Cd2+ and Co2+ at micromolar concentrations stimulate catecholamine secretion by increasing the cytosolic free Ca2+ concentration in cat adrenal chromaffin cells.

Cd2+ and Co2+ at micromolar concentrations increased the cytosolic free Ca2+ concentration, which was measured by fura-2 microfluorometry, in cat adrenal chromaffin cells. Simultaneously, these divalent cations stimulated catecholamine secretion from the perfused adrenal. The present findings suggest that these cations increase the Ca2+ influx by depolarizing the cell membrane and consequently stimulate catecholamine secretion.