Korsgaard B
Institute of Biology, University of Southern Denmark, Odense, Campusvej 55, 5230 Odense M, Denmark.
Mar Environ Res. 2006 Jul;62 Suppl:S205-10. doi: 10.1016/j.marenvres.2006.04.033. Epub 2006 Apr 18.
In the present experiment male and female eelpout, Zoarces viviparus were exposed to different doses of the model androgen 17alpha-methyltestosterone (MT) and the effects on the plasma level of vitellogenin and the gonadosomatic index were investigated. In females exposed to different doses of MT (nominal concentrations 10, 25, 50, 100 and 500 ng/L) in the ambient seawater, the concentrations of the circulating yolk-precursor protein vitellogenin (vtg) were shown to decrease in all groups but only significantly in the MT-100 group when compared to controls. No significant effects could be observed on the GSI during early vitellogenesis (April/May). Males exposed to E2 under flow through conditions during 10 days showed an induced synthesis of vtg as depicted by a high level of circulating vtg. When the estrogen-exposed males were subsequently exposed to different doses of MT only, during another 10 days, the levels of vtg decreased significantly in three of the MT-treated groups when compared with the level of vtg in plasma of the estrogen-treated group after the first 10 days. The gonadosomatic index was observed to decrease by the estradiol-treatment but to increase in a dose-dependent manner in the MT-exposed groups, indicating that MT had the capacity to override the effect of the preceding exposure to estradiol-17beta.
在本实验中，将雄性和雌性欧洲鳗鲡（Zoarces viviparus）暴露于不同剂量的模型雄激素17α-甲基睾酮（MT），并研究其对血浆卵黄蛋白原水平和性腺体指数的影响。在环境海水中暴露于不同剂量MT（标称浓度为10、25、50、100和500 ng/L）的雌性中，所有组循环中的卵黄前体蛋白卵黄蛋白原（vtg）浓度均显示下降，但与对照组相比，仅MT-100组显著下降。在早期卵黄发生期（4月/5月），未观察到对性腺体指数有显著影响。在流动条件下暴露于E2 10天的雄性显示出vtg的诱导合成，表现为循环中的vtg水平较高。当随后仅将暴露于雌激素的雄性再暴露于不同剂量的MT 10天时，与雌激素处理组在最初10天后血浆中的vtg水平相比，三个MT处理组中的vtg水平显著下降。观察到性腺体指数在雌二醇处理后下降，但在MT暴露组中呈剂量依赖性增加，表明MT有能力克服先前暴露于17β-雌二醇的影响。
