Effect of Compound Cdri 84/35 and Synthetic Estrogen on the Seminiferous Epithelium of Immature Rat

Abstract

Compound CDRI 84/35 (a piperazine derivative--a potent antispermatogenic agent) has been shown to cause significant inhibition in testicular spermatogenesis without affecting Leydig cell and accessory sex organ function in adult rats. The present study was conducted to determine its effect on the germ cell population and Leydig cell morphology in immature rats (40-50 gm) administered CDRI 84/35 (100 mg/kg/day p.o.), synthetic estradiol benzoate (EB; 5 microg/rat/day) and vehicle at the age of 21 days. Animals were killed 24 h later following 7 and 14 days' treatments. Bouin's fixed testes were sectioned (at 5 microm) and stained with PAS-hematoxylin. Quantitative determination of Sertoli Cell-Germ Cell ratio was carried out in 150 round seminiferous tubules in each group of 5 rats. Results revealed a significant decrease in number of the spermatocytes (non-pachytene and pachytene) and early (round) spermatids in step 1-8 of spermiogenesis without affecting Leydig cell morphology in rats administered CDRI 84/35 for 7 and 14 days as compared to corresponding controls. In contrast, the testes of rats injected with synthetic EB, caused a marked inhibition in these meiotic and post-meiotic germ cell types, as well as in the diameters of round seminiferous tubules, and Leydig cells nuclei (only in 14 days treatment), and testicular weight on autopsy days 8 and 15 as compared to CDRI 84/35-treated rats. While the number of pre-meiotic spermatogoniae was observed to be slightly decreased after only 14 days treatment in both CDRI 84/35 and EB treatment groups, the Sertoli cell number did not show any significant change as compared to controls. The present investigation confirms the antispermatogenic effect of compound CDRI 84/35 in immature rats similar to that reported in adult rats. Marked inhibition in pachytene spermatocytes and other testicular parameters following synthetic estrogen treatment might be due to its antiandrogenic action, contrasting with the non-hormonal profile of CDRI compound.