Toxicity of dopamine and dopaminochrome on cultured cells.

Cultured rat fibroblasts, monkey kidney tumor cells (line Vero) and murine neuroblastoma cells were exposed to dopamine or dopaminochrome in the presence and absence of ascorbic acid. Ascorbic acid is able to potentiate the toxicity of both dopamine and dopaminochrome for all the tested cells. The toxicity of dopaminochrome was higher than that of dopamine. There is a correlation between toxicity and levels of bioreductive defenses of the cells, e.g. DT-diaphorase (NAD(P)H:quinone oxidoreductase EC 1.6.99.2) and glutathione. In general, tumor cells have lower defenses and seem to be more sensitive to the toxic action.