腺苷对心肌梗死兔非梗死区心室细胞快钠通道跨壁异质性的影响及其离子机制  

Effects of adenosine on the rabbit sodium current transmural heterogeneity of action potential after myocardial infarction and its ionic mechanism

作　　者：姚浩洁[1] 齐书英[2] 何振山[2] 崔俊玉[2] 史力生[2] 

机构地区：[1]河北省廊坊市人民医院心内科,河北廊坊065000 [2]白求恩国际和平医院心内科

出　　处：《中国老年学杂志》2006年第5期656-659,共4页Chinese Journal of Gerontology

摘　　要：目的探讨腺苷(Ado)对急性心肌梗死(AM I)后非梗死区心肌细胞快钠通道电流(INa)跨壁异质性的影响。方法36只兔随机分为4组,其中两组建立AM I动物模型,分别为Ado组和M I组,其余两组为正常对照组和假手术对照组。1个月后,用膜片钳技术研究左室非梗死区3层心肌细胞INa的改变。结果正常对照组左室3层细胞的钠电流存在异质性,中层心肌(M)细胞的峰值INa是心内膜层(Endo)和心外膜层(Ep i)的2倍多;M细胞的INa失活最快;对照组与假手术组无明显差别。M I组3层细胞的INa电流密度下降,以M细胞变化最显著,INa稳态失活曲线均左移,以Ep i变化最显著;Ado组3层细胞INa电流密度下降显著,稳态失活曲线左移最明显并趋向一致,失活后恢复曲线均恢复减慢。结论左室心肌细胞的INa存在跨壁异质性;AM I对INa的跨壁异质性有明显影响;而Ado减弱AM I后INa的跨壁异质性。Objective To study the transmural heterogeneity of sodium currents （ INa ） of rabbit myocytes from non-infarcted zone of myocardial infarcted hearts and observe the effects of adenosine. Methods 36 rabbits were randomly divided into 4 groups： adenosine （Ado） group,myocardial infarction （MI） group, control group, sham-operated group. One month later, INa was recorded using patch-clamp techniques from non-infarcted zone of left ventricular free walls. Results There was heterogeneity in the INa of Epi, M and Endo from control group. The peak Ira density in M cells was over two times bigger than that in Endo and Epi ; M cells inactivated faster than Endo and Epi cells;There were no significant differences between control group and sham-operated group. INa current densities from Epi ,M and Endo of MI group were reduced,the change of M was most obvious,the INa inactivation curves of three subtypes of cells shifted in the hyperpolarization direction, expecially Epi cells. INa current densities from the three subtypes of cells of Ado group were decreased significantly, the INa inactivation curves of three subtypes of cells shifted in the hyperpolarization direction most significantly,INa recovery from inactivation curves of M, Endo and Epi cells recovered slowly. Conclusions There is transmural heterogeneity of INa in the rabbit left free wall ; AMI affects the INa heterogeneity significantly ; Adenosine reduces the transmural heterogeneity of INa after AMI.

关 键 词：腺苷 心肌梗死 异质性 膜片钳 钠通道 

分 类 号：R542.22[医药卫生—心血管疾病]