Studies on the induction and development of lymphosarcoma by N-Nitrosobutylurea in RF Mice. 2. Immunological observations

The induction and development of tumors by chemical carcinogens are explained by the correlation of the tumor antigen and host. Especially the immunity of the host is regarded as important. Therefore, the immunological effect on the host was studied. 1. The serum protein analysis showed an increase of β(2)-globulin due to an increase of transferrin and decrease of γ-globulin suggesting a decline of immunity. 2. The plaque forming cells of the spleen and thymus four days after a single i.p. injection of 0.2ml of 20 percent sheep red cells were decreased from the early stage of administion of NBU and markedly decreased already before the induction of tumors and were very rare during the tumor growth. 3. The hemolysin and hemagglutinin titers four days after a single i.p. injection of 0.2ml of 20- percent sheep red cells also showed similar changes.