大鼠消化道平滑肌细胞K_(ATP)通道的牵张敏感性  

Mechanosensitivity of ATP-Sensitive Potassium Channels in Rat Colonic Smooth Muscle Cells

作　　者：王伟[1] 黄海霞[1] 张丽娟[1] 麻涛[1] 刘萍[1] 魏华[1] 钮伟真[1] 

机构地区：[1]首都医科大学基础医学院生理学系

出　　处：《首都医科大学学报》2007年第3期341-344,共4页Journal of Capital Medical University

基　　金：国家自然科学基金(30570663)资助项目~~

摘　　要：目的探讨大鼠结肠平滑肌细胞上是否存在ATP敏感K+通道(ATP-sensitive potassium channel,KATP)及其牵张敏感性。方法用RT-PCR方法检测SD大鼠结肠平滑肌组织KATPmRNA的表达;联合应用单通道膜片钳技术和压力钳技术,采用inside-out模式记录大鼠结肠平滑肌细胞上KATP通道的电活动。结果在大鼠结肠平滑肌组织中可检测出较高水平的KATPmRNA的表达;用inside-out模式在大鼠结肠平滑肌上可记录到KATP通道的电活动,该通道在膜电位钳制电压为+60 mV时电导值为(44.5±1.5)pS。KATP通道特异性阻断剂——glibenclamide能抑制该通道的活动。且该KATP通道在负压刺激下开放概率增加。结论大鼠结肠平滑肌细胞上分布有KATP通道,该KATP通道对牵张刺激敏感。Objective To study the expression and mechanosensitivity of ATP-sensitive potassium channel（ KATP） in rat colonic smooth muscle cells. Methods Reverse transcription polymerase chain reaction （RT-PCR） was used to measure mRNA expression of KATP in colonic smooth muscle. KATP channel activities were investigated with patch-clamp techniques and pressure-clamp techniques in inside-out mode on isolated smooth muscle myocytes. Results RT-PCR amplified the expected product of 727 bp for KATP from total RNA isolated from colonic smooth muscle. In this mode, KATP activities were recorded on isolated smooth muscle cells, the mean conductance was （44.5 ± 1.5）pS at ＋ 60 mV. The activities were blocked by glibenclamide （10 μmol）. The open probability of KATP channels was increased by -40 mmHg suction pressure. Conclusion KATP channels are expressed in rat colonic smooth muscle cells and are sensitive to stretch stimuli. These results suggest that the channel may be involved in the regulation of electric and mechanic activities of colonic smooth muscle in rats.

关 键 词：KATP通道 牵张敏感性 结肠平滑肌细胞 

分 类 号：R331.31[医药卫生—人体生理学]