Localization of the glucocorticoid receptor in testis and accessory sexual organs of male rat

Localization of glucocorticoid receptor-like immunoreactivity (GR-LI) was studied in adult rat testis, epididymis, ejaculatory duct, seminal vesicle and prostate by light and electron microscopic immunocytochemistry. In the interstitium of the testis GR-LI was seen in the nuclei of Leydig cells, macrophages, fibroblasts, smooth muscle cells and endothelial cells of blood vessels. Furthermore, GR-LI was observed in zygotene and early pachytene primary spermatocytes of some seminiferous tubules during stages XIII-XIV and I-III of the spermatogenic cycle. Other spermatogenic cells and Sertoli cells were devoid of staining. GR-LI was also found in peritubular myoid cells, fibroblasts and basal cells of the epididymis, vas deferens and prostate. Localization of GR-LI in primary spermatocytes and Leydig cells suggests that glucocorticoids directly affect spermato- and steroidogenesis in the testis. The absence of GR-LI from functional, stromal cells of the male accessory sexual organs suggests that they are not targets for glucocorticoid hormones.