A retrospective study of the usefulness of acid secretory testing.
BACKGROUND: Gastric analysis is useful for diagnosing and monitoring the control of hypersecretory conditions and to distinguish appropriate from inappropriate causes of hypergastrinaemia. Pentagastrin, used to measure maximal acid output (MAO), is no longer available in the USA. METHODS: We examined the University of Pennsylvania Health System gastric analysis database, which includes demographic data, study indications, gastric analysis, and serum gastrin and secretin testing results according to referral indications, paying specific attention to discordant basal acid output (BAO) and MAO measurements. RESULTS: One hundred and twenty-four gastric analyses were performed in 103 patients (42 males, mean age 47.5 years, 14 with prior acid-decreasing surgery). Recurrent ulceration or pain unresponsive to antisecretory therapy was the indication in 42 patients. Twelve were hypersecretory, including three each with isolated elevations of BAO or MAO. Hypergastrinaemia was the indication in 35 patients. Five were hypersecretory (four with Zollinger-Ellison syndrome), three had isolated MAO elevations and 16 were hypo- or achlorhydric, indicating appropriate hypergastrinaemia. Of the seven patients with isolated MAO elevations, two had clear benefit from the stimulated portion of the study (four additional patients had equivocal benefit). CONCLUSIONS: Gastrin concentrations cannot be interpreted without knowledge of acid secretory capacity. MAO measurement has a small but significant benefit over measuring BAO alone. (+info)
Stomachs of mice lacking the gastric H,K-ATPase alpha -subunit have achlorhydria, abnormal parietal cells, and ciliated metaplasia.
The H,K-ATPase of the gastric parietal cell is the most critical component of the ion transport system mediating acid secretion in the stomach. To study the requirement of this enzyme in the development, maintenance, and function of the gastric mucosa, we used gene targeting to prepare mice lacking the alpha-subunit. Homozygous mutant (Atp4a(-/-)) mice appeared healthy and exhibited normal systemic electrolyte and acid-base status but were achlorhydric and hypergastrinemic. Immunocytochemical, histological, and ultrastructural analyses of Atp4a(-/-) stomachs revealed the presence of chief cells, demonstrating that the lack of acid secretion does not interfere with their differentiation. Parietal cells were also present in normal numbers, and despite the absence of alpha-subunit mRNA and protein, the beta-subunit was expressed. However, Atp4a(-/-) parietal cells had dilated canaliculi and lacked typical canalicular microvilli and tubulovesicles, and subsets of these cells contained abnormal mitochondria and/or massive glycogen stores. Stomachs of adult Atp4a(-/-) mice exhibited metaplasia, which included the presence of ciliated cells. We conclude that ablation of the H,K-ATPase alpha-subunit causes achlorhydria and hypergastrinemia, severe perturbations in the secretory membranes of the parietal cell, and metaplasia of the gastric mucosa; however, the absence of the pump appears not to perturb parietal cell viability or chief cell differentiation. (+info)
Acute gastritis with hypochlorhydria: report of 35 cases with long term follow up.
BACKGROUND: Between 1976 and 1987, 35 cases of acute gastritis with hypochlorhydria (AGH) were seen in our research laboratory. The aims of this study were to determine the natural history of AGH and the role of Helicobacter pylori in its pathogenesis. METHODS: Archived serum and gastric biopsy samples obtained from AGH subjects were examined for evidence of H pylori colonisation. Twenty eight of 33 (85%) surviving AGH subjects returned a mean of 12 years after AGH for follow up studies, including determination of H pylori antibodies, basal and peak acid output, endoscopy, and gastric biopsies. A matched control group underwent the same studies. RESULTS: Archived material provided strong evidence of new H pylori acquisition in a total of 14 subjects within two months, in 18 within four months, and in 22 within 12 months of recognition of AGH. Prevalence of H pylori colonisation at follow up was 82% (23 of 28) in AGH subjects, significantly (p<0.05) higher than in matched controls (29%). Basal and peak acid output returned to pre-AGH levels in all but two subjects. CONCLUSIONS: One of several possible initial manifestations of H pylori acquisition in adults may be AGH. While H pylori colonisation usually persists, hypochlorhydria resolves in most subjects. (+info)
Heterogeneity of gastric histology and function in food cobalamin malabsorption: absence of atrophic gastritis and achlorhydria in some patients with severe malabsorption.
BACKGROUND: The common but incompletely understood entity of malabsorption of food bound cobalamin is generally presumed to arise from gastritis and/or achlorhydria. AIM: To conduct a systematic comparative examination of gastric histology and function. SUBJECTS: Nineteen volunteers, either healthy or with low cobalamin levels, were prospectively studied without prior knowledge of their absorption or gastric status. METHODS: All subjects underwent prospective assessment of food cobalamin absorption by the egg yolk cobalamin absorption test, endoscopy, histological grading of biopsies from six gastric sites, measurement of gastric secretory function, assay for serum gastrin and antiparietal cell antibodies, and direct tests for Helicobacter pylori infection. RESULTS: The six subjects with severe malabsorption (group I) had worse histological scores overall and lower acid and pepsin secretion than the eight subjects with normal absorption (group III) or the five subjects with mild malabsorption (group II). However, histological findings, and acid and pepsin secretion overlapped considerably between individual subjects in group I and group III. Two distinct subgroups of three subjects each emerged within group I. One subgroup (IA) had severe gastric atrophy and achlorhydria. The other subgroup (IB) had little atrophy and only mild hypochlorhydria; the gastric findings were indistinguishable from those in many subjects with normal absorption. Absorption improved in the two subjects in subgroup IB and in one subject in group II who received antibiotics, along with evidence of clearing of H pylori. None of the subjects in group IA responded to antibiotics. CONCLUSIONS: Food cobalamin malabsorption arises in at least two different gastric settings, one of which involves neither gastric atrophy nor achlorhydria. Malabsorption can respond to antibiotics, but only in some patients. Food cobalamin malabsorption is not always synonymous with atrophic gastritis and achlorhydria, and hypochlorhydria does not always guarantee food cobalamin malabsorption. (+info)
Hypochlorhydria induced by a proton pump inhibitor leads to intragastric microbial production of acetaldehyde from ethanol.
BACKGROUND: Acetaldehyde, produced locally in the digestive tract, has recently been shown to be carcinogenic in humans. AIM: To examine the effect of iatrogenic hypochlorhydria on intragastric acetaldehyde production from ethanol after a moderate dose of alcohol, and to relate the findings to the changes in gastric flora. METHODS: Eight male volunteers ingested ethanol 0.6 g/kg b.w. The pH, acetaldehyde level and microbial counts of the gastric juice were then determined. The experiment was repeated after 7 days of lansoprazole 30 mg b.d. RESULTS: The mean (+/- S.E.M.) pH of the gastric juice was 1.3 +/- 0.06 and 6.1 +/- 0.5 (P < 0.001) before and after lansoprazole, respectively. This was associated with a marked overgrowth of gastric aerobic and anaerobic bacteria (P < 0. 001), by a 2.5-fold (P=0.003) increase in gastric juice acetaldehyde level after ethanol ingestion, and with a positive correlation (r=0. 90, P < 0.001) between gastric juice acetaldehyde concentration and the count of aerobic bacteria. CONCLUSIONS: Treatment with proton pump inhibitors leads to hypochlorhydria, which associates with intragastric overgrowth of aerobic bacteria and microbially-mediated acetaldehyde production from ethanol. Since acetaldehyde is a local carcinogen in the concentrations found in this study, long-term use of gastric acid secretory inhibitors is a potential risk-factor for gastric and cardiac cancers. (+info)
Assessment of gastric acidity of Japanese subjects over the last 15 years.
The gastric acidity of young to elderly Japanese subjects from 1989 to 1999 was assessed and compared with that obtained in 1984, using GA-Test capsules containing acid-dissolving granules of riboflavin. The percentage of achlorhydric subjects increased with age as observed before, however, an over all decrease in all age categories year by year was noted. The percentage of achlorhydric subjects aged 50 years in 1995-1999 was about 40%, which was lower than that (60%) in 1984. However, such a chronological change was not observed when the percentage of achlorhydric subjects was determined according to birth year, indicating that it is related to the birth year of subjects. The percentage of achlorhydric subjects correlated with infection by Helicobacter pylori. Considering the high percentage of achlorhydric elderly, bioavailability and bioequivalence studies should be performed taking into consideration the effects of gastric acidity on the in vivo performance of drug products. (+info)
Marginal ulcer in achlorhydric patients.
Recurrent gastrojejunal ulceration is reported in three patients with histamine-fast achlorhydria. In none of these patients was extruding suture material responsible for the ulceration. However, all three patients had a history of alcohol abuse, and one abused aspirin as well. These cases demonstrate that achlorhydria does not protect against anastomotic ulceration. It is suggested that surgical manipulation produces an increased susceptibility to mucosal damage, and that it is erroneous to consider all anastomotic ulceration as a continuation or recurrence of acid peptic disease. (+info)
Vagal impairment of gastric secretion in diabetic autonomic neuropathy.
Gastric acid output in response to insulin-induced hypoglycaemia and pentagastrin was measured in 18 diabetic patients with symptoms of autonomic neuropathy. Two patients had achlorhydria but the rest responded normally to pentagastrin. The acid output evoked by insulin-induced hypoglycaemia was low in 10 of the 16 patients who secreted acid in response to pentagastrin. These changes suggest that vagal impairment is common in diabetics with autonomic symptoms, which might explain the infrequency of duodenal ulcer in diabetics. (+info)