Abstract: | In tissues of non-lineal rats receiving dimethyl amino-azobenzene (DAAB) or its non-carcinogenic analog diethyl amino-azobenzene (DEAB) there was found, using rabbit serum against an artificial complex RNA + MBSA (methylated bovine serum albumin), the RNA-haptene in the reaction of counter-immunoelectrophoresis in the liver and serum of rats in definite terms since the start of DAAB administration. RSR reaction and immunoelectrophoresis have demonstrated the presence of circulating antibodies against hepatic cell RNA. The kinetic of antibodies against RNA is characterized by their increase after 15 DAAB injections, their decrease to the 60th day and again an increase by the time of the tumor appearance. It is suggested that the phenomena of sensibilization and desensitization to the antigens arising in the process of carcinogenesis play a definite role in "cancelling" the antitumor immunity. |