Ryan J, Cohen S
Am J Physiol. 1976 Mar;230(3):553-6. doi: 10.1152/ajplegacy.1976.230.3.553.
The effect of cholecystokinin (CCK), the octapeptide of cholecystokinin (CCK-OP), gastrin I, and secretin was studied on guinea pig gallbladder smooth muscle in vitro. Both CCK and CCK-OP stimulated gallbladder contraction, with CCK-OP being more potent. Gastrin I, over a wide dose range, had no effect on gallbladder contractility. Secretin alone also showed no effect on gallbladder smooth muscle but in combination with CCK-OP it produced a noncompetitive type of inhibition. Michaelis-Menten kinetics showed the calculated maximum response of the secretin plus CCK-OP interaction to be less than with CCK-OP alone. There was no change in the dose required to achieve half-maximal response, D50. These studies indicate that: a) CCK-OP has a greater effect on gallbladder contractility than CCK, b) gastrin I has no effect on gallbladder muscle tone, and c) secretin acts as a noncompetitive antagonist of CCK-OP. These findings suggest that gallbladder motor function may be determined in part by the interaction of secretin and CCK rather than solely in response to CCK.
研究了胆囊收缩素（CCK）、八肽胆囊收缩素（CCK-OP）、胃泌素I和促胰液素对豚鼠离体胆囊平滑肌的作用。CCK和CCK-OP均刺激胆囊收缩，CCK-OP的作用更强。在很宽的剂量范围内，胃泌素I对胆囊收缩性无影响。单独的促胰液素对胆囊平滑肌也无作用，但与CCK-OP联合使用时会产生非竞争性抑制。米氏动力学表明，促胰液素加CCK-OP相互作用的计算最大反应小于单独使用CCK-OP时。达到半数最大反应所需的剂量（D50）没有变化。这些研究表明：a）CCK-OP对胆囊收缩性的影响大于CCK；b）胃泌素I对胆囊肌张力无影响；c）促胰液素作为CCK-OP的非竞争性拮抗剂起作用。这些发现提示胆囊运动功能可能部分由促胰液素和CCK的相互作用决定，而不是仅对CCK作出反应。
