[DNA flow cytometric evaluation of spermatogenesis of the rebound phenomenon with testosterone in adult male rats].

To examine the effects of the rebound phenomenon on the rat testis, adult male Wistar rats were treated with 0.3 mg/day of testosterone propionate (TP) for 39 days. Observations were made on 0, 26, 52, 78 and 104 days following the TP treatment. The response of the testis was investigated by determining the testicular weight and DNA flow cytometric analysis in the testicular cells. The % haploid cells (spermatids) increased at the 52nd and the 78th day after TP treatment, and were equal to the rate of the control group. The % diploid cells and % tetraploid cells showed no change. The duration of the rebound phenomenon was about 2-2.5 months.