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Roland, M., Berstad, A. & Liavag, I. Acid and pepsin secretion in duodenal ulcer patients in response to graded doses of pentagastrin or pentagastrin and carbacholine before and after proximal gast...

The effect of graded doses of pentagastrin on the gastric scretion of acid was compared in patients with and without gastritis. Biopsies were taken from the body of the stomach. Ten subjects had normal gastric mucosa, eight had superficial gastritis, and 10 atrophic gastritis. Pentagastrin in a dose of 1·5 μg/kg/hr elicited a near maximal HCl response from both the normal gastric mucosa and the mucosa with gastritis. The response to 0·3 μg/kg/hr was significantly lower than the response to 7·5 μg/kg/hr in the subjects with atrophic gastritis, while there was no significant difference in the response between the dose levels in the subjects with a normal mucosa.

Graded doses of pcntagastrin (0.15, 0.9, and 5.4 μg/kg-hour) and of secretin (0.1, 0.5, and 2.5 CU/kg-hour) were given on different days, either alone or combined with a fixed dose of the other agent, to each of 3 healthy young males in random order. Four additional subjects received 0.1 CU/kg-hour of secretin alone and combined with 0.15 pg/kg-hour of pentagastrin. The gastric and duodenal contents were recovered by means of thc gastroduodenal Lagerlof tube. Pentagastrin showed no significant effect on the secretion of bicarbonate and proteolytic enzymes into the duodenum either alone or in combination with secretin.

The stimulating effect on the gastric secretion of pepsin of an intravenous injection of one clinical unit of pure secretion per kg body weight was compared to the effect of a subcutaneous injection of 50 μg histamine dihydrochloride per kg body weight in the same series of subjects. The pattern of the pepsin response differed markedly. The ratio between the amounts of pepsin and HCl secreted decreased after injection of histamine, whereas it increased after injection of secretin. The effect of secretin on the pepsin/HCl ratio lasted for about two hours.

Graded doses of histamine dihydrochloride (0.4 to 26.2 μg/kg-h) and of pentagastrin (0.055 to 7.0 μg/kg-h) were infused intravenously on separate days in each of 3 healthy subjects. The maximal acid response was similar with histamine and pentagastrin, whereas both the observed and the calculated maximal pepsin response were greater with histamine, owing to lower concentrations of pepsin in the pentagastrin-stimulated gastric secretions. The pepsin/acid ratio, which was lower with pentagastrin than with histamine, decreased with increasing doses of the stimulants. It would therefore appear that pentagastrin is inferior to histamine as a stimulant of pepsin secretion in man.

The ‘basal’ gastric secretion collected during 3 hours with a gastric Levin tube and a gastroduodenal Lagerlof tube was compared in 11 subjects. The Lagerlof tube gave significantly higher pepsin output, pepsin concentration, and pepsin/acid ratio than the Levin tube, and showed a significant non-steady state level of volume, acid concentration, acid output, pepsin output, and pepsin/acid ratio. The effect of the Lagerlof tube was not dependent on the duodenal drainage. Perfusing the duodenum with secretin-stimulated duodenal juice in 4 subjects did not stimulate more pepsin than the tube alone.

Petersen, H. & Berstad, A. 1970. Effect of Secretin on Histamine- and Pentagastrin-Stimulated Secretion of Acid in Man. Scand. J. Gastroent. 5, 529-532.The gastric secrction of acid in response to ...

Berstad, A. 1970. A Modified Hemoglobin Substrate Method for the Estimation of Pepsin in Gastric Juice. Scand. J. Gastroent. 5, 343-348.Human hemoglobin was used as substrate for the estimation of ...

To obtain information about the destruction of pepsin by regurgitation of duodenal juice into the stomach, the effect of pH on the stability of pepsin in human gastric juice was examined in vitro. At pH below 6 no inactivation of pepsin was found by mixing duodenal juice or sodium bicarbonate with gastric juice. Similar results were obtained if glycine was added to gastric juice and the pH raised carefully by NaOH. At pH 6–8 duodenal juice irreversibly inactivated pepsin much more rapidly than did sodium bicarbonate, possibly owing to digestion of pepsin by duodenal juice enzymes.

Acidification of the duodenum of healthy young subjects with 40 mEq of acid during 1 h resulted in a 45-percent inhibition of acid output in response to 0.15 μg/kg/h of pentagastrin, but had no effect on acid output stimulated with 6.0 μg/kg/h of pentagastrin. There was no significant effect of duodenal acidification on the total output of pepsin. Since secretin stimulates pepsin secretion, endogenous secretin alone cannot account for the inhibition of acid secretion. Duodenal acidification with the subjects own gastric acid had no significant effect on gastric secretion. The physiological significance of the effects described seems, therefore, uncertain.

Pure natural secretin (75 U) was administered twice as a rapid intravenous injection and twice as a continuous intravenous one-hour infusion, on different days to each of five healthy young volunteers. The bicarbonate response to infusion of secretin was higher and more sustained than the response to injection. The peak bicarbonate response occurred preferably after stopping the infusion. The bicarbonate response to injection of secretin showed the greatest individual variations whereas the reproducibility was similar for the two modes of administration.

A double-blind trial with oxyphencyclimine hydrochloride and placebo was carried out in 13 patients with dyspepsia, of whom 9 had previously had duodenal ulcers. Eleven of the patients remained for evaluation. Ten mg of oxyphencyclimine perorally decreased mean basal volume, acid and pepsin output by about 60 per cent. Acid and pepsin concentration and pepsin/acid ratio were not significantly affected. Oxyphencyclimine had no significantly better effect on the dyspeptic complaints than placebo. The effect of oxyphencyclimine was similar after 1 week and after 2 months of treatment.