Effect of Secretin and Cholecystokinin on Gastric Emptying and Gastric Secretion in Man

Abstract

The effects of secretin and cholecystokinin on gastric emptying and gastric secretion of acid were studied in man. The intravenous administration of secretin in a dose of 1 U per kg of body weight caused a significant decrease in gastric emptying measured 15 min after the intragastric instillation of 500 ml of normal saline solution in 10 subjects. The mean percentage of gastric emptying following the administration of secretin was 40.7% as compared with a control value of 85.2%. A decrease in gastric emptying of similar magnitude was observed in 9 subjects following the intravenous administration of cholecystokinin in a dose of 0.5 Ivy dog unit per kg. Gastric secretion of acid was stimulated by a continuous intravenous infusion of pentagastrin or histamine acid phosphate and both gastric and duodenal contents were collected simultaneously. The intravenous administration of secretin in a dose of 1 U per kg resulted in marked inhibition of acid secretion stimulated by either pentagastrin in a dose of 0.12 μg per kg per hr or histamine acid phosphate in a dose of 0.02 mg per kg per hr in 10 subjects. Secretin appeared to have a greater inhibitory effect on acid secretion stimulated by pentagastrin than on histamine-stimulated secretion. Inhibition of acid secretion similar in magnitude to that produced by secretin was observed following the administration of cholecystokinin in a dose of 1 U per kg. Gastric secretion of acid stimulated by pentagastrin in a dose of 6 μg per kg per hr or histamine acid phosphate in a dose of 0.04 mg per kg per hr, however, was not influenced by the same dose of secretin in a dose similar to that which inhibited smaller doses of these stimuli.