睫状体色素上皮细胞容积激活性氯电流(英文)  

Volume-activated chloride current in pigmented ciliary epithelial cells

作　　者：陈丽新[1] 王立伟[1] 

机构地区：[1]广东医学院生理教研室,湛江524023

出　　处：《生理学报》2000年第5期421-426,共6页Acta Physiologica Sinica

摘　　要：为研究睫状体色素上皮 (pigmentedciliaryepithelial,PCE)细胞容积激活性Cl-电流的特性 ,用膜片箝全细胞记录技术记录了猪的低渗液诱发的容积激活性Cl-电流。此电流外向占优势 ,几乎没有时间依赖性失活 ,电流 电压曲线显示此电流反转电位 (- 6 3± 0 5mV)很接近氯离子平衡电位的计算值 (ECl=0mV)。电流的激活依赖于细胞内ATP ,细胞外ATP抑制外向电流和内向电流 ,但外向电流抑制率大于内向电流抑制率 (92 %比 74% ,P <0 0 1)。氯离子通道阻断剂tamoxifen抑制外向电流和内向电流 ,两个抑制率几乎相等 (85 %比 87% ,P >0 0 5 )。此电流特性与其他类型细胞的P糖蛋白相关电流很相似。WT5”BZ] To characterize the volume activated Cl - current in bovine pigmented ciliary epithelial (PCE) cells, the whole cell patch clamp technique was employed. Exposure to a hypotonic solution induced a volume activated Cl - current. The activation of the current depended on intracellular ATP. The current showed a characteristic outward rectification. There was no, or negligible, time dependent inactivation of the current. The current voltage relationship showed that the reversal potential of the hypotonic activated current (-6 3±0 5 mV) was close to the calculated equilibrium potential for Cl - (E Cl =0 mV). Extracellular ATP inhibited both outward and inward currents, but the inhibition of outward currents was larger than that of inward currents (92% vs 74%, P <0 01). The current was also blocked by extracellular application of tamoxifen, a Cl - channel inhibitor, the effects of which were almost equal for both outward and inward currents (85% vs 87%, P >0 05). The properties of this current are quite similar to those of the volume activated Cl - current associated with P glycoprotein in other cell types, suggesting that P glycoprotein may be involved in the activation of the volume activated Cl - current in PCE cells.

关 键 词：氯离子通道 睫状体色素上皮细胞 P糖蛋白 ATP 

分 类 号：Q436[生物学—生理学] Q424