Effect of taurine on action potentials and ATP-sensitive posstiaum channel activity during hypoxia in ventricular muscle of guinea pig / 中国病理生理杂志

ABSTRACT

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 K_~ATP channel. [