Lee Y H, Du J L, Yen F P, Lee C Y, Dufour S, Huang J D, Sun L T, Chang C F
Department of Aquaculture, National Taiwan Ocean University, 202, Taiwan, Republic of, Keelung, China.
Comp Biochem Physiol B Biochem Mol Biol. 2001 Jun;129(2-3):399-406. doi: 10.1016/s1096-4959(01)00337-2.
Plasma gonadotropin II (GTH II) concentrations were significantly higher (approx. 15-20-fold) in estradiol-17beta (E(2)) treated (1.0 microg or 2.5 microg g(-1) body weight) female black porgy from days 4 to 12 compared with the control. E(2) (1 microg g(-1) wt.) had a stronger stimulation on plasma GTH II in early recrudescent phase (low GSI) males (11-fold) than in high GSI and late spermiating males (2.6-fold, P< 0.05). No effect of androgens (testosterone, T; 5alpha-dihydrotestosterone, DHT) on plasma GTH II levels was observed either sex. The levels of plasma GTH II were stimulated in 1,4,6-androstatriene-3,17-dione (ATD, 1 microg g(-1), 2 microg g(-1) body wt.) and fadrozole-treated (1 microg g(-1), 3 microg g(-1) body wt.) groups compared to control. Tamoxifen (1 microg g(-1), 3 microg g(-1) body wt.) but not enclomiphene could stimulate high GTH II levels in plasma. In another experiment of ATD in combination with T, T treatment further attenuated the ATD stimulation of plasma GTH II levels. We concluded that GTH II secretion is positively regulated by an estrogen-specific effect in female and male black porgy. Gonadal stage had significant effects on the responsiveness of GTH II to E(2) stimulation in males. A negative aromatase-dependent feedback control of plasma GTH II levels was also suggested in the protandrous black porgy, Acanthopagrus schlegeli.
与对照组相比，在第4至12天，用17β-雌二醇（E₂）处理（1.0微克或2.5微克/克体重）的雌性黑鲷血浆促性腺激素II（GTH II）浓度显著更高（约15 - 20倍）。E₂（1微克/克体重）对处于早期性腺复苏期（性腺成熟指数低）的雄性黑鲷血浆GTH II的刺激作用（11倍）强于性腺成熟指数高和处于精子形成后期的雄性（2.6倍，P<0.05）。未观察到雄激素（睾酮，T；5α-双氢睾酮，DHT）对任何性别的血浆GTH II水平有影响。与对照组相比，1,4,6-雄甾三烯-3,17-二酮（ATD，1微克/克、2微克/克体重）和法倔唑处理组（1微克/克、3微克/克体重）的血浆GTH II水平受到刺激。他莫昔芬（1微克/克、3微克/克体重）而非氯米芬能刺激血浆中GTH II达到高浓度。在另一项ATD与T联合使用的实验中，T处理进一步减弱了ATD对血浆GTH II水平的刺激。我们得出结论，在雌性和雄性黑鲷中，GTH II的分泌受到雌激素特异性效应的正向调节。性腺阶段对雄性黑鲷中GTH II对E₂刺激的反应性有显著影响。同时也表明，在雌雄同体的黑鲷（黑棘鲷）中，存在一种依赖芳香化酶的对血浆GTH II水平的负反馈控制。
