EFFECT OF TRIFLUOPERAZINE AND CALMODULIN ON CATECHOLAMINE SECRETION BY SAPONIN-SKINNED CULTURED CHROMAFFIN CELLS

The effect of trifluoperazine on catecholamine [CA] secretion was studied in chemically skinned, cultured adrenal chromaffin cells which require only ATP and Ca for secretion. CA secretion was unaffected by the drug in the presence or absence of Ca and ATP over the range 0.1 to 10 .mu.M. At 100 .mu.M trifluoperazine, CA release was Ca- and ATP-independent and represented 70-80% of the total cellular content. High concentrations of exogenous calmodulin had no effect on secretion in the presence or absence of Ca. Apparently, low concentrations of the drug have no effect on secretion while high concentrations cause non-physiological CA release.