异丙酚对兔未成熟心室肌细胞动作电位及L型钙通道电流的影响  

Effects of propofol on action potential and L-type calcium current of immature cardiac myocytes in bunnies

作　　者：王龙[1] 周青山[1] 涂仲凡[2] 王希[3] 黄海波[1] 刘先义[1] 

机构地区：[1]武汉大学人民医院麻醉科,430060 [2]武汉大学人民医院心胸外科,430060 [3]武汉大学人民医院心内科,430060

出　　处：《中华小儿外科杂志》2005年第2期97-100,共4页Chinese Journal of Pediatric Surgery

摘　　要：目的探讨异丙酚对心血管系统抑制作用的机制,以及对缺血心肌保护作用的分子学机制,为临床合理安全应用异丙酚提供新的理论依据.方法采用改良的Taniguchi法分离3～4周龄幼兔心室肌细胞.随机选取单个心室肌细胞,按Hamill法用膜片钳全细胞记录技术记录两种浓度异丙酚(50μmol/L,250μmol/L)灌流前、后的单个心室肌细胞的AP及ICal的变化.结果与给药前相比,两种浓度异丙酚(50 μmol/L,250μmol/L)灌流均能明显缩短心室肌细胞动作电位时程(APD)(P分别＜0.05和＜0.01),高浓度异丙酚(250μmol/L)较低浓度异丙酚(50 μmol/L)更能缩短APD(P＜0.05),但不改变动作电位幅度(APA);与给药前相比,低、高两种浓度异丙酚均使各指令电位下ICal明显减小,分别使钳制电位+10 mV时ICal峰值由对照组的769.6±83.2 pA(n=6)减小至573.4±25.1 pA(P＜0.05,n=6)和368.1±31.4 pA(P＜0.05,n=6).结论异丙酚能明显减小未成熟心室肌细胞ICal,从而降低细胞内Ca2+浓度,抑制兴奋收缩耦联过程.Objective The purpose of the research is to observe the effects of propofol on action potential and L type Calcium current of single immature cardiac myocytes and to study the possible mechanisms of the negative inotropic effects. Methods Cardiac myocytes were enzymatically isolated from 3-4 week old healthy New Zealand white rabbits. The effects of propofol(50μmol/L or 250μmol/L) on action potential(AP), L type calcium current(I_~Cal ) was studied with the whole cell patch clamp technique. The AP was recorded at current clamp with 600pA, I_~Cal was elicited by progressively depolarizing cells from 30 to +60mV. Results Compared with baseline, the action potential duration (APD) was shortened significantly after 50μmol/L or 250μmol/L propofol perfusion, but there was no change in action potential amplitude (APA). I_~Cal at all command potential decreased in cardiac myocytes receiving 50μmol/L or 250μmol/L~ propofol perfusion, the peak I_~Cal decreased from ~769.6 ±~83.2 pA in control to ~573.4 ±~25.1 pA or ~368.1 ±~31.4 pA, respectively(P<~0.05 ,n=6). Conclusions These findings suggest that the negative inotropic action of propofol is at least partly due to the decreased I_~Cal.

关 键 词：异丙酚 单个心室肌细胞 未成熟 动作电位 L型钙通道 灌流 给药 峰值 低浓度 指令 

分 类 号：R965[医药卫生—药理学]