[The modifying effect of ortho-cresol on benzo(a)pyrene-induced carcinogenesis in mice].

A modifying influence of ortho-cresol (o-cresol) on the carcinogenic effect of benzo(a)pyrene (B(a)P) in their combined peroral administration to CC57Br mice has been revealed. During the simultaneous administration of the o-cresol (1 mg) and B(a)P (1 mg) the rate of tumours, their multiplicity index, the degree of malignancy increased and the latent period shortened. In case of o-cresol administration before or after B(a)P (in the same doses) the decrease of carcinogenic effect has been revealed. In case of simultaneous administration of 10 mg of the o-cresol and 5 mg of the B(a)P the tumor incidence did not change in comparison with the animals of the control group which received only B(a)P. But their progression was hampered which was confirmed by a decrease of the malignancy rate, frequent occurrence and prolongation of the period of the malignization beginning.