大鼠左心房肌单相动作电位的增龄性变化  

Age-associated change of monophasic action potential of left atrial muscle in rat

作　　者：丁文茂[1] 黄从新[1] 李岚[1] 

机构地区：[1]武汉大学人民医院心内科,湖北武汉430060

出　　处：《中华老年心脑血管病杂志》2005年第2期124-126,共3页Chinese Journal of Geriatric Heart,Brain and Vessel Diseases

摘　　要：目的　研究年龄对大鼠左心房肌单相动作电位(monophasicactionpotential,MAP)的影响。方法　选取实验用Wistar大鼠4 0只,按出生年龄分为青年组、成年组、中年组及老年组,每组10只。体外Langendorff灌流心脏,右心室刺激。分别记录各组左心房肌在4 0 0ms刺激周长下动作电位复极到90 %、5 0 %及2 0 %时的单相动作电位时程(MAPD90 )、MAPD50 、MAPD2 0 和心房有效不应期,以及在不同刺激周长下的MAPD90 、MAPD50 、MAPD2 0 。结果　MAPD各时相和有效不应期都随着年龄的增加而出现延长(P <0 .0 1) ;但老年组缩短。在同一年龄组中,刺激频率增加使动作电位时程都相应缩短,以MAPD90 明显;中年组MAPD改变明显。结论　年龄是影响心脏电活动重要的独立因素之一。Objective To study the effect of age on monophasic action potential （MAP） of atrial muscle.Methods According to their age, Wistar rots （ n = 40） were divided into 4 groups： young group, adult group, middle-aged group and old group. The MAP at 20% （MAPD20）,50% （MAPD50） and 90% （MAPD90） repolarization and effective refractory period （ERP） of left atrium at the same pacing cycle length （S1 S1 = 400ms）, and the MAPD at other shorter pacing cycle length were assayed for each group. Result With age advancing, all phases of MAP and ERP were prolonged （ P 〈 0.01 ）, while the MAPD and ERP of left atrial muscle in old group became short. In the same age group, the MAPD shortened with pacing frequency increasing.The change in middle-aged group was marked, and mainly appeared in MAPD90. Conclution Age is an important factor influencing heart electrophysiology.

关 键 词：电生理学 电位测定法 心肌 年龄因素 大鼠 

分 类 号：R541.7[医药卫生—心血管疾病]