Re-establishment of spermatogenesis by diethylstilbestrol after 2,5-hexanedione-induced irreversible testicular atrophy in rats.

To investigate the effects of diethylstilbestrol (DES) in reestablishing spermatogenesis and the mechanism by which estrogen works on spermatogenesis, rats were exposed to 1% 2,5-HD for 5 week. Then 0.1 mL of DES was given (s.c.) at a rate of 0.3 microg/kg, 30 microg/kg, 3 mg/kg every other day for 2 weeks respectively (DES group) while the other rats received ethyldeate only. Plasma testosterone (T) and LH were measured on the 8th week after the treatment. The rats were killed at the 18th week. The left testis was histopathologically examined. In all the rats in the DES groups, spermatogenesis was re-established and the rats in the 30 microg/kg group showed the best results. Serum T was suppressed markedly in rats of 30 microg/kg and 3 mg/kg groups while T was only mildly inhibited in 0.3 g/kg group, without significant difference found in serum LH. It is concluded that the nearly complete testicular atrophy could be reversed by DES treatment in rats. Estrogen plays an important part in spermatogenesis, and the role of estrogen in spermatogenesis is more than suppressing the hypothalamo-pituitary-testis axis.