Suzuki T, Kishimoto Y, Misawa M, Nagase H, Takeda F
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
Life Sci. 1999;64(1):PL1-7. doi: 10.1016/s0024-3205(98)00537-2.
We previously reported that the morphine-induced place preference was attenuated under inflammation produced by the unilateral injection of 2.5 % formalin (50 microl) into the hind paw of rats. In the present study, to elucidate the mechanism of this attenuation, the effects of pretreatment with delta- and kappa-opioid receptor antagonists, naltrindole (NTI) and nor-binaltorphimine (nor-BNI), on the development of the morphine-induced place preference under inflammation were examined in rats. Nor-BNI, but not NTI, eliminated the suppression of the morphine-induced place preference in inflamed groups. These results suggest that endogenous kappa-opioid systems may be activated in the presence of chronic inflammatory nociception; as a result, the development of morphine's rewarding effect may be suppressed under inflammation.
我们之前报道过，在大鼠后爪单侧注射2.5%福尔马林（50微升）所产生的炎症状态下，吗啡诱导的位置偏爱会减弱。在本研究中，为了阐明这种减弱的机制，我们检测了δ-阿片受体拮抗剂纳曲吲哚（NTI）和κ-阿片受体拮抗剂nor-环丙甲羟二氢吗啡酮（nor-BNI）预处理对炎症状态下吗啡诱导的位置偏爱形成的影响。nor-BNI而非NTI消除了炎症组中吗啡诱导的位置偏爱的抑制。这些结果表明，内源性κ-阿片系统可能在慢性炎性伤害性感受存在时被激活；因此，吗啡奖赏效应的形成在炎症状态下可能会受到抑制。
