Effects of sildenafil citrate, isoniazid, and streptomycin on testicular tissue and epididymal semen quality in rats.

OBJECTIVE: To evaluate the effects of isoniazid (INH) and streptomycin (STR) on epididymal semen quality and testicular tissue, and to evaluate the protective effect of sildenafil citrate (SC) on possible testicular toxicity induced by STR and INH in rats.

METHODS: Eighty adult male Sprague-Dawley rats were divided randomly into 8 groups including control, SC, INH, STR, STR+INH, SC+INH, SC+STR, and SC+INH+STR. After 45 days of treatment, the reproductive organ weights, epididymal semen quality, testicular histopathological findings, levels of serum nitric oxide, testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were investigated.

RESULTS: SC significantly increased the epididymal sperm motility and concentration, and the levels of FSH, LH, and testosterone. The STR group had a significantly higher percentage of sperm head defect than the control group (P < .05). The INH group had lower Johnsen Testicular Biopsy Score than the control group (P < .001). Although SC and INH treatment alone did not affect the epididymal semen quality negatively, the SC+INH group had significantly higher spermatozoon tail and total morphologic defect ratios than the control group (P < .05).

CONCLUSION: It has been concluded from this study that (1) SC has positive effects on spermatogenesis, sperm production, and semen quality; (2) STR affected the testicular biopsy score and spermatozoon head morphology negatively, but positively affected the other spermatologic traits; (3) INH did not effect the epididymal semen quality negatively, but decreased testicular biopsy score; and (4) SC can prevent the spermatozoon head defects induced by STR and can decrease the testicular toxicity induced by INH.