免疫去势和未去势猪睾丸上生长激素释放肽的定位及其基因表达

目的:探讨生长激素释放肽在猪睾丸中的定位及其基因表达,以及免疫去势对猪睾丸中生长激素释放肽表达的影响.方法:14头9周龄公猪随机分为免疫去势组和对照组(未去势组),25周龄时屠宰,取血清和睾丸组织,放射免疫法检测血清睾酮的水平,免疫组织化学PV-9000两步法确定生长激素释放肽在睾丸中的细胞定位,实时荧光定量PCR法分析睾丸中生长激素释放肽mRNA的变化.结果:免疫去势组猪血清睾酮水平显著地低于未去势组;免疫组织化学显示表达生长激素释放肽的细胞为精原细胞、初级精母细胞、精子细胞、支持细胞和间质细胞,且免疫去势猪阳性细胞数显著多于未去势猪.另外,猪睾丸中有生长激素释放肽mRNA,但免疫去势组与未去势组间差异无统计学意义.结论:猪睾丸中广泛存在生长激素释放肽及其mRNA,免疫去势导致生长激素释放肽的表达增多.

Localization and gene expression of ghrelin in the testes of gonadally intact male and immunocastrated pig

Objective: To investigate the distribution and gene expression of ghrelin in the testes of pigs, and the effects of immunocastration on the expression of ghrelin in the testes of pigs. Methods: Fourteen 9-week-old male pigs were randomly divided into two groups: immunocastration and control (gonadally intact male pigs). All boars were sacrificed at age of 25 weeks. Testicular tissue and serum samples were collected.The concentration of testosterone in serum was determined by radioimmunoassay, the localization and gene expression of ghrelin in testicular tissues were detected by immunohistochemical PV-9000 2-step and real-time fluorescent quantitative PCR analysis, respectively. Results: The concentration of serum testosterone in immunocastrated pigs was significantly reduced than that in the gonadally intact boars. Ghrelin immunopositive cells was mainly found in spermatogonia, primary spermatocyte, spermatid, Sertoli cell and interstitial cell. However, the number of immunopositive cells in immunocastration boars was significantly more than that of the gonadally intact boars. In addition, ghrelin mRNA was present in the testis of pigs, but there was no significant difference in the quantity of ghrelin mRNA in immunocastration boars when compared to that in the gonadally intact boars. Conclusion: The results suggest that ghrelin mRNA and ghrelin-producing cells exist in the testis of boars, and the expression of ghrelin increased in immunocastrated boars.