【摘要】 目的观察α肾上腺素能受体激动剂间羟胺对大鼠心室肌动作电位及L-型钙电流的影响。方法采用全细胞膜片钳方法,记录离体大鼠心室肌细胞动作电位和L-型钙电流。结果 200μmol/L间羟胺可使心室肌细胞L-型钙电流增大(P<0.05),动作电位时程(APD)明显延长(P<0.01),动作电位复极50%和90%时间(APD50and APD90)明显延长(P<0.01)。100μmol/L酚妥拉明可使增大的的L-型钙电流和APD、APD50、APD明显恢复。结论间羟胺可明显延长大鼠心室肌动作电位时程,而酚妥拉明可不同程度地拮抗此效应。更多还原

【Abstract】 Objective To investigate the effects of metaraminol on action potential(AP) and L-type calcium channel current(ICa-L) in isolated rat ventricular myocytes Methods Action potentials and L-type calcium current in the isolated ventricular myocytes were recorded by whole-cell recording patch clamp technique.Results Metaraminol 200 μmol/L could increase L-type calcium current(P<0.05) and prolong the duration of action potential(APD),50% and 90% of duration of action potential(APD50 and APD90) significantly(P<0.01).Phentolamine 100μmol/L restored the increased ICa-L and APD,APD50 and APD90.Conclusion Metaraminol can significantly increase ICa-L and prolong APD,APD50 and APD90 in rat ventricular myocytes and phentolamine can antagonize the effects of metaraminol.更多还原