Appleyard S M, Patterson T A, Jin W, Chavkin C
Neurobiology Graduate Program, University of Washington, Seattle 98195-7280, U.S.A.
J Neurochem. 1997 Dec;69(6):2405-12. doi: 10.1046/j.1471-4159.1997.69062405.x.
Antipeptide antibodies against the kappa-opioid receptor were used to test whether acute or chronic exposure to kappa agonists altered the phosphorylation state of the kappa-opioid receptor. Immunoprecipitation of the kappa receptor from guinea pig hippocampal slices preincubated in [32P]orthophosphoric acid revealed a basal phosphorylation of the kappa-opioid receptor. The amount of 32P incorporation into the receptor was increased following a 75-min treatment with the kappa agonist U50,488H. This effect was blocked by the selective kappa receptor antagonist norbinaltorphimine. The time course of this change in the phosphorylation state of the receptor correlated with a desensitization of the electrophysiological response to kappa agonists measured in the dentate gyrus of hippocampal slices. The phosphorylation state of the kappa-opioid receptor was also elevated in brain slices from guinea pigs made tolerant to U50,488H by 5 days of continuous exposure and then maintained in kappa agonist to avoid acute opiate withdrawal. The results of this study show that the kappa-opioid receptor was phosphorylated in an agonist-dependent manner in brain slices taken from untreated and U50,488H-tolerant animals.
抗κ-阿片受体的抗肽抗体被用于检测急性或慢性暴露于κ激动剂是否会改变κ-阿片受体的磷酸化状态。从预先在[32P]正磷酸中孵育的豚鼠海马切片中免疫沉淀κ受体，显示κ-阿片受体存在基础磷酸化。在用κ激动剂U50,488H处理75分钟后，受体中32P的掺入量增加。这种效应被选择性κ受体拮抗剂诺宾那托啡阻断。受体磷酸化状态的这种变化的时间进程与在海马切片齿状回中测量的对κ激动剂的电生理反应脱敏相关。在通过连续暴露5天对U50,488H产生耐受性然后维持在κ激动剂中以避免急性阿片戒断的豚鼠脑切片中，κ-阿片受体的磷酸化状态也升高。这项研究的结果表明，在从未经处理和对U50,488H产生耐受性的动物获取的脑切片中，κ-阿片受体以激动剂依赖性方式被磷酸化。
