摘要
高钾(12mmol/L)条件下,突然增快刺激频率(1HZ-4Hz),豚鼠乳头肌发生两轮2:1电-机械交替(EMA)。第一轮EMA历时约22-30s宽的动作电位(AP)马低的收缩力(Fc)相对应。间隔性AP脱落期发生在两轮EMA之间,历时约4-6min。第二轮EMA期间,高宽的AP与高的Fc相对应。AP交替消失时Fc交替也随之消失。第二轮EMA历时22-34min(26±5min,n=7),奎尼丁(1μg/ml)显著增强第二轮EMA,异搏定(0.5μg/ml)则相反。提示高钾诱发的EMA可能与Na+,Ca2+离子流有关。
Two sets of 2:1 electromechanicalalternans (EMA)wereobserved in isolated guinea pig papaillary muscles exposed tohyperkalemia (12mmol/L)-Tyrode’s solution withrapid pacing (4Hz).Theprolonged durationof action potential(APD)were associated with low contractile force in the first set EMA which usually lasted for 22-30 second.The discontinuous actionpotential dropping phase occurred between the first and the second sets of EMA and usually lasted for 4-6 min During the secondsetof EMA which lastedfor22-34ming bothprolonged and high action potentials were associated with high contractile force .Themechanicalalternans died awaywith disappearanceof the electrical alternans Quinidine caused amarked augmentation inthesecond EMA set , but verapamilattenuated it 。The results suggested that hyperkalemiainduced EMAmight be associatedwith Na+and Ca2+current
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
1997年第1期38-41,共4页
Chinese Journal of Pathophysiology
基金
冶金工业部有偿与资助课题
关键词
钾
血钾过多
动作电位
心肌收缩
维拉帕米
Me SH Hyperkalemia Action potentilas Myocardial contration Quinidine Verapamil