Abstract

Experimental studies were performed to observe the effects of anticancer agents on the immune response in the rabbit. Horse serum immunization and the injection of anticancer agents were continued for 3 weeks with controlled intervals. The pyroninophilic cells in the spleen, mesenteric lymphnodes and thymus were counted for the indication of antibody formation. The following results and conclusion were obtained. 1) Injections of anticancer agents show an increased number of pyroninophilic cells in the spleen and lymphnodes. The degree of this increase is highest in the mitomycin C treated group, and follows 6Mp, 5Fu, methotrexate, nitromin and nitrogen mustard treated groups in decreasing order. 2) Injections of anticancer agents with horse serum immunization show remarkable decrease of the pyroninophilic cells in the spleen and lymphnodes. This effect is most conspicuous in methotrexate and nitrogenmustacd treated group, less conspicuous in nitromin, 6MP and 5Fu treated group, and inconspicuous in mitomycin Ctreated group. 3) It may be concluded that the anticancer agents have inhibitory effects on the experimental antibody formation and the degree of this inhibitory effects is conspicuous in methotrexate, nitrogen mustard, nitromin, 6MP. 5Fu, and Mitomycin C in decreasing order. 4) The pyroninophilic cells in the thymus is neglisible in number in all experimental groups of rabbits.