| Eel as widely distributed seaward migration fish is very famous in many countries all over the world, such as Japanese are like to eat the Anguilla japonica very much. And meat of the eel is very delicious and the nutrition is abundant. But the reproduction breeding of the eel still have many problems to riddle, so in t HSI study we focus on the sex steroid hormones change and content of the gonad and the serm in the period of artificial production of the eel( Anguilla marmorata and Anguilla japonica).The sex steroid hormones are necessary for growth and development of the gonad, especially in the artificial reproduction of teleost, testosterone(T), progesterone(P), estrone(E1), estradiol(E2), estriol(E3), 17α, 20β- dihydroxy-4-en-3-one pregnant(DHP), 17α- hydroxyprogesterone(17α-OHP) play the important role of vitellogenesis and germinal vesicle breakdown(GVBD) in the early development, the middle development and the late development.Once a week we injected the carp pituitary extract(carp pituitary extract,20mg/kg) and human chorionic gonadotropin(h CG,300IU/kg) for Anguilla marmorata to induce development and maturation of gonad. In t HSI study we used Beckman Coulter immunoassay analyzer chemiluminescent immunoassay(CLIA) to explore glycoprotein hormones(follicle stimulating hormone(FSH), luteinizing hormone(LH), human chorionic gonadotropin(h CG)) change in serum and analysis three steroid hormones(testosterone, progesterone, 17β-estradiol) content in the early development(after the second injection), the middle development(after the ninth injection), the mid-late development(after the 13 th injection), the late development(after the 16 th injection), the developmental stage(after the 20 th injection). The results show compared with the control group that the gonad have been gradually matures in the experimental group, and GSI increased significantly. After 16-19 injections, egg arrivs nuclear shift stage, and then we injected the 17α- hydroxyprogesterone could successfully induce maturation and ovulation of the gonad in the Anguilla marmorata. Compared with the control group, the serum of 17β-estradiol in the experimental group continue to rise, especially significantly increased in the mid-late development to the developmental stage. And progesterone(P) rose to the highest in the late development, a significant reduction in the period of the late development to the developmental stage; testosterone(T) appears the highest value in the late development. The experimental group glycoprotein hormones—h CG, significant change at different times, reach the highest value in the developmental stage, the reasons may be related to oxytocin injection; FSH, LH, progesterone have the similar change. In addition, the research found that after 12 h, 24 h and 72 h hormone injection there is a small period of the early developmental changes of the serum progesterone, after 12 h injection it significantly lower; the E2 of the serum peaked at after injection 24 h.Ultra-performance liquid chromatography coupled with electronspray ionization-triple quadrupole mass spectrometry(UPLC/MS/MS) method was applied to determine the content and changes of 6 steroid hormones in the ovaries of female farmed marbled eels during artificially induced maturation through carp pituitary extract and h CG injection. The results showed that the chromatographic separation of 6 gonad steroid hormones, namely testosterone(T), progesterone(P), estradiol-17β(E2), estriol(E3), 17α,20β-dihydroxy-4-pregnen-3-one(DHP), and 17α-hydroxyprogesterone(17α-OHP) was well performed using an x Bridge C18 column. The linear regression coefficients(R) of T、P、E2、E3、DHP、17α-OHP were above 0.99 in the range of 0~200ng/ml and the limits of detection were above 0.1~0.2 ng/g. Average recoveries of T, P, E2, E3, DHP, 17α-OHP also reached more than 89.00%, and relative standard deviations were less than 7.3%. The results indicated that the 6 steroid hormones increased with the development of gonad maturation, and the UPLC/MS/MS method is a sensitive and stable approach with high recovery rate in simultaneously quantifying 6 gonad steroid hormones in the fish.The method of artificial production in female Anguilla japonica was by injections of CPE. In the developmental stage, we analyzed and compared the content of six steroid hormones(testosterone, progesterone, estradiol, estriol, 17α, 20β-dihydroxy-4-pregnene-3-one, 17α- hydroxyprogesterone) in the gonad for the different conditions(development group, undeveloped group, dystocia group, nature spawn group). We found that E2 cannot detected both in control group and undeveloped group, the content of E3 was also very low which closed to the control group(0.1ng/g); in the dystocia group, DHP was very high, it beyond 40ng/g. Therefore, estrogen may be decide the starter to the development for the female Anguilla japonica. So when the estrogen is very in the gonad, no matter how much exogenous hormones injected to the Anguilla japonica, it cannot be develop, maybe something blocked the formation of the estrogen. And the overhigh level of DHP maybe caused the dystocia of the fish.In a word, in t HSI paper we research the content and the change of the sex steroid hormones in different period, and found that some of the sex steroid hormones increased significantly with the develop of the gonad. Use the same method to induce the mature of the eel by the artificial reproduction, there is a big gap between the different groups that is mainly because of the sex steroid hormones in the gonad, they may be play a important role during the development of the fish, especially in promoting the growth and maturation of oocytes. But t HSI article does not study the way of the key factor enzyme how to transformed the hormones, therefore, the research of the sex steroid hormones needs to be continued. |
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