海藻酸钠-HCG制剂对雌性金鱼(Carassius auratus)生殖激素水平的影响

采用海藻酸钠(Na Alg)-HCG缓释制剂进行激素埋植实验。实验开始时,雌性金鱼(Carassius auratus)卵母细胞处于Ⅲ期。实验期间记录雌性金鱼性腺发育、放免(RIA)法测定血清性激素含量并且通过RT-PCR检测激素相关基因表达。结果表明,埋植Na Alg-HCG缓释激素后,雌性金鱼性成熟系数(GSI)在6-21 d显著高于对照组,血清睾酮(T)和雌二醇(E2)水平在6-30 d显著高于对照组;性腺芳香化酶基因(CYP19A基因)和雌激素受体基因(ERα基因)m RNA相对表达量分别在2-21 d、14-30 d内显著高于对照组,其性腺GH基因m RNA相对表达量变化不显著。研究结果显示,一次性埋植Na Alg-HCG缓释制剂,与雌性金鱼繁殖相关的生物学指标、激素水平、基因表达量较对照组产生明显变化,同时这种缓释制剂可以作为埋植激素的载体。

Effects of Sustained-Release Delivery of Sodium Alginate Microsphere-Human Chorionic Gonadotropin (NaAlg-HCG) on Reproductive Hormones in Female Goldfish Carassius auratus (Linnaeus) var

The sustained-release delivery system of human chorionic gonadotropin （HCG） has been considered as a good method to induce gonad maturation in cultured fish. Sodium alginate microsphere is a new type of sustained-release delivery system of Human Chorionic Gonadotropin （NaAlg-HCG）. In this study we implanted the NaAlg-HCG into female goldfish at regular intervals and examined its effects on the gonadal development, the level of major sex hormone in serum, and the expression of genes associated with reproduction hormones. The serum hormone level was measured with Radiate Immuno Assay （RIA） and the gene expression was examined using RT-PCR. Initially most oocytes of female golden fish were at stage III. From the Day 6 to Day 21 after the implantation, the gonadosomatic index （GSI） of fish implanted with NaAlg-HCG was significantly higher than that of the control group （P〈0.05）. From the Day 6 to Day 30, the levels of both estradiol （E2） and testosterone （T） in the serum of NaAlg-HCG group were significantly higher than those of the control group （P〈0.05）. RT-PCR results showed that from Day 6 to Day 21, the relative expression level of CYP19A of the NaAlg-HCG group was significantly higher than that of the control group （P〈0.05）. From Day 14 to Day 30, the ERαmRNA in the gonad of the NaAlg-HCG group was significantly higher than that of the control group （P〈0.05）. There was no difference in the relative expression level of GH in the gonad between the NaAlg-HCG group and control （P〉0.05）, except for the 2nd day after the implantation of NaAlg-HCG （P〈0.05）. These results suggested that after one-time implantation of NaAlg-HCG, HCG could be released steadily and regularly in 21 days. During this period NaAlg-HCG significantly increased the gonadosomatic index （GSI）, the level of sex hormone in the serum, and the relative expression of genes associated with reproduction. The sodium alginate microsphere-based sustained-release delivery system therefore coul