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E Kittang

Publications and source records attributed to E Kittang.

8 recordsLinked to original sources

The effect of omeprazole on gastric acidity and the absorption of liver cobalamins.

The effect of gastric anacidity on the absorption of food-bound cobalamins is uncertain. Omeprazole, an inhibitor of the enzyme H-K-ATPase in the parietal cell, is the most potent inhibitor of gastric acidity known so far. In 17 healthy male volunteers the absorption of liver-bound cobalamins was assessed after a single intravenous dose of omeprazole (80 mg) or placebo in a double-blind, crossover manner. The effect of omeprazole on pH, gastric acidity, and intrinsic factor (IF) concentration was measured in aspirates of gastric juice 5 min before and 30 and 60 min after the administration of liver homogenate containing 0.74 nmol of 57Co-labelled cobalamins. Omeprazole treatment resulted in anacidity (pH values above 6.0) in 14 individuals 30 min after the liver dose and in 15 individuals after 60 min. The IF concentration was unchanged in the omeprazole experiment as compared with the placebo experiment. The absorption of liver-bound cobalamins was 310 pmol (189-501 pmol) in the omeprazole experiment as compared with 415 pmol (150-549 pmol) in the placebo experiment (median values and range, p = 0.5228). We suggest that anacidity induced by omeprazole does not reduce the absorption of liver-bound cobalamins.

Absorption

Effect of gastric anacidity on the release of cobalamins from food and their subsequent binding to R-protein.

Rabbit liver homogenate, labelled in vivo with 57Co, was used to investigate the effect of anacid gastric juice on the release of cobalamins from food and on the cobalamin binding to proteins in humans. The cobalamin release was investigated in vitro by incubating the liver homogenate with native and neutralized gastric juice. The cobalamin release and the amount of cobalamins bound to R-protein were significantly higher with native than with neutralized gastric juice. To investigate the effect of anacidity on cobalamin release in vivo, 14 healthy volunteers were given omeprazole or placebo in a double-blind crossover fashion. 57Co-labelled liver-bound cobalamins were given orally, and aspirates were collected from the stomach and the upper jejunum. After omeprazole gastric anacidity (pH greater than 6.0) was obtained in 11, 12, and 10 individuals after 5, 30, and 60 min, respectively. In the gastric aspirates obtained after omeprazole there was a slight inhibition in cobalamin release after 5 and 30 min (p less than 0.05). In the jejunal aspirates the cobalamin release was close to 90% in both the placebo and the omeprazole experiment, and there was no significant difference in the percentage of cobalamins bound to R-protein in the two groups. The percentage of cobalamins bound to R-protein was much lower in the jejunal aspirates (26.6% and 23.7% in omeprazole and placebo, respectively) than in the gastric aspirates (65.8% and 68.6%).

Animals

Cystic fibrosis: protease activity in saliva evaluated with chromogenic substrates.

The protease activities in saliva from individuals with cystic fibrosis (CF) were studied using four different chromogenic substrates. In the CF-group a significantly decreased protease activity in the range 50-70% was found, compared to an age- and sex-matched control group, but with considerable overlap between the CF-patients and the control patients. The trypsin-like activity found in CF-patients without chronic colonisation with Pseudomonas aeruginosa was significantly decreased and without overlap compared to the control patients. The results indicate that determination of salivary protease activity using chromogenic substrates may give additional information in patients with suspected cystic fibrosis, and indicate the possibility of an additional diagnostic test.

Adolescent

Effect of omeprazole on the secretion of intrinsic factor, gastric acid and pepsin in man.

The effect of an intravenous infusion of omeprazole (0.35 mg/kg) and placebo on basal and stimulated (pentagastrin 1.0 microgram/kg/h) secretion of gastric acid, intrinsic factor and pepsin was studied in 10 healthy male subjects. Omeprazole caused a marked inhibition of basal and stimulated acid output. The inhibition of pepsin output was less marked, but also significant. The output of intrinsic factor, however, showed no significant change. The results indicate that acid and intrinsic factor might have different secretory mechanisms within the parietal cell.

Adult

Determination of the R-protein and the R-protein-vitamin B12-complex in saliva and gastrointestinal juice by FPLC Mono S cationic chromatography.

The binding of vitamin B12 to the two vitamin B12 binding proteins--intrinsic factor and R-protein--in gastrointestinal juice is pH dependent. It is therefore of importance that binding studies are carried out at pH values near the physiological pH of the gastric juice. In the present study the vitamin B12 complexes of the two vitamin B12 binders were separated at a pH of 1.8 using the cationic exchange chromatograph Mono S attached to the fast protein liquid chromatography (FPLC) system. The R-protein concentration was measured in saliva and gastric juice with high accuracy and with highly significant correlation compared to the serum-coated charcoal method of Gottlieb. The method showed a decreased recovery in duodenal juice and in samples with high bile content.

Bile

The effect of ranitidine on the absorption of food cobalamins.

The effect of the histamine H2-receptor antagonist ranitidine on the absorption of food cobalamins was investigated in 20 healthy volunteers randomized to treatment with ranitidine or placebo for 1 week. Liver homogenates containing cobalamins labelled in vivo with cobalt-57 was obtained by repeated injections of 57Co-labelled cyanocobalamin in rabbits. Test doses (0.37 nmol) of the 57Co-labelled liver cobalamins were administered orally together with 51CrCl3 and carmine red, and the absorption of 57Co-labelled cobalamins was assessed from the ratio of the two isotopes in the stool collection that had been coloured by the carmine red. There was no significant difference in the mean absorption before (47.4%) and after (50.7%) the treatment.

Adult

Absorption of food cobalamins assessed by the double-isotope method in healthy volunteers and in patients with chronic diarrhoea.

To make a food preparation containing radioactively labelled cobalamins, rabbits were given repeated injections with 57Co-labelled cyanocobalamin. The liver was removed, homogenized, and fried for 1 min or boiled for 30 min. Of the radioactivity in the fried homogenate 41.7% was recovered in the centrifuged supernatant compared with 50.8% in the boiled homogenate. The radioactivity in the supernatants had a molecular size close to that of free 57Co-labelled cyanocobalamin. Forty-two per cent of the radioactivity in the whole homogenate had been incorporated into 5-deoxyadenosyl-, 10% into methyl-, and 16.5% into hydroxy-cobalamin. To assess the validity of a double-isotope method for measuring the intestinal absorption of doses of the 57Co-labelled liver cobalamins, 51CrCl3 was used as a non-absorbable marker. In 14 healthy volunteers the correlation coefficient between the absorption measured by the double-isotope technique and the faecal excretion test was highly significant (r = 0.96, p less than 0.005), and there was only a small variation in the 57Co/51Cr ratio in successive stool collections. In 11 patients with chronic diarrhoea there was a significant correlation between the absorption measured by the double-isotope technique and the faecal excretion test (r = 0.92, p less than 0.005), but in some patients there was considerable variation in the 57Co/51Cr ratio in successive stool collections.

Adult