乌头碱对大鼠心肌细胞钙通道阻滞作用的单通道分析

用膜片钳法,在培养的Wistar大鼠心室肌细胞上记录了L型钙通道的单通道活动。乌头碱50μg·ml^-1能显著阻断L型钙通道的活动,使其开放时间缩短、关闭时间延长、开放概率下降。与对照组比较,有显著性统计学差异(P<0.01)。而对通过L型钙通道的钡离于流幅值无明显影响。

SINGLE CHANNEL ANALYSIS OF ACONITINE BLOCKADE OF CALCIUM CHANNELS IN RAT MYOCARDIOCYTES

Ventricular myocardiocytes from neonatal Wistar rats were isolated and cultured.Aconitine,Ca²⁺ channel blocker verapamil or Ca²⁺ channel activator BAY K8644 were added to thebath solution separately. Using the cell-attached configuration of the patch clamp technique ,the singlechannel activities of L type Ca²⁺ channel were recorded before and after addition of all three drugs.The results showed the blocking effect of aconitine (50μg· ml-1)on L type Ca²⁺ channels. Itsmechanism may be relevant to the decrease in both open state probability and the mean open time ofCa²⁺ channel. The difference was statistically significant compared with control group(P<0.01).The amplitude of Ba²⁺ currents ,which flow through open L type Ca²⁺ channel was unchanged.