高钾诱发外毛细胞的运动

Motile response of the outer hair cells induced by high potassium

分离出的单个外毛细胞在５．３６ｍｍｏｌ／Ｌ钾含量的Ｈａｎｋ平衡盐液（ＨＢＳＳ）中，观察３０分钟无明显形态改变。高钾环境（１２５ｍｍｏｌ／Ｌ）里，外毛细胞会发生沿纵轴方向的收缩运动，钾可引起外毛细胞去极化，通过电压依赖钙通道而升高细胞内的钙含量。用Ｖｅｒａｐａｍｉｌ阻断钙通道或以无钙的溶液灌注，外毛细胞在高钾环境中依然发生持续性收缩反应。实验表明：钾去极化引起外毛细胞的收缩反应很有可能是电渗性收缩，这种收缩不依赖钙和收缩蛋白。

The isolated outer hair cells show no change in shape in the 30 minute course of bathing in standard Hank’s ballanc salt solution(HBSS)containing 5.36 mmol/L potassium. High potassium HBSS(125 mmol/L),however,leads to their remarkable logitudinal contraction. Potassium-induced depolarization elevates intracellar calcium in outer hair cells through the voltage-gated calcium channels of the cells. Interrupted calcium channels of the cells with verapamil or perfused with calcium-free HBSS, the successive longitudinal contraction of outer hair cells in high potassiurn enviroment can be viewed still.These results demonstrate that K+-depolarization induces an osmotic contraction of the outer hair cells which is independent of calcium and contractile proteins.