[Effect of 7,12-dimethylbenz(alpha)anthracene metabolites on its capacity to induce skin tumors in mice].

Induction of skin tumors by 7,12-dimethylbenz(a)anthracene (DMBA) in the presence of its metabolites-7-hydroxymethyl-12-methylbenz(a)anthracene (7-OHM-12-MBA) and 7,12-dihydroxymethylbenz(a)anthracene (7,12-diOHMBA) has been studied in mice. The skin of mice was treated repeatedly with benzene or acetone solutions of DMBA (22 mug in two droplets) or with the same amount of DMBA solution together with one of the above mentioned metabolites (the molecular ratio 1 : 1 or 1 : 0.5). Neither of the metabolites affected the carcinogenic activity of DMBA under the given conditions. 7,8-benzoflavone, an inhibitior of the DMBA metabolism, strongly suppressed DMBA tumorigenesis under the same experimental conditions. Whereas the effect of benz(a)-anthracene, an inducer of aryl hydrocarbon hydroxylase activity, was less pronounced.