Barr G A, Paredes W, Erickson K L, Zukin R S
Brain Res. 1986 Oct;394(2):145-52. doi: 10.1016/0165-3806(86)90090-8.
The prototypic kappa opiate ketocyclazocine produced robust analgesia in 10-day-old rats in the tail-flick nociceptive test. The kappa-opiate behavioral response coincided with the onset of a rapid rise to adult levels in brain kappa receptor site density. In contrast, morphine (prototypic mu opiate) was without marked effect until 14 days of age. The period of rapid mu receptor increase did not take place until days 14-16, which was after kappa receptor levels had already plateaued. Further, there was no or incomplete cross-tolerance between ketocyclazocine and morphine at 14 days of age. The present study, therefore, establishes a role for the kappa binding site in thermal analgesia in the tail flick test and differentiates its ontogenetic pattern from that of the mu receptor.
原型κ阿片类药物酮环唑辛在10日龄大鼠的甩尾伤害感受性试验中产生了强烈的镇痛作用。κ阿片类行为反应与脑κ受体位点密度迅速上升至成年水平的开始时间相吻合。相比之下，吗啡（原型μ阿片类药物）直到14日龄才有明显作用。μ受体快速增加的时期直到14 - 16日才出现，这是在κ受体水平已经趋于平稳之后。此外，在14日龄时，酮环唑辛和吗啡之间不存在或仅有不完全的交叉耐受性。因此，本研究确定了κ结合位点在甩尾试验热镇痛中的作用，并将其个体发生模式与μ受体的模式区分开来。
