Linked Life Data

11790332

Source:http://linkedlifedata.com/resource/pubmed/id/11790332

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-1-15
pubmed:abstractText
Ovarian samples from fear sea bass, Dicentrarchus labrax, were collected for the in vitro incubations during the spawning period. Follicles with fully developed vitellogenic oocytes showing central germinal vesicle (stage I follicles) and follicles with oocytes showing initial germinal vesicle migration (stage II follicles) were treated with either (1) 20 microg sea bass hypophysis plus 50 ng 17-hydroxyprogesterone (17-P), (2) 20 microg hypophysis alone, (3) 50 ng 17-P alone and (4) media alone. Structure-activity experiments used stage II follicles treated with several dosages (0.1, 1.0 and 10.0 ng/ml) of either 17-P, 17,20beta-P, or 17,20beta,21-P. Free and conjugated (sulfates and glucuronides) levels of the established teleost oocyte maturation inducing steroids (MIS), i.e. 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) and 17,20beta,21-trihydroxy-4-pregnen-3-one (17,20beta,21-P) were measured in the incubation media by high performance liquid chromatography. Our results show that the synthesis of free and conjugated 17,20beta-P is constant (0.1-0.2 ng/ml) in all incubates. In contrast, the synthesis of free and conjugated 17,20beta,21-P is higher in incubates containing stage II follicles (up to 5 ng/ml) than in those having stage I follicles (up to 3 ng/ml; P<0.01). Structure-activity data reveal that 17-P is not effective at inducing in vitro germinal vesicle breakdown whereas both 17,20beta-P and 17,20beta,21-P are equally potent and highly effective. These results demonstrate that 17,20beta-P and 17,20beta,21-P are synthesized in vitro by follicles of sea bass and that sulfation is the main route for the metabolism of the C(21)-steroids in riper follicles. The highest levels of 17,20beta,21-P, found in incubates containing stage II follicles, points at 17,20beta,21-P, rather than 17,20beta-P, as the most probable MIS in sea bass, nonetheless, this hypothesis requires further confirmation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1532-0456
pubmed:author
pubmed:issnType
Print
pubmed:volume
125
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-91
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Steroid metabolism by ovarian follicles of the sea bass Dicentrarchus labrax.
pubmed:affiliation
High Institute of Health Sciences-North, Paredes, Portugal.
pubmed:publicationType
Journal Article