鳗鲡繁殖生物学研究Ⅴ．性类固醇激素诱导雌鳗促性腺激素（GtH）分泌和卵巢发育的作用

STUDIES ON THE BREEDING BIOLOGY OF THELEL(ANGUILLA JAPONICA TEMMINCK & SCHLEGEL)V. Effects of sex steroids on gonadotropin synthesis and secretion, as well as ovarian devel-opment in female silver eel.

多次注射雌二醇或睾酮对雌鳗促性腺激素（ＧｔＨ）的合成与分泌活动以及卵巢发育都有明显的促进作用，其中睾酮的作用更较雌二醇显著；多次注射ＬＨＲＨ－Ａ的促进作用则不明显。多次埋植雌二醇或睾酮都能促使脑垂体合成ＧｔＨ，但所取血清样品中的ＧｔＨ含量都未见明显增加；多次埋植雌二醇后血清中卵黄蛋白原的含量明显增加，但卵巢ＧＳＩ增长幅度小，表明埋植雌二醇虽能促使肝细胞合成卵黄蛋白原并释放到血液中，但未能全部渗入卵母细胞内；多次埋植睾酮后血清中的卵黄蛋白原含量虽未见明显增加，但卵巢明显发育长大，这表明埋植睾酮能促使肝细胞合成的卵黄蛋白原迅速地通过血液运送到卵巢，并渗入卵母细胞内。

The effects of sex steroids on gonadotropin(GtH)synthesis and release as well asovarian development in female silver eels were investigated.Multiple injections of17β-estradiol or testosterone stimulated GtH synthesis and secretion as well as ovarian de-velopment; testosterone was more effective than estradiol in this respect.Multiple injectionsof LHRH-A were ineffeetive on pituitary GtH content and ovarian development.Multipleimplantations of l7β-estradiol or testosterone stimulated the increase n pituitary GtH con-tent,but no significant changes in serum GtH levels were detected at the samplingtimes.M ultiple implantations of 17β-estradi ol resulted in a marked increase in serumvitellogeain content,but ovarian development was not significantly stimulated ,multipleimplantations of testostero ne were e ffective in stimulating an increase in ovariandevelopment,although there were no significant differences in the serum vitellogenin levelwhen compared with the controls.Multiple implantations of testosterone in combinationwith LHRH-A did not stimulate further increase in pituitary GtH content or ovarian devel-opment.In a given duration of experiment,the effects of multiple implantations oftestosterone in stimulating ovarian development were similar to those of multiple injections oftestosterone.These results demonstrate that serial implantations of testosterone alone canstimulate the brain-pituitaryovary axis of the eel to enhance GtH synthesis in the pituitaryand to induee ovarian development.