Histological changes of the testis and epididymis in adult rats as a result of Leydig cell destruction after ethane dimethane sulfonate treatment： a morphometric study

Aim： To quantitatively study the histological changes of the testis and epididymis as a result of a drastic reduction of testosterone secretion. Methods： Fourteen adult Sprague-Dawley rats were injected intraperitoneally with ethane dimethane sulfonate （EDS, 75 mg/kg） and the same number of animals were injected with normal saline as a control. At days 7 and 12 （after treatment）, respectively, half of the animals from each group were killed. The testes and epididymides were removed and tissue blocks embedded in methacrylate resin. The cell number per testis was estimated using the stereological optical disector and some other parameters were obtained using other morphometric methods. Results： The EDS treatment resulted in an almost complete elimination of Leydig cells but had no effect on the numbers of Sertoli cells per testis. At day 7 after EDS treatment, many elongated spermatids were retained in the seminiferous epithelium and many round spermatids could be seen in the epididymal ducts. At day 12, a looser arrangement of spermatids and spermatocytes became evident, with apparent narrow empty spaces being formed between germ cells in an approximately radial direction towards the tubule lumen; the numbers （per testis） of non-type B spermatogonia and spermatocytes were similar to controls, whereas that of type B spermatogonia increased by 59%, and that of early round, elongating and late elongated spermatids decreased by 37%, 72% and 52%, respectively. Conclusion： The primary spermatogenic lesions following EDS administration were （i） spermiation failure and （ii） detachment of spermatids and spermatocytes associated with impairment in spermiogenesis and meiosis.

Protective effects of vitamin E on ethane dimethane sulfonate-induced testicular toxicity in rats

Aim： To evaluate the protective/ameliorative effects of vitamin E （vit E） on ethane dimethane sulfonate （EDS） induced testicular toxicity in rats. Methods： The rats were assigned to eight groups, seven rats in each, and were injected intraperitoneally with vehicle, a single dose of ethane dimethane sulfonate （EDS） （75 mg/kg bodyweight）, vit E （100 mg/kg bodyweight） or EDS ＋ vit E for 3-7 days. Thereafter, the rats were weighed, anaesthetized with ether and killed by cervical dislocation. The left testis weights were recorded and the relative testis weights were calculated. The left testes were processed for routine paraffin embedding. Three right testes from each group were taken randomly and then processed for routine electron microscopy. Tissue sections were examined using light and electron microscopy, and were scored for histopathological changes. Results： Vit E coadministration did not prevent the bodyweight loss on days 3 and 7. However, vit E administration prevented the EDS-induced testicular-weight loss in rats that received vit E for 3 days but not 7 days. The relative testis weight was higher on day 3 （instead of on day 7） than other groups. Nevertheless, the testis histology was not markedly protected by vit E in the EDS-treated rats. Detailed microscopic assessment showed few Leydig cells and abundant fibroblast-like cells indicating only some protection. Conclusion： Vit E cotreatment showed partial protective effects on the testicular weight and testicular histology in rats that received EDS.

二甲磺酸乙烷致间质细胞破坏所引起的成年大鼠睾丸和附睾的组织学变化:形态定量研究

Aim:To quantitatively study the histological changes of the testis and epididymis as a result of a drastic reduction of testosterone secretion.Methods:Fourteen adult Sprague-Dawley rats were injected intraperitoneally with ethane dimethane sulfonate(EDS,75 mg/kg)and the same number of animals were injected with normal saline as a control. At days 7 and 12(after treatment),respectively,half of the animals from each group were killed.The testes and epididymides were removed and tissue blocks embedded in methacrylate resin.The cell number per testis was esti- mated using the stereological optical disector and some other parameters were obtained using other morphometric methods.Results:The EDS treatment resulted in an almost complete elimination of Leydig cells but had no effect on the numbers of Sertoli cells per testis.At day 7 after EDS treatment,many elongated spermatids were retained in the seminiferous epithelium and many round spermatids could be seen in the epididymal ducts.At day 12,a looser arrangement of spermatids and spermatocytes became evident,with apparent narrow empty spaces being formed between germ cells in an approximately radial direction towards the tubule lumen;the numbers(per testis)of non- type B spermatogonia and spermatocytes were similar to controls,whereas that of type B spermatogonia increased by 59%,and that of early round,elongating and late elongated spermatids decreased by 37%,72% and 52%,respectively. Conclusion:The primary spermatogenic lesions following EDS administration were(i)spermiation failure and(ii) detachment of spermatids and spermatocytes associated with impairment in spermiogenesis and meiosis.