Changes in daily sperm production rate in rats under the influence of a potent antispermatogenic agent, CDRI 84/35

CDRI 84/35, a potent nonsteroidal antispermatogenic agent, causes total sterility in rats by directly acting on germ cells while having no effect on Sertoli/Leydig cells. This study was conducted to evaluate the effect of the compound on gametogenic activity of testes and to identify stages of spermatogenesis that were affected. Adult male rats administered either compound 84/35 at minimum effective dose or estradiol (5 micrograms) or water only were killed on days 22, 41, and 64 of the treatment period to evaluate the effect on spermatid, spermatocyte, and spermatogonial stages, respectively. Daily sperm production (DSP) was measured employing a homogenization technique. Results showed a decline in testis weight and DSP with a drastic reduction (approximately 95%) in DSP in 84/35-treated rats on day 41 of the treatment period. Estradiol was more potent in reducing the testis weight; however, 84/35 had an edge over estradiol in reducing the DSP. After withdrawal of treatment for 120 days, a phenomenal recovery (> 90%) in DSP per gram parenchyma was noted in 84/35-treated animals. Results indicate a direct effect of estradiol on spermatogonia, whereas 84/35 seems to affect the spermatocyte stage.