PHOTOBIOCHEMISTRY IN THE DARK - PHOTOHEMOLYSIS OF RED-CELLS SENSITIZED BY CHLORPROMAZINE-BIOENERGIZED TRIPLET ACETONE SYSTEM

Chlorpromazine is decomposed when it is treated with bioenergized triplet acetone from the 2-methylpropanal/red cells/O2 system, forming chlorpromazine-5-oxide, with a concomitant strong hemolytic effect observed by a spectrophotometric method. Experiments with external superoxide dismutase, catalase, benzoate and bicarbonate indicate the absence of O2 •, H2O2 and OH· species as the precursor of the hemolytic effect. Comparison between the 2-methylpropanal/peroxidase/O2 system and the 2-methylpropanal/red cells/O2 system in the presence of chlorpromazine, indicate that essentially the same type of mechanism occurs in both cases. These results could explain the invivo hemolytic and toxic effect of chlorpromazine in the dark. © 1979.