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兔主动脉前庭自律细胞与窦房结电生理特性的比较

张晓云, 陈彦静, 葛赋贵, 王德宝

张家口医学院生理教研室.河北,张家口 075029

摘要

该实验利用常规的玻璃微电极细胞内记录技术,观察了一些离子通道阻断剂分别对离体兔窦房结起搏细胞与左心室流出道慢反应自律细胞的电生理特性的影响,重点探讨了这两种自律细胞的0期、4期去极离子流的异同。结果表明:(1)用1#mu#mol/L维拉帕米(VER)灌流后,窦房结及主动脉前庭自律细胞的动作电位幅值(APA)、0相最大除极速率(V_(max))、最大舒张电位(MDP)绝对值、舒张期除极速率(VDD)、自发放电频率(RPF)均明显下降,复极90%时间(APD_(90))延长(P<0.05)。(2)用180#mu#mol/L氯化镍(NiCl_(2))灌流,两自律细胞的VDD均明显下降;APA、V_(max)和RPF也显著降低,且窦房结细胞的APD_(90)明显延长。(3)给予2mmol/L 4-氨基吡啶(4-AP)后,窦房结及主动脉前庭自律细胞的VDD均明显增快,MDP绝对值、APA和V_(max)显著下降,APD_(90)明显延长(P<0.05)。(4)给予2mmol/L氯化铯(CsCl),两自律细胞的VDD及RPF均明显变慢。结果提示:(1)主动脉前庭自发慢反应电位的0相、4相去极离子流及复极离子流均与窦房结优势起搏细胞相似。(2)主动脉前庭起搏细胞Ca~(2+)内流为其0相主要去极离子流,复极过程主要由K~(+)外流引起,4相自动除极以K~(+)外流衰减为主,另外,I_(Ca-T)、I_(Ca-L)及I_(f)城起搏电流中也起一定作用。

关键词： 主动脉前庭; 窦房结; 电生理; 比较研究

Comparison of the electrophysiological features between the rhythmic cells of the aortic vestibule and the sinoatrial node in the rabbit

Zhang Xiaoyun, Chen Yanjing, Ge Fugui, Wang Debao

Department of Physiology,Zhangjiakou Medical College.Zhajiakou 075029,Hebei

Abstract

These results suggested: (1) the ion currents in phase 0 and phase 4 of depolarization and repolarization of slow-response activity in aortic vestibule are similar to those in dominant pacemaker cells of sinoatrial node; (2) for the pacemaker cells in the left ventricular outflow tract, Ca~(2+) current is the main depolarizing ion current of the phase 0, K~(+) current is the main factor responsible for the repolarization. Attenuation of K~(+) current is reponsible for the phase 4 spontaneous depolarization. In addition, it seems that I_(Ca-T), I_(Ca-L) and I_(f) play some role in the pacemaker currents.

Key words: Aortic vestibule;Sinoatrial node;Electrophysiology;Comparative research

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引用本文：

张晓云, 陈彦静, 葛赋贵, 王德宝. 兔主动脉前庭自律细胞与窦房结电生理特性的比较[J]. 生理学报 2003; 55 (4): .

Zhang Xiaoyun, Chen Yanjing, Ge Fugui, Wang Debao. Comparison of the electrophysiological features between the rhythmic cells of the aortic vestibule and the sinoatrial node in the rabbit. Acta Physiol Sin 2003; 55 (4): (in Chinese with English abstract).