Negus S S, Mello N K
McLean Hospital--Harvard Medical School, Belmont, Massachusetts 02178, USA.
Exp Clin Psychopharmacol. 1999 Nov;7(4):307-17. doi: 10.1037//1064-1297.7.4.307.
This study examined the effects of the kappa opioid agonists U50,488 and ethylketocyclazocine (EKC) on cocaine discrimination in rhesus monkeys trained to discriminate cocaine (0.4 mg/kg) from saline. Administration of U50,488 and EKC alone produced primarily saline-appropriate responding. Kappa agonist pretreatments produced variable effects on cocaine discrimination across monkeys, attenuating the discriminative stimulus effects of cocaine in some monkeys, but either having no effect on cocaine discrimination or enhancing the discriminative stimulus effects of cocaine in other monkeys. The effects of kappa agonists on cocaine discrimination were reversed by pretreatment with the opioid antagonist naloxone (1.0 mg/kg). These results indicate that kappa agonists do not consistently block the discriminative stimulus effects of cocaine in rhesus monkeys.
本研究考察了κ阿片受体激动剂U50,488和乙基酮环唑辛（EKC）对经训练能区分可卡因（0.4毫克/千克）和生理盐水的恒河猴可卡因辨别能力的影响。单独给予U50,488和EKC主要产生与生理盐水相符的反应。κ激动剂预处理对不同猴子的可卡因辨别能力产生了不同影响，在一些猴子中减弱了可卡因的辨别刺激效应，但在其他猴子中对可卡因辨别能力要么没有影响，要么增强了可卡因的辨别刺激效应。阿片受体拮抗剂纳洛酮（1.0毫克/千克）预处理可逆转κ激动剂对可卡因辨别能力的影响。这些结果表明，κ激动剂并不能始终如一地阻断恒河猴中可卡因的辨别刺激效应。
