阿霉素对豚鼠单一心肌细胞钙电流(I_(Ca-L))的影响

目的　探讨阿霉素 (adriamycin ,ADR)诱发心肌病的发病机制。方法　采用膜片钳全细胞记录方法 ,研究ADR对豚鼠单一心肌细胞L型钙通道电流 (ICa L)的影响。结果　用 0 1mmol·L-1ADR灌流前后豚鼠心肌细胞ICa L电流 电压 (I U)关系曲线近似倒钟形 ,其峰值电压在 + 10mV ;0 1mmol·L-1ADR可使ICa L明显增大 ,由灌流前的 ( -0 93± 0 0 5 )nA(n =8)增大到 ( - 1 3 1± 0 0 8) (n =8) (P <0 0 1) ,其增大百分率为灌流前的 ( 4 1 6± 12 3 ) % (n =8)。结论　ADR激活电压依赖性钙通道促进钙内流很可能是ADR造成心肌细胞内钙超载 ,从而诱发心肌病的机制之一。

Effect of adriamycin on calcium current in single cardiac myocyte of gunea pig

AIM To analyze the mechanism of the adriamycin induced cardiomyopathy. METHODS The patch clamp technique in the whole cell recording was used to study the effect of adriamycin on L type calcium channel current( I Ca L ) in the isolated cardiomyocyte of the guinea pig. RESULTS The current voltage( I U ) curveshowed the bell shape in the control and in 0 1 mmol·L -1 adriamycin. Their peak potentials were about +10 mV. The amlitude of peak calcium current increased from (-0 93±0 05) nA to (-1 31±0 08) nA( P<0 01,n=8 ), the increaed rate with 0 1 mmol·L -1 adriamycin was (41 6±12 3)%( n=8 ). CONCLUSION Adriamycin activates the voltage dependent calcium channel in cardiac myocyte and increased calcium influx. It may be one of mechanisms of the calcium overload by adriamycin in cardiac myocyte in the genesis of adriamycin induced cardiomyopathy.