Effect of taurine on action potentials and ATP-sensitive posstiaum channel activity during hypoxia in ventricular muscle of guinea pig

AIM: To study the effects of taurine on ATP sensitive potassium channel (IK-ATP) during hypoxia in single ventricular myocyte. METHODS: The model of myocardial hypoxia was induced by unmixed and saturated nitrogen. IK-ATP activities were measured by whole-cell patch clamp recording. RESULTS: Activities of IK-ATP in the cell membrane of hypoxia ventricular myocyte significantly increased, compared to that in the normal. Extracellular injection of taurine (5，10，20 mmol/L) inhibited the increase in the IK-ATP activity in the hypoxia myocardium in a concentration-depend manner. Injection of taurine also recovered shorten APD during hypoxia. CONCLUSIONS: Taurine produces its cardioprotective effect by inhibiting the activity of IK-ATP in the hypoxia cardiomycytes of guinea pig. The results suggest that the depletion of taurine during myocardial hypoxia contributes to the early activation of the KATP channel.