Effect of prenatal exposure to diethylstilbestrol on gubernacular development in fetal male mice

To study the effect of prenatal exposure to diethylstilbestrol (DES) and the role of actin and proliferating cell nuclear antigen (PCNA) on testicular gubernaculum development in fetal male Kunming mice. Methods: Pregnant mice were randomly assigned to 6 groups and injected with DES subcutaneously from gestational day 9 (E9) to day 17 (E17) at doses of 0, 25, 50, 100, 200 mug(.)kg(-1.)d(-1) in 0.2 mL dimethyl sulfoxide (DMSO). On E17 they were sacrificed and fetuses quickly removed for fixation. Male fetuses were sliced on serial coronal plane. Histological changes were observed under the light microscope (LM) and ultrastructural changes with the scanning and transmission electron microscopes (SEM & TEM). The expression intensity of actin and PCNA in the gubernacula was quantitated by immunohistochemistry. Results: The mortality of the fetuses was higher in the DES-treated groups than that in the DMSO and saline controls (P<0.05). Under LM the gubernacula were seen to be poorly developed with smaller bulbs. On SEM the bulbs lose the clear demarcation between the mesenchymal inner core and the muscular outer layer and looked like a small cone instead of the normal cylindrical appearance. On TEM there were some smaller disordered myofibrils and sparse cytoplasmic organelles in the gubernacular muscular cells of the treated groups. The expression intensity of actin and PCNA in the gubernacula was significantly weaker in the treated groups than that in the DMSO and saline controls (P<0.05). Conclusion: DES induces underdevelopment of the gubernacula in a dose-dependent manner in fetal male mice and down regulates the actin and PCNA expression.