%0 Journal Article
%T Cholecystokinin receptor-1 mediates the inhibitory effects of exogenous cholecystokinin octapeptide on cellular morphine dependence
%A Di Wen
%A Chung-ling Ma
%A Ya-jing Zhang
%A Yan-xin Meng
%A Zhi-yu Ni
%A Shu-jin Li
%A Bin Cong
%J BMC Neuroscience
%D 2012
%I BioMed Central
%R 10.1186/1471-2202-13-63
%X Forty-eight hours after treating SH-SY5Y cells with morphine (10£¿¦ÌM), naloxone (10£¿¦ÌM) induced a cAMP overshoot, indicating that cellular morphine dependence had been induced. The CCK receptor and endogenous CCK were up-regulated after chronic morphine exposure. The CCK2 receptor antagonist (LY-288,513) at 1¨C10£¿¦ÌM inhibited the naloxone-precipitated cAMP overshoot, but the CCK1 receptor antagonist (L-364,718) did not. Interestingly, CCK-8 (0.1-1£¿¦ÌM), a strong CCK receptor agonist, dose-dependently inhibited the naloxone-precipitated cAMP overshoot in SH-SY5Y cells when co-pretreated with morphine. The L-364,718 significantly blocked the inhibitory effect of exogenous CCK-8 on the cAMP overshoot at 1¨C10£¿¦ÌM, while the LY-288,513 did not. Therefore, the CCK2 receptor appears to be necessary for low concentrations of endogenous CCK to potentiate morphine dependence in SH-SY5Y cells. An additional inhibitory effect of CCK-8 at higher concentrations appears to involve the CCK1 receptor.This study reveals the difference between exogenous CCK-8 and endogenous CCK effects on the development of morphine dependence, and provides the first evidence for the participation of the CCK1 receptor in the inhibitory effects of exogenous CCK-8 on morphine dependence.
%K Cholecystokinin octapeptide
%K CCK1 receptor
%K CCK2 receptor
%K Morphine
%K Cellular dependence
%K cAMP overshoot
%U http://www.biomedcentral.com/1471-2202/13/63/abstract