Lonovics J, Guzman S, Devitt P G, Hejtmancik K E, Suddith R L, Rayford P L, Thompson J C
Endocrinology. 1981 May;108(5):1925-30. doi: 10.1210/endo-108-5-1925.
We have studied the effect of exogenous porcine pancreatic polypeptide (PP; 0.8 and 2.1 microgram/kg . h, iv) on endogenously stimulated pancreatic exocrine secretion in five pancreatic-fistula dogs. Plasma levels of cholecystokinin (CCK), secretin, and PP were measured in addition to pancreatic secretion of water, bicarbonate, and protein. Intraduodenal infusions of acid and a mixture of phenylalanine and tryptophan were used to stimulate hormone release. PP caused a dose-dependent inhibition of endogenously stimulated pancreatic secretion, whereas the release of CCK and secretin was not affected. Duodenal acidification and intraduodenal infusion of phenylalanine and tryptophan caused a significant release of PP. This study shows that: 1) PP suppresses pancreatic secretion by means of a mechanism that is probably direct; this effect is not mediated through inhibition of release of CCK or secretin, and 2) phenylalanine and tryptophan, both strong stimulants of CCK release, cause a substantial rise in PP in peripheral blood. The mechanism of PP release may involve CCK (in previous studies, we have shown a rise in circulating PP levels after iv CCK infusion).
我们研究了外源性猪胰多肽（PP；0.8和2.1微克/千克·小时，静脉注射）对五只胰瘘犬内源性刺激的胰腺外分泌的影响。除了测量胰腺分泌的水、碳酸氢盐和蛋白质外，还测定了血浆中胆囊收缩素（CCK）、促胰液素和PP的水平。十二指肠内输注酸以及苯丙氨酸和色氨酸的混合物用于刺激激素释放。PP对内源性刺激的胰腺分泌产生剂量依赖性抑制，而CCK和促胰液素的释放未受影响。十二指肠酸化以及十二指肠内输注苯丙氨酸和色氨酸导致PP显著释放。本研究表明：1）PP通过可能直接的机制抑制胰腺分泌；这种作用不是通过抑制CCK或促胰液素的释放介导的；2）苯丙氨酸和色氨酸这两种CCK释放的强刺激物会导致外周血中PP大幅升高。PP释放的机制可能涉及CCK（在先前的研究中，我们已表明静脉注射CCK后循环中PP水平会升高）。
