cholecystokinin and Helicobacter-Infections

Helicobacter pylori infection affects the concentration of regulatory peptides such as gastrin, somatostatin and cholecystokinin and the concentration and activity of glutathione and glutathione S-transferases in the gastric mucosa.. Literature review.. Although some of these peptides have been known since the beginning of this century, their action has changed since the discovery of H. pylori infection in 1983. Chronic infection with H. pylori might lead to an increased risk in developing gastric cancer. Glutathione S-transferases are involved in the cellular detoxification of xenobiotics and other toxic compounds. Since there is a close inverse relationship between the activity of glutathione S-transferase and incidence of malignancies in the gastrointestinal tract, the possible relation between H. pylori infection and activity of glutathione S-transferases in the gastric mucosa is discussed.. The effect of H. pylori infection on regulatory peptides and glutathione/glutathione S-transferases might play a role in the development of neoplastic changes of the H. pylori-infected gastric mucosa.

Topics: Animals; Biomarkers; Cholecystokinin; Chronic Disease; Disease Progression; Gastric Mucosa; Gastrins; Gastritis; Glutathione; Glutathione Transferase; Helicobacter Infections; Helicobacter pylori; Humans; Somatostatin; Stomach Neoplasms

In patients who present with chronic unexplained upper abdominal pain or discomfort (functional dyspepsia), therapy should ideally be targeted on correcting the individual's disturbed pathophysiology. Here, putative mechanisms implicated in functional dyspepsia and potential approaches to therapy are critically reviewed in order to determine if targeting treatment is of value. Pharmacological therapies reviewed include those that aim to correct disordered gastric emptying (e.g. cisapride, dopaminergic receptor antagonists, macrolides), reduce visceral hypersensitivity (e.g. somatostatin analogues, cholecystokinin antagonists, opioid agonists, serotonin type 3 receptor antagonists), reduce gastric acid secretion (e.g. H2-blockers, acid pump inhibitors), cure Helicobacter pylori infection, enhance muscosal defence (e.g. sucralfate, bismuth) or modify central nervous system processes. It is concluded that the imperfectly understood pathophysiology of functional dyspepsia contributes to the paucity of established efficacious therapies.

Topics: Abdominal Pain; Antidepressive Agents; Bismuth; Calcium Channel Blockers; Cholecystokinin; Dyspepsia; Gastric Emptying; Helicobacter Infections; Humans; Narcotics; Nitric Oxide; Prostaglandins, Synthetic

Unlike the stimulation of gastric acid secretion, which clearly involves the release of gastrin, the mechanisms of inhibition of this secretory process are poorly defined although recent studies in animals with the use of highly selective cholecystokinin (CCK) antagonists indicate that CCK may play a crucial role in this inhibition. Duodenal ulcer patients (DU) differ from healthy controls by higher total acid secretory rates and diminished inhibition of acid secretion. Several possible pathomechanisms of the abnormal gastric secretory function in DU patients were previously proposed. The deficiency of CCK-induced gastric inhibition in DU patients together with the somatostatin hypothesis appear to be attractive, particularly so the suggestion that a deficiency of somatostatin activity exists in DU patients.

Topics: Animals; Cholecystokinin; Duodenal Ulcer; Gastric Acid; Gastrins; Gastritis; Helicobacter Infections; Humans; Reference Values; Somatostatin

Exogenous cholecystokinin (CCK) is known to effect gastric secretory and motor functions but its physiological role in the control of these functions in healthy subjects and duodenal ulcer (DU) patients is unknown.. In this study involving four series of young healthy normal and DU subjects, the gastric secretory tests were performed under basal conditions and following stimulation by modified sham-feeding (MSF), i.v. infusion of caerulein, gastrin releasing peptide (GRP) or pentagastrin (p-gastrin) (series A), after 500 ml of standard meal without or with addition of 15% soybean oil (series B) or acidification of meal to pH 2.5 (series C), and finally after eradication of Helicobacter pylori (HP) (series D). Studies were carried out without or with the pretreatment with placebo or loxiglumide, a specific antagonist of type A CCK receptors. In series A, the gastric secretion obtained by aspiration technique was measured after secretagogues (MSF, caerulein, GRP or p-gastrin), whereas in series B, C, and D intragastric pH was measured before and after test meal and plasma gastrin, CCK and somatostatin were assayed by specific radioimmunoassays.. In healthy subjects, MSF increased gastric acid outputs to about 36% of p-gastrin maximum and treatment with loxiglumide failed to affect this secretion. Standard meal enhanced acid output to about 50% of p-gastrin maximum and raised plasma levels of gastrin, CCK but not somatostatin. The pretreatment with loxiglumide resulted in further increase both in gastric acid secretion and plasma gastrin and CCK, while somatostatin level was significantly reduced. Infusion of graded doses of caerulein or GRP resulted in dose-dependent stimulation of gastric acid secretion reaching, respectively, 35% and 25% of p-gastrin maximum. When loxiglumide was added, the acid responses to caerulein and GRP were further increased by 2-3 folds, attaining a peak similar to the p-gastrin maximum. Administration of loxiglumide resulted in a significant increase in plasma gastrin and CCK responses to GRP, whereas plasma somatostatin was not significantly altered. Addition of fat to standard meal prolonged gastric emptying of this meal by about 50% both in healthy subjects and DU patients (series B). Fat in healthy subjects significantly increased and prolonged intragastric pH after the meal while reducing the increments in plasma gastrin and enhancing plasma CCK without alteration of plasma somatostatin. Pretreatment with loxiglumide significantly reduced postprandial pH from control 4.8 to 2.5 and reversed the changes in pH caused by addition of fat. The increments in plasma gastrin and CCK were markedly augmented, whereas those of somatostatin were attenuated. DU patients showed lower postprandial pH (3.0) in tests with or without fat and higher increments in plasma gastrin. CCK antagonism failed to affect significantly the pH profile or the increments in plasma gastrin or CCK. CCK antagonism failed to affect significantly the pH profile or the increments in plasma gastrin. Intragastric application of standard meal of pH 3.0 in healthy subjects and DU patients (series C) resulted in significantly lower median 3 h intragastric pH as compared to that after meal of pH 6.5. After pretreatment with loxiglumide, the median pH after meals of both pHs was significantly lower in healthy subjects but not in DU patients. This reduction in pH was accompanied by more pronounced increase in plasma gastrin response to a meal of pH 6.5 only in healthy controls but not in DU subjects and by a significant increase in plasma CCK and decrease in plasma somatostatin.

Topics: Adult; Anti-Bacterial Agents; Cholecystokinin; Dietary Fats; Duodenal Ulcer; Eating; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Hormones; Humans; Hydrogen-Ion Concentration; Male; Proglumide; Reference Values; Somatostatin

Increased gastric emptying and defective action of endogenous cholecystokinin (CCK), that is known to inhibit this emptying, have been implicated in the pathogenesis of duodenal ulcer (DU). The aim of this double blind study was to assess whether CCK and somatostatin participate in the impairment of gastric motility in active DU patients before and after Helicobacter pylori eradication.. Tests were undertaken in 10 DU patients without or with elimination of the action of endogenous CCK using loxiglumide, a selective CCK-A receptor antagonist, before and 4 weeks after eradication of H. pylori with 1 week triple therapy that resulted in healing of all DUs tested. The gastric emptying rate after feeding was determined using the 13C-acetate breath test. Before each test, samples of gastric juice were obtained by aspiration using a nasogastric tube for determination of somatostatin using specific radioimmunoassay.. Prior to H. pylori eradication gastric emptying half-time was 31 +/- 6 min in placebo-treated DU patients and this emptying rate was not significantly affected in tests after pretreatment with loxiglumide (10 mg/kg i.v.). Following eradication of H. pylori, in tests with placebo gastric emptying half-time was significantly longer (48 +/- 9 min) compared to that prior to H. pylori eradication. Pretreatment with loxiglumide in H. pylori eradicated DU patients significantly enhanced the gastric emptying rate with an emptying half-time of only 33 +/- 4 min. Eradication of H. pylori resulted in a significant increase in somatostatin concentration in gastric juice and loxiglumide significantly reduced this luminal somatostatin in H. pylori-eradicated subjects compared to values before anti-H. pylori therapy.. 1) H. pylori infection in DU patients is accompanied by enhanced gastric emptying and reduction in luminal release of somatostatin; 2) the failure of loxiglumide to affect gastric emptying in H. pylori-infected DU patients might be attributed, at least in part, to the failure of endogenous CCK to control gastric motility due to deficient release of somatostatin; and 3) H. pylori-infected patients appear to exhibit a deficient somatostatin release by endogenous CCK that can be reversed by the eradication of H. pylori indicating that both CCK and somatostatin may contribute to normalization of gastric emptying following H. pylori eradication in DU patients.

Topics: Adolescent; Adult; Analysis of Variance; Cholecystokinin; Duodenal Ulcer; Follow-Up Studies; Gastric Emptying; Gastric Mucosa; Gastrins; Gastroscopy; Helicobacter Infections; Helicobacter pylori; Hormone Antagonists; Humans; Injections, Intravenous; Male; Postprandial Period; Probability; Proglumide; Reference Values; Sensitivity and Specificity; Somatostatin; Sucralfate; Treatment Outcome

Helicobacter pylori (Hp) infection may be associated with duodenal ulcer (DU) and accompanied by increased release of gastrin and deficiency of somatostatin (S-S) but the mechanisms of these changes in DU patients after eradication of Hp have been little studied. Cholecystokinin (CCK) has been implicated in the feedback control of gastric acid secretion in healthy subjects but its contribution to secretory disorders in DU patients has been little examined. This study, therefore, investigated whether CCK participates in the impairment of postprandial gastrin release and gastric acid secretion in active DU patients. Tests were undertaken in 10 DU patients without or with elimination of the action of endogenous CCK using loxiglumide (LOX), a selective CCK-A receptor antagonist, before and 4 wk. after eradication of Hp with triple therapy (omeprazole, amoxycillin and bismuth). In Hp positive DU patients, the postprandial acid secretion (measured by continuous intragastric pH monitoring) was accompanied by a pronounced increment in plasma gastrin with negligible increase of intraluminal release of S-S. The administration of LOX in these patients did not affect significantly the postprandial pH profile and the rise in plasma gastrin. After eradication of Hp the median postprandial intragastric pH increased to about 4.3 (compared to 3.5 before the Hp eradication); the postprandial gastrin concentration was reduced by about 40%, while luminal release of S-S was increased 2 folds. The administration of LOX resulted in significantly greater decrease in median pH (3.1) and higher rise in postprandial plasma gastrin in these patients. Also the postprandial plasma S-S showed a small, but significant decline (by about 25%) as compared to that in placebo treated patients. This study provides evidence that: (1) Hp infection in DU patients is accompanied by enhanced gastrin release and the reduction in luminal release of S-S; (2) The failure of LOX to affect gastric secretion and plasma gastrin DU Hp infected patients could be attributed, at least in part, to the failure of endogenous CCK to control gastric acid secretion via release of S-S; (3) Hp infected patients appear to exhibit a deficiency of S-S release that can be reversed by the eradication of Hp indicating that both peptides may contribute to the acceleration of the ulcer healing following Hp eradication in DU patients; (4) The test with LOX and gastric luminal S-S assay may be useful in identification of Hp po

Topics: Adult; Cholecystokinin; Duodenal Ulcer; Gastric Acid; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Hormone Antagonists; Humans; Male; Proglumide; Somatostatin

Exogenous cholecystokinin (CCK) is known to effect gastric secretory and motor functions but its physiological role in the control of these functions in healthy subjects and duodenal ulcer (DU) patients is unknown.. In this study involving four series of young healthy normal and DU subjects, the gastric secretory tests were performed under basal conditions and following stimulation by modified sham-feeding (MSF), i.v. infusion of caerulein, gastrin releasing peptide (GRP) or pentagastrin (p-gastrin) (series A), after 500 ml of standard meal without or with addition of 15% soybean oil (series B) or acidification of meal to pH 2.5 (series C), and finally after eradication of Helicobacter pylori (HP) (series D). Studies were carried out without or with the pretreatment with placebo or loxiglumide, a specific antagonist of type A CCK receptors. In series A, the gastric secretion obtained by aspiration technique was measured after secretagogues (MSF, caerulein, GRP or p-gastrin), whereas in series B, C, and D intragastric pH was measured before and after test meal and plasma gastrin, CCK and somatostatin were assayed by specific radioimmunoassays.. In healthy subjects, MSF increased gastric acid outputs to about 36% of p-gastrin maximum and treatment with loxiglumide failed to affect this secretion. Standard meal enhanced acid output to about 50% of p-gastrin maximum and raised plasma levels of gastrin, CCK but not somatostatin. The pretreatment with loxiglumide resulted in further increase both in gastric acid secretion and plasma gastrin and CCK, while somatostatin level was significantly reduced. Infusion of graded doses of caerulein or GRP resulted in dose-dependent stimulation of gastric acid secretion reaching, respectively, 35% and 25% of p-gastrin maximum. When loxiglumide was added, the acid responses to caerulein and GRP were further increased by 2-3 folds, attaining a peak similar to the p-gastrin maximum. Administration of loxiglumide resulted in a significant increase in plasma gastrin and CCK responses to GRP, whereas plasma somatostatin was not significantly altered. Addition of fat to standard meal prolonged gastric emptying of this meal by about 50% both in healthy subjects and DU patients (series B). Fat in healthy subjects significantly increased and prolonged intragastric pH after the meal while reducing the increments in plasma gastrin and enhancing plasma CCK without alteration of plasma somatostatin. Pretreatment with loxiglumide significantly reduced postprandial pH from control 4.8 to 2.5 and reversed the changes in pH caused by addition of fat. The increments in plasma gastrin and CCK were markedly augmented, whereas those of somatostatin were attenuated. DU patients showed lower postprandial pH (3.0) in tests with or without fat and higher increments in plasma gastrin. CCK antagonism failed to affect significantly the pH profile or the increments in plasma gastrin or CCK. CCK antagonism failed to affect significantly the pH profile or the increments in plasma gastrin. Intragastric application of standard meal of pH 3.0 in healthy subjects and DU patients (series C) resulted in significantly lower median 3 h intragastric pH as compared to that after meal of pH 6.5. After pretreatment with loxiglumide, the median pH after meals of both pHs was significantly lower in healthy subjects but not in DU patients. This reduction in pH was accompanied by more pronounced increase in plasma gastrin response to a meal of pH 6.5 only in healthy controls but not in DU subjects and by a significant increase in plasma CCK and decrease in plasma somatostatin.

Topics: Adult; Anti-Bacterial Agents; Cholecystokinin; Dietary Fats; Duodenal Ulcer; Eating; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Hormones; Humans; Hydrogen-Ion Concentration; Male; Proglumide; Reference Values; Somatostatin

Gastrin, which induces gastric acid secretion, and a structurally similar hormone, cholecystokinin (CCK)-a potent acid inhibitor, may each play a role in gastric cancer. However, few studies have investigated this hypothesis in humans. We therefore investigated whether serum gastrin or CCK concentrations at baseline were associated with the incidence of gastric non-cardia adenocarcinomas (GNCA), oesophagogastric junctional adenocarcinomas (EGJA) or gastric carcinoid tumours over 24 years of follow-up in a study nested within the all-male Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study of Finnish smokers.. Totals of 283 incident GNCA, 96 EGJA and 10 gastric carcinoid cases, and 778 matched controls, were included in our analysis. Gastrin and CCK were measured using specific radioimmunoassays. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by multivariable logistic regression with adjustment for all known or suspected confounding factors, including Helicobacter pylori seropositivity.. Those with high gastrin (Q4 vs Q1), had an increased risk of GNCA (fully adjusted OR: 1.92; 95% CI: 1.21, 3.05) and gastric carcinoids, though the small number of carcinoid cases meant the fully adjusted model was unstable (age-adjusted continuous model OR: 4.67; 95% CI: 2.67, 8.15). CCK was associated with risk of GNCA only for those in Q3 relative to Q1 (OR: 0.56; 95% CI: 0.33, 0.96), and no significant trend was observed.. Our data suggest that high serum concentrations of gastrin may be associated independently with an increased risk of gastric cancer; the role of CCK in cancer risk is less clear.

Topics: Adenocarcinoma; Case-Control Studies; Cholecystokinin; Esophageal Neoplasms; Finland; Follow-Up Studies; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Incidence; Logistic Models; Male; Middle Aged; Multivariate Analysis; Prospective Studies; Risk Factors; Smokers; Stomach Neoplasms

Gastric lipase is one of the prepancreatic lipases found in some mammalian species and in humans. Our knowledge of the hormonal regulation of gastric lipase secretion in children and adolescents is still very limited. The aim of this study was to compare the activity of human gastric lipase (HGL) in gastric juice in healthy adolescents and in patients with gastritis. The adolescents were allocated to three groups: the first including patients with Helicobacter pylori gastritis (HPG; n = 10), the second including patients with superficial gastritis caused by pathogens other than H. pylori (non-HPG; n = 14) and the control group including healthy adolescents (n = 14). Activity of HGL was measured in gastric juice collected during endoscopy. Plasma concentrations of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured in all adolescents. Activity of HGL in the non-HPG group was significantly lower than in the HPG group (p < 0.005) and the control group (p < 0.005). Mean plasma GIP levels in the control group were lower than in the non-HPG group (p < 0.003) and the HPG group (p < 0.01). We conclude that the regulation of HGL secretion by GLP-1 and CCK is altered in patients with gastritis. Moreover, GIP is a potent controller of HGL activity, both in healthy subjects and in patients with gastritis.

Topics: Adolescent; Body Mass Index; Body Weight; Case-Control Studies; Cholecystokinin; Fasting; Gastric Inhibitory Polypeptide; Gastritis; Gastrointestinal Tract; Glucagon-Like Peptide 1; Helicobacter Infections; Humans; Hydrogen-Ion Concentration; Lipase; Young Adult

The adipokine plasminogen activator inhibitor (PAI)-1 is increased in plasma of obese individuals and exhibits increased expression in the stomachs of individuals infected with Helicobacter. To investigate the relevance of gastric PAI-1, we used 1.1 kb of the H(+)/K(+)β subunit promoter to overexpress PAI-1 specifically in mouse gastric parietal cells (PAI-1-H/Kβ mice). We studied the physiological, biochemical, and behavioral characteristics of these and mice null for PAI-1 or a putative receptor, urokinase plasminogen activator receptor (uPAR). PAI-1-H/Kβ mice had increased plasma concentrations of PAI-1 and increased body mass, adiposity, and hyperphagia compared with wild-type mice. In the latter, food intake was inhibited by cholecystokinin (CCK)8s, but PAI-1-H/Kβ mice were insensitive to the satiating effects of CCK8s. PAI-1-H/Kβ mice also had significantly reduced expression of c-fos in the nucleus tractus solitarius in response to CCK8s and refeeding compared with wild-type mice. Exogenous PAI-1 reversed the effects of CCK8s on food intake and c-fos levels in the nucleus tractus solitarius of wild-type mice, but not uPAR-null mice. Infection of C57BL/6 mice with Helicobacter felis increased gastric abundance of PAI-1 and reduced the satiating effects of CCK8s, whereas the response to CCK8s was maintained in infected PAI-1-null mice. In cultured vagal afferent neurons, PAI-1 inhibited stimulation of neuropeptide Y type 2 receptor (Y2R) expression by CCK8s. Thus, gastric expression of PAI-1 is associated with hyperphagia, moderate obesity, and resistance to the satiating effects of CCK indicating a new role in suppressing signals from the upper gut that inhibit food intake.

Topics: Animals; Cholecystokinin; Gastric Mucosa; Helicobacter felis; Helicobacter Infections; Hyperphagia; Mice; Obesity; Plasminogen Activator Inhibitor 1; Receptors, Urokinase Plasminogen Activator; Satiation

Cholesterol gallstones are associated with slow intestinal transit in humans as well as in animal models, but the molecular mechanism is unknown. We investigated in C57L/J mice whether the components of a lithogenic diet (LD; 1.0% cholesterol, 0.5% cholic acid and 17% triglycerides), as well as distal intestinal infection with Helicobacter hepaticus, influence small intestinal transit time. By quantifying the distribution of 3H-sitostanol along the length of the small intestine following intraduodenal instillation,we observed that, in both sexes, the geometric centre (dimensionless) was retarded significantly (P <0.05) by LD but not slowed further by helicobacter infection (males, 9.4±0.5 (uninfected), 9.6±0.5 (infected) on LD compared with 12.5±0.4 and 11.4±0.5 on chow). The effect of the LD was reproduced only by the binary combination of cholesterol and cholic acid. We inferred that the LD-induced cholesterol enrichment of the sarcolemmae of intestinal smooth muscle cells produced hypomotility from signal-transduction decoupling of cholecystokinin (CCK), a physiological agonist for small intestinal propulsion in mice. Treatment with ezetimibe in an amount sufficient to block intestinal cholesterol absorption caused small intestinal transit time to return to normal. In most cholesterol gallstone-prone humans, lithogenic bile carries large quantities of hepatic cholesterol into the upper small intestine continuously, thereby reproducing this dietary effect in mice. Intestinal hypomotility promotes cholelithogenesis by augmenting formation of deoxycholate, a pro-lithogenic secondary bile salt, and increasing the fraction of intestinal cholesterol absorbed.

Topics: Animals; Azetidines; Bile; Bile Acids and Salts; Biological Transport; Cholecystokinin; Cholesterol; Cholic Acid; Diet, High-Fat; Ezetimibe; Female; Gallbladder; Gallstones; Gastrointestinal Transit; Helicobacter hepaticus; Helicobacter Infections; Intestinal Absorption; Intestine, Small; Lipid Metabolism; Male; Mice; Mice, Inbred C57BL; Myocytes, Smooth Muscle; Sarcolemma; Sterols

Physiology of gastric acid secretion is one of the earliest subjects in medical research and education. Gastric acid secretion has been sometimes inadequately expressed as pH value rather than amount of gastric H(+) secreted per unit time. Gastric acid secretion is regulated by endocrine, paracrine and neurocrine signals via at least three messenger pathways: gastrin-histamine, CCK-somatostatin, and neural network. These pathways have been largely validated and further characterized by phenotyping a series of knockout mouse models. The complexity of gastric acid secretion is illustrated by both expected and unexpected phenotypes of altered acid secretion. For examples, in comparison with wild-type mice, gastrin and CCK double knockout and SSTR(2) knockout mice displayed a shift in the regulation of ECL cells from somatostatin-SSTR(2) pathway to galanin-Gal1 receptor pathway; a shift in the regulation of parietal cells from gastrin-histamine pathway to vagal pathway; and a shift in the CCK(2) receptors on parietal cells from functional silence to activation. The biological function of glycine-extended gastrin in synergizing gastrin-17 has been revealed in gastrin knockout mice. The roles of gastric acid secretion in tumorigenesis and ulceration have not been fully understood. Transgenic hypergastrinemic INS-GAS mice developed a spontaneous gastric cancer, which was associated with an impaired acid secretion. Gastrin knockout mice were still able to produce acid in response to vagal stimulation, especially after H. pylori infection. Taken together, phenotyping of a series of genetically engineered mouse models reveals a high degree of complexity of gastric acid secretion in both physiological and pathophysiological conditions.

Topics: Animals; Cholecystokinin; Gastric Acid; Gastrins; Gene Targeting; Helicobacter Infections; Helicobacter pylori; Humans; Mice; Mice, Knockout; Paracrine Communication; Peptic Ulcer; Receptors, Somatostatin; Stomach Neoplasms

Cholecystokinin (CCK) plays an important role in the regulation of postprandial gastric motor activity which was found to be abnormal in duodenal ulcer patients. This study was designed to compare the influence of CCK on gastric myoelectrical function in duodenal ulcer patients and healthy controls. Fifteen patients with active duodenal ulcer and Helicobacterpylori (H. pylori) infection and 15 healthy controls were included into this study. Electrogastrography (EGG) was performed before and 4 weeks after the eradication of H. pylori in ulcer patients and in healthy controls. We compared EGG parameters in the fasting and postprandial period and during intravenous infusion of caerulein, an analog of CCK with or without addition of loxiglumide, a specific CCK-1 receptor antagonist. The amplitude of fasting EGG in duodenal ulcer patients was similar to that in control subjects and was not affected by H. pylori eradication. In contrast, the amplitude of postprandial EGG was markedly increased in duodenal ulcer patients when compared to that in healthy controls and it was significantly reduced following the eradication of H. pylori. The blockade of CCK-1 receptors with loxiglumide in healthy controls or H. pylori eradicated ulcer patients significantly enhanced postprandial EGG amplitude almost to the level observed in the infected duodenal ulcer patients, but failed to affect this amplitude in ulcer patients. Exogenous caerulein, an analog of CCK, failed to affect EGG amplitude in duodenal ulcer patients with H. pylori infection, but it reduced significantly EGG amplitude in these patients after H. pylori eradication and in control subjects. This inhibitory effect of caerulein in H. pylori negative ulcer patients and healthy controls was abolished by the addition of loxiglumide. Ulcer patients showed significant dysrhythmia with tachygastria up to 20% of the recording time both under basal conditions and postprandially and H. pylori eradication was followed by a significant decrease in tachygastria to about 5%, the value being similar to that in healthy controls. We conclude that the amplitude and frequency of gastric myoelectrical activity are enhanced in duodenal ulcer patients and impaired in response to CCK but these changes can be normalized by successful H. pylori eradication.

Topics: Adult; Ceruletide; Cholecystokinin; Duodenal Ulcer; Electrophysiology; Fasting; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Myoelectric Complex, Migrating; Postprandial Period; Reference Values; Stomach

There is no general agreement as regards the effect of Helicobacter pylori infection on gastric emptying in patients with functional dyspepsia. Food releases several gastrointestinal hormones, and some of these are known to contribute to the regulation of gastric emptying. The aim of this study was to investigate the influence of H. pylori on gastric emptying in dyspeptic and healthy subjects and to verify whether different hormone secretion patterns are affected by the presence of the bacterium. Twenty-seven patients affected by functional dyspepsia and 30 asymptomatic healthy subjects entered the study. H. pylori presence was assessed in controls by IgG antibodies to H. pylori and [13C] urea breath test, and that in patients by Warthin-Starry stain on gastric biopsies. After ingesting a standard solid-liquid meal, an ultrasound examination of gastric emptying was performed. Plasma concentrations of gastrin, cholecystokinin, and pancreatic polypeptide were measured in the fasting and postprandial period for 4 hours. The incidence of H. pylori infection was not higher in functional dyspepsia patients than in controls. As regards gastric emptying, no difference was detected between patients and controls with and without H. pylori infection. On the contrary, the presence of H. pylori infection determined alterations in gastrin levels, which were higher in controls than in patients. Basal CCK levels were higher in the H. pylori-negative patients than H. pylori-positive patients and controls. In conclusion, H. pylori infection seems not to cause alterations in gastric emptying, but rather alterations in gastrin levels. In contrast, the altered levels of CCK account for its involvement in the pathophysiology of H. pylori-negative dyspepsia.

Topics: Adolescent; Adult; Cholecystokinin; Dyspepsia; Female; Gastric Emptying; Gastrins; Gastrointestinal Hormones; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Pancreatic Polypeptide

Leptin, a protein product of obese gene expressed primarily by adipocytes, provides feedback information on the size of energy stores to central OB receptors controlling the food intake, energy expenditure and body weight homeostasis. It has recently been detected in the rat stomach, especially after cholecystokinin (CCK) administration and in human stomach infected with Helicobacter pylori, but its role in gastric secretory functions in humans has not been revealed. This study was designed to determine the involvement of leptin in the control of basal, CCK- and meal-induced gastric H+ secretion and plasma gastrin and CCK levels in humans before and after an eradication of H. pylori.. Two groups (A and B) of subjects were used; group A (n = 7), for comparison of the effects of CCK and leptin on basal gastric H+ and plasma hormone (leptin, gastrin and CCK) levels, and group B (n = 6), for studies on the involvement of leptin in gastric secretory and plasma hormonal responses to vagal stimulation and gastric peptone meal before and after H. pylori eradication.. In H. pylori-positive subjects, CCK (12-200 pmol kg(-1) h(-1)) given i.v. caused a dose-dependent increase of gastric H+ accompanied by a dose-dependent rise in plasma CCK and leptin levels. In contrast, leptin administered i.v. in graded doses (5-80 pmol kg(-1) h(-1)) resulted in a gradual inhibition of basal gastric H+ secretion and in adose-dependent increment in plasma leptin accompanied by an increase in plasma gastrin without alteration of plasma CCK level. Following eradication of H. pylori by 1-week triple therapy in group B patients, the infusion of CCK produced a significantly smaller increase in gastric H+ secretion and significantly smaller rise in plasma leptin as compared to those before the eradication. Cephalic phase stimulation of gastric secretion induced by modified sham-feeding in group B H. pylori-positive subjects increased gastric H+ secretion to about 40% of pentagastrin maximum without affecting plasma leptin, gastrin, or CCK level, while gastric peptone meal resulted in the increase in gastric H+ response reaching about 70% of pentagastrin maximum accompanied by a marked rise in plasma leptin, gastrin and CCK. The treatment with a standard dose of leptin (20 pmol kg(-1) h(-1)) failed to affect sham-feeding-induced gastric H+ secretion but reduced significantly the peptone meal-stimulated H+ secretion, while raising plasma gastrin in response to this meal. Plasma CCK under basal conditions and after sham-feeding was not affected, but plasma CCK response to gastric meal was significantly reduced by leptin infusion. Eradication of H. pylori did not affect basal or sham-feeding-induced H+ secretion but resulted in a significant fall in gastric meal-induced H+ and plasma leptin, gastrin and CCK levels.. 1) The gastric meal and CCK enhance the release of leptin in H. pylori-positive patients and this leptin is capable of inhibiting basal and meal-stimulated gastric H+ secretion, while raising plasma gastrin and reducing the plasma CCK levels, and 2) the eradication of H. pylori reduces the postprandial gastric H+ and plasmagastrin responses as well as the release of leptin in response to CCK and meal.

Topics: Adult; Cholecystokinin; Eating; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Leptin; Male

To investigate the mechanism of the hypergastrinaemia associated with Helicobacter pylori infection by examining the effect of H. pylori infection and the cytokine tumour necrosis factor-alpha (TNF-alpha) on gastrin release from human antral fragments.. In-vitro experimental study.. Human antral biopsy fragments were cultured for 6 h with and without TNF-alpha (20 ng/ml) and the gastrin released over the following 2-h stimulation period measured by radioimmunoassay. The integrity of the paracrine feedback loop inhibiting gastrin release was tested by concurrent administration of cholecystokinin (CCK).. H. pylori-positive fragments were associated with significantly greater bombesin-stimulated gastrin release (increased by 40%, P < 0.05) and less inhibition produced by CCK administration (decreased by 55%, P < 0.05), than H. pylori-negative fragments. TNF-alpha treatment of H. pylori-negative fragments significantly enhanced bombesin-stimulated gastrin release (by 82%, P < 0.01) and diminished inhibitory feedback by CCK (by 53%, P < 0.05).. H. pylori infection is associated with enhanced gastrin release from human antrum and TNF-alpha produces a similar effect. Proinflammatory cytokines generated in the antrum in response to the infection are likely to play a significant role in the hypergastrinaemia of H. pylori infection.

Topics: Bombesin; Cholecystokinin; Gastric Mucosa; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; In Vitro Techniques; Pyloric Antrum; Radioimmunoassay; Tumor Necrosis Factor-alpha

Helicobacter pylori infection may be associated with duodenal ulcer (DU) and accompanied by enhanced gastrin release but the mechanism of this H pylori related hypergastrinaemia in DU patients is unclear. Cholecystokinin (CCK) has been implicated in the feedback control of gastrin release and gastric acid secretion in healthy subjects. This study therefore investigated if CCK participates in the impairment of postprandial gastrin release and gastric secretion in six DU patients. Tests were undertaken with and without elimination of endogenous CCK by loxiglumide, a selective CCK-A receptors antagonist, before and after eradication of H pylori with triple therapy (omeprazole, amoxicyllin, bismuth). In H pylori positive DU patients, the post-prandial decline in pH (with median pH 3.5) was accompanied by a pronounced increment in plasma gastrin but the administration of loxiglumide did not affect significantly this postprandial rise in plasma gastrin and gastric pH profile. After eradication of H pylori, the plasma gastrin concentration was reduced while the median postprandial pH was significantly increased (median pH 4.3). The administration of loxiglumide resulted in significantly greater increase in postprandial plasma gastrin and greater decrease in pH (median pH 3.1) in these patients. This study shows that (a) infection with H pylori is accompanied by an enhanced gastrin release and gastric acidity in DU patients, (b) the failure of loxiglumide to affect plasma gastrin or gastric acid secretion in H pylori infected DU patients could be attributed, at least in part, to the failure of endogenous CCK to control gastrin release and gastric secretion by releasing somatostatin, and (c) the test with loxiglumide may be useful in the identification of patients with impaired feedback control of gastrin release and gastric secretion resulting from infection with H pylori.

Topics: Adult; Cholecystokinin; Duodenal Ulcer; Eating; Gastric Acid; Gastrins; Helicobacter Infections; Helicobacter pylori; Humans; Hydrogen-Ion Concentration; Male; Monitoring, Physiologic; Proglumide; Somatostatin

The aim of the present study was to clarify the effects of Helicobacter pylori infection and its eradication on gastric emptying.. Out of a total of 52 patients with non-ulcerative dyspepsia, 34 H.pylori-positive patients were enrolled. Antimicrobial drugs for the eradication of H. pylori were administered to 19 out of the 34 H. pylori-positive patients. Gastric emptying was evaluated according to the acetaminophen method. Inflammatory changes and intracellular periodic acid-Schiff-positive substances in the antral mucosa were examined in biopsy specimens.. Although gastric emptying was significantly prolonged in the patients with non-ulcerative dyspepsia compared with the control group (P < 0.01), there was no difference in gastric emptying between H. pylori-positive and -negative patients, with all patients showing significantly less gastric emptying than the control group. The H. pylori eradication rate was 58% (11 out of 19) and gastric emptying improved significantly in seven patients whose infection was eradicated and whose dyspeptic symptoms disappeared. The ammonia concentration in gastric juice, inflammatory changes in the gastric mucosa and the index of periodic acid-Schiff-positive substances improved significantly when H. pylori was successfully eradicated compared with patients in whom eradication was unsuccessful. As gut hormones may affect gastroduodenal motility associated with H. pylori infection, we also studied the levels of serum gastrin and cholecystokinin. In the patients whose infection was eradicated, serum gastrin decreased significantly, but the cholecystokinin level did not change significantly, although there was a non-significant trend for cholecystokinin to increase.. These results suggest that delayed gastric emptying is partly associated with H. pylori infection and that the infection may contribute to the development of non-ulcerative dyspepsia.

Topics: Adult; Aged; Amoxicillin; Cholecystokinin; Dyspepsia; Female; Gastric Emptying; Gastrins; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Penicillins