牛磺酸镁配合物对豚鼠心室肌细胞钠离子和钙离子通道的影响

目的研究牛磺酸镁配合物(TMC)对正常豚鼠心室肌细胞钠电流(INa)和L-钙电流(ICa,L)的影响,旨在探讨其抗心律失常作用的可能机制。方法酶解法分离豚鼠单个心室肌细胞,全细胞膜片钳技术记录单个心室肌细胞的INa和ICa,L。结果TMC50μmol·L-1不影响INa,而100～200μmol·L-1浓度依赖性地抑制INa;TMC50～200μmol·L-1浓度依赖性地增加ICa,L,使ICa,L的稳态失活曲线右移,对ICa,L的稳态激活曲线无影响。结论TMC对心室肌细胞INa的阻滞可能是其抗心律失常作用的机制之一;对ICa,L的促进可能有利于其发挥正性肌力作用。

Effects of taurine magnesium coordination compound on sodium and calcium channels in guinea pig ventricular cardiomyocytes

AIM To investigate the effect of taurine magnesium coordination compound (TMC) on sodium current (I_Na) and L-type calcium current (I_Ca,L) of ventricular cardiomyocytes to study the possible antiarrhythmic mechanism of TMC. METHODS Whole-cell patch clamp was used to record I_Na and I_Ca,L in single ventricular cardiomyocytes of guinea pig. RESULTS In ventricular cardiomyocytes of guinea pig, I_Na was blocked by 100-200 μmol·L^-1 TMC, while I_Ca,L increased following 50-200 μmol·L^-1 TMC in a concentration-dependent fashion. The steady-state inactivation curve of I_Ca,L shifted to right, however the steady-state activation curve did not changed. CONCLUSION TMC blocks I_Na of ventricular cardiomyocytes, which may be one of its antiarrhythmic mechanism, and TMC increases I_Ca,L of ventricular cardiomyocytes, which may be beneficial to its positive myocardial effects.