不同浓度锌对豚鼠心室乳头肌细胞电活动的影响

以含不同浓度 Zn~(2+)的实验液分别灌流豚鼠心室乳头肌标本,用玻璃微电极引导细胞内的电信号,输入紫金Ⅱ微机系统;对所记录图形用博士851程序进行采样、分析和存储,并将图形和分析结果打印。实验结果表明,低浓度 Zn~(2+)灌流可使心肌细胞复极化过程延长,特别是APD_(50)延长尤为明显。Zn 可使 Ca~(2+)内流受阻,对抗由于细胞内 Ca~(2+)超负荷所引起的心肌细胞损伤。随着 Zn~(2+)浓度的增大,Ca~(2+)内流严重受阻,心肌细胞不能维持必要的 Ca~(2+)内流使 APD 逐渐缩短,特别是 APD_(50)缩短更为显著。

EFFECTS OF PERFUSED SOLUTION CONTAINING DIFFERENT Zn~(2+)CONCENTRATIONS ON THE ELECTRICAL ACTIVITIES OF THE PAPILLARY MUSCLE CELLS OF GUINEA PIG

The changes of the electrical activities of papillary muscle cells ofguinea pigs were induced by glass microelectrode and recorded by microcom-puter,before and after perfusion with experimental solution containingdifferent Zn~(2+) concentrations respectively.The results showed that the APDswere prolonged in the low Zn~(2+)concentration group,especially obviouslythe APD_(50).Along with the increasing Zn~(2+) concentration,the slow influxof Ca~(2+) was blcoked seriously,the APDs were gradually shortened,theplateau periods were so shortened that they almost disappeared.In view of the effects of Zn~(2+) on the electrical activities of these cellsand the Zn contents being lower in endemic areas,the relationship betweenZn and etiology of Keshan disease should be drawn more attention.