Bilińska B, Leśniak M, Schmalz B
Laboratory of Animal Endocrinology and Tissue Culture, Jagiellonian University, Kraków, Poland.
Reprod Fertil Dev. 1997;9(2):193-9. doi: 10.1071/r96038.
The conversion of testosterone into oestradiol by ovine Leydig cells cultured in vitro was studied using the non-steroidal aromatase inhibitor CGS 16949A. Additionally, aromatase activity was detected by immunohistochemical staining of cultured Leydig cells or cryosections. The cells were obtained from testes of Polish Mountain rams 5-6 months old (immature) or 12-15 months old (mature). Leydig cells were cultured alone (controls) or incubated for 6 h in the presence of testosterone. Aromatase inhibitor was then added to the cultures which were incubated for a further 18 h. After a 24-h incubation period, testosterone and oestradiol secretion were determined by testing the culture medium using radioimmunological methods. The addition of testosterone to the culture medium enhanced oestradiol synthesis, suggesting that exogenous testosterone could also be aromatized to oestradiol by ovine Leydig cells in vitro. In the presence of CGS 16949A, the conversion of testosterone to oestradiol was significantly suppressed in a dose-dependent manner. All Leydig cells obtained from testes of mature rams and stained immunohistochemically were positive for aromatase, whereas Leydig cells from immature males were negative. The localization of immunoreactive aromatase appeared to be dependent on the age of the donor ram. It is suggested therefore, that mature Leydig cells in the ram are not only the site for testosterone synthesis, they are also capable of converting androgens into oestrogens.
利用非甾体芳香化酶抑制剂CGS 16949A研究了体外培养的绵羊睾丸间质细胞将睾酮转化为雌二醇的过程。此外，通过对培养的睾丸间质细胞或冷冻切片进行免疫组织化学染色来检测芳香化酶活性。细胞取自5 - 6月龄（未成熟）或12 - 15月龄（成熟）的波兰山地公羊的睾丸。睾丸间质细胞单独培养（作为对照）或在睾酮存在下孵育6小时。然后向培养物中添加芳香化酶抑制剂，并再孵育18小时。在24小时的孵育期后，通过放射免疫法检测培养基来测定睾酮和雌二醇的分泌。向培养基中添加睾酮可增强雌二醇的合成，这表明外源性睾酮在体外也可被绵羊睾丸间质细胞芳香化为雌二醇。在CGS 16949A存在的情况下，睾酮向雌二醇的转化以剂量依赖的方式被显著抑制。所有取自成熟公羊睾丸并经免疫组织化学染色的睾丸间质细胞对芳香化酶呈阳性反应，而取自未成熟公羊的睾丸间质细胞呈阴性。免疫反应性芳香化酶的定位似乎取决于供体公羊的年龄。因此，有人提出，公羊体内成熟的睾丸间质细胞不仅是睾酮合成的场所，它们还能够将雄激素转化为雌激素。
