RÉSUMÉ
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 μg/kg, 30 μg/kg, 3 ms/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 histopathologieally examined. In all the rats in the DES groups, spermatogenesis was re-established and the rats in the 30 μg/kg group showed the best results. Serum T was suppressed markedly in rats of 30 μg/kg and 3 mg/kg groups while T was only mildly inhibited in 0.3 μg/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.