INTERNAL SECRETIONS OF THE GASTROINTESTINAL TRACT

Abstract

<h3>GASTRIC SECRETION—GASTRIN</h3> The secretory response of the gastric glands to a meal is due in part at least to a humoral mechanism. This has been amply demonstrated by means of transplanted pouches of the stomach.¹Just what proportion of the total secretory response is mediated humorally is difficult to determine. There is still no direct evidence to indicate what area or areas of the gastrointestinal tract are the site of action for the stimuli which give rise to the humoral phase. It has recently been shown,²contrary to earlier views, that the fundus is sensitive to chemical stimuli, although less so than the pyloric region. Whether a humoral mechanism is elicited from either area is not known. The weak point in the gastrin theory has been the difficulty in demonstrating that the humoral secretion is due to a hormone rather than to the absorption of secretagogues or to