κ-阿片受体也会增加钾离子电导率。
kappa-Opioid receptors also increase potassium conductance.
作者信息
Grudt T J, Williams J T
机构信息
Vollum Institute, Oregon Health Sciences University, Portland.
出版信息
Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):11429-32. doi: 10.1073/pnas.90.23.11429.
Decrease of calcium conductance induced by opioid agonists has been reported by others for mu-, delta-, and kappa-opioid receptors. On the other hand, only mu- and delta-opioid receptors have been reported to increase potassium conductance. Intracellular recordings were made from guinea pig substantia gelatinosa neurons in a brain slice. A subset of cells (29 of 83) were hyperpolarized by the kappa-opioid receptor agonist U69593 with an EC50 of 23 nM. The kappa-opioid receptor antagonist norbinaltorphimine (10 nM) blocked the hyperpolarization by U69593 but had no effect on the mu-opioid hyperpolarization present in these cells. Naloxone (300 nM) shifted the U69593 dose-response curve to the right, giving an estimated Kd for naloxone of 7.5 and 8.1 nM measured in two cells. The hyperpolarization caused by U69593 was mediated by a potassium conductance as determined with voltage clamp experiments. This demonstrates, depending on the cell type, that all three major opioid receptors (mu, delta, and kappa) can increase potassium conductance as well as decrease calcium conductance.
其他人已报道，μ-、δ-和κ-阿片受体可被阿片类激动剂诱导钙电导降低。另一方面，据报道只有μ-和δ-阿片受体可增加钾电导。在脑片中对豚鼠脊髓背角胶状质神经元进行细胞内记录。一部分细胞（83个细胞中的29个）被κ-阿片受体激动剂U69593超极化，其半数有效浓度（EC50）为23 nM。κ-阿片受体拮抗剂纳洛酮啡肽（10 nM）可阻断U69593引起的超极化，但对这些细胞中存在的μ-阿片超极化无影响。纳洛酮（300 nM）使U69593剂量反应曲线右移，在两个细胞中测得纳洛酮的解离常数（Kd）估计值分别为7.5 nM和8.1 nM。电压钳实验表明，U69593引起的超极化是由钾电导介导的。这表明，取决于细胞类型，所有三种主要的阿片受体（μ、δ和κ）均可增加钾电导以及降低钙电导。
Zotero 插件