Zetler G
Eur J Pharmacol. 1979 Nov 23;60(1):67-77. doi: 10.1016/0014-2999(79)90053-0.
Morphine, beta-endorphin, Met-enkephalin, and Leu-enkephalin antagonized intestinal actions of cholecystokinin octapeptide (CCK-8), caerulein, and pentagastrin in a manner partly suggesting physiologically competitive antagonism. Further, these acidic peptides (CCK-8, caerulein, pentagastrin) were much more sensitive to the actions of opioids than was angiotensin. Tetrodotoxin also caused changes in the concentration-effect curves, but these were different from the shifts due to the opioids and differentiated between CCK-8, caerulein, and pentagastrin. Naloxone did not modify the response to CCK-8 and caerulein, but completely abolished the antagonistic influence of the opioids. The potencies of morphine and the opioid peptides as antagonists of CCK-8, were of nearly the same order of magnitude. This and the presence in gut and brain of both CCK-like and opioid peptides suggests the hypothesis that these two groups of peptides interact on both myenteric and central nervous system receptors, and thus are directly involved in the regulation of both intestinal motility and satiety.
吗啡、β-内啡肽、甲硫氨酸脑啡肽和亮氨酸脑啡肽对胆囊收缩素八肽（CCK-8）、蛙皮素和五肽胃泌素的肠道作用具有拮抗作用，这种拮抗方式在一定程度上提示了生理竞争性拮抗。此外，这些酸性肽（CCK-8、蛙皮素、五肽胃泌素）对阿片类药物的作用比血管紧张素更为敏感。河豚毒素也会引起浓度-效应曲线的变化，但这些变化与阿片类药物引起的偏移不同，且能区分CCK-8、蛙皮素和五肽胃泌素。纳洛酮不会改变对CCK-8和蛙皮素的反应，但能完全消除阿片类药物的拮抗作用。吗啡和阿片肽作为CCK-8拮抗剂的效力几乎处于同一数量级。肠道和大脑中同时存在CCK样肽和阿片肽，这提示了这样一种假说，即这两类肽在肌间神经丛和中枢神经系统受体上相互作用，从而直接参与肠道运动和饱腹感的调节。
