重症休克时细动脉平滑肌细胞膜ATP敏感钾通道的变化

Characteristic Changes of ATP sensitive Potassium Channels in Arteriolar Smooth Muscle Cells During Severe Hemorrhagic Shock

目的探讨重症休克血管反应性降低时细动脉平滑肌ＡＴＰ敏感钾通道（ＫＡＴＰ通道）特性的改变。方法酶性分离正常及休克大鼠肠系膜细动脉平滑肌细胞，用膜片钳技术（细胞贴附式和内面向外式）记录ＫＡＴＰ通道特性。结果重症休克使通道电导由正常的（１１１±６．５）ｐｓ增大到（１２９±９．５）ｐｓ；通道动力学也发生了改变，其中通道平均开放时间延长，通道开放时间常数τ０１，τ０２达１．８８ｍｓ、１３．１２ｍｓ，通道开放概率明显增大，并诱导通道多级开放。结论重症休克时细动脉平滑肌细胞膜ＫＡＴＰ通道开放，带来细胞膜超极化。

Abstract Aim To elucidate the characteristic changes of ATP sensitive potassium (K ATP ) channels when vascular hyporeactivity occurred during severe hemorrhagic shock (HS). Methods Single channel current was studied on cell attached and inside out patches of enzymatically isolated arteriolar smooth muscle cells. Results Single K ATP channel conductance increased from (111±6.5) ps in normal to (129±9.5) ps in HS. The channels kinetics also changed in HS, which included the increase of mean open time and open probability. HS elicited multichannel activities in some patches, too. Conclusion K ATP channels are activated during HS, which induces membrane hyperpolarization of smooth muscle cells and involves in the pathogenesis of vascular hyporeactivity.