title: Changes in 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase messenger ribonucleic acid, activity and protein levels during the estrous cycle in the bovine ovary.
abstract: A 1169 base pair fragment of bovine 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD) cDNA was used to quantitate 3 beta-HSD messenger RNA (mRNA) levels in the bovine ovary during the estrous cycle. The content of 3 beta-HSD protein was measured by immunoblot analysis using an antiserum developed in rabbits against human 3 beta-HSD, whereas 3 beta-HSD activity was measured using [3H]pregnenolone, [3H] dehydroepiandrosterone, and [3H]androst-5-ene-3 beta,17 beta-diol as substrates. There was a parallel increase in 3 beta-HSD mRNA, protein content, and enzymatic activity levels from days 1-3 after estrus to maximal values at 50-100% above control on days 8-11 after estrus. Thereafter, all values decreased progressively until days 16-17 before a dramatic fall to 5% or less than maximal values on days 18-20 after estrus. Almost superimposable results of enzymatic activity were obtained with the three substrates, thus suggesting a unique 3 beta-HSD or parallel changes in the activity of multiple 3 beta-HSDs. The above-described changes observed during the luteal phase are almost exclusively due to variations in corpora lutea. In fact, 3 beta-HSD activity in ovarian follicles was approximately 10,000 lower than that measured in corpora lutea. The close correlation observed over a wide range of 3 beta-HSD mRNA, protein content, and activity levels suggests that changes of ovarian 3 beta-HSD activity are controlled at the level of 3 beta-HSD gene expression and/or 3 beta-HSD mRNA stability.
authors.affiliation: Medical Research Council Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Couët
authors.forename: C
authors.initials: C
authors.lastname: Martel
authors.forename: E
authors.initials: E
authors.lastname: Dupont
authors.forename: V
authors.initials: V
authors.lastname: Luu-The
authors.forename: M A
authors.initials: MA
authors.lastname: Sirard
authors.forename: H F
authors.initials: HF
authors.lastname: Zhao
authors.forename: G
authors.initials: G
authors.lastname: Pelletier
authors.forename: F
authors.initials: F
authors.lastname: Labrie
mesh_terms: D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000378:metabolism; D004971:Estrus / Q000378:metabolism*; D005260:Female; D005498:Follicular Phase; D015151:Immunoblotting; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism; D006080:Ovarian Follicle / Q000378:metabolism; D010053:Ovary / Q000378:metabolism*; D011375:Progesterone Reductase / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D013251:Steroid Isomerases / Q000235:genetics* / Q000378:metabolism
chemical_list: C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D009097:Multienzyme Complexes; D012333:RNA, Messenger; D011375:Progesterone Reductase; D013251:Steroid Isomerases