Research work · 1974
Inhibition of gastric secretion by the pyloric antrum
Malcolm H. Wheeler
Gut
Abstract
Progress report Inhibition of gastric secretion by the, pyloric antrum Early ConceptsThe observation that the secretion of hydrochloric acid and pepsin by the stomach was markedly increased after ingestion of a meal and virtually abolished during the interdigestive phase formed a basis for the suspicion that gastric secretion was regulated by the interaction of both stimulatory and inhibitory processes.The credit for recognizing an inhibitory mechanism regulating gastric secretion must go to Pavlov and his coworkers.It was Sokolovl, working at St Petersburg, who found that the introduction of 0.5 % hydrochloric acid into the canine stomach could diminish the output of acid from a Pavlov pouch in response to a meat meal.But, early opinion regarding the existence of an intragastric mechanism controlling gastric secretion was somewhat divided.Pavlov2 postulated that gastric juice was secreted at a constant acidity but that alkaline mucus altered the acidity either by dilution or neutralization.Otherss agreed with Pavlov but felt that acid secretion had to cease before any mucus effect could take place.MacLean and his coworkers4 5,6 believed that the strength of acid either placed in the stomach or secreted by the stomach itself and allowed to accumulate reached a certain level at which point the parietal cells ceased to secrete hydrochloric acid.Demonstrating this phenomenon in canine innervated fundic (Pavlov) pouches and the intact human stomach, they felt that gastric acidity having reached a certain level was then diluted by the secretion of fluid rich in neutral chlorides.These views were really modifications of the hypothesis advanced by Rose- mann7 that the gastric glands secreted acid and neutral chlorides in varying proportions according to the intensity of the stimulus.Evidence against such a mechanism however came from the work of Hollander8'9, who found a direct relationship between total chloride and acid concentration in the gastric juices over a considerable range of acidity.Some investigators attributed the regulation of gastric acidity to the neutralizing effect of alkaline fluid, either regurgitated from the duodenum10. 11or secreted by the pyloric mucosa12,13.Confirmation of Sokolov's finding that the intragastric acidity was of importance in regulating gastric acid secretion was provided by Wilhelmj and others14.Collecting acid via a gastric tube they found that the canine gastric secretory response to a test meal was inhibited by adding hydrochloric acid to the meal before its ingestion.This inhibition was proportional to the con- centration of hydrochloric acid added to the meal, being pronounced with 0.077 normal acid and virtually complete at a concentration of 0-1 normal.
DOI: 10.1136/gut.15.5.420