Orchidectomy and the immune response II. Response of orchidectomized mice to antigens

The responses of orchidectomized mice to several antigens have been investigated. Orchid-ectomy was associated with an accelerated rejection of skin allograft, which was prevented by androgen administration, abrogated by anti-lymphocyte serum and potentiated by cyclophosphamide. Reactivity of orchidectomized mice to oxazolone, sheep red blood cells and graft versus host disease, which are limited by thymus-processed cells, was increased whereas production of antibodies to bovine serum albumen, skin allografts and pneumococcal poly-saccharide was unchanged. It is proposed that orchidectomy augments cell mediated immune responses, but has no direct effect on responses transacted mainly by B cells. The effect of cyclophosphamide may be due to the withdrawal of a restraining influence on cell mediated immunity normally exercised by humoral antibody.