培养大鼠心肌细胞阿片受体分型及其功能

Identification of Subtype of Opiate Receptor in Cultured Rat Cardiac Myocytes and its Function

本工作采用不合神经组织的体外原代培养大鼠乳鼠心肌细胞制备,研究了几种阿片物质对心肌细胞搏动功能的直接作用特点。我们的工作表明,除了神经组织,心肌细胞膜上也存在阿片类物质结合位点,具有一般受体特性,且以κ受体为主的多种亚型共存,在构型上有正协同作用,吗啡,α-CAO可以减缓细胞自发搏动频率,β-内啡肽和甲硫脑啡肽则提高搏动频率。纳洛酮有其对抗作用。提示阿片类物质可通过其特异性受体发挥对心肌细胞自发搏动功能的调控。

To datermine whether opiates have direct effects on myocardium and the presence of opiate receptors. We studied the effects of a number of opiates on contractil activity in spontaneously beating monolayer cultures of neonatal rat ventricularcells, a preparation devoid of intact neural elements. Morphine and α-CAO grately decresed the spontaneously beating rate in a dose-related manner. In contrast,β-Endorphin and Enkephalin incresed the beating rate, and when the observation of time prolonged, the arrhythmia occured. Naloxone reversed all the action of opiates observed above. Analysis of 3H-Etorphine binding cuvers under equilibrium conditions indicated that 3H-Etorphine bound specifically to membranes of cultured heart cell with KD=3.18 ±0.57nmol/L and Bmax=62 .5±7.6fmol/mg .pr. Analysis of competitive binding revealed the presence of k-receptor of opiate dominantly in the memberanes of cultured heart cells.These novel result suggeste that there are different direct effects of opiates on myocardial cells via specific o.piate receptors.