CALCIUM EFFLUX FROM CULTURED BOVINE ADRENAL CHROMAFFIN CELLS INDUCED BY BRADYKININ

The effect of bradykinin on Ca2+ efflux from cultured bovine adrenal chromaffin cells was examined. Bradykinin enhanced the efflux of Ca-45(2+) from the cells in a concentration dependent manner (10(-9)-10(-6)M). This effect was inhibited by a specific bradykinin B-2-receptor antagonist, but not by a B-1-receptor antagonist. Nifedipine, Co2+ and Cd2+ did not inhibit the bradykinin-stimulated Ca-45(2+) efflux from the cells. 12-O-Tetradecanoyl phorbol 13-acetate, an activator of protein kinase C, also had no effect on the efflux of Ca-45(2+) from the cells. The increase in bradykinin-stimulated Ca-45(2+) efflux was reduced by removal of extracellular Na+(.) These results suggest that bradykinin stimulates Na+/Ca2+ exchange in cultured bovine adrenal chromaffin cells.