The aim: of this work was to experimentally study the modifying role of toxic substances (phenol) in the manifestation of genotoxic and immunological changes in the body when exposed to a carcinogen (benzo[a]pyrene). Materials and methods: Investigations were carried out in the chronic experiment on white random-bred male mice. Genotoxic (micronucleus test), immunologic and pathomorphological methods were used. Results: As a result of the experiment on white outbred mice during the isolated peroral administration of benzo[a]pyrene (a single dose of 0.1 mg) and in combination with phenol (single doses of 0.1 mg; 0.002 mg) a carcinogenic effect (forestomach papillomas) has been established as well as general patterns of the manifestation of genotoxic and immunological changes regarding carcinogenesis and their dependence on the dose and duration of the administration of the substances in the early stages of the experiment. The established patterns involved parallelism of development and unidirectionality of the genotoxic effect (increasing of micronucleus incidence) and suppression of the T-cell immunity by the end of the month as well as reliable negative correlation between them. Conclusions: It has been established that phenol has a modifying effect on carcinogenesis, which was shown as an increase in the micronuclei frequency, intensification of immunosuppression in the early stages and an increase in the multiplicity factor of the development of forestomach tumors.

The aim of the work was assessment of the criterial significance of the complex of early immunological reactions of the organism, pathomorphological and genotoxic changes in the organs for the acceleration of testing and hygienic assessment of carcinogenic danger of chemical substances. Materials and methods: Investigations were carried out in the chronic experiment on white random-bred male mice and included 2 series of the investigations: 1 – application of benz(a)pyrene on skin in different doses (10.5μg; 2.1μg; 0.21μg); 2 - peroral administration of benz(a)pyrene and phenol (single dose - 0.1 mg). Genotoxic changes in skin and forestomach were assessed with the help of micronuclear test. Results: Under carcinogen exposure, regardless of routes of administration we determined an increase frequency of the cells with micronuclei and suppression of T-link of immune system during the first month which were characterized by a parallelism of development, unidirectional relative to carcinogenesis and presence of reliable reverse correlative connection between them. In the period between the 1t and the 3d months we observed a stabilization of the number of cells with micronuclei and deepening of immunosuppression at the expense of the suppression of humoral chain of the immunity. Conclusions: The obtained data became a basis for the development of methodic scheme of accelerated testing of the chemical substances under investigations for carcinogenicity and hygienic setting of genotoxic carcinogens.