Effects of diethylstilbestrol on the expression of estrogen receptor and endothelial nitric oxide synthase in testis and epididymis of male Xiang pigs

Objective To investigate the effect of diethylstilbestrol( DES) on the expression of estrogen receptors and endothelial nitric oxide synthase in the testis and epididymis of male Xiang pigs. Methods Twenty( 20-25-days-old)pigs were randomly divided into four groups,one control group and three treatment groups,with 5 pigs in each group. The animals in 3 treatment groups were intraperitoneally injected diethystilbestrol at doses of 0. 03 mg /( kg·d),0. 3mg /( kg·d),3mg /( kg·d),respectively for 9 days. The left testes of each animal was excised 24 hours after last injection. The testicular and epididymal tissues were sectioned at a thickness of 5μm for immunohistochemical staining. The immunohistochemistry technique was used to observe estrogen receptors,including ERα and ERβ,and endothelial nitric oxide synthetase distribution. Results The immunohistochemical positive staining for ERα was only distributed in the nuclei of the efferent ductule epithelia and the ERβ was distributed in the nuclei of the epithelia of both the efferent ductule and epididymis tube. The ERβ was distributed in the cytoplasm of the seminiferous tubule. The percentage of ERα positive cells in the efferent ductule was significantly decreased,whereas is ERβ positive cells in the efferent ductule and epididymis tube were increased( P 0. 05) after exposure to DES,but the percentage of ERβ-positive cells of testis seminiferous tubule significantly decreased at 0. 03 mg / kg dose of DES( P 0. 05),and no ERβ expression in testes seminiferous tubule at 0. 3 mg / kg,3 mg / kg dose of DES. The e NOS immunoreactivity was distributed in the seminiferous tubule and efferent ductule epithelia. The percentage of e NOS positive cells in seminiferous tubule was significantlyincreased( P 0. 05). In the contrast,e NOS positive cells in efferent ductule epithelia were decreased( P 0. 05) after exposure to DES. Conclusion DES has a significant effect on the expression of ERs and e NOS in testis.