Changed antitumor resistance as a genetic consequence of prolonged exposure to spectrum of radionuclides of Chernobyl discharge

Antitumor resistance was investigated in progeny (F-1-F-2) of C57BI males w ho had been exposed for a long time to irradiation in the Chernobyl NPP zon e without exposure of the progeny to above-natural background loads in the embryonic and postnatal periods. Uniform-type changes were found in antitum or resistance to both highly antigenic (B-16 melanoma) and low antigenic (L ewis carcinoma) tumors. The character of changes in antitumor resistance wa s shown to vary in different generations of exposed animals' progeny. Depen ding on the activity of effecters of non-specific antitumor responses, effe cters of specific immune cytolysis, and suppressor activity, antitumor resi stance to the transplantable model tumors studied was reduced (in F-1), unc hanged or even increased (in F-2). Our findings suggest that changed antitu mor resistance may be reckoned as one of the genetic effects of prolonged e xposure of one of the parents (male) to combined irradiation in low doses.