Figlewicz D P, Nadzan A M, Sipols A J, Green P K, Liddle R A, Porte D, Woods S C
Department of Psychology, University of Washington, Seattle 98195.
Am J Physiol. 1992 Oct;263(4 Pt 2):R863-7. doi: 10.1152/ajpregu.1992.263.4.R863.
Intraventricular cholecystokinin COOH-terminal octapeptide (CCK-8) decreases meal size in the meal-trained baboon. In the present study, we tested whether this action is mediated by CCK-A receptors, CCK-B receptors, or both. Intraventricular administration of the selective CCK-A receptor agonist A71623 at 1 and 10 nmol/kg suppressed 30-min meal size 69 +/- 22% and 75 +/- 7%, respectively. Additionally, intraventricular A71623 was equipotent to CCK-8 at 1 nmol/kg (% suppression of meal by CCK = 59 +/- 17). However, intraventricular administration of the CCK-B receptor agonist A63387 at 10 nmol/kg had no effect on 30-min meal size (% suppression = 18 +/- 29). Intravenous administration of 10 nmol/kg A71623 did not result in an alteration of meal size, but prandial plasma insulin and glucose responses were delayed and blunted. Basal plasma insulin levels doubled after intravenous administration of A71623. Both behavioral and metabolic responses to A71623 in the baboon are virtually identical to those we have previously observed after CCK-8 treatment. Thus we conclude that the predominant receptor population with which intraventricular CCK-8 interacts are type-A CCK receptors that are accessible to the ventricular system of the baboon.
脑室内注射胆囊收缩素羧基末端八肽（CCK-8）可减少经进食训练的狒狒的进食量。在本研究中，我们测试了这种作用是由CCK-A受体、CCK-B受体介导，还是由两者共同介导。脑室内注射选择性CCK-A受体激动剂A71623，剂量为1和10 nmol/kg时，分别使30分钟的进食量减少了69±22%和75±7%。此外，脑室内注射1 nmol/kg的A71623与CCK-8等效（CCK对进食量的抑制百分比=59±17）。然而，脑室内注射10 nmol/kg的CCK-B受体激动剂A63387对30分钟的进食量没有影响（抑制百分比=18±29）。静脉注射10 nmol/kg的A71623不会导致进食量改变，但餐后血浆胰岛素和葡萄糖反应延迟且减弱。静脉注射A71623后，基础血浆胰岛素水平翻倍。狒狒对A71623的行为和代谢反应与我们之前观察到的CCK-8治疗后的反应几乎相同。因此，我们得出结论，脑室内CCK-8相互作用的主要受体群体是狒狒脑室系统可接触到的A型CCK受体。
