Quantitative interactions in weight of lymphoid organs and steroid hormonal organs in hamsters under several experimental conditions.

The adrenal and gonadal steroid hormones may continue to regulate lymphoid cells in tissues of mammals throughout their life span. To examine quantitative interrelationships between the endocrine and immune systems, we measured weights of the organs and compared them. The results showed that: (1) The relative weight of the adrenals in adult male hamsters significantly exceeded that of age-matched females. The adult thymus and spleen were heavier in females. (2) Adult gonadectomy induced marked involution of the thymus and adrenal hypertrophy in both sexes. (3) A single oestrone injection at suckling has severe, long lasting effects, with gonadal atrophy and hypertrophy of lymphoid tissues in both sexes for I year. (4) Testosterone in the same way produced adrenal hypertrophy in female hamsters, and adrenal atrophy in males. (5) Thymectomy, at 3 weeks of age, resulted in marked atrophy of the gonads in late adulthood in both sexes. (6) Repeated pulses of cortisone acetate led to marked involution of the thymus and steroid organs, the adrenals and testes. The rather unexpected results, as in (2), (3) and (5), probably represent the ultimate consequence of serial interactions among these organs after treatment. These findings suggest that there is thymus-gonads interdependence even in adulthood, and that subtle counterbalancing co-operation between the adrenals and gonads may regulate lymphocyte functions in tissues. between the adrenals and gonads may regulate lymphocyte functions in tissues.