Inhibition of synexin activity and exocytosis from chromaffin cells by phenothiazine drugs.

Synexin activity was found to be inhibited by low concentrations of the phenothiazine drugs, trifluoperazine and promethazine. Both drugs were also similarly effective at blocking nicotine and veratridine-induced catecholamine secretion from cultured chromaffin cells. These data thus indicate that synexin may be a target of phenothiazine drugs when they block secretion from chromaffin cells.