Synthesis of 17,20beta,21-trihydroxypregn-4-en-3-one by ovaries of reproductively mature Atlantic cod Gadus morhua.
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.
Tveiten
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Nofima Marin, Tromsø, Postboks 6122, 9291 Tromsø, Norway. helge.tveiten@nofima.no
Frantzen
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Scott
A M
AM
Scott
A P
AP
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
D006908:Hydroxyprogesterones; C007433:17,20-dihydroxy-4-pregnen-3-one; C005674:4-pregnene-17 alpha,20 beta,21-triol-3,11-dione; D003348:Cortisone