Effects of estrogen on human seminiferous tubules: light and electron microscopic analysis

Morphological features of testes from four subjects after long-term treatment with ethinyl-estradiol (1--2 mg daily) and from five non-treated patients with prostatic carcinoma were studied by means of light and electron microscopy. The non-treated seminiferous tubules contained spermatagonia, spermatocytes, spermatids, spermatozoa, and Sertoli cells and showed no apparent morphologic abnormalities. On the other hand, the estrogen-treated testicular tissue contained only Sertoli cells and very few spermatogonia within the seminiferous tubules. The nuclei of Sertoli cells occasionally contained two nucleoli. The nucleolar complex was composed of a fine granular spherical body surrounded by a large granular, reticular network. The cytoplasm of the Sertoli cell contained osmiophilic lipid-like bodies. These lipid-like bodies appeared more pronounced in patients treated with higher doses of estrogen, suggesting a diminution of secretion of Sertoli cell hormone. Blebbing from the outer nuclear membrane appeared to have formed numerous vesicles in the cytoplasm. These vesicles usually contained several membrane-bound granular bodies. In the estrogen-treated testes, there was a marked increase in thickness and infolding of the basement membrane. Two unusual patterns of the basement membrane were observed: one appeared to be a reticular anastomosis, the other, an electron-dense trilayer. The morphological picture of seminiferous tubules from the estrogen-treated subjects appeared to correlate well with the suppressed plasma and testicular levels of testesterone, the undetectable circulating gonadotrophins, and the elevated plasma and testicular levels of estradiol-17 beta reported by Rodriguez-Rigau et al. ('77).