Effects of Somatostatin on Gastric Secretion and Gastrin Release in Man

Abstract

Somatostatin, a recently synthesized hypothalamic growth hormone release-inhibiting factor (GIF), was used in the cyclic and linear form. In all subjects studied, the cyclic GIF inhibited gastrin secretion during basal conditions as well as during a standard food stimulus, with immediate rebound after the infusion was stopped. Similar responses were observed in a hypophysectomized patient, indicating that this effect of GIF was independent of suppression of growth hormone secretion. Cyclic and linear GIF, when administered in normal subjects during an infusion of synthetic human gastrin I, almost totally suppressed gastric secretion. The results indicate that GIF is a potent inhibitor of gastric secretion and gastrin release.

Gastric mammalian target of rapamycin signaling, hormone production and energy metabolism

“…Only 1/3 of gastrin cells contain mTOR signaling molecules, suggesting that regulation of gastrin synthesis and secretion may involve multiple mechanisms [20] . Somatostatin: Somatostatin was originally isolated as a hypothalamic somatotropin-release inhibiting factor [49] and was soon found to potently inhibit the secretion of multiple hormones, including gastrin [50] . However, production of somatostatin appears not to be affected by gastric mTOR.…”

Somatostatin and the Stomach

“…It has been found that the acid secretion stimulated by a small dose of pentagastrin is inhibited more markedly than that stimulated by a larger dose of pentagastrin, suggesting competitive kinetics [12], In hibition of gastric secretions by somatostatin appears to be independent of vagal integrity, mucosal blood flow, and circulating serum gastrin. This conclusion is reached from findings in vagally innervated and denervated stomach pouches in which somatosta tin reduced acid and pepsin secretion equally [13] and in which mucosal blood flow did not change during somatostatin in fusion [12]. Food-stimulated gastric secre tion appears most sensitive to the inhibitory action of somatostatin, probably due to its dual effects, suppression of both the release and the action of GI hormones involved in the postprandial secretory activities of the oxyntic glands [12,14].…”

Effects of Somatostatin on Human Satiety

“…For example, direct inhibition of human parietal cell secretion of acid [9,10], pancreatic acinar cell secre tion of enzymes [11], p-cell secretion of insulin [7], and primate resting lower esophageal sphincter pressure [12] have been reported. Furthermore, it has been demon strated that exogenous ST inhibits motility functions in the human gastrointestinal tract [13].…”