细胞外Ca^2＋内流入胞质的机制

细胞外Ｃａ＾２＋主要是通过塌压依赖性Ｃａ＾２＋通道和钙池耗竭依赖性Ｃａ＾２＋通道而内流的。前者主要见于电兴奋细胞，这一过程比较清楚；后者主要见非兴奋细胞，情况远较复杂：外来信号激活内贮钙池，钙池在释放Ｃａ＾２＋同时通过目前尚不清楚的途径将直接或间接传至质膜Ｃａ＾２＋通道，而诱发Ｃａ＾２＋内流。

Mechanisms of the Calcium Influx Across the Plasma Membrane

The Ca2 influx is mainly mediated by voltage-dependent Ca2 channels and store depletion-dependent Ca2 channels. The former ,which mainly acts to regulate Ca2 influx in excitable cells,is relatively clear; However,thelater, which mainly functions in nonexcitable cells,remains enigmatically complicated.Following activation of the intracellular Ca2 store,the depletion of the store provides a signal for activating Ca2 entry across the plasma membrane via presently unknown mechanisms.This paper reviews the rapid progress in this field.