Selcer Kyle W, Smith Stacy, Clemens Jeffrey W, Palmer Brent D
Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA.
Comp Biochem Physiol B Biochem Mol Biol. 2005 May;141(1):61-70. doi: 10.1016/j.cbpc.2005.01.013.
Circulating androgens reach high concentrations in females of some reptiles and amphibians. We are testing the hypothesis that androgens can act directly in female reptilian reproductive tissues, via the androgen receptor. In this study, we sought to determine if androgen receptors are present in the oviduct of the turtle, Trachemys scripta, using radioligand-binding assays and immunological assays. An androgen-binding site was detected in turtle oviductal cytosol and oviductal nuclear extract by radioligand binding assay, using (3)H-dihydrotestosterone (DHT) as the ligand. This site was saturable (B(max)=11 pmol/g tissue), had a high affinity (10(-10) M), and showed specificity typical of androgen receptors (DHT>testosterone, progesterone>>estradiol, cortisol). Western blotting using an anti-androgen receptor antibody revealed a band of immunoreactivity in oviductal cytosol at approximately 115 kDa, and a more prominent band at 50 kDa, possibly indicating a truncated form of the androgen receptor. Immunohistochemistry revealed crossreactivity of the androgen receptor antibody against oviductal glandular cells but not against oviductal luminal epithelial or muscularis cells. The presence of androgen receptor in the turtle oviduct suggests that androgens have a role in female reproduction and that their action can be mediated directly by androgen receptor.
在一些爬行动物和两栖动物的雌性个体中，循环雄激素会达到高浓度。我们正在验证一个假说，即雄激素可通过雄激素受体直接作用于雌性爬行动物的生殖组织。在本研究中，我们试图利用放射性配体结合分析和免疫分析来确定在滑龟（Trachemys scripta）的输卵管中是否存在雄激素受体。通过使用（3）H-双氢睾酮（DHT）作为配体的放射性配体结合分析，在龟输卵管胞质溶胶和输卵管核提取物中检测到一个雄激素结合位点。该位点具有饱和性（B(max)=11 pmol/g组织），具有高亲和力（10(-10) M），并表现出雄激素受体典型的特异性（DHT>睾酮，孕酮>>雌二醇，皮质醇）。使用抗雄激素受体抗体进行的蛋白质免疫印迹分析显示，在输卵管胞质溶胶中约115 kDa处有一条免疫反应带，在50 kDa处有一条更明显的带，这可能表明是雄激素受体的截短形式。免疫组织化学显示，雄激素受体抗体与输卵管腺细胞有交叉反应，但与输卵管腔上皮细胞或肌层细胞无交叉反应。龟输卵管中存在雄激素受体表明雄激素在雌性生殖中起作用，并且它们的作用可由雄激素受体直接介导。
