Chronic Effects of Di(2-ethylhexyl)phthalate on Stereological Parameters of Testis in Adult Wistar Rats

Objective(s) In recent years concerns have been raised regarding the incidence of male reproductive disorders from exposure to endocrine disruptors. So, chronic effects of di(2-ethylhexyl)phthalate were studied on histological and stereological structure of testis in adult Wistar rats. Materials and Methods Thirty two adult Wistar rats were randomly divided in four equal experiment groups; oil vehicle group and three treated groups which received 10, 100 and 500 mg/kg/day di(2- ethylhexyl)phthalate by gavage for 90 days, respectively. At the end of exposure period the volume of testes was measured by Cavellieri method, testes weight was recorded and then fixed in Bouin’s solution. Following tissue processing, 5 μm sections were stained with haematoxylin-eosin and evaluated with quantitative techniques. Seminiferous tubule diameter, germinal epithelium height, relative and total volumes of seminiferous tubules, tubular lumen and interstitial tissue were estimated. Results The results showed that mean weight and volume of testis were decreased significantly (35.2% and 23.9% respectively) in rats treated with 500 mg/kg/day DEHP for 90 days. Seminiferous tubules diameter reduced, 4.4% and 13.4% in 100 and 500 mg/kg/day DEHP-treated groups, respectively. Relative volumes of tubular lumen and interstitial tissue were increased significantly in 100 (P< 0.05) and 500 (P< 0.01) mg/kg/day doses groups. Also, testosterone serum levels were significantly higher (P< 0.05) in rats exposed to 500 mg/kg/day DEHP. Conclusion Present study indicated dose-dependent reductions of testicular parameters in adult male rats chronically exposed to di(2-ethylhexyl)phthalate.