The Effect Of Estrogen On Sertoli Cells,Spermatogenic Cells And ERs Of Guizhou Xiang Pig Testes

Estrogen, with a broad spectrum of biological activities, is a steroid compound hormone produced in animal's body; it has an important role in female and male animal reproductive system development and reproductive processes. A large number of studies have indicated that exogenous estrogen can affect normal development and function of male reproductive system, but the mechanism of estrogen action is unclear. The action of Estrogen was mediated by corresponding receptor, Estrogen may also affect male reproductive function by regulating the expression of steroid synthesis key factors. In addition,the regulatory effect of the estrogen on NO expression, may be one of the mechanisms of Estrogen affecting male reproductive functions, The mouse or rat is one of the most extensively used animals in previous research on the mechanism of action of Estrogen. While these results may not be directly applied to livestock and other animals. Meanwhile, immature male animal may be more sensitive to estrogen. Therefore, In this study, immunohistochemistry and ELISA were used for identifying testis cells expressing the estrogen receptor or e NOS, and investigating the effect of different doses of Estradiol(control group, 0 mg?d^-1; low dose group, 0.1mg?d^-1; medium dose group, 0.5mg?d^-1; high dose group,2.5mg?d^-1)on Sertoli cell and germ cell number of seminiferous, the expression of estrogen receptor, the content of SF^-1, 3?-HSD and NOS in the testicular tissue of immature xiang pig. Furthermore, Cell culture was used to study the effect of Estradiol on Sertoli cell proliferation at different doses. The results showed that,1. The effects of E₂ on Sertoli cell and germ cell number of immature xiang pig. Immunohistochemical detection showed that different doses of E₂ could significantly decreased germ cell number?P < 0.05?, while there was no significant difference between three different-dose groups. Compared with control and low dose groups,the Sertoli cell number of medium and high dose groups significantly decreased?P < 0.05?. The cell culture results showed that low concentrations of E₂(10^-7 mol/L, 10^-8 mol/L, 10^-9 mol/L) had no significant effect on Sertoli cell proliferation, and the high levels of E₂(10-6 mol/L, 10^-7 mol/L) can decrease the Sertoli cell proliferation?P < 0.05?.2. The effect of E₂ on the expression of estrogen receptor in testis of immature xiang pig. Immunohistochemical detection showed that ER? staining was negative in testis and ER? immunoreactivity was only distributed in the nuclei of the germ cell. Statistical analysis showed that the percentage of ER? positive cells of seminiferous tubule were significantly decreasing with increasing the dose of E₂?P < 0.05?.3. The effect of E₂ on the expression of e NOS and the content of NOS in testis of immature xiang pig. Immunohistochemical detection showed that e NOS immunoreactivity was observed only in the cytoplasm of germ cell, while the Ledig cell and the Sertoli cell showed no expression of e NOS. Statistical analysis showed that the percentage of e NOS positive cells in medium and high dose groups were significantly higher than that of control and low dose groups?P < 0.05?. Furthermore, Enzyme Linked Immunosorbent Assay?ELISA? was used to measure the content of NOS in testis.The results showed that the expression of NOS in the three E₂-treated groups were increased significantly?P <0.05?, compared with the control group.4. The effect of E₂ on the expression of steroid synthesis key factors in testis of immature xiang pig. The content of SF^-1 and 3?-HSD in testis were measured by Enzyme-linked immunosorbet assay. We found that the expression level of SF^-1 significantly increased?P <0.05? with increasing E₂ doses. Moreover, E₂ could increase the expression level of 3?-HSD in the testis. The highest expression level of 3?-HSD was measured at 0.5 mg?d^-1 dose of E₂?P <0.05?,but the expression level significantly decreased at 2.5 mg?d^-1 dose?P <0.05?.