中文摘要：

利用全细胞膜片钳技术,研究了胞外锌离子对鲫鱼视网膜H1型水平细胞内向整流钾通道（inward-rectifying potassium channel,Kir）的调控特性。研究发现：1）当胞外为弱酸环境（pH=6.8）时,毫摩尔级浓度的锌离子对Kir电流具有压抑作用,而微摩尔级浓度的锌离子对Kir电流没有任何影响;2）当胞外pH为正常生理范围值（7.2）时,无论锌离子浓度高或低,都对Kir电流没有影响。以上结果表明,锌离子对Kir的调控与胞外的pH环境密切相关。弱酸环境下,高浓度的锌离子对Kir通道产生压抑作用,在某些病理情况下（如组织缺血缺氧）,这个过程可能起到了保护神经元免于凋亡的作用。

英文摘要：

The Zn2＋ modulatory effect on inward rectifying potassium channel（Kir） was examined using whole-cell patch clamp technique.The main results of the present study are： 1） Zn2＋ at millimolar concentration has inhibitory effect on Kir currents when extracellular pH is 6.8,but micromolar concentration of Zn2＋ has no effect;2） Zn2＋ has no effect on Kir currents when extracellular pH is in physiological rang（pH=7.2）.These results suggest that the modulatory effect of Zn2＋ on Kir currents is related to extracellular pH.Such Zn2＋ inhibitory effect on Kir currents may contribute to protect the neurons from apoptosis in condition of hypoxia/ischemia.