壳聚糖-HCG缓释制剂对鱼类生殖内分泌机能的影响

摘要

以壳聚糖为原料制备壳聚糖-HCG 缓释制剂，进行激素埋植实验，间隔一定时间检测雌和雄鱼性腺发育、血清主要性激素含量和繁殖内分泌相关基因表达特征。结果表明：在埋植壳聚糖-HCG 缓释激素后，雌鱼性成熟系数(GSI)、血清睾酮(T)水平、血清雌二醇(E2)水平在6-30d内较对照组效果明显；雄鱼GSI仅在第6天显著高于对照组，血清T水平在第2、第14天高于对照组。血清E2水平在实验期间与对照组无显著差异。RT-PCR结果显示：性腺型P450芳香化酶(CYP19A)在性腺中表达丰富，心脏中最少。雌鱼性腺P450芳香化酶(CYP19A)基因mRNA相对表达量在第2、第6天显著高于对照组，雄鱼在第6天显著高于对照，雌鱼性腺雌激素受体(ERα)基因mRNA相对表达量在14-30d显著高于对照组，雄鱼在第6至第21天显著高于对照组。研究表明，壳聚糖-HCG 缓释制剂一次埋植后可在21d 内稳定持久地释放激素，对调节鱼类的生殖机能具有良好的促进效果。%With Sustained-release delivery systems of Chitin-Human Chorionic Gonadotropin (Chitin-HCG), at regular intervals after implantation of Chitin-HCG, we detected the gonadal developments, the levels of major sex hormones in serum and the relative expression levels of genes for reproduction endocrine function of female and male fish. The re-sults showed that implanted the Chitin-HCG, the gonado-somatic index (GSI), levels of testosterone (T) and estradiol (E2) of female fish were more effective than the controlled group from the 6th day to the 30th day. TheGSIof male fish was significantly higher than the controlled group only at the 6th day after implantation. The levels of testosterone (T) of male fish were significantly higher than the controlled group at the 2nd and the 14th day after implantation and the levels of estradiol (E2) of male fish showed no significant difference with the controlled group. With the RT-PCR, it showed that the content of the relative expression level ofCYP19A mRNA was the most significant in gonad and the least sig-nificant in heart. The result of RT-PCR showed that the relative expression level ofCYP19A mRNA in gonad of female fish was significantly higher than the controlled group at the 2ndand the 6th day after implantation, and that of the male fish was significantly higher than the controlled group at the 6th day after implantation. The relative expression level of ERαmRNA in gonad of female fish was significantly higher than the controlled group from the 14th day to 30th day after implantation, and that of the male fish was significantly higher than the controlled group from the 6th day to the 21st day after implantation. In conclusion, after implantation of Chitin-HCG, the HCG can be released steadily and regularly in 21 days, promoting and regulating the reproduction endocrine function of fish.