目的：研究细胞内酸中毒对细动脉平滑肌细胞膜ＫＡＴＰ 通道的影响。方法：应用膜片钳技术的内面向外式记录酶性分离的细动脉平滑肌上ＫＡＴＰ 通道。结果：当细胞内无ＡＴＰ 时，细胞内酸中毒降低通道电导，通道平均开放时间（Ｔｏｍ） 和开放时间长成分有所增大，对通道开放概率无明显影响；当细胞内有ＡＴＰ 时，细胞内酸中毒使通道电导增大，通道开放概率增加。结论：平滑肌细胞内酸中毒减弱ＡＴＰ 对ＫＡＴＰ 通道的抑制作用，并能在ＡＴＰ 存在条件下激活ＫＡＴＰ 通道，是酸中毒降低血管平滑肌反应性的重要机制之一 Objective: To study the effect of intracellular acidosis on KATP channel of arteriole smooth muscle cell membrane. METHODS: KATP channels were recorded on the arteriolar smooth muscle isolated enzymatically using a patch-clamp technique. Results: Intracellular acidosis decreased the conductance of the channel when there was no ATP in the cells. The average channel opening time (Tom) and the open time length component increased, but had no effect on the open channel probability. When ATP was in the cell, Acidosis increased the conductance of the channel, increasing the probability of open channel. CONCLUSIONS: Acidosis in smooth muscle cells attenuates the inhibitory effect of ATP on KATP channel and activates KATP channel in the presence of ATP, which is one of the important mechanisms of acidosis to reduce the vascular smooth muscle reactivity