不同温度对离体大鼠心室肌单相动作电位、电兴奋性的影响  

Effects of different temperatures on monophasic action potential and myocardial electrical excitability in isolated rat hearts

作　　者：王贵龙 高鸿 王子君 李伟超 李华宇 代东君 余晓旭 符校魁 刘艳秋 WANG Guilong;GAO Hong;WANG Zijun;LI Weichao;LI Huayu;DAI Dongjun;YU Xiaoxu;FU Xiaokui;LIU Yanqiu(Guizhou Medical University,Guiyang 550004,China)

机构地区：[1]贵州医科大学麻醉学院,贵阳550004 [2]贵州医科大学附属医院

出　　处：《山东医药》2019年第3期47-50,共4页Shandong Medical Journal

摘　　要：目的观察不同温度对离体大鼠心室肌单相动作电位、电兴奋性的影响。方法 24只健康成年雄性SD大鼠随机分为C组、H1组、H2组各8只,腹腔注射麻醉后迅速开胸取出心脏,制备Langendorff离体心脏灌注模型,经K-H液平衡灌注15 min,C组继续灌注37℃的K-H液30 min,H1组继续灌注35℃的K-H液30 min,H2组继续灌注32℃的K-H液30 min。于平衡灌注末(T0)、继续灌注30 min(T1)时点记录HR及左心室前壁外膜层、中层、内膜层心肌心室肌单相动作电位(MAP),计算MAP复极90%的时程(MAPD90)。T1时行程控刺激并测量有效不应期(VERP)及电传导速度(CV)。另记录心律失常发生率。结果与同组T0时点、C组、H1组比较,H2组T1时点HR减慢(P均<0.05)。与同组T0时点比较,H2组T1时点外膜、中膜、内膜MAPD90延长(P均<0.05);与C组、H1组比较,H2组外膜、中膜、内膜MAPD90延长(P均<0.05)。与C组、H1组比较,H2组CV减慢、VERP延长(P均<0.05)。与C组、H1组比较,H2组心律失常发生率高(P均<0.05)。结论 37、35℃的温度对离体大鼠心脏MAP、电兴奋性无明显影响,而32℃低温可延长心室肌MAPD90、降低离体大鼠心脏电兴奋性,这可能是低温下心律失常发生风险增加的机制。Objective To study the effects of different temperatures on monophasic action potential(MAP)and myocardial electrical excitability in isolated rat hearts.Methods Twenty-four healthy adult male SD rats were randomly divided into the groups C,H1,and H2.After intraperitoneal injection of anesthesia,the hearts were quickly removed and the Langendorff isolated heart perfusion model was prepared.The model was perfused with K-H solution for 15 minutes,and then the rats in the group C continued to be perfused with 37℃K-H solution for 30 min,the H1 group with 35℃K-H solution and the H2 group with 32℃K-H solution.Heart rate(HR)and MAP were recorded at the end of balanced perfusion(T0)and continuous perfusion of 30 min(T1).The time course of 90%repolarization of MAP(MAPD90)was calculated.The effective refractory period(VERP)and conduction velocity(CV)were measured at T1 by programmed electrical stimulation(PES).The incidence of arrhythmia was also recorded.Results Compared with T0,HR in the groups C,H1,and H2 decreased at T1(P<0.05).Compared with T0,the MAPD90 of epicardium,mid-layer myodardium and endocardium prolonged at T1 in the groupH2(P<0.05).Compared with the groups C and H1,the MAPD90 of epicardium,midlayer myodardium and endocardium prolonged at T1 in the groupH2(P<0.05).Compared with the groups C and H1,CV slowed down and VERP prolonged in the groupH2(P<0.05).Compared with the groups C and H1,the incidence of arrhythmia was higher in the groupH2(P<0.05).Conclusion Temperature at 37℃and 35℃has no significant effect on the MAP and electrical excitability of isolated rat hearts,but low temperature of 32℃can prolong the MAPD90 of ventricular myocardium and decrease the electrical excitability of isolated rat hearts,and this may be the mechanism of increased risk of arrhythmia under low temperature.

关 键 词：心室肌单相动作电位 心室肌电兴奋性 心律失常 

分 类 号：R331.3[医药卫生—人体生理学]