influx of extracellular calcium via L-type channels and activation of protein kinase C.

Topics: Animals; Bombesin; Calcium Channels, L-Type; Cells, Cultured; Colforsin; Disease Models, Animal; Gastrin-Secreting Cells; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Platelet Activating Factor; Protein Kinase C; Rabbits

Further elucidation of the consequences of Helicobacter pylori infection on gastric mucosal inflammation and gastric secretory function would be facilitated by an animal model that is susceptible to infection with H. pylori, is broadly similar in gastric physiology and pathology to people, and is amenable to repeated non-invasive evaluation. The goal of this study was to examine the interrelationship of bacterial colonization, mucosal inflammation and gastric secretory function in cats with naturally acquired H. pylori infection.. Twenty clinically healthy cats with naturally acquired H. pylori infection (cagA-, picB) and 19 Helicobacter-free cats were evaluated. Gastric colonization was determined by tissue urease activity, light microscopy, culture and PCR. The mucosal inflammatory response was evaluated by light microscopy, and by RT-PCR of the pro-inflammatory cytokines IL-1alpha, IL-1beta, IL-8 and TNF-alpha in gastric mucosa. Gastric secretory function was assessed by measuring pentagastrin-stimulated acid secretion, fasting plasma gastrin, and antral mucosal gastrin and somatostatin immunoreactivity.. H. pylori colonized the pylorus, fundus and cardia in similar density. Bacteria were observed free in the lumen of gastric glands and were also tightly adherent to epithelial cells where they were associated with microvillus effacement. Mononuclear inflammation, lymphoid follicle hyperplasia, atrophy and fibrosis were observed primarily in H. pylori-infected cats, with the pylorus most severely affected. Neutrophilic and eosinophilic infiltrates, epithelial dysplasia, and up-regulation of mucosal IL-1beta and IL-8 were observed solely in infected cats. Fasting plasma gastrin concentrations and pentagastrin-stimulated acid output were similar in both infected and uninfected cats. There was no relationship of bacterial colonization density or gastric inflammation to plasma gastrin concentrations or gastric acid output.. The pattern of colonization and the mucosal inflammatory response in cats with naturally acquired H. pylori are broadly similar to those in infected people, particularly children, and non-human primates. The upregulation of IL-8 in infected cats was independent of cagA and picB. Our findings argue against a direct acid-suppressing effect of H. pylori on the gastric secretory-axis in chronically infected cats.

Topics: Animals; Antigens, Bacterial; Bacterial Proteins; Cardia; Cat Diseases; Cats; Disease Models, Animal; Female; Gastric Acidity Determination; Gastric Fundus; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Interleukin-1; Interleukin-8; Male; Pyloric Antrum; Reverse Transcriptase Polymerase Chain Reaction; Somatostatin; Tumor Necrosis Factor-alpha

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

A model of sub-clinical parasitism in young red deer, using concurrent trickle infections of lungworm (Dictyocaulus sp.) and mixed gastro-intestinal (GI) nematodes of deer-origin was evaluated. 20 parasite-free deer calves were artificially reared indoors from 4 days of age. A further five calves were naturally reared on pasture with their dams, treated with anthelmintic and brought indoors at 3-4 months. At 4-4.5 months of age they were individually housed and allocated to five groups (n=5). Groups were dosed 3 x per week, for 9 weeks with 0, 100 and 500, 200 and 1000 (2 groups), 400 and 2000 infective larvae of lungworm and mixed GI nematodes, respectively, cultured from deer faeces. Liveweight and voluntary feed intake measurements and faecal and blood samples were taken weekly. In the fourth week following cessation of trickle infection, deer were euthanased and lung and GI nematodes recovered. Both lungworm and GI nematode infections became patent at Week 4 of infection. Maximum group arithmetic mean faecal egg counts were 100-190 epg. Maximum group arithmetic mean faecal lungworm larval counts were 58-123 lpg. Group arithmetic mean nematode counts at slaughter ranged from 439-806 for GI nematodes and 31-73 for lungworm, respectively. Despite low nematode counts, reduced liveweight gain, voluntary feed intake and serum albumin concentration, elevated serum pepsinogen, gastrin and globulin concentrations and elevated peripheral eosinophil counts and slight haemoconcentration, but no clinical signs, were observed. The reduction in liveweight gain was related to the reduction in voluntary feed intake (r2=0.83; p<0.088). Naturally-reared deer had similar liveweight gains, voluntary feed intake and nematode counts to artificially-reared deer. Thus, methods of infection to produce concurrent sub-clinical lungworm and GI nematode burdens for study of sub-clinical parasitism in young deer have been defined.

Topics: Animals; Deer; Dictyocaulus; Dictyocaulus Infections; Digestive System; Disease Models, Animal; Eating; Feces; Female; Gastrins; Hemoglobins; Intestinal Diseases, Parasitic; Linear Models; Male; Nematoda; Nematode Infections; Parasite Egg Count; Pepsinogen A; Random Allocation; Serum Albumin; Serum Globulins

Oxyntic atrophy is the hallmark of chronic gastritis. Many studies have sought to develop animal models for oxyntic atrophy, but none of them are reversible. We now report that rats administered high doses of DMP 777 demonstrate reversible oxyntic atrophy.. DMP 777 was administered to CD-1 rats by oral gavage (200 mg. kg(-1). day(-1)). Serum gastrin level, in vivo acid secretion, and gastric histological changes were evaluated in DMP 777-dosed animals. Direct effects of DMP 777 on parietal cells were evaluated by assessment of aminopyrine accumulation into isolated rabbit parietal cells, as well as by assessment of DMP 777 effects on acridine orange fluorescence and H(+),K(+)-adenosine triphosphatase (ATPase) activity in isolated tubulovesicles.. Oral dosing with DMP 777 caused a rapid increase in serum gastrin levels and severe hypochlorhydria. DMP 777 inhibited aminopyrine accumulation into rabbit parietal cells stimulated with either histamine or forskolin. DMP 777 reversed a stimulated proton gradient in isolated parietal cell tubulovesicles. Oral dosing with DMP 777 led to rapid loss of parietal cells from the gastric mucosa. In response to the acute loss of parietal cells, there was an increase in the activity of the progenitor zone along with rapid expansion of the foveolar cell compartment. DMP 777 treatment also led to the emergence of bromodeoxyuridine-labeled cells and cells positive for periodic acid-Schiff in the basal region of fundic glands. With extended dosing over 3-6 months, foveolar hyperplasia and oxyntic atrophy were sustained while chief cell, enterochromaffin-like cell, and somatostatin cell populations were decreased. No histological evidence of neoplastic transformation was observed with dosing up to 6 months. Withdrawal of the drug after 3 or 6 months of dosing led to complete restitution of the normal mucosal lineages within 3 months.. DMP 777 acts as a protonophore with specificity for parietal cell acid-secretory membranes. DMP 777 in high doses leads to the specific loss of parietal cells. Foveolar hyperplasia, loss of normal gland lineages, and the emergence of basal mucous cells appear as sequelae of the absence of parietal cells. The results suggest that parietal cells are critical for the maintenance of the normal mucosal lineage repertoire.

Topics: Acridine Orange; Aminopyrine; Animals; Anti-Inflammatory Agents, Non-Steroidal; Atrophy; Azetidines; Carbon Radioisotopes; Disease Models, Animal; Enzyme Inhibitors; Fluorescent Dyes; Gastric Acid; Gastrins; Gastritis; H(+)-K(+)-Exchanging ATPase; Ionophores; Leukocyte Elastase; Male; Necrosis; Nigericin; Parietal Cells, Gastric; Piperazines; Rabbits; Rats; Rats, Sprague-Dawley; Regeneration; Stomach

We investigated the recurrence of ulcers in rats after treatment with FRG-8813, (+/-)-2-(furfurylsulfinyl)-N-[4- [4-(piperidinomethyl)-2-pyridyl] oxy-(Z)-2-butenyl] acetamide, a novel histamine H(2)-receptor antagonist. Chronic gastric ulcers were induced by serosa-searing with a hot metal bar, and the ulcer healing and recurrence after treatment with FRG-8813 or famotidine were evaluated by endoscopy for 160 days. At the dose of 30 mg/kg p. o., once daily, the treatment with FRG-8813 or famotidine for 60 days, which was stopped earlier if the ulcer had healed, accelerated the ulcer healing significantly. A subsequent follow-up study on the healed rats showed that the cumulative recurrence rate of rats healed by FRG-8813 was lower than that of naturally healed rats or rats healed by famotidine. In many cases of rats healed by FRG-8813, the regenerated mucosa was normal in contrast with the control of famotidine-healed animals. The mucosal regeneration index of the gastric ulcer after 10 days' administration of FRG-8813 was significantly higher than that obtained with famotidine. After cessation of the treatment with famotidine for 7 days, rebound hyperacidity was induced; but such rebound did not occur with FRG-8813. Considering the low recurrence rate of ulcers after FRG-8813 treatment, we suggest that FRG-8813 treatment may provide additional benefits in peptic ulcer therapy.

Topics: Acetamides; Animals; Disease Models, Animal; Endoscopy, Gastrointestinal; Famotidine; Gastric Acidity Determination; Gastrins; Histamine H2 Antagonists; Male; Outcome Assessment, Health Care; Piperidines; Pyridines; Rats; Rats, Wistar; Secondary Prevention; Stomach Ulcer

Mutations in the adenomatous polyposis coli (APC) tumor suppressor gene occur in most colorectal cancers and lead to activation of beta-catenin. Whereas several downstream targets of beta-catenin have been identified (c-myc, cyclin D1, PPARdelta), the precise functional significance of many of these targets has not been examined directly using genetic approaches. Previous studies have shown that the gene encoding the hormone gastrin is activated during colon cancer progression and the less-processed forms of gastrin are important colonic trophic factors. We show here that the gastrin gene is a downstream target of the beta-catenin/TCF-4 signaling pathway and that cotransfection of a constitutively active beta-catenin expression construct causes a threefold increase in gastrin promoter activity. APC(min-/+) mice overexpressing one of the alternatively processed forms of gastrin, glycine-extended gastrin, show a significant increase in polyp number. Gastrin-deficient APC(min-/+) mice, conversely, showed a marked decrease in polyp number and a significantly decreased polyp proliferation rate. Activation of gastrin by beta-catenin may therefore represent an early event in colorectal tumorigenesis and may contribute significantly toward neoplastic progression. The identification of gastrin as a functionally relevant downstream target of the beta-catenin signaling pathway provides a new target for therapeutic modalities in the treatment of colorectal cancer.

Topics: Adenomatous Polyposis Coli; Animals; Base Sequence; beta Catenin; Cytoskeletal Proteins; Disease Models, Animal; DNA Primers; Female; Gastrins; Gene Expression; Genes, APC; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mutation; Promoter Regions, Genetic; Signal Transduction; TCF Transcription Factors; Trans-Activators; Transcription Factor 7-Like 2 Protein; Transcription Factors; Transfection

Hypergastrinemia secondary to low acid secretion is associated with gastric carcinoid formation in Mastomys. We investigated the effect of gastrin on oxyntic epithelial apoptosis and proliferation in this model.. Hypergastrinemia and mucosal hyperplasia were induced by irreversible H(2) receptor blockade with loxtidine. Gastrin levels were normalised in some animals by 10 days' loxtidine withdrawal. Serum gastrin was determined by radioimmunoassay, proliferative, enterochromaffin-like cells and Bcl-2 protein family expression by immunohistochemistry, and apoptotic cells by terminal deoxyuridine nucleotide nick end labeling (TUNEL).. Proliferating cells were increased 4-fold in loxtidine-treated animals, and returned to normal upon loxtidine withdrawal. Enterochromaffin-like cell number increased 2-fold with loxtidine, and did not decrease after withdrawal. Apoptotic epithelial cells were located at the luminal surface and increased 1.8-fold with loxtidine, returning to control levels upon withdrawal. The ratio of proliferative to apoptotic cells was lower in the control and withdrawn groups than in the loxtidine group (0.26+/-0.05 and 0.26+/-0.08 vs. 0.77+/-0.12). With hypergastrinemia, the expression of Bcl-2 and Bak was increased and Bax decreased in the middle of the gland.. Hypergastrinemia is associated with alterations in both proliferation and apoptosis in Mastomys gastric mucosa. This may contribute to the pathogenesis of mucosal hyperplasia in this model.

Topics: Animals; Apoptosis; Carcinoid Tumor; Cell Division; Disease Models, Animal; Female; Gastric Acid; Gastric Mucosa; Gastrins; Immunohistochemistry; Male; Muridae; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms

Injury to the gastric mucosa caused by duodenogastric reflux (DGR) is often encountered after gastrectomy or truncal vagotomy (V) with pyloroplasty. This study was designed to investigate the histological features of the gastric mucosa under such conditions. A rat model of DGR and DGR+V was established and the thickness of the oxyntic mucosa was measured. Cellular dynamics in the presence of injury to the gastric mucosa caused by DGR were investigated by the immunohistochemical staining of bromodeoxyuridine (BrdU) and heat shock protein 70 (HSP70). The relationship between persistent hypergastrinemia and mucosal injury was also studied. Duodenogastric reflux activated the intracellular induction of HSP70 in our rat model of DGR. Hypergastrinemia was noted in the V group. Compared with values from the DGR group, the numbers of BrdU-labeled cells increased, the glandular proliferation zone expanded, and the thickness of the oxyntic mucosa was significantly higher in the DGR+V group. Compared with the DGR group, there was greater induction of HSP in the DGR+V group during the acute stage. This finding suggests that denervation of the gastric mucosa and hypergastrinemia after vagotomy may be associated with the expression of HSP.

Topics: Animals; Bromodeoxyuridine; Disease Models, Animal; Duodenogastric Reflux; Gastric Mucosa; Gastrins; HSP70 Heat-Shock Proteins; Immunohistochemistry; Male; Rats; Rats, Wistar; Vagotomy

Helicobacter pylori infection in humans is a major risk factor for peptic ulcer, but studies on the relation between H. pylori infection and gastric pathology are limited due to a deficiency of convenient animal models resembling this infection in humans.. We studied the effects of inoculation of conventional BALB/c mice with CagA and VacA positive (type I) H. pylori or CagA and VacA negative H. pylori (type II) strains on gastric secretion and healing of chronic acetic acid-induced ulcers in mouse stomachs. The ulcer area, gastric blood flow, plasma interleukin (IL)-1beta and IL-12, as well as plasma gastrin and gastric luminal somatostatin were determined. Gastric mucosal biopsy samples were also taken for assessment of the presence of viable H. pylori using a rapid urease test, H. pylori-culture and the RT-PCR analysis of the signal for H. pylori CagA.. Gastric acid and pepsin secretion was reduced by over 50% immediately after H. pylori inoculation and accompanied by a significant increment in plasma gastrin and fall in gastric luminal somatostatin content observed over all test days, particularly in mice infected with type I H. pylori. The area of ulcers in vehicle-treated controls decreased significantly starting from day 2 after ulcer induction and then continued to decline for a further 14 days to heal almost completely after 28 days. In contrast, the ulcers were present until day 28 in all mice infected with type I or type II H. pylori strains, being significantly larger, especially with type I H. pylori infection. The gastric blood flow at the ulcer margin and ulcer crater in vehicle-treated mice gradually increased with decreasing ulcer size, after 14 and 28 days reaching a value which was not significantly different from that in vehicle-administered mice. In contrast, the gastric blood flow in type I H. pylori and, to a lesser extent, in type II H. pylori infected mice was significantly lower than in vehicle controls, both at the margin and at the crater of ulcers at all tested days. Histological changes such as oedema or congestion of surface epithelium were found after 7 days whereas mucosal inflammatory infiltration appeared after 14 days with a further increase after 28 days, especially in type I H. pylori and to a lesser extent in type II H. pylori infected mice. Plasma IL-1beta and IL-12 were significantly elevated at all tested days of ulcer healing and their increments were significantly higher in type I than in type II H. pylori infection.. Conventional mice with gastric ulcers can be successfully infected by both toxigenic and nontoxigenic H. pylori strains, and this infection causes an immediate suppression of gastric secretion and markedly delays the healing of ulcers due to the fall in mucosal microcirculation in the ulcer region, cytokine release and an impairment in the gastrin-somatostatin link that appears to be independent of gastritis and more pronounced with infection of toxigenic than nontoxigenic strains.

Topics: Animals; Antigens, Bacterial; Bacterial Proteins; Colony Count, Microbial; Disease Models, Animal; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Interleukin-1; Interleukin-12; Male; Mice; Mice, Inbred BALB C; Regional Blood Flow; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Somatostatin; Stomach; Stomach Ulcer

A Mongolian gerbil model was used to clarify whether long-term colonization by Helicobacter pylori is an important risk factor for the development of gastric cancer. Fifty-nine gerbils (3 controls and 56 gerbils inoculated with H. pylori) were killed at various times (average, 23 months) more than 12 months after H. pylori inoculation. In the H. pylori-inoculated group, poorly differentiated adenocarcinoma was observed in the pylorus of 1 gerbil, and carcinoid was observed in the fundus of the stomach in 18 gerbils. No lesions were found in the stomachs of the 3 control gerbils. The results imply that long-term colonization by H. pylori is an important risk factor for the development of gastric adenocarcinoma and carcinoid.

Topics: Adenocarcinoma; Animals; Antibodies, Bacterial; Carcinoid Tumor; Disease Models, Animal; Duodenum; Gastrins; Gerbillinae; Helicobacter Infections; Immunoglobulin G; Intestinal Mucosa; Metaplasia; Stomach Neoplasms; Time

In this study, ischemia-reperfusion produced in rats by clamping the celiac artery for 0.5 h followed by 1 h of reperfusion was used to develop a new model of superficial gastric erosions progressing to deeper ulcers. Ischemia alone resulted in an immediate fall in gastric blood flow but no gross mucosal lesions were observed. When ischemia was followed by reperfusion, gastric erosive lesions occurred, reached a maximum at 12 h and then declined after 24 h. These acute erosions progressed into deeper lesions 24 h after ischemia-reperfusion and reached a peak after 3 days. Gastric blood flow and the mucosal generation of prostaglandin E(2) were significantly suppressed immediately following ischemia-reperfusion, but with the healing of deeper gastric ulcers, both gastric blood flow and prostaglandin E(2) generation were gradually restored. Cyclooxygenase-1 mRNA was detected by reverse transcription-polymerase chain reaction in intact gastric mucosa and throughout the recovery of the mucosa from acute ischemia-reperfusion lesions, whereas cyclooxygenase-2 mRNA, was recorded only after ischemia-reperfusion. NS-398 and rofecoxib, selective inhibitors of cyclooxyganase-2, failed to affect prostaglandin E(2) generation in the non-ulcerated gastric mucosa but inhibited it significantly in the ulcer area. The two cyclooxygenase-2 inhibitors as well as resveratrol, a specific cyclooxygenase-1 inhibitor and indomethacin and meloxicam, non-specific inhibitors of cyclooxygenase, augmented acute gastric erosions induced by ischemia-reperfusion and delayed significantly the progression of these lesions into deeper ulcers at each time interval after ischemia-reperfusion. We conclude that prostaglandins generated by both cyclooxygenase-1 and cyclooxygenase-2 contribute to the healing of gastric lesions induced by ischemia-reperfusion.

Topics: Animals; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Gastric Mucosa; Gastrins; Gene Expression Regulation, Enzymologic; Indomethacin; Interleukin-1; Isoenzymes; Lactones; Meloxicam; Membrane Proteins; Nitrobenzenes; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Rats; Regional Blood Flow; Reperfusion Injury; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stilbenes; Stomach Ulcer; Sulfonamides; Sulfones; Thiazines; Thiazoles; Time Factors

The antral endocrine cells were investigated in nonobese diabetic (NOD) mice by means of immunohistochemistry, image analysis, and radioimmunoassays (RIA). As controls BALB/CJ mice of the same age and sex as the NOD mice were used. The number of gastrin- and somatostatin-immunoreactive cells was significantly decreased in both prediabetic and diabetic mice. There was no statistical difference between the NOD mice and controls regarding the serotonin-immunoreactive cells. Somatostatin levels as revealed by RIA in the antrum of both prediabetic and diabetic NOD mice were lower than those of the controls. There was no statistical difference in the level of antral gastrin between NOD mice and the controls. It was concluded that the changes in antral cells are primary to the onset of diabetes, and that the abnormalities observed in the antral cells in an animal model for diabetes type I might have relevance for the upper gastrointestinal dysfunction displayed in human diabetes.

Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Enteroendocrine Cells; Female; Gastrins; Image Processing, Computer-Assisted; Immunohistochemistry; Mice; Mice, Inbred BALB C; Mice, Inbred NOD; Pyloric Antrum; Radioimmunoassay; Somatostatin

Helicobacter pylori infection in humans has been shown to be associated with changes in gastric physiology, including exaggerated basal and meal-stimulated gastrin levels. This has been suggested to be due to the direct effects of the bacterium through inflammation and its urease enzyme. The gastric bacteria Helicobacter felis and Helicobacter heilmannii colonize the antrum of rats in large numbers and induce no significant inflammatory response. Thus, the direct effect of Helicobacter infection on gastric physiology, independent of gastritis, could be studied. Basal, freely fed and stimulated acid and gastrin levels were recorded from animals infected with H. felis, H. heilmannii or uninfected controls over a 30 week period. No significant difference was found between freely fed gastrin over 7 weeks or fasting gastrin over 24 weeks or basal and stimulated acid over 30 weeks between all three groups. Triple therapy did not alter gastrin or acid output. The antrum of all Helicobacter-infected rats was well colonized; triple therapy cleared H. felis but not H. heilmannii. Very little inflammation was seen in control or Helicobacter-infected animals. In conclusion, Helicobacter-induced effects on gastric physiology are unlikely to be due to direct bacterial effects, but are best explained by other factors (i.e. inflammatory damage).

Topics: Animals; Disease Models, Animal; Female; Gastric Acid; Gastrins; Helicobacter Infections; Inflammation; Rats; Urease

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

Psammomys obesus fed a high-calorie diet develops a NIDDM-like syndrome. The use of reverse-phase high-performance liquid chromatography (HPLC) to study Psammomys insulin biosynthesis and release revealed a very delayed elution time for the Psammomys insulin peak appearing near the position of human proinsulin. This unusual peak was initially thought to represent partially processed insulin on the basis of its molecular size and susceptibility to trimming by carboxypeptidase B (CpB). However, the findings of an active carboxypeptidase E (CpE) enzyme and the normal amidated forms of gastrin and cholecystokinin octapeptide (CCK-8) in Psammomys tissues were inconsistent with CpE-related aberrant processing of insulin. Moreover, amino acid sequencing of the delayed peak of Psammomys insulin revealed fully processed insulin with amino acid sequence as predicted by the cDNA. The unique presence of a B-30 phenylalanine residue, resulting in an increased hydrophobicity of the insulin molecule, probably underlies the marked delay in elution time on HPLC. The unusual structure of Psammomys insulin does not appear to contribute to the proinsulinemia observed in diabetic Psammomys since the HPLC-purified molecule did not inhibit PC1 and PC2 convertase activities in an in vitro assay.

Topics: Amino Acid Sequence; Animals; Base Sequence; Blotting, Western; Carboxypeptidases; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 2; Diet; Disease Models, Animal; DNA Primers; Furin; Gastrins; Gerbillinae; Humans; Insulin; Islets of Langerhans; Molecular Sequence Data; Pituitary Gland; Polymerase Chain Reaction; Proinsulin; Protein Precursors; Rats; Rats, Sprague-Dawley; Sincalide; Subtilisins

To examine the effect of gastrin on spontaneous and induced pancreatic carcinogenesis in the hamster.. Two sets of experiments were carried out, one involving long term hypergastrinaemia and one involving cancer induction during hypergastrinaemia. The effect of hypergastrinaemia accomplished by gastric fundectomy was studied for eight months. Neither fundectomised hamsters nor sham operated controls developed premalignant or malignant pancreatic lesions. In the fundectomy group, the mean pancreatic weight, total protein content, and DNA content was increased by 28%, 25%, and 25% respectively. No such increases were found in fundectomised animals receiving a cholecystokinin-B receptor antagonist during the last 24 days of the experiment. In the cancer induction study, the effect of fundectomy on N-nitrosobis(2-oxopropyl) amine induced pancreatic carcinogenesis was studied for three months. There were no significant differences in the incidence or [3H]-thymidine labelling index of focal pancreatic lesions between fundectomised and sham operated control animals.. Fundectomy with chronic hypergastrinaemia induces pancreatic hypertrophy, but does not enhance N-nitrosobis (2-oxopropyl)amine induced pancreatic carcinogenesis in the hamster. The increases in growth were inhibited by a cholecystokinin-B receptor antagonist, indicating that the trophic effect of fundectomy is mediated by gastrin.

Topics: Animals; Benzodiazepinones; Carcinogens; Cholecystokinin; Cricetinae; Disease Models, Animal; Gastric Fundus; Gastrins; Hypertrophy; Male; Mesocricetus; Neoplasms, Experimental; Nitrosamines; Pancreas; Pancreatic Neoplasms; Phenylurea Compounds; Receptors, Cholecystokinin

To evaluate whether the small bowel can be distracted by mechanical stress in analogy to limb lengthening by osteodistraction, a gut-lengthening apparatus was designed. This distractor was placed at the antimesenterical side of a defined jejunum segment in rabbits. Distraction was performed by 1 mm lengthening of the distractor once daily using extracorporal screws. An effective gut lengthening was achieved of 9.9 +/- 0.5 mm (approximately 100%) within 3 weeks. Treated animals gained weight and remained in good general condition. Fasting plasma levels of cholecystokinin, neurotensin, glucagon-like peptide-1, gastric inhibitory polypeptide, and insulin remained unaffected. Postoperative factor XIII levels were significantly diminished and gastrin was elevated during gut distraction. DNA and protein concentrations in the mucosa of the distracted gut segments corresponded to controls. Mucosal lactase and saccharase activities were reduced. In the distracted bowel segments total tunica muscularis thickness was more than doubled due to muscle cell hypertrophy. In distracted segments villous width was increased. Detection of proliferating mucosal crypt cells utilizing BrdUrd labeling revealed no effects. In conclusion, small gut lengthening by mechanical distraction is possible without major changes in gut morphology. This technique may hint a novel experimental approach for the treatment of short bowel syndrome.

Topics: Animals; beta-Galactosidase; Disease Models, Animal; DNA; Factor XIII; Gastrins; Immunohistochemistry; Intestinal Mucosa; Intestine, Small; Lactase; Male; Muscle, Smooth; Organ Size; Rabbits; Short Bowel Syndrome; Stress, Mechanical; Sucrase

Persons infected with Helicobacter pylori show an enhanced meal-stimulated gastrin release compared with uninfected controls. The aim of this study was to determine in animal models whether this gastrin release could be related to chronic gastric inflammation, elevated luminal ammonia level, or a combination of these factors.. Two rat models of mild gastric inflammation were studied. Rats given a long-term diet of 20 g/dL ammonium acetate (AmAc) in rat chow or 0.1% iodoacetamide in drinking water for 2-3 weeks underwent a short-term challenge with a normal or AmAc-supplemented meal. Serum gastrin and antral gastrin messenger RNA levels were measured.. Compared with normal postprandial gastrin release, animals given the long-term AmAc feeding showed a normal response to rat chow but a greatly exaggerated response to rat chow plus 20 g/dL AmAc. Long-term feeding with iodoacetamide also resulted in enhanced gastrin release and antral gastrin messenger RNA in response to a meal supplemented with AmAc, but not to a normal meal or one supplemented with sodium acetate.. Inflamed gastric mucosa is more sensitive to the effects of luminal ammonia and responds with an increase in both synthesis and release of gastrin. These animal models may provide insight into the pathogenesis of hypergastrinemia associated the H. pylori infection.

Topics: Acetates; Ammonia; Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Iodoacetamide; Irritants; Male; Peroxidase; Radioimmunoassay; Rats; Rats, Sprague-Dawley; RNA, Messenger

We surgically prepared a hypergastrinemia model in rats and studied the effects of hypergastrinemia on chemically induced carcinogenesis in the esophagus. Operations were performed on 5-week-old male Donryu rats as follows: (1) truncal vagotomy plus pyloroplasty (group V), (2) segmental gastrectomy plus pyloroplasty (group G), (3) antrectomy (group A), and (4) no operation (group C) as a control. From the age of 6 weeks, the animals were given 0.003% N-methyl- N-amylnitrosamine (MAN) solution as drinking water for 8 weeks. After 20 weeks of MAN administration, the animals were bled and killed. The average serum gastrin levels in groups V and G were significantly higher than those groups C or A. There were significant differences between C and V in the incidence of carcinoma, and between V and A in the incidence of carcinoma including severe dysplasia. The incidence of histologically identified lesions per animal was determined, and significant differences were observed between C and both V and G in the incidence of carcinoma including severe dysplasia. Furthermore, we also detected gastrin receptors in the esophageal lesions produced by the oral administration of MAN to rats. The results of the present study suggest that endogenous hypergastrinemia has a positive influence on chemically induced carcinogenesis in the rat esophagus.

Topics: Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Disease Models, Animal; Esophageal Neoplasms; Gastrins; Male; Nitrosamines; Precancerous Conditions; Rats; Rats, Inbred Strains; Receptors, Cholecystokinin

Gastrin activates histidine decarboxylase (HDC) and increases HDC and chromogranin A (CGA) mRNA levels in histamine-producing enterochromaffin-like (ECL) cells in the rat stomach. We have studied how histamine depletion by subcutaneous infusion of the HDC inhibitor alpha-fluoromethyl-histidine (alpha-FMH) affects how ECL cells respond to hypergastrinemia in terms of HDC and CGA mRNA levels.. In one experiment rats received alpha-FMH for 24 h. In another experiment rats received alpha-FMH, omeprazole (perorally), or a combination of the two drugs for 10 days. In a third experiment antrectomized rats were treated with alpha-FMH for 48 h. The circulating gastrin level, oxyntic mucosal histamine concentration, HDC activity, and HDC and CGA mRNA levels were determined.. alpha-FMH for 24 h increased the HDC and CGA mRNA levels without increasing the serum gastrin concentration. alpha-FMH for 10 days increased the serum gastrin concentration twofold. alpha-FMH + omeprazole resulted in the same serum gastrin concentration as after omeprazole alone (eightfold increase). HDC mRNA levels were higher after alpha-FMH + omeprazole than after omeprazole alone. alpha-FMH alone induced an HDC mRNA level that was similar in magnitude to that observed after omeprazole, although the serum gastrin concentration after alpha-FMH was much lower. In antrectomized rats alpha-FMH increased the HDC and CGA mRNA levels without increasing the serum gastrin concentration.. ECL-cell histamine depletion will increase mRNA levels for HDC and CGA by a gastrin-independent mechanism, possibly involving abolished histamine autofeedback inhibition.

Topics: Animals; Anti-Ulcer Agents; Culture Techniques; Disease Models, Animal; Enterochromaffin Cells; Enzyme Inhibitors; Female; Gastric Mucosa; Gastrins; Histamine; Histidine Decarboxylase; Methylhistidines; Omeprazole; Rats; Rats, Sprague-Dawley; RNA, Messenger

Histamine is thought to play a central role in the regulation of gastric acid secretion. In the rat oxyntic mucosa most of the histamine is synthesized and stored in enterochromaffin-like (ECL) cells, and the rest resides in mast cells. The present study examines the role of ECL-cell histamine in the control of acid secretion in the intact, conscious rat.. Rats were treated with alpha-fluoromethylhistidine (alpha-FMH) to inhibit histamine synthesis. alpha-FMH was given by continuous subcutaneous infusion (3 mg/kg/h) for up to 9 days. An additional oral dose of alpha-FMH (50 mg/kg) was given 2 h before each acid secretion test. Acid secretion was studied in pylorus-ligated rats and in chronic gastric fistula rats stimulated with histamine, gastrin-17, or insulin after 2-6 days of alpha-FMH infusion.. Treatment with alpha-FMH lowered oxyntic mucosal histamine synthesis by 80%. From previous observations this is thought to reflect depletion of histamine from the ECL cells. The remaining 20% resides in mucosal and submucosal mast cells, which seem to be resistant to alpha-FMH. Basal acid secretion was inhibited by more than 60% after alpha-FMH treatment and by more than 80% by ranitidine. Histamine-stimulated secretion was unaffected by alpha-FMH and abolished by the histamine H2-receptor antagonist ranitidine. The acid response to gastrin-17 was almost abolished in histamine-depleted rats and abolished by ranitidine. Vagally induced acid secretion (provoked by the injection of insulin or by pylorus ligation) was unaffected by alpha-FMH treatment but abolished by ranitidine and by the muscarinic M1-receptor antagonist pirenzepine.. The results suggest that gastrin stimulates acid secretion by releasing histamine from ECL cells. Vagally induced acid secretion is also dependent on a histaminergic pathway but not on ECL-cell histamine.

Topics: Animals; Disease Models, Animal; Enterochromaffin Cells; Enzyme Inhibitors; Female; Gastric Acid; Gastric Fistula; Gastrins; Histamine; Methylhistidines; Parietal Cells, Gastric; Rats; Rats, Sprague-Dawley

The enterochromaffin-like (ECL) cells in the rat oxyntic mucosa produce histamine and contain cytoplasmic granules, microvesicles, and secretory vesicles. The cells respond to gastrin by the release of histamine (associated with loss of secretory vesicles), which is thought to mediate the gastrin-induced stimulation of the parietal cells. Gastric acid secretion is stimulated also by vagal excitation, which can be induced, for instance, by pylorus ligation. The present study addresses the question whether the ECL cells are involved in the acid response to pylorus ligation.. Rats were subjected to pylorus ligation and killed 4 or 16 h later. Other rats were subjected to sham operation (laparotomy). Some of the rats received human Leu15-gastrin-17 (5 nmol/kg/h) by intravenous infusion for 30 or 60 min before being killed. The serum gastrin concentration, the oxyntic mucosal histidine decarboxylase (HDC) activity, HDC mRNA concentration, histamine concentration, and gastric acid output were measured. Specimens from the oxyntic mucosa were processed for transmission electron microscopy. Electron micrographs of ECL cells were analyzed planimetrically.. The gastric acid output was high, but the serum gastrin concentration was not affected by the pylorus ligation. The HDC activity and the level of HDC mRNA in the oxyntic mucosa were reduced, but the histamine concentration was unchanged. The secretory vesicles and granules of the ECL cells were unaffected, whereas the number and volume density of the microvesicles were reduced. Gastrin administration to sham-operated and pylorus-ligated rats lowered the oxyntic mucosal histamine concentration and increased the HDC activity in both groups.. ECL cells in the rat stomach do not mediate the gastric acid response to pylorus ligation, and ECL cells in the pylorus-ligated stomach retain their ability to respond to gastrin with activation.

Topics: Animals; Disease Models, Animal; Enterochromaffin Cells; Gastric Acid; Gastrins; Histamine; Ligation; Male; Parietal Cells, Gastric; Pylorus; Rats; Rats, Sprague-Dawley

Topics: Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Helicobacter Infections; Humans; Immunity, Mucosal; Lymphocytes; Mice; Mice, Inbred BALB C; Phenotype

Topics: Animals; Colorectal Neoplasms; Disease Models, Animal; Gastrins; Humans; Omeprazole; Rats

Pyloric stenosis produces gastric hypersecretion and is thought to stimulate the growth of the gastric mucosa in the rat, the dog, and man. However, the mechanisms behind the hypersecretion and the trophic effect of pyloric stenosis are little known. The purpose of the present study was to examine whether the postulated trophic effects described include growth of the histamine-producing enterochromaffin-like (ECL) cells and whether circulating gastrin can be held responsible.. Pyloric stenosis was produced in rats by tying a ligature around the pylorus, thereby narrowing the passage through the sphincter. The animals were left for 4 to 12 weeks.. The operation dilated the stomach, increased the serum gastrin concentration approximately twofold, and increased the oxyntic mucosal weight, volume, and surface area but not the mucosal thickness and total DNA content. The interglandular space was increased, and the DNA concentration was reduced. The density of the ECL cells (that is, the number of ECL cells per visual field) was reduced at 4 weeks and back to control values at 8 and 12 weeks. The calculated total volume of the ECL cell population was unchanged at first but showed a less than twofold increase 12 weeks after the operation. The volume density of the ECL cells (that is, the proportion of the mucosa made up of ECL cells) was reduced at 4 and 8 weeks and was back to normal at 12 weeks. The ECL cells are rich in histidine decarboxylase (HDC); whenever the cells are stimulated, the enzyme activity increases. The HDC activity in the oxyntic mucosa was reduced at first and returned to control values 12 weeks later.. Pyloric stenosis per se does not affect the total number of oxyntic mucosal cells, but causes the ECL cell population to grow somewhat, probably because of the moderate hypergastrinemia. Interestingly, however, there was no increase in the HDC activity, suggesting that the ECL cells are not much activated by the operation.

Topics: Animals; Cell Count; Disease Models, Animal; Enterochromaffin Cells; Gastrins; Gastritis, Hypertrophic; Male; Parietal Cells, Gastric; Pyloric Stenosis; Rats; Rats, Sprague-Dawley

Male young adult Wistar rats were treated parenterally with cortisol and cortisol combined with salmon calcitonin for 28 and 56 days and the stomach was investigated histologically as well as the G cells using immunohistochemistry. After 28 days of cortisol administration desquamation of the superficial layers of gastric mucosa was found and after 56 days ulcer-like changes developed and increased gastrin immunoreactivity was observed. Administration of high doses of salmon calcitonin together with cortisol resulted in a significant hypoplasia of G cells and prevented the pathological changes in the gastric mucosa.

Topics: Animals; Calcitonin; Disease Models, Animal; Drug Interactions; Gastric Mucosa; Gastrins; Hydrocortisone; Immunohistochemistry; Injections, Intraperitoneal; Male; Rats; Rats, Wistar; Stomach Ulcer

The effects of cimetidine, omeprazole and atropine sulfate on the healing of acetic acid-induced gastric ulcers in rats with limited food intake time (9:00-10:00 a.m. and 5:00-6:00 p.m.) were evaluated 15 days after the acid injection. Oral repeated administration of cimetidine (25-100 mg/kg twice daily) or omeprazole (10-50 mg/kg once daily) dose dependently accelerated ulcer healing. Atropine sulfate (10 mg/kg twice daily, p.o.) was ineffective. A single oral administration of omeprazole (50 mg/kg) or cimetidine (100 mg/kg) resulted in potent and long-lasting anti-acid secretory and gastrin-releasing actions. The degree and duration of anti-acid secretion by atropine sulfate were equal to those of cimetidine, but the elevation of gastrin release by atropine sulfate was weak and temporary. These results indicate that the gastric ulcers of rats with a limited food intake time are useful for evaluating the healing effects of cimetidine and omeprazole on gastric ulcers. In addition, the effects of both drugs may be related to the increased gastrin release rather than to the reduced acid secretion.

Topics: Acetates; Acetic Acid; Administration, Oral; Analysis of Variance; Animals; Atropine; Cimetidine; Disease Models, Animal; Dose-Response Relationship, Drug; Eating; Gastric Acid; Gastrins; Hydrogen-Ion Concentration; Male; Omeprazole; Rats; Rats, Sprague-Dawley; Stomach Ulcer; Wound Healing

Daily oral administration of cimetidine or omeprazole markedly accelerated the healing of acetic acid-induced gastric ulcers in rats with a limited food intake time. The increased gastric acid secretion induced by daily treatment with histamine affected neither the spontaneous healing of the ulcers nor the healing-promoting actions of both agents. Pretreatment of rats with ulcers with 6-hydroxydopamine significantly inhibited the increase in the antrum gastrin cells, serum gastrin levels and corpus mucosal thickness elicited by repeated administration of cimetidine or omeprazole. Pretreatment with 6-hydroxydopamine did not affect the inhibitory actions of cimetidine and omeprazole on acid secretion, but completely abolished the ulcer healing-promoting actions of both drugs. Daily intraperitoneal administration of pentagastrin accelerated ulcer healing. These results suggest that cimetidine and omeprazole mainly accelerate the healing of gastric ulcers by the trophic action of gastrin via the increase in gastrin secretion, while the inhibition of acid secretion may play a minor role in ulcer healing.

Topics: Analysis of Variance; Animals; Cimetidine; Disease Models, Animal; Drug Interactions; Drug Synergism; Eating; Gastric Acid; Gastric Mucosa; Gastrins; Histamine; Male; Omeprazole; Oxidopamine; Pentagastrin; Pyloric Antrum; Rats; Rats, Sprague-Dawley; Stomach Ulcer; Wound Healing

The effects of 4-week indomethacin administration (1mg/kg/day, orally) on gastrin cell (G-cell), somatostatin cell (D-cell) and prostaglandin E2 (PGE2) of gastric mucosa were examined in pyloric stenosis rats. As a result, pyloric stenosis rats showed hypergastrinemia, G-cell hyperplasia and D-cell hyperplasia with normal PGE2 concentration of gastric mucosa compared with sham operated rats. However, indomethacin administration completely abolished these endocrinic changes of pyloric stenosis by reducing PGE2 concentration of gastric mucosa in both fundic and pyloric regions. These results underline the importance of gastric mucosal PGE2 concentration on the proliferation of G-cells and D-cells in pyloric stenosis.

Topics: Administration, Oral; Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Indomethacin; Male; Pyloric Stenosis; Rats; Rats, Wistar; Somatostatin

Although associated primarily with the cardiovascular system, atrial natriuretic factor (ANF) has been found to increase the magnitude of duodenal contractions and may play a role in salt and water absorption across gastrointestinal epithelium. Because secretory diarrhea and increased peristalsis are commonly associated with conditions related to hypergastrinemia, we examined an animal model of hypergastrinemia (fundusectomy) to evaluate a possible role for ANF. Sprague-Dawley rats underwent either fundusectomy or sham operation. Circulating levels of gastrin (1085 +/- 105 vs 59 +/- 5 pg/ml), ANF (209 +/- 50 vs 59 +/- 10 pg/ml), and pro-ANF 1-98 (786 +/- 80 vs 599 +/- 49 pg/ml) were elevated significantly 3 months after fundusectomy versus control animals. The increased levels of ANF and pro-ANF 1-98 correlated with the increased gastrin levels (p less than 0.05). Tissue content of ANF and pro-ANF 1-98 were determined at sequential sites in the stomach and small intestine. In normal rats ANF concentrations were greatest in the small intestine; pro-ANF 1-98 content was similar in all tissues except ileum (increased). In rats that underwent fundusectomy, ANF and pro-ANF 1-98 were markedly increased in duodenum compared with all other tissues. Only duodenum showed a difference in peptide levels between normal rats and rats that underwent fundusectomy, (ANF, 1.5 +/- 0.5 vs 16.7 +/- 2.3 ng/gm; pro-ANF 1-98, 0.6 +/- 0.3 vs 51.2 +/- 36.1 ng/gm). Circulating ANF and pro-ANF 1-98 are increased in rats that have undergone fundusectomy. Our results suggest that duodenum may be the source of these increased levels.

Topics: Animals; Atrial Natriuretic Factor; Disease Models, Animal; Gastric Fundus; Gastric Mucosa; Gastrins; Intestine, Small; Male; Peptide Fragments; Protein Precursors; Radioimmunoassay; Rats; Rats, Inbred Strains

Oral pancreatic enzyme replacement therapy generally benefits patients with severe pancreatic deficiency. However, the fate of oral pancreatic supplements in the digestive lumen and their possible effects on circulating gut hormones are only partially known. The purpose of this article is to validate an experimental model that produces total pancreatic insufficiency in pigs, and to study the fate of orally administered Eurobiol, a whole pancreas lyophilized preparation, and its effects on circulating plasma levels of five digestive hormones. Pancreatic insufficiency was created by pancreatic duct ligation, and the duodenal, jejunal and ileal contents were sampled through cannulas before a normal meal and 0.5-24 h later. Blood samples were taken at the same times, and plasma neurotensin, pancreatic polypeptide, secretin, cholecystokinin (CCK), and gastrin were measured. In pigs with pancreatic insufficiency, Eurobiol, given during the meal, induced a significant increase in all enzyme activities in the duodenum and the jejunum, and in the levels of amylase, trypsin, and chymotrypsin in the ileum, relative to placebo. In the duodenum, the peak concentrations of enzyme activities were 19, 11, 17, and 29% (p less than 0.001) of the postprandial peak activities measured in control pigs with an intact pancreas for lipase, amylase, trypsin, and chymotrypsin, respectively. In the jejunum, the same activities were, respectively, 30, 11, 25, and 36% (p less than 0.01-0.001) of normal peaks. In pigs with pancreatic insufficiency, basal and integrated meal-stimulated neurotensin levels were increased; basal, peak, and integrated meal-stimulated pancreatic polypeptide and secretin levels were increased, whereas gastrin and CCK were not different from controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Administration, Oral; Amylases; Animals; Cholecystokinin; Chymotrypsin; Disease Models, Animal; Exocrine Pancreatic Insufficiency; Gastrins; Intestines; Lipase; Male; Neurotensin; Pancreas; Pancreatic Extracts; Pancreatic Polypeptide; Secretin; Swine; Trypsin

This study describes the model of chronic gastric and duodenal ulcerations induced by the application of acetic acid on a strictly defined area of the serosal surface of the stomach and duodenum for 10 and 20 s, respectively. Acetic acid applied for longer (20-60 s) or on a larger area (28-64 mm2) resulted in the formation of severe ulcerations which penetrated into the surrounding organs and had very prolonged healing time. Ulcers induced by the application of acetic acid for 10-20 s on a smaller area (7-13.8 mm2) healed spontaneously within 2-3 weeks, thus constituting a model suitable for evaluation of drugs affecting the process of ulcer healing. Our preliminary results of 7- to 14-day treatment with certain drugs indicate that sucralfate and De-Nol, at the dose which does not affect gastric acid secretion, accelerated the healing rate of both gastric and duodenal ulcers so that the observed ulcer healing effect could be attributed to their ulcer healing property. In contrast, 16, 16-dimethyl PGE2 (dmPGE2) in cytoprotective dose was completely ineffective in enhancing ulcer healing. Higher, gastric inhibitory dose of dmPGE2 accelerated the healing of duodenal but not gastric ulcerations, indicating that the inhibition of gastric secretion rather that cytoprotective activity is responsible for ulcer healing effect of this prostaglandin.

Topics: Animals; Bismuth; Chronic Disease; Dinoprostone; Disease Models, Animal; Gastric Acid; Gastric Mucosa; Gastrins; Male; Pepsin A; Peptic Ulcer; Prostaglandins E; Rats; Rats, Inbred Strains; Sucralfate

We have established an experimental model of chronic gastric ulcer, in rats which transection of the lower horizontal portion of the duodenum and anastomosis of the forestomach to the upper part of the jejunum caused regurgitation of all duodenal juice into the stomach. After 3, 6, 12, and 30 wk, all treated rats developed an ulcer in the prepyloric region on the lesser curvature of the stomach. More than half of the antrum was finally involved in the ulcer. Histologic studies revealed chronic ulcers quite similar to human ones. As a control series, transection at the pylorus failed to produce an ulcer. Although many papers have appeared regarding the experimental production of chronic gastric ulcer, most of the studies reported have applied chemicals, drugs, or mechanical injury to the gastric mucosa. Our model produced chronic regurgitation of duodenal juice as a natural phenomenon, and uniformly resulted in ulcer formation. Intragastric total bile acid concentrations were significantly elevated in the reflux group. Serum gastrin levels, the thickness of the fundic mucosa, and the height of fundic gland were also significantly increased. Thus, the detergent action of bile acids and the increased acid secretion were assumed to play an important role in ulcer formation. Further studies using this model are warranted on the pathogenesis of chronic peptic ulceration.

Topics: Animals; Bile Acids and Salts; Chronic Disease; Disease Models, Animal; Duodenogastric Reflux; Gastric Mucosa; Gastrins; Hydrogen-Ion Concentration; Rats; Rats, Inbred Strains; Stomach Ulcer

A reproducible model of acute gastric stress ulceration has been described in the tetraplegic rat. The characteristics of the development of acute gastric ulceration and the concentrations of plasma gastrin have been examined. There was a significant increase in gastric stress ulceration within 4 h of producing the tetraplegia. The ulceration was confined to the glandular portion of the stomach and occurred equally on crests and rugal troughs. Plasma gastrin concentrations were not changed by spinal cord section. This characterized model can serve as a basis for further investigation of the aetiology and prophylaxis of acute gastric ulceration in quadriplegia.

Topics: Animals; Body Temperature; Disease Models, Animal; Erythrocyte Volume; Female; Gastric Mucosa; Gastrins; Male; Quadriplegia; Rats; Rats, Inbred WKY; Spinal Cord Injuries; Stomach Ulcer; Stress, Physiological

Hypertrophic gastritis, histologically characterized by a depletion of parietal and chief cells and by varying degrees of lymphocyte infiltration along the thickened muscularis mucosa, could be induced by neonatal thymectomy (Tx) without any additional treatment in about 50% of mice (C3H/HeMs X 129/J)F1 (C3.129). The thickness of the mucosa in gastritic mice increased with age, forming giant folds. In Tx mice with an early stage of abnormal mucosal folds at 6 months of age, numbers of parietal cells per mucosal tissue unit area (parietal cell densities) and ratios of parietal cells to mucous cells became lower than in control mice, and serum gastrin levels became contrastingly higher with the increasing severity of gastritis. Circulating antibodies against parietal cells (APA) were detected by indirect immunofluorescence (IFL) in the mice. A good correlation was observed between APA and gastritis: APA with high titers (more than 1,000-fold dilutions) appeared when severe lesions were found. In mice with giant mucosal folds at 18 months of age, serum protein levels were within normal limits, but fecal clearance rates of 125I-labelled polyvinylpyrrolidone (125I-PVP) were significantly increased. These results suggest that the hypertrophic gastritis induced by neonatal Tx is characterized by hypergastrinemia due to parietal cell depletion caused by the presence of circulating APA and the protein loss from the hypertrophic mucosa. Both histological and physiopathological similarities were found between the gastritis in the mice and Menetrier's disease in man.

Topics: Animals; Animals, Newborn; Autoantibodies; Blood Proteins; Disease Models, Animal; Gastric Mucosa; Gastrins; Gastritis; Gastritis, Hypertrophic; Hypertrophy; Immunoglobulin G; Male; Mice; Thymectomy

The effect of duodenogastric reflux on systemic and portal venous blood concentrations of somatostatin has been studied in the dog. Duodenogastric reflux suppressed somatostatin concentrations in both systemic and portal venous blood, but this did not occur when bile alone was diverted into the stomach. The suppression was also much less marked when truncal vagotomy accompanied the reflux. These findings suggest that altered somatostatin activity may play a part in the production of the pathophysiological changes occurring in clinical conditions such as peptic ulceration, in which there is an increase in duodenogastric reflux.

Topics: Animals; Bile; Disease Models, Animal; Dogs; Duodenogastric Reflux; Gastrins; Portal Vein; Somatostatin; Vagotomy

Using the bile duct ligated (BDL) pig as a model of experimental peptic ulceration, a study was made of the effects of highly selective vagotomy (HSV) upon basal and stimulated acid and pepsin secretion, tissue levels of n-acetylglucosaminidase, prostaglandins (PgE2) and gastrin, and gastric venous plasma gastrin. In addition to reducing basal acid and pepsin output, HSV was found to return towards normal the elevated tissue prostaglandin and depressed antral gastrin levels after BDL. In addition, it was observed that gastric juice specimens were markedly viscid. It is suggested that there may be effects of HSV other than acid and pepsin reduction which require attention.

Topics: Acetylglucosaminidase; Animals; Dinoprostone; Disease Models, Animal; Female; Gastric Acid; Gastric Mucosa; Gastrins; Lysosomes; Pepsin A; Peptic Ulcer; Prostaglandins E; Swine; Vagotomy, Proximal Gastric

The functional and morphological effects of duodeno-gastric reflux have been studied in the dog. Reflux causes hypersecretion of acid to pentagastrin and a hypergastrinaemic response to a standard meal, associated with antral gland hyperplasia. It is suggested that these changes are mediated by suppressed somatostatin activity, and that they may play an important part in the pathogenesis of peptic ulceration.

Topics: Animals; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Duodenal Diseases; Duodenum; Gastric Acid; Gastric Mucosa; Gastrins; Histamine; Male; Pentagastrin; Peptic Ulcer; Somatostatin; Stomach; Stomach Diseases

Topics: Animals; Disease Models, Animal; Equipment Design; Foreign Bodies; Gastrins; Hypertrophy; Male; Obesity; Rats; Stomach; Stomach Diseases

A dose of exogenous serotonin (0.1 mg/kg/min) previously described to cause maximal acid inhibition, was infused into six chronically awake dogs and significantly inhibited acid output. Integrated basal gastrin output was inhibited from a mean of 232.6 pg-min/ml to 31.6 pg-min/ml (p < 0.05) by serotonin infusion. Antral explantation significantly increased gastrin levels from a mean control level of 163 +/- 71.1 pg/ml to a mean of 991.0 +/- 663.4 pg/ml (p < 0.05). These elevated gastrin levels were then not significantly inhibited by serotonin. The effect of serotonin on gastrin output has not previously been documented. Whereas acid inhibition was uniformly achieved, serotonin inhibited basal gastrin output (integrated gastrin output) but not a stimulated level of gastrin output. Serotonin may be an important 'enterogastrone', and its release may play a role both in acid inhibition and in preventing ulcer disease.

Topics: Animals; Disease Models, Animal; Dogs; Gastric Acid; Gastrins; Infusions, Intravenous; Pyloric Antrum; Radioimmunoassay; Serotonin; Serotonin Agents; Stomach Ulcer

Praomys (Mastomys) natalensis, an African rodent ranging in size between a mouse and a rat, is more susceptible to the induction of duodenal ulcers by constant infusion of exogenous histamine through an osmotic minipump implanted subcutaneously than other rodent species tested such as mouse, rat, or guinea-pig. By increasing the doses of infused histamine, there were increases in the incidence, intensity, and perforation rate of duodenal ulcers in Mastomys. The induction of duodenal ulcers in Mastomys by tetra- and pentagastrins was unsuccessful, probably because of the limited releasing capacity of the present minipump for use of these two peptides which were sparingly soluble in water. More soluble human synthetic gastrin I was approximately three to four times as potent as histamine for inducing duodenal ulcers in Mastomys. The susceptibility of Mastomys to the induction of duodenal ulcer by cysteamine appears to be comparable to that of rat. The complete suppression of histamine-induced duodenal ulcers of Mastomys was possible by repeated subcutaneous injections of cimetidine.

Topics: Animals; Cimetidine; Cysteamine; Disease Models, Animal; Duodenal Ulcer; Female; Gastrins; Guinea Pigs; Histamine; Male; Mice; Mice, Inbred DBA; Pentagastrin; Rats; Rodentia; Species Specificity; Tetragastrin

The rate of disappearance from the circulation of exogenous heptadecapeptide gastrin was studied before and after 50% distal small-bowel resection in four rhesus monkeys. For each study, venous blood samples were drawn during, and at frequent intervals after, a one-hour peripheral venous infusion of synthetic human gastrin 1 given at a constant rate within the range of 0.4 to 2.4 microgram/hr/kg of body weight. The rate of disappearance of infused gastrin was not affected by small-bowel resection (mean half-time before operation, 2.50 minutes; mean half-time after operation, 2.47 minutes). These data indicate that in the rhesus monkey, the rate of catabolism of exogenous gastrin is not decreased after distal small-bowel resection, and indicate that other mechanisms are responsible for the hypergastrinemia and gastric acid hypersecretion observed in this animal model.

Topics: Animals; Disease Models, Animal; Gastrins; Intestine, Small; Macaca mulatta; Male

Topics: Adolescent; Adult; Aged; Animals; Blood Group Antigens; Child; Coronary Disease; Disease Models, Animal; Disease Susceptibility; Diseases in Twins; Ethnicity; Female; Gastric Emptying; Gastrins; Genetic Markers; Humans; Kidney Calculi; Lung Diseases; Male; Mice; Mice, Inbred NZB; Middle Aged; Models, Genetic; Multiple Endocrine Neoplasia; Pepsinogens; Peptic Ulcer; Urticaria Pigmentosa; Zollinger-Ellison Syndrome

Topics: Animals; Antigens; Disease Models, Animal; Dogs; Dumping Syndrome; Gastrins; Glucagon; Insulin; Intestinal Secretions; Intestines; Mesentery; Regional Blood Flow; Water-Electrolyte Balance

Topics: Acute Disease; Animals; Chronic Disease; Cysteamine; Disease Models, Animal; Duodenal Ulcer; Duodenum; Female; Gastric Juice; Gastrins; Male; Rats

In adult male rats, fundusectomy decreased acid secretion but significantly increased total antral gastrin and both fasting and food-stimulated serum gastrin levels. The rise in fasting serum gastrin could be inhibited by antral acidification, suggesting that decreased acidity caused postfundusectomy hypergastrinemia. The mechanism for the increase in total gastrin in antral tissue is probably the same. These studies provide a useful experimental model for the increasing of antral gastrin and for the production of hypergastrinemia.

Topics: Animals; Cattle; Disease Models, Animal; Gastrectomy; Gastric Juice; Gastric Mucosa; Gastrins; Humans; Hydrogen-Ion Concentration; Pyloric Antrum; Rabbits; Radioimmunoassay; Rats

The unusual finding of peptic esophagitis and duodenal ulceration in a dog was associated with a malignant pancreatic islet cell tumor producing gastrin and ACTH. The finding of a gastrinoma in a non-human species introduces the potential for developing an animal model for the study of the protean genetic biochemical, physiologic and metabolic aspects of the Zollinger-Ellison syndrome.

Topics: Adrenocorticotropic Hormone; Animals; Disease Models, Animal; Dog Diseases; Dogs; Female; Gastrins; Radioimmunoassay; Zollinger-Ellison Syndrome

Topics: Animals; Antacids; Disease Models, Animal; Gastrins; Humans; Peptic Ulcer; Stress, Physiological; Swine

Topics: Animals; Antacids; Disease Models, Animal; Gastrins; Peptic Ulcer; Stress, Physiological

After administration of antacids, gastric stress lesions due to hemorrhagic shock appear in the pig stomach quicker and more markedly than in animals which have been similarly treated with an indifferent substance or not at all. However, once treated, the administration of antacids seems to favor the healing of mucosal lesions after the end of the stress. At the same time it was observed that after administration of antacids in hemorrhagic shock, the serum gastrin level rises and does not remain constant, as in the control group. An attempt is made to explain the favorable effect of antacids on the genesis of hemorrhagic stress lesions in the pig's stomach through this observation.

Topics: Animals; Antacids; Disease Models, Animal; Female; Gastric Mucosa; Gastrins; Gastrointestinal Hemorrhage; Male; Shock, Hemorrhagic; Stomach Diseases; Stomach Ulcer; Stress, Physiological; Swine; Time Factors

Ten dogs were used to study antral gastrin secretion in hemorrhagic shock. Dogs that had a vagotomy were compared with normal dogs. Acute hemorrhage, imposed upon operative stress, produced increased gastrin secretion in normal dogs but not in dogs after vagotomy. During the acute hemorrhage, the level of circulating gastrin in normal dogs increased to about 50 to more than 100 per cent of the control values. The concentration of gastrin in the dogs having a vagotomy was essentially unchanged in the face of acute hemorrhage. Results of this study suggest that the increased concentration of circulating gastrin in normal dogs subjected to severe stress may play a role in the development of a stress ulcer.

Topics: Animals; Blood Glucose; Disease Models, Animal; Dogs; Gastrins; Insulin; Pyloric Antrum; Secretory Rate; Shock, Hemorrhagic; Stomach Ulcer; Vagotomy

The Exalto-Mann-Williamson procedure produces peptic ulceration in nearly 100% of experimental animals but the mechanism is unknown. To investigate the possible hormonal role of the gastric acid hypersecretion seen after this procedure, we investigated preoperative and postoperative serum gastrin and secretin concentrations. There was no significant change in serum gastrin; however, serum secretin concentrations increased to 2 1/2 times the preoperatve value, most likely secondary to the enhanced secretion of gastric acid. These data do not suppport the theory that alterations in circulating secretin or gastrin levels are responsible for the gastric acid hypersecretion following the Exalto-Mann-Williamson operation.

Topics: Animals; Disease Models, Animal; Dogs; Fasting; Fistula; Gastric Juice; Gastrins; Gastroenterostomy; Jejunum; Peptic Ulcer; Secretin; Stomach

Topics: Animals; Disease Models, Animal; Dogs; Esophagogastric Junction; Esophagus; Gastrins; Gastroesophageal Reflux; Hernia, Diaphragmatic; Hernia, Hiatal; Manometry; Stimulation, Chemical

Topics: Animals; Carnivora; Disease Models, Animal; Fistula; Gastric Juice; Gastric Mucosa; Gastrins; Histamine; Peptide Hydrolases; Stomach