Maximal Acid Output Research Articles

Gastric secretion in patients with caustic ingestion: A prospective study

Caustic ingestion can lead to structural changes in the upper gastrointestinal tract. However, there are limited data on the effect of caustic ingestion on gastric secretion. This study was planned to determine the changes in gastric acid output in patients with caustic ingestion. It was a prospective study done at a tertiary care center in northern India. Twenty consecutive patients in chronic phase of caustic ingestion were evaluated for the study. The gastric secretory function was estimated in the basal state and following pentagastrin stimulation. These results were compared with normal values for our laboratory. The mean age of the included patients (n = 20) was 27.35 ± 2.96years and 14 patients were male. Sixteen (80%) patients had a history of acid ingestion. Patients with caustic ingestion had significantly lower mean gastric acid secretion (0.8 ± 0.4mEq/h vs. 4 ± 0.4mEq/h; p < 0.001) compared to controls. After pentagastrin stimulation, the mean gastric juice volume (31.8 ± 6mL/h vs. 62.3 ± 11.7mL/h; p < 0.01) and acidity (15.3 ± 5.1mEq/L vs. 39.6 ± 9.3mEq/L; p < 0.001) increased in patients with caustic ingestion, but were lower than those in control subjects. Patients with a lower esophageal stricture (n = 6) had decreased maximum acid output (0.62 ± 0.32mEq/h vs. 6.05 ± 0.55mEq/h; p < 0.05) compared to patients with stricture in the upper or middle esophagus. Caustic ingestion is associated with reduced gastric juice volume and acid output. Patients with stricture in the lower one third of the esophagus are at ahigher risk of hypochlorhydria compared to patients with stricture in either the upper or middle esophagus.

Non-invasive method for the assessment of gastric acid secretion.

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

Su1110 - Individual Assessment of Gastric Acid Production by Means of a Non-Invasive Test: Relationship between Maximal Acid Output and Pepsinogen I Levels

Su1110 - Individual Assessment of Gastric Acid Production by Means of a Non-Invasive Test: Relationship between Maximal Acid Output and Pepsinogen I Levels

P.02.1: Individual Assessment of Gastric Acid Production by Means of a Non-Invasive Test: Relationship Between Maximal Acid Output and Serum Pepsinogen I Levels in Patients with Different Upper GI Diseases

P.02.1: Individual Assessment of Gastric Acid Production by Means of a Non-Invasive Test: Relationship Between Maximal Acid Output and Serum Pepsinogen I Levels in Patients with Different Upper GI Diseases

No increase in gastric acid secretion in healthy Japanese over the past two decades.

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide over recent decades. A previous study demonstrated that gastric acid secretion, thought to be an important factor in the increase in the rate of GERD, in Japanese individuals increased in the era from the 1970s to the 1990s. The aim of this study was to evaluate whether gastric acid secretion has altered over the past two decades with and without the influence of Helicobacter pylori infection in nonelderly and elderly Japanese. Gastric acid secretion, the concentrations of serum gastrin, pepsinogen I, and pepsinogen II, and H. pylori infection were determined in 78 healthy Japanese subjects. The findings were compared with data obtained in the 1990s. Basal acid output (BAO) and maximal acid output (MAO) gradually decreased with age in H. pylori-negative subjects. In addition, those with H. pylori infection tended to show decreased gastric acid secretion as compared with those without infection, particularly in the elderly group. MAO decreased gradually with age in males, whereas it remained unchanged with age in females. MAO in H. pylori-negative subjects has not changed over the past two decades (17.7 mEq/h vs 17.6 mEq/h in nonelderly subjects, and 15.2 mEq/h vs 12.7 mEq/h in elderly subjects). In contrast to the increased prevalence of GERD, gastric acid secretion has not increased over the past two decades in Japanese. However, secretion has decreased with age in males but not in females, which may partly explain the sex difference in the age-related GERD prevalence.

Sa1862 Are All Patients With Histological Diagnosis of Atrophic Gastritis Really At Risk of Developing Gastric Cancer? Assessment of Gastric Acid Production by Correlation Between Maximal Acid Output and Pepsinogen I

Sa1862 Are All Patients With Histological Diagnosis of Atrophic Gastritis Really At Risk of Developing Gastric Cancer? Assessment of Gastric Acid Production by Correlation Between Maximal Acid Output and Pepsinogen I

Calcium Carbonate Breath Test for Non-Invasive Estimation of Gastric Acid Secretion

Gastric acid measurement is useful in assessing the effectiveness of antisecretory drugs, however, the conventional tests involve invasive nasogastric intubation. Orally administered ¹³C-labeled calcium carbonate (Ca¹³CO₃) reacts with gastric acid to produce ¹³C-labeled carbon dioxide (¹³CO₂), which is then excreted in the breath. The objective of this study was to evaluate the suitability of Ca¹³CO3 breath test for estimating gastric acid secretion in human noninvasively. First, the Ca¹³CO₃ breath test and the measurement of pooled gastric acid under a fasting condition were performed in 6 healthy volunteers to evaluate the correlation between the two parameters. Next, endoscopic gastric acid collection and the Ca¹³CO₃ breath test were performed on different days after pentagastrin injection in 20 subjects to evaluate the correlation between the tests and the reproducibility. Finally, the same studies were repeated in 4 subjects before and after 1-week rabeprazole, a proton pump inhibitor, administration. The maximum CO₂ concentration (Cmax) correlated very well with the amount of pooled gastric acid (r = 0.95), suggesting that Ca¹³CO₃ breath test values well reflected the fasting intragastric acidity. The ¹³CO₂ concentration after pentagastrin injection correlated well with pentagastrin-stimulated maximal acid output (r = 0.79 at 20 min). The reproducibility of the Ca¹³CO₃ breath test under pentagastrin-stimulation was good (coefficient of variation = 0.11). Rabeprazole administration markedly reduced the values of the Ca¹³CO₃ breath test, suggesting that it can sensitively assess the efficacy of rabeprazole. The Ca¹³CO₃ breath test can potentially be a useful method for non-invasive estimation for gastric acid secretion in human.

A new method for determining gastric acid output using a wireless pH-sensing capsule.

Gastro-oesophageal reflux disease (GERD) and gastric acid hypersecretion respond well to suppression of gastric acid secretion. However, clinical management and research in diseases of acid secretion have been hindered by the lack of a non-invasive, accurate and reproducible tool to measure gastric acid output (GAO). Thus, symptoms or, in refractory cases, invasive testing may guide acid suppression therapy. To present and validate a novel, non-invasive method of GAO analysis in healthy subjects using a wireless pH sensor, SmartPill (SP) (SmartPill Corporation, Buffalo, NY, USA). Twenty healthy subjects underwent conventional GAO studies with a nasogastric tube. Variables impacting liquid meal-stimulated GAO analysis were assessed by modelling and in vitro verification. Buffering capacity of Ensure Plus was empirically determined. SP GAO was calculated using the rate of acidification of the Ensure Plus meal. Gastric emptying scintigraphy and GAO studies with radiolabelled Ensure Plus and SP assessed emptying time, acidification rate and mixing. Twelve subjects had a second SP GAO study to assess reproducibility. Meal-stimulated SP GAO analysis was dependent on acid secretion rate and meal-buffering capacity, but not on gastric emptying time. On repeated studies, SP GAO strongly correlated with conventional basal acid output (BAO) (r=0.51, P=0.02), maximal acid output (MAO) (r=0.72, P=0.0004) and peak acid output (PAO) (r=0.60, P=0.006). The SP sampled the stomach well during meal acidification. SP GAO analysis is a non-invasive, accurate and reproducible method for the quantitative measurement of GAO in healthy subjects. SP GAO analysis could facilitate research and clinical management of GERD and other disorders of gastric acid secretion.

Lack of cholinergic innervation in gastric mucosa does not affect gastrin secretion or basal acid output in neurturin receptor GFRα2 deficient mice

Efferent signals from the vagus nerve are thought to mediate both basal and meal-induced gastric acid secretion, and provide trophic support of the mucosa. However, the underlying mechanisms are incompletely understood. Neurturin, signalling via glial cell line-derived neurotrophic factor (GDNF)-family receptor α2 (GFRα2), is essential for parasympathetic innervation of many target tissues but its role in gastric innervation is unknown. Here we show that most nerve fibres in wild-type mouse gastric mucosa, including all positive for gastrin-releasing peptide, are cholinergic. GFRα2-deficient (KO) mice lacked virtually all cholinergic nerve fibres and associated glial cells in the gastric (oxyntic and pyloric) mucosa but not in the smooth muscle, consistent with the selective expression of neurturin mRNA in the gastric mucosa. 2-Deoxyglucose and hexamethonium failed to affect acid secretion in the GFRα2-KO mice indicating the lack of functional innervation in gastric mucosa. Interestingly, basal and maximal histamine-induced acid secretion did not differ between wild-type and GFRα2-KO mice. Moreover, circulating gastrin levels in both fasted and fed animals, thickness of gastric mucosa, and density of parietal and different endocrine cells were similar. Carbachol-stimulated acid secretion was higher in GFRα2-KO mice, while atropine reduced basal secretion similarly in both genotypes. We conclude that cholinergic innervation of gastric mucosa depends on neurturin-GFRα2 signalling but is dispensable for gastrin secretion and for basal and maximal acid output. Basal acid secretion in the KO mice appears to be, at least partly, facilitated by constitutive activity of muscarinic receptors.

Hydrolysis of digoxin by acid.

Predictable hydrolysis of [3H]digoxin-12alpha occurred in vitro with incubation in HCl or gastric juice. Hydrolysis varied with pH, time, temperature and agitation. Digoxin, the bis- and mono-digitoxosides of digoxigenin and digoxigenin were separated by silica gel thin-layer chromatography using chloroform-ethyl acetate-glacial acetic acid (25:25:1 v/v) and were quantitated by liquid scintillation spectrometry. Hydrolysis with incubation at 37 degrees and pH 3 for 90 min was minimal, but increased with increasing acidity until greater than 70% was hydrolysed at pH 1-2 after 30 min and greater than 96% after 90 min incubation. At pH 0-9, 87% was hydrolysed after 30 min. In vitro hydrolysis in gastric fluid was slightly less than in HCl at the same pH. A volunteer was given 150 muCi[3H]digoxin-12alpha by nasogastric tube during a pentagastrin infusion when gastric pH was 0-94. He remained on his left side and samples were aspirated at intervals and immediately neutralized. Ethanol-chloroform 50-50 (v/v) extracts of the gastric fluid aspirated after 90 min and of all the urine specimens collected for 5 days were applied to a DEAE Sephadex LH-20 column. The radioactivity appeared in a single peak as digoxigenin in the 90 min gastric aspirate and in all urine specimens. Extensive intragastric hydrolysis of digoxin may occur under conditions of maximum acid output.

Helicobacter pylori dupA and gastric acid secretion are negatively associated with gastric cancer development

Few reports have described the cancer prevalence of peptic ulcer patients with long-term follow-up studies. We have conducted a long-term retrospective cohort study of Japanese peptic ulcer patients and evaluated the risk factors for the occurrence of gastric cancer (GCa). A total of 136 patients diagnosed with peptic ulcers from 1975 to 1983 were enrolled. These 136 cases [102 males and 34 females; 69 gastric ulcer (GU) and 67 duodenal ulcer (DU) patients at the time of enrollment; mean follow-up period of 14.4 years (range 1-30 years)] after being matched with a tumour registry database in Hiroshima prefecture were surveyed for GCa. We investigated Helicobacter pylori duodenal ulcer promoter gene A (dupA) using paraffin-embedded gastric biopsy specimens in 56 cases. Gastric acid secretion and basal acid output (BAO) in 40 cases, and maximal acid output in 68 cases, had been measured at first diagnosis of peptic ulcers. GCa was detected in 24 patients (17 with GU, 7 with DU) during the follow-up. The prevalence of GCa was significantly higher in GU patients than in DU patients (log-rank test P<0.05). dupA-positive H. pylori was detected not only in DU patients (9/20) but also in GU patients (9/36). Gastric acid output was significantly larger in quantity in patients with dupA-positive H. pylori than in those with dupA-negative H. pylori (P<0.05). The occurrence of GCa was significantly lower in patients with dupA-positive H. pylori and a high BAO level (log-rank test P<0.05). DUs, higher acid output and dupA-positive H. pylori were negatively associated with GCa.

Effect of antrectomy on Capsicum annuum induced gastric acid secretion in rats

Background: The induction of gastric acid secretion by Capsicum annuum is attributed to its active principle, capsaicin, whose effect on the parietal cell is indirect. Capsaicin acutely stimulates sensory neurons to liberate acetylcholine which can release histamine from the enterochromaffin like cells. It also releases gastrin from the antral G cells. Aim: To establish the effectiveness of antrectomy in reducing gastric acid secretion. Methods: Maximum acid output (MAO) in two groups of eight rats comprising of males and females was determined. The first group was the control group while the second had antrectomy. The rats were fasted overnight with liberal access to water. They were anaesthetized with 25% w/v ethyl carbonate (urethane) 0.6 ml/100 g body weight, and then surgically prepared. Determination of gastric acid secretion was effected by the continuous perfusion technique of Gosh and Schild. Ranitidine 0.5 mg/ml was given intravenously as a positive control agent. Results: Ranitidine and antrectomy, each alone inhibited the MAO by 67.6% and 37.8% respectively. The combined inhibitory effect of antrectomy and ranitidine on MAO was 86.5%. Antrectomy which removes most of the G - cells in the excised antral tissue significantly (p

The value of gastric muscle layer vagotomy in the treatment of duodenal ulcer perforation

Objective To evaluate the effect of gastric muscle layer vagotomy for the treatment of duo-denal ulcer perforation. Methods Since 1998 February,have treated 52 cases patients of duodenal ulcer perfo-ration by gastric muscle layer vagotomy and,41 cases treated with simplicity suture of the perforation duodenal ulcer. Results A(therapy groups), B (comparison groups)With postoperative pentagastrin stimulation:the base acid output (BAO), maximum acid output (MAO) and peak acid output (PAO), There were significant difference between in two groups (P < 0. 01). All patients were followed up from 3 months to six years. There was no ulcer recurrence in the therapy groups. Recurrence was found of 12 cases (29. 3%)in the comparison groups, again surgical operation 7 cases(17%). Using a Visick grading,94. 2% of patients were classified as Ⅰ and Ⅱ in the therapy groups and 48.8% in the comparison groups. Conclusion The gastric muscle layer vagotomy is an easy and rapid procedure with less complications, The curative effect is better than simplicity suture of the duodenal ulcer perforation. Key words: Duodenal ulcer perforation; Vagotomy; Simplicity suture

Rebamipide, a Cytoprotective Drug, Increases Gastric Mucus Secretion in Human: Evaluations with Endoscopic Gastrin Test

We have previously developed a rapid, simple endoscopic method for evaluating gastrin-stimulated maximal acid output (the endoscopic gastrin test, EGT). In EGT, gastric fluid newly secreted over 10 min after gastrin stimulation is collected under direct endoscopic visualization. In this study, employing the EGT, we evaluated the effect of rebamipide, a cytoprotective anti-ulcer drug, on gastric mucus secretion. In ten Helicobacter pylori-negative healthy volunteers, gastric juice was collected by EGT prior to and after 4-week administration of rebamipide. The collected gastric juice was subjected to analysis for gastric mucus output. Total gastric mucin output was significantly increased by 53% by rebamipide administration from 3.2 ± 1.2 mg hexose/10 min to 4.9 ± 2.2 mg hexose/10 min (P < 0.01). Further analysis by ion-exchange chromatography revealed that rebamipide administration induced a specific increase in acidic mucin rich in sialic acid. Applying EGT, this study demonstrated that rebamipide administration increased gastric mucus secretion in human.

Activation of the calcium sensing receptor stimulates gastrin and gastric acid secretion in healthy participants

In 17 adults on a fixed metabolic diet, an 11-day course of cinacalcet increased serum gastrin and basal gastric acid output, but not maximal gastric acid output, compared with a placebo. These findings indicate that the calcium sensor receptor plays a role in the regulation of gastric acid. Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cinacalcet, a CaR allosteric agonist, increases serum gastrin and gastric acid secretion. Seventeen healthy adults with normal gastric acid output were placed on an 18-day metabolic diet. On day 8 (baseline), participants were given cinacalcet (15 then 30 mg/day) or placebo for 11 days. Changes in gastric acid output, serum gastrin, and other measures were compared in the two groups. Changes in serum gastrin and basal acid output (adjusted for baseline body weight) were significantly more positive in the cinacalcet group compared with placebo (P = 0.004 and P = 0.039 respectively). Change in maximal acid output was similar in the two groups (P = 0.995). As expected, cinacalcet produced significant decreases in serum PTH (P < 0.001) and ionized calcium levels (P = 0.032), and increases in serum phosphorus levels (P = 0.001) and urinary calcium (P = 0.023). This study provides in vivo evidence that activation of the CaR increases serum gastrin levels and basal gastric acid secretion in healthy adults.

Higher Gastric Mucin Secretion and Lower Gastric Acid Output in First-degree Relatives of Gastric Cancer Patients

Patients infected by Helicobacter pylori who have first-degree relatives with gastric cancer have an 8-fold increased risk of developing gastric cancer themselves. Mucins are high-molecular-weight glycoproteins that play a cardinal role in the protective mechanism of the gastric epithelium. To study gastric acid and mucin secretion in dyspeptic patients with and without a family history of gastric cancer and H. pylori infection. Twenty-six dyspeptic patients underwent esophago-gastro-duodenoscopy, gastric biopsies, and acid and mucin secretory tests. The sample was divided by family history of gastric cancer and H. pylori status. Patients who were infected by H. pylori had a significantly higher degree of inflammation than those who were not. H. pylori-positive patients with a positive family history had a lower basal and maximal gastric acid output than infected patients with no family history and noninfected controls, and a higher basal and maximal mucin output than infected patients with no family history. MUC5AC was the major mucin species expressed in gastric juice. In patients with relatives with gastric cancer, H. pylori infection is associated with a more severe inflammatory reaction consisting of decreased gastric acid secretion and increased mucin secretion.

Oral pantoprazole in the form of granules or tablets are pharmacodynamically equivalent in suppressing acid output in patients with gastro‐oesophageal reflux disease and a history of erosive oesophagitis

To demonstrate the pharmacodynamic comparability between oral 40 mg pantoprazole delayed-release granules and tablets. This was a multicentre, randomized, open-label, 2-period, 2-sequence, 9-week crossover study in patients aged 18-65 years with gastro-oesophageal reflux disease and documented erosive oesophagitis. The primary endpoint was a comparison of the inhibition of pentagastrin-stimulated maximum acid output (MAO) at steady state after once daily dosing for 1 week and 23 h after the last dose of pantoprazole granules and tablets. Basal acid output was measured prior to MAO. Standard safety evaluations were performed. The one-sided t-test was used to test the null hypothesis that granules - 1.2 x tablet >/= 0 against the alternative hypothesis that this difference was <0 for both MAO and basal acid output values. Sixty patients completed the study. The mean MAO values were 7.11 +/- 4.98 and 7.29 +/- 4.77 mmol/h, while the mean basal acid output values were 0.74 +/- 0.91 and 0.58 +/- 0.63 mmol/h for the granules and tablets, respectively. The two formulations were shown statistically to be pharmacodynamically equivalent in suppressing MAO (P = 0.006), safe and well tolerated. Patients with gastro-oesophageal reflux disease who are unable to swallow the tablet may safely be prescribed the pantoprazole sodium granules.

Gastric acid secretory capacity falls after repeated within-day pentagastrin testing in fed subjects.

Between-day pentagastrin testing yields highly reproducible stimulated gastric acid output values, but little is known of the reproducibility of repeated within-day pentagastrin tests. We have performed three pentagastrin tests within the 1 day in nine healthy subjects. Within-day tests were 6 hours apart; the first followed an overnight fast and the second and third were both 4 hours after a substantial meal. A further test was performed the following morning, again after an overnight fast, which allowed comparison of within-day and between-day testing. In the second and third within-day tests there was a marked decrease of stimulated gastric acid output, with both maximal and peak acid output decreased to approximately half of the value of the first test (P less than 0.01). By contrast there were no significant differences in the acid output values obtained in between-day tests (both following an overnight fast). Possible mechanisms for the decreased output on repeated within-day testing include alterations in the sensitivity of the gastrin receptor, or some neurohumoral influence secondary to the preceding meal. Future studies of the duration of action of drugs affecting acid secretion may need to take account of these findings.

The Effects Of Capsicum Annuum And Capsicum Frutescens-Induced Gastric Acid Secretion In The Rat Is By H2 Receptor Stimulation.

Background:Peppers, containing Capsicum annuum and Capsicum frutescens are frequently consumed as spice in food. It is also known that the capsaicin content of peppers is a cause of hyper acidity. Aims:This study was undertaken to assess the mechanism of action of the extracts of Capsicum annuum and Capsicum frutescens on gastric acid secretion. Method: Aqueous extracts of Capsicum annuum and Capsicum frutescens prepared by simple maceration were administered to urethane anaesthetized rats, and gastric acid secretion assessed using the continuous perfusion method. The effects of ranitidine on Capsicum annuum and Capsicum frutescens-induced gastric acid secretion in albino rats of both sexes were also investigated. Results: Aqueous extracts of Capsicum annuum or Capsicum frutescens induced gastric acid secretion dose-dependently. Maximum acid output induced by either crude extract was significantly (p 0 Keywords : Capsicum annuum, Capsicum frutescens, gastric acid, secretion, ranitidine. Highland Medical Research Journal Vol. 5 (2) 2007 pp. 38-41

Comparison of Pentagastrin-Stimulated Maximum Acid Output in Patients with a History of Erosive Esophagitis Treated with 40 mg of Oral Pantoprazole Granules or Tablets

Comparison of Pentagastrin-Stimulated Maximum Acid Output in Patients with a History of Erosive Esophagitis Treated with 40 mg of Oral Pantoprazole Granules or Tablets