Margolis R L, Moran T H, McHugh P R
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Peptides. 1989 Jan-Feb;10(1):157-61. doi: 10.1016/0196-9781(89)90092-2.
In previous studies of the rat gastrointestinal (GI) tract, we have demonstrated specific binding of cholecystokinin (CCK) to the pylorus and of bombesin (BN) to the gastric fundus, gastric antrum, duodenum, and ileum. We now present the results of an investigation of the in vitro response of the same regions of the rat GI tract to CCK-8 (the active octapeptide of CCK) and BN. Sections of rat fundus, antrum, pylorus, duodenum, and ileum were suspended in a Tyrode buffer and attached to an isometric pressure transducer in a longitudinal orientation. Dose-response curves to CCK-8 and BN were generated for each tissue. CCK-8 consistently induced a change only in pylorus, while BN induced a response from fundus, antrum and duodenum. With the exception of the lack of ileal response to BN, the regions of the rat GI tract which biologically respond (i.e., contract or relax) to CCK-8 or BN were the same regions in which we have located BN and CCK-8 binding sites. This correlation supports the hypothesis that GI function is modified by specified hormone-receptor interactions with these peptides.
在以往对大鼠胃肠道的研究中，我们已证明胆囊收缩素（CCK）与幽门有特异性结合，而蛙皮素（BN）与胃底、胃窦、十二指肠和回肠有特异性结合。我们现在展示大鼠胃肠道相同区域对CCK-8（CCK的活性八肽）和BN的体外反应的研究结果。将大鼠胃底、胃窦、幽门、十二指肠和回肠的切片悬浮于台氏缓冲液中，并纵向连接到等长压力换能器上。为每个组织生成CCK-8和BN的剂量反应曲线。CCK-8始终仅在幽门引起变化，而BN则引起胃底、胃窦和十二指肠的反应。除回肠对BN无反应外，大鼠胃肠道中对CCK-8或BN产生生物学反应（即收缩或舒张）的区域与我们定位到BN和CCK-8结合位点的区域相同。这种相关性支持了以下假设：胃肠道功能是通过这些肽与特定激素受体的相互作用而改变的。
