右美托咪定对大鼠心室肌细胞动作电位时程的影响及α2受体在其中的作用  

Effect of dexmedetomidine on action potential duration of rat ventricular myocytes and the role of α2 receptors

出　　处：《中华麻醉学杂志》2017年第10期1247-1249,共3页Chinese Journal of Anesthesiology

摘　　要：目的 评价右美托咪定对大鼠心室肌细胞动作电位时程（APD）的影响及α2受体在其中的作用.方法 酶解法急性分离SD大鼠心室肌细胞18个,采用随机数字表法分为3组（n=6）：右美托咪定组（D组）、育亨宾组（Y组）和右美托咪定＋育亨宾组（DY组）.先给予单独台式液灌流2 min,采用全细胞膜片钳技术记录 APD90,随后 D 组、Y 组和 DY 组分别采用含有右美托咪定10^-9 mol∕L、育亨宾10-6mol∕L和右美托咪定10^-9mol∕L＋育亨宾10^-6mol∕L的台式液灌流2 min,记录APD90,计算APD90变化百分比.结果 与单独灌流比较,D组心室肌细胞APD90延长（P〈0.01）,Y组和DY组心室肌细胞APD90差异无统计学意义（P〉0.05）;与D组比较,Y组和DY组心室肌细胞APD90变化百分比降低（P〈0.05）.结论 右美托咪定可延长大鼠心室肌细胞 APD,其机制与激动 α2受体有关.Objective To evaluate the effect of dexmedetomidine on action potential duration （APD）of rat ventricular myocytes and the role of α2receptors. Methods Eighteen ventricular myocytes acutely isolated from Sprague-Dawley rats by enzymatic hydrolysis were divided into 3 groups（n=6 each） using a random number table： dexmedetomidine group（D group）, yohimbine group（Y group）and dexmedetomidine plus yohimbine group（DY group）. Isolated ventricular myocytes were first perfused for 2 min with Tyrode′s solution alone, and APD at 90% repolarization（APD90）was recorded using whole-cell patch-clamp technique. D, Y and DY groups were subsequently perfused for 2 min with Tyrode′s solution containing dexmedetomidine 10^-9mol∕L, yohimbine 10^-6mol∕L, and dexmedetomidine 10^-9mol∕L plus yo-himbine 10-6mol∕L, respectively, and APD90was recorded. The percentage of changes in APD90was calcu-lated. Results Compared with the isolated ventricular myocytes perfused with Tyrode′s solution alone, APD90of ventricular myocytes was significantly prolonged in group D（P〈0. 01）, and no significant change was found in APD90of ventricular myocytes in Y and DY groups（P〉0.05）. The percentage of changes in APD90of ventricular myocytes was significantly shortened in group DY and group Y when com-pared with group D（P〈0.05）. Conclusion Dexmedetomidine can prolong APD90of rat ventricular myo-cytes, and the mechanism is related to activating α2receptors.

关 键 词：右美托咪啶 肌细胞 心脏 受体 肾上腺素能α2 动作电位 

分 类 号：R614[医药卫生—麻醉学]