The Effect on Cardiac Plasma Membrane K_(ATP) Channel by Brief Hypoxia

Objective In order to study the role of the cardiac myocyte membrane K ATP channel in ischemic preconditioning(IP) in vitro. Method The effect of 10 min hypoxia on K ATP channel of isolated ventricular myocyte was observed, by using patch clamp technique (cell-attached configuration). Result The result show that K ATP channel can be easily opened by 10 min brief hypoxia, and inhibited by reoxygenation within 2 min or by 2 mmol/L ATP. The opening of K ATP channel was in burst. The single-channel conductance activated by hypoxia was 89 7 pS, the P o (open state probability) was increased by hypoxia, and the secondary opening of K ATP channel was also induced. Conclusion Brief hypoxia could activated cardic plasma membrane K ATP channel and the results proved that K ATP channel should take part in the IP.