title: Synthesis of 17,20beta,21-trihydroxypregn-4-en-3-one by ovaries of reproductively mature Atlantic cod Gadus morhua.
abstract: Atlantic cod Gadus morhua ovaries were incubated in vitro with tritiated 17-hydroxypregn-4-ene-3,20-dione (17-P) to determine whether 17,20beta-dihydroxypregn-4-en-3-one (17,20beta-P) or 17,20beta, 21-trihydroxypregn-4-en-3-one (17,20beta,21-P), or both, were more likely to be the steroid responsible for inducing oocyte final maturation (i.e. resumption of meiosis). Only 17,20beta,21-P was produced, in addition to 11-deoxycortisol (17,21-P), which is intermediate between 17-P and 17,20beta,21-P. Also, the 5beta-reduced forms of 17-P, 17,21-P and 17,20beta,21-P were all found. Some sulphation of 21-hydroxylated steroids was demonstrated. The ability of female G. morhua to make 17,20beta,21-P but not 17,20beta-P was confirmed by radioimmunoassay of plasma samples from spawning fish. Although small amounts of 17,20beta-P immunoreactivity were detected in a few plasma samples, this was shown, by thin-layer chromatography, to be mostly due to cross-reaction with other unidentified compounds. The evidence strongly suggests that 17,20beta,21-P is more likely than 17,20beta-P to be the maturation-inducing steroid in G. morhua.
authors.affiliation: Nofima Marin, Tromsø, Postboks 6122, 9291 Tromsø, Norway. helge.tveiten@nofima.no
authors.forename: H
authors.initials: H
authors.lastname: Tveiten
authors.forename: M
authors.initials: M
authors.lastname: Frantzen
authors.forename: A M
authors.initials: AM
authors.lastname: Scott
authors.forename: A P
authors.initials: AP
authors.lastname: Scott
mesh_terms: D000818:Animals; D003348:Cortisone / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D005260:Female; D048389:Gadus morhua / Q000097:blood / Q000378:metabolism*; D006908:Hydroxyprogesterones / Q000097:blood / Q000378:metabolism; D010053:Ovary / Q000378:metabolism*; D011863:Radioimmunoassay
chemical_list: D006908:Hydroxyprogesterones; C007433:17,20-dihydroxy-4-pregnen-3-one; C005674:4-pregnene-17 alpha,20 beta,21-triol-3,11-dione; D003348:Cortisone