低氧激活海马神经元上ATP敏感性钾通道

Hypoxia activates an ATP sensitive potassiunm channel in hippocampal neurons

目的观察ＡＴＰ敏感性钾通道（ＫＡＴＰ通道）在低氧时的状态及细胞内高浓度ＡＴＰ对它的影响。方法采用膜片钳全细胞及单通道两种方法直接证实低氧时ＫＡＴＰ通道的开放。结果低氧时ＫＡＴＰ通道开放，且这种开放状态可被细胞内注射５ｍｍｏｌ·Ｌ－１ＡＴＰ所阻断。ＫＡＴＰ通道开放剂与低氧时激活的通道类似。单通道记录发现，低氧后通道开放的频率、幅度明显加大。结论低氧时外向钾电流明显增加，它来源于ＫＡＴＰ通道的开放。

AIM The state of K ATP channel and effect of intracellular high concentration of ATP on it during hypoxia were studied. METHOD Using whole cell and single channel recordings, we directly proved that K ATP channels were opened during hypoxia. RESULTS K ATP channels were opened during hypoxia and it was abolished by intracellular injection of 5 mmol·L -1 ATP. The frequence and amplitude of K ATP channel were increased obviously. CONCLUSION Outward K + currents elevated significantly and come from K ATP channel during hypoxia.