Differential effects of castration in sexually immature and mature rats on the phenotypic profile of thymocytes

Abstract

In order to assess the influence of gonadal hormones on the process of intrathymic T cell-maturation, peripubertal(30 days old) and young adult (60 days old) rats were castrated and the total thymic cellularity as well as the cellularity of the main thymocyte subpopulations defined by the expression of CD4 and CD8 molecules, and TCRab were analyzed in adult (75 days old) rats. The total yield of thymocytes was significantly increased in adults castrated at day 30 over the controls. Also, the total number of CD4+/CD8+ double positive (DP) thymocytes as well as the total number of both the CD4+/CD8- and CD4-/CD8+ single positive (SP) and TCR alpha beta positive thymocytes were significantly increased in these rats. However, castration performed in young adult rats affected neither the total thymic cellularity nor the cellularity of the main thymocyte subpopulations. Results clearly indicate that: a) castration performed before sexual maturity affects the process of intrathymic T cell maturation in adults and b) the process of intrathymic T cell development is not altered in adults of the same age castrated in very early adulthood.