Synergistic effect of chlorpromazine and alkanals on the human red blood cells.

The hemolysis of human red cells in the presence of chlorpromazine and 2-methylpropanal, or propanal, has been studied by a spectrophotometric method. A strong synergistic effect was observed concomitant to the quenching of photon emission. The synergistic effect is consistent with the view that triplet excited species generated from a hemoprotein-catalyzed aerobic oxidation of aldehydes promotes "in situ" the photooxidation of chlorpromazine leading to products which have shown hemolytic effects. This view is supported by protection, albeit weak, offered by energy acceptors such as eosin and the 9,10-dibromoanthracene-2-sulfonate ion.