The effect of epitestosterone on spermatogenesis in rats

The effect of 3-week treatment with increasing doses of endogenous steroid with antiandrogenic properties, epitestosterone (ET), on the spermatogenesis was studied in adult male rats by flow cytometry and correlated with the effect on gonadotropin gene expression and secretion, on testosterone and dihydrotestosterone plasma levels and on the weight of testes and prostates. Epitestosterone was administered to the rats by means of silastic capsules of different lengths filled with the steroid. A decrease of the number of total spermatides in the epitestosterone treated animals was observed. In the group with the lowest dose of ET the number of elongated spermatides was significantly reduced. The number of germ cell types and their relative proportions were correlated with the endocrine parameters reported previously. Significant negative correlation between the pituitary content of LH and total number of germ cells per 1 g of testicular tissue and of the number of spermatides/g and between testosterone level in serum and the number of diploid cells in the animals treated with higher doses of ET was found. In the group with highest ET dose a negative correlation of diploid cells and serum dihydrotestosterone was observed, too. The naturally occurring antiandrogen epitestosterone can be considered as one of the endogenous factors influencing spermatogenesis.