In Utero Exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Affects the Development of Reproductive System in Mouse

PURPOSE: Exposure of male reproductive organs to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) has been reported to cause developmental changes. In this study, we evaluated the effects of in utero TCDD exposure on male reproductive development. MATERIALS AND METHODS: Pregnant C57BL/6 mice were administered a single intraperitoneal injection of TCDD (1 µg/kg) on gestation day (GD) 15. The offspring were examined in the immature stage on postnatal day (PND) 30 and in the mature stage on PND 60. The testes were examined for histological changes, androgen receptor (AR), proliferating cell nuclear antigen (PCNA) and apoptosis following the measurement of morphological changes. RESULTS: Anogenital distance (AGD) and testis weights were reduced by TCDD exposure both on PND 30 and PND 60 while body weights and length of male offspring were not affected by TCDD. The regular sperm developmental stage was impaired with TCDD treatment on PND 30. However, no difference was found between the control group and TCDD groups on PND 60. Simultaneously, the expression of AR was also reduced on PND 30, while it was increased on PND 60 compared with the control group. The expression of PCNA was decreased whereas apoptosis was not affected by TCDD both on PND 30 and PND 60. CONCLUSION: These results suggest that in utero exposure to TCDD influences the development of testes by inhibiting the expression of AR and PCNA. Moreover, the adverse effects of TCDD on male offspring reduced over time.