Enhancement of the T-type Calcium Current by Hyposmotic Shock in Isolated Guinea-pig Ventricular Myocytes

It is known that swelling and shrinkage of cardiac cells can modulate their electrical activity. However, the effects of osmotic manipulation on cardiac T-type calcium current (I(CaT)) has not been previously reported. In this study, we have examined the effects of cell swelling on I(CaT), using the whole cell patch clamp configuration. Isolated guinea-pig ventricular myocytes were swollen by an external hypotonic challenge (0.7 T). We found...