摘要
用离体孵育的方法研究了睾酮 (T)对日本鳗鲡 (Anguillajaponica)完整的下丘脑 脑垂体复合物(hypothalamus pituitarycomplex ,HPC)、分离的下丘脑 (hypothalamus,H)加脑垂体 (pituitary ,P)以及单独的脑垂体 (pituitary ,P)促性腺激素 (GtH)合成与释放的影响。在不加T的孵育液中孵育 ,HPC组的孵育液及其脑垂体中的GtH含量最高 ,H +P组次之 ,而P组最低 ,表明下丘脑通过GnRH直接刺激脑垂体GtH的合成与释放。在加入T的孵育液中孵育 ,P组的孵育液及脑垂体中的GtH含量显著增加 ,并且和孵育液中的T呈剂量依存的正反馈作用。当T和H与P一起孵育时 ,低浓度的T (0 1和 1μmol/L)刺激HPC组和H +P组的GtH释放 ,呈现正反馈作用 ,而高浓度的T (10 μmol/L)则抑制HPC组和H +P组的GtH释放 ,表现负反馈作用。这些结果直接证明日本鳗鲡下丘脑对脑垂体GtH分泌的调控以及性类固醇激素 (如雄鳗的睾酮 )
The effects of testosterone (T) on the synthesis and release of gonadotropin (GtH) in the hypothalamus pituitary complex or pituitary alone of Japanese eel (Anguilla japonica) were investigated in vitro. The intact hypothalamus-pituitary complex (HPC), the separate hypothalamus plus pituitary (H+P) or the pituitary (P) of male eel were incubated with TC 199 medium without (control) or with different concentrations of testosterone (0.1, 1.0, or 10.0 μmol/L) for 8 h. In the control group, the GtH content of HPC group was the highest both in medium or pituitaries while the P group was the lowest. It indicated that the gonadotropin-releasing hormone (GnRH) reaches pituitary directly. Incubation of pituitary alone with different concentrations of T increased the GtH content in a dose dependent manner either in medium or pituitary. We suggested that T acted directly as a positive feedback on the synthesis and release of GtH in eel pituitary. Low dosages of T (0.1 and 1.0 μmol/L) stimulated the synthesis and release of GtH in both HPC group and H+P group after 8 h incubation, indicating that there was a positive feedback effect of T on either hypothalamus or pituitary in eel; whereas a negative feedback effect of T were observed when HPC or H+P incubated with high dosage of T (10.0 μmol/L). In the highest dosage group, the inhibitory effect of GtH release was more significant than the GtH synthesis. These results demonstrated that the synthesis and release of pituitary GtH was regulated by hypothalamus via GnRH. Testosterone in male fish had feedback effects on either hypothalamus or pituitary in Japanese eel.
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2002年第1期64-68,共5页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金资助项目 (No .39770 10 1)~~
关键词
日本鳗鲡
下丘脑
脑垂体
促性腺激素
睾酮
GtH
合成
分泌
Japanese eel (Anguilla japonica), Hypothalamus, Pituitary, Gonadotropin, Testosterone