Effect of Digestion on Gastric and Pancreatic Secretion Regulated by Gastrointestinal Hormones

众所周知，胰腺酶在肠道消化中具有最重要的作用，胃和胰腺的分泌受消化产物的调节。本研究探讨了胃肠激素介导的胃肠营养物质（蛋白质和脂肪）对大鼠胃和胰腺分泌的调节作用。1.研究了十二指肠内脂肪（脂肪、脂肪酶消化的脂肪和脂肪酸）对胃酸分泌和胃泌素释放的影响。虽然脂肪酶消化的脂肪和脂肪酸抑制胃酸分泌和胃泌素释放，脂肪下转移的胰液的抑制作用失败。说明脂肪酶消化脂肪是十二指肠内脂肪抑制胃酸分泌的必要条件。2.研究了十二指肠内长链和中链甘油三酯（LCT和MCT）的胰腺刺激作用。在十二指肠有胰液存在的情况下，LCT刺激胰腺分泌和CCK释放，但不受MCT的影响，在胰液分流的情况下，LCT不能刺激胰腺分泌。因此，LCT被胰液消化是刺激胰腺分泌所必需的。3.研究了十二指肠内蛋白质（酪蛋白）和氨基酸对胰腺分泌及促胰液素和CCK释放的影响。酪蛋白刺激CCK释放和酶分泌。另一方面，氨基酸刺激分泌素释放和碳酸氢盐分泌。因此，蛋白质消化影响激素释放和胰腺分泌。4.十二指肠内施用氨基酸以及脂肪，抑制胃酸分泌和胃泌素释放。氨基酸的抑制作用是由氨基酸释放的内源性分泌素介导的。

It has been well known that pancreatic enzymes have a most important role in the intestinal digestion, and gastric and pancreatic secretion is regulated by digestive products. We investigated the regulation of gastric and pancreatic secretion in response to intestinal nutrients (protein and fat) mediated by gastrointestinal hormones in rats.1.Effect of intraduodenal fat (fat, lipase-digested fat, and fatty acid) on gastric acid secretion and gastrin release was studied. Although lipase-digested fat and fatty acid inhibited acid secretion and gastrin release, fat failed the inhibitory effect under diversion of pancreatic juice. It means that fat digestion by lipase is necessary for the inhibitory action of intraduodenal fat on gastric acid secretion.2.Pancreatic stimulatory effect of intraduodenal long-and medium-chain trigyceride (LCT and MCT) was studied. Pancreatic secretion and CCK release was stimulated by LCT under pancreatic juice existed in the duodenum, but not affected by MCT.Under pancreatic juice diversion, LCT failed to stimulate pancreatic secretion. Thus, LCT digestion by pancreatic juice is necessary for stimulating pancreatic secretion.3.Effect of intraduodenal protein (casein) and amino acids on pancreatic secretion and release of secretin and CCK was studied. Casein protein stimulated CCK release and enzyme secretion. On the other hand, amino acids stimulated secretin release and bicarbonate secretion. Thus, protein digestion affects hormone release and pancreatic secretion.4.Intraduodenal administration of amino acids as well as fat, inhibited gastric acid secretion and gastrin release. The inhibitory action of amino acids was mediated by endogenous secretin released by amino acids.