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  • 1
    Electronic Resource
    Electronic Resource
    In vitro synthesis of 20α-reduced and of 11- and 21-oxygenated steroids and their sulfates by testes of the goldfish (Carassius auratus): Testicular synthesis of corticosteroids (1993)
    Springer
    Fish physiology and biochemistry 11 (1993), S. 287-292 
    Details
    ISSN: 1573-5168
    Keywords: goldfish ; Carassius auratus ; testis ; sulfates ; 11-deoxycortisol ; 11-ketotestosterone ; corticosteroids ; 17,20α-dihydroxy-4-pregnen-3-one
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des testicules de poissons rouges en cours de spermiation ont été incubés avec de la [3H]17-hydroxyprogestérone. L'androsténédione, l'androstènetrione, la 11β-hydroxyandrosténédione, la 11-cétotestostérone, la 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) et le 11-déoxycortisol, ont été identifiés comme composés majeurs parmi les stéroîdes non conjugués. La testostérone est présente essentiellement sous forme de glucuronide, mais son taux de synthèse reste faible (1–3%). Les composés sulfatés prédominants sont la 17,20αP et le déoxycortisol. La cortisone, produite à un taux faible (〈 2,5%), a été identifiée aussi bien sous forme libre que sulfatée. C'est la première démonstration d'une biosynthèse de corticostéroîde par un testicule de poisson téléostéen. Du fait des taux élevés de synthèse de la 17,20αP, du deoxycortisol, et de leurs sulfates, leur rôles potentiels, en relation avec la spermiation du poisson rouge, mériteraient d'être davantage explorés.
    Notes: Abstract Testes from spermiating goldfish were incubated with [3H]17-hydroxyprogesterone. The major products in the unconjugated fraction were identified as androstenedione, androstenetrione, 11-β-hydroxyandrostenedione, 11-ketotestosterone, 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) and 11-deoxycortisol. Testosterone was present predominantly in the glucuronide fraction, but yields were low (1–3%). The major components of the sulfate fraction were 17,20αP and 11-deoxycortisol. The identification of cortisone in low yield (〈 2.5010) in both the free and sulfate fractions is the first report of corticosteroid biosynthesis by a teleost testis. The high yields of 17,20αP and 11-deoxycortisol and their sulphates suggests that their possible role in spermiation of the goldfish should be further investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00004577
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  • 2
    Electronic Resource
    Electronic Resource
    Gonadotropins I and II do not stimulate thein vitro secretion of 17α,20β-dihydroxy-4-pregnen-3-one 20-sulphate by rainbow trout gonads during final sexual maturation (1996)
    Springer
    Fish physiology and biochemistry 15 (1996), S. 149-156 
    Details
    ISSN: 1573-5168
    Keywords: 17α,20β-P-sulphate ; maturation ; gonadotropin ; rainbow trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thein vitro secretion of 17α,20β-dihydroxy-4-pregnen-3-one 20-sulphate (17α,20β-P-sulphate) and the free steroid 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-P), by rainbow trout (Oncorhynchus mykiss) gonads, in response to gonadotropin (GTH) I and GTH II, were studied during the final stages of sexual maturation. Substantial amounts of 17α,20β-P-sulphate were produced, by both mature ovaries and testes, indicating considerable 20β-hydroxysteroid sulphotransferase (20β-HST) activity within these tissues. In the post-ovulatory ovary the level of 17α,20β-P-sulphate (36.6 ng ml−1) greatly exceeded that of 17α,20β-P (8.59 ng ml−1). The amount of 17α,20β-P-sulphate produced in incubations of both mature ovary and testes was unaffected by either GTH I or GTH II treatment at physiological concentrations up to 100 ng ml−1. Similarly, incubations of maturing ovary and testes, treated with GTH I or GTH II, in the presence of added 17α,20β-P at 100 ng ml−1 of medium, produced levels of 17α,20β-P-sulphate that were similar to those of the controls. In incubations of mature ovarian follicles at the stages of germinal vesicle breakdown and preovulation, both GTHs significantly stimulated secretion of 17α,20β-P, although GTH II was always more potent than GTH I. GTH II significantly elevated the levels of 17α,20β-P in testicular incubations from mature males more than 4-fold relative to GTH I and controls, which did not differ from one another. In conclusion, 20β-HST, the enzyme responsible for the sulphate conjugation of 17α,20β-P, was found to be active in the ovaries and testes of rainbow troutin vitro. However, the levels of this enzyme do not appear to be regulated by either GTH I or GTH II.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01875594
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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