Rademacher David J, Steinpreis Rhea E
Department of Psychology, University of Wisconsin-Milwaukee, 224 Garland Hall, 2441 East Hartford Avenue, Milwaukee, WI 53211, USA.
Neurosci Lett. 2002 Nov 8;332(3):159-62. doi: 10.1016/s0304-3940(02)00950-3.
Administration of the non-selective opioid receptor antagonists, naloxone and naltrexone, attenuate the rewarding effects of cocaine. The relative contributions of specific opioid receptor subtypes that underlie this effect have not been well characterized. Administration of 20.0 mg/kg cocaine resulted in a conditioned place preference. Pretreatment with 20.0 mg/kg but neither 10.0 nor 1.0 mg/kg of the selective mu(1)-opioid receptor antagonist, naloxonazine, blocked cocaine-induced conditioned place preference. On the days in which rats received cocaine only, locomotor behavior was elevated. Pretreatment with the selective mu(1)-opioid receptor antagonist, naloxonazine, regardless of dose, had no effect on cocaine-induced hyperlocomotion. These findings indicate that the rewarding effects of cocaine can be blocked solely by mu(1)-opioid receptor antagonism and are consistent with the view that the locomotor and rewarding effects of drugs can be dissociated.
给予非选择性阿片受体拮抗剂纳洛酮和纳曲酮可减弱可卡因的奖赏效应。介导此效应的特定阿片受体亚型的相对贡献尚未得到充分表征。给予20.0mg/kg可卡因会导致条件性位置偏爱。用20.0mg/kg而非10.0mg/kg或1.0mg/kg的选择性μ(1)阿片受体拮抗剂纳洛嗪预处理，可阻断可卡因诱导的条件性位置偏爱。在大鼠仅接受可卡因的日子里，运动行为增强。用选择性μ(1)阿片受体拮抗剂纳洛嗪预处理，无论剂量如何，对可卡因诱导的运动亢进均无影响。这些发现表明，可卡因的奖赏效应可仅通过μ(1)阿片受体拮抗作用来阻断，这与药物的运动和奖赏效应可分离的观点一致。
