[Effect of taurine of the membrane electrical properties in guinea pig hearts].

The effects of taurine on electrical properties of isolated ventricular fibres were studied in guinea pig. The action potential amplitude was decreased while the plateau and the repolarization phase was not altered. Voltage clamp experiments at 18 degrees C revealed that taurine reduced the fast inward sodium current and the potassium current. The slow inward calcium current remained unchanged. These results suggest that the inotropic effects of taurine on guinea pig heart contractions already described were not due to modifications of the membrane permeability for calcium but rather to intracellular changes in calcium availability.