蒺藜皂苷对成年豚鼠心室肌细胞钾电流的影响

Effect of GSTT on potassium current of ischemic cardiocytes in guinea pigs

目的:研究蒺藜皂苷(GSTT)对成年豚鼠心室肌细胞动作电位和钾通道的影响,初步探讨其抗心律失常的作用及机制。方法:分离豚鼠心肌细胞,建立缺氧模型,分为正常对照组、模型组及GSTT10和30mg·L-1组,采用全细胞膜片钳记录各组成年豚鼠单个心肌细胞的电位变化及测定钾通道电流。结果:与模型组比较,GSTT30mg·L-1组缺氧细胞动作电位平台期即动作电位复极时程(50%和90%)延长(P<0.01)。将保持电位控制在-40mV,测试电位从-100mV到+100mV,阶跃命令为+10mV,时程300ms。正常对照组豚鼠心室肌细胞钾通道处于关闭状态,GSTT10和30mg·L-1剂量组在+80mV时其峰值电流分别为(1.19±0.20)和(1.15±0.10)nA,与模型组[(1.50±0.20)nA]比较差异有显著性(P<0.05和P<0.01)。结论:GSTT可阻碍缺氧导致的钾电流增加,即减少缺氧引起的钾离子外流,改善胞内钾离子丢失状态,显著延长缺氧细胞动作电位复极时程,延长有效不应期,从而改善缺氧及钾丢失导致的心肌细胞电生理异常,减少心律失常的发生,保护心肌细胞。

Objective To Study the effect of Gross Saponins of Tribulus Terrestris on active potential and potassium current of ischemic cardiocytes in guinea pigs,and approach its initial anti-arrhythmia effect and mechanism.Methods The cardiocytes of adult guinea pigs were isolated and hypoxia models were set up,the effects of injected GSTT on the cellular membrane active potential and electricity flow of potassium channel were recorded with whole cell patchclamp system.Results Compared with model group,the active pl...