米诺环素对大鼠心室肌细胞L型钙电流的影响

目的 研究米诺环素对大鼠心室肌细胞L型钙电流（Ica-L）动力学特性的影响.方法 以酶解法分离获得单个心室肌细胞,采用全细胞膜片钳技术,研究米诺环素对Ica-L的影响.结果 10、50、250 μmol/L米诺环素对峰电位的抑制率分别为11%±5.86%,54.79%±6.32%,71.73%±5.29%,使Ica-LI-U曲线上移,激活曲线右移,并延长失活后恢复时间.结论 米诺环素通过延长钙通道的激活及失活后恢复时间,抑制心肌细胞Ica-L,预防钙超载.

Effects of minocycline on L-type calcium current in rat ventricular myocytes

Objective To study the effects of minocycline on the activation kinetics of L-type calcium current(ICa-L )in single ventricular myocyte. Methods The whole-cell patch-clamp technique was used to investigate the effects of minocycline on ICa-L in acutely isolated ventricular myocytes in adult rat. Results Minocycline inhibited the current density of ICa-L, and the peak rates of ICa-L were decreased by 11% ± 5.86%,54. 79% ± 6. 32% ,71.73% ± 5.29% at 10,50,250 μmol/L group,respectively. The current-voltage curve was shifted upwards, and the steady-state activation curve was shifted to right by minocycline in the concentration of 50,250 μmol/L,which also prolonged the recovery time from inactivation. Conclusion Minocycline inhibited ICa-L to prevent calcium overload,which may contribute to its cardioprotection effect.