Chlorpromazine and its metabolites alter polymerization and gelation of actin.

Hepatic hydroxylated metabolites of chlorpromazine (10(-5)M to 10(-4)M), a frequently used phenothiazine tranquilizer, produce solid gel formation with filamentous actin, but the less toxic chlorpromazine sulfoxide metabolite does not. At higher concentrations (5 x 10(-4)M) chlorpromazine inhibits actin polymerization. These dose-response relationships parallel the drug's hepatic toxicity in vivo and suggest that interactions between chloropromazine or chlorpromazine metabolites and actin could be an underlying mechanism of cell injury.