雄烯二酮和甲基睾酮诱导雄性日本鳗鲡性腺发育的作用

多次埋植雄激素雄烯二酮（ADSD）或甲基睾酮（MT）均可促进雄性日本鳗鲡（Anguilla japonica)性腺发育成熟，明显提高脑和垂体mGnRH，垂体GtH含量，埋植3次后，MT处理组的GSI及垂体GtH含量显著高于ADSD处理组，MT处理组血清GtH含量在第1次埋植后显著升高，而ADSD处理组在第4次埋植后才显贰高于对照组。这些结果表明：埋植ADSD和MT可反馈作用于雄性日本鳗鲡脑和垂体，促进GnRH和TtH的合成和分泌，进一步诱导精巢发育。而且MT的作用效果较ADSD快。

Effects of 4-Androstene -3，17-Dine and 17α-Methyl-testosterone on Induction of Gonadal Maturation in the Male Japaneses Eel (Anguilla japonica)

The effects of 4-androstene-3，17-dine (ADSD) and 17α-methyl-testosterone (MT) via implantation at intervals of 15 days on maturation of the male silver eel，and their effects on brain and pituitary GnRH levels，pituitary and serum GtH levels were studied. Multiple implantations of ADSD and MT increased the GSI and stimulated gonadal maturation of the male silver eel. After 3 implantations，the GSI of males treated with MT were significantly higher than that treated with ADSD，whereas after 6 implantations their GSI were not significantly different. The mGnRH contents in the brain and pituitary were significantly increased after 3 and 6 implantations of ADSD and MT，and the mGnRH contents were elevated with increasing times of implantations. The pituitary GtH levels of male eels were significantly increased by multiple implantations of ADSD and MT，and after 3 implantations the pituitary GtH level of MT-treated male eels was significantly higher than that treated with ADSD. Serum GtH levels of MT-treated male eels were increased significantly after 1st implantation，however，serum GtH levels in the male eel treated with ADSD were significantly increased only after 4 implantations. Taken together，these results indicated that ADSD and MT could stimulate gonadal development and had positive feedback effects at the brain and pituitary in the male eel，and the higher potency of MT in the induction of gonadal development maybe due to its higher ability to stimulate GtH synthesis and release in the male eels.