Prepubertal orchidectomy induces thymic abnormalities in aging (NZB X SJL) F1 male mice
Dumont, F.; Barrois, R.; Habbersett, R.C.
Journal of Immunology 129(4): 1642-1648
1982
ISSN/ISBN: 0022-1767 PMID: 7108219 Document Number: 183470
Female but not male (NZB .times. SJL)F1 (NS) mice develop abnormalities of their intrathymic lymphocyte population in the course of aging. To determine the role played by androgens in this sex-related difference, the evolution of the cellular composition of the thymus was monitored in NS males deprived of androgens by prepubertal orchiectomy. Although in young mice this operation resulted in a 2-fold enlargement of the thymus, there was no histologic alteration or major change in the surface phenotype and mitogenic reactivities of the thymocytes, which suggests that all thymocyte subsets were increased to the same extent. In 12 mo. old control (BALB/c .times. SJL)F1 mice, prepubertal orchiectomy also produced an equal expansion (1.4-fold increase) of all thymocyte subsets. In 12 mo. old orchiectomized NS males, there was a marked depletion of the thymic cortex and a hyperplasia of the medullary lymphoid tissue reflecting the selective expansion of a subset of phenotypically mature T cells (dull Thy-1+, Lyt-1+2.+-., dull PNA+), together with the emergence of intrathymic surface Ig-bearing cells. These latter cells probably represented B cells because there was a concomitant augmentation of the mitogenic responsiveness in vitro of thymic cell suspensions to lipopolysaccharide. Such thymic abnormalities induced by prepubertal orchiectomy in old NS males resemble those occurring spontaneously in the NS females. The absence of thymic disease in intact NS males is probably primarily due to a suppressive effect of androgens.