黄皮酰胺促钾通道开放

Facilitation of Clausenamide on the Opening of Potassium Channel

一种新发现的具有促智作用的药物——黄皮酰胺能抑制去甲肾上腺素(NE)或KCl引起的血管平滑肌收缩。本研究旨在应用膜片钳(patch clamp)技术探讨黄皮酰胺对Wistar大鼠尾动脉平滑肌细胞膜钾离子通道的作用。单个平滑肌细胞用酶法分离,以细胞封接方式记录离子通道活动。在细胞池内注入2μM黄皮酰胺后,钾离子通道活动明显增强。用本实验室开发的计算机软件(patch clamp analysis system,Version 1.0)计算分析通道活动的特征参数。

It is recently found that a newly discovered nootropia drug clausenamide inhibits the NE or KCl induced contraction in vascular smooth muscle. The goal of this study is to examine the effect of clausenamide on single potassium channel of tail artery smooth muscle cells in Wistar rats by using the cell-attached mode of the patch clamp technique. Single cells were enzymatically dispersed.The single potassium channel were recorded under the step generated clamping voltages from-60mV to +60mV. From th data processing analysis, two types of conductances of the potassium channels, appearing 26.9±3.8pS (n = 6) and 72.2±5.9pS (n = 5) ,were found. Clausenamide at 2nM, 30 seconds after applied outside the pipette, appearently increased channel activity by increasing the conductances to 2-3 fold of the control being 81.2±4.3pS (n=6) and 221.6±2.0pS (n=4) and mean open time from 0.8ms prolonged to 1.8ms, and mean P0 from 0.15 increased to 0.27. These findings may account for the dependence of clausenamide induced vasodilatation on facilitating the opening of potassium channel.