Hormones and immunological capacity. II. Reconstitution of antibody production in hormonally deficient mice by somatotropic hormone, thyrotropic hormone and thyroxin.

Hypopituitary dwarf mice are immunologically deficient. This deficiency can be overcome by injection of somatotropic hormone and thyroxin. Antibody formation in hormonally reconstituted mice as measured by the number of plaque-forming cells against sheep erythrocytes equals or surpasses that of normal mice. The number of nucleated spleen cells is increased in both normal and dward mice after treatment with hormones. The hypotrophic thymus and peripheral lymphoid tissue of dwarf mice can be reconstituted to normal by treatment with somatotropic hormone and thyroxin. Anti-somatotropic hormone and anti-thyrotropic hormone antisera produce suppression of antibody formation. These effects can be reversed by somatotropic hormone and thyrotropic hormone. The anti-hormone antisera produce an involution of thymus and other lymphatic organs. A parallelism exists between involution of the lymphoid tissue, neutralization of circulating somatotropic hormone and depression of antibody production. These results stress the importance of the thymus—hypophysis relationship for cell differentiation with particular reference to the maturation of the immunological capacity.