维生素C对低硒低铬大鼠心肌细胞电生理的影响

目的 :　阐明克山病心肌细胞损害的电生理机制。方法 :　用细胞内微电极技术分别观察正常对照、单纯低 Se、低 Se高维生素 C、单纯低 Cr、低 Cr高维生素 C、低 Se低 Cr、低 Se低Cr伴高维生素 C饲料饲养 1 4w后大鼠心肌细胞电生理的改变。结果 :　单纯低 Cr组无变化 ;单纯低硒组静息电位 ( RP)、动作电位幅度 ( APA)降低、动作电位时程 ( APD50 、APD90 )延长 ;低 Se低Cr组 RP、APA降低 ,APD50 、APD90 明显延长 ;低 Se高维生素 C组仅 RP降低 ,APA、APD与对照组相比差异无显著性意义。结论 :　低 Se低 Cr可明显改变心肌细胞的电生理特性 ,维生素 C可以对抗低 Se低 Cr所致的这种变化。

EFFECT OF VITAMIN C ON THE ELECTROPHYSIOLOGICAL PROPERTY OF MYOCARDIAL CELLS OF THE RATS FED LOW SELENIUM AND LOW CHROMIUM FODDER

Objective:To elucidate the etiology of the impairment of myocardial cells in Keshan disease. Methods:With intracellular microelectrode technique, we observed the electrophysiological changes of the eight groups of rats fed separately:normal, low Se, low Se high VC, low Cr, low Cr high VC, low Se low Cr and low Se low Cr high VC fodders. Results:Compared with the control, there was no change in low Cr group. However, in low Se group, RP and APA decreased, APD 50 and APD 90 prolonged. In low Se low Cr group, APA decreased, APD 50 and APD 90 prolonged significantly. In low Se with high vitamin C groups, though RP still decreased, no change had been detected on APA and APD. Conclusion:It is suggested that Se and Cr deficiency may jointly change the electrophysiological properties of myocardial cells significantly. However, vitamin C may protect myocardial cells against the injury effectively.