Journal ArticleDOI
Inhibition of the Pregnenolone Δ5–3β-Hydroxysteroid Dehydrogenase-Δ5-4 Isomerase Systems of Human Placenta and Corpus Luteum of Pregnancy
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TLDR
The inhibition of the pregnenolone Δ 5–3Β-hydroxysteroid dehydrogenase-Δ5-4 isomerase systems in microsomes of human placenta or corpus luteum of pregnancy is inhibited.Abstract:
The inhibition of the pregnenolone Δ5–3Β-hydroxysteroid dehydrogenase-Δ5-4 isomerase systems in microsomes of human placenta or corpus luteum of pregnancy has been investigated using three steroidal substances: 2Α-cyano- 4,4,17Β-trimethylandrost-5-en-17Α-ol-3-one (cyanoketone), 2- hydroxymethylene, 17Α-methyl-5Α-androstan-17Β-ol-3-one (oxymetholone), and estradiol 17Β. The inhibition is of the competitive type with the synthetic steroids. The apparent Ki’s are approximately 0.3xl0-5 M and 0.2xI0-5 m for cyanoketone in the placental and ovarian systems, respectively, and the apparent Ki produced by oxymetholone is 0.6x10-6 m in the ovarian system, however, that for the placental system is much smaller, 5.5xl0-8 M. Approximately 50% inhibition was obtained in both systems with 2–5xl0-5 M estradiol-17Β. Oxymetholone may be useful for the inhibition of corpora luteal function in women.read more
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Journal ArticleDOI
Placental steroid hormone biosynthesis in primate pregnancy.
TL;DR: The basic mechanisms underlying regulation of steroidogenesis within the fetoplacental unit during primate pregnancy appear similar, in important ways, to those of widely used laboratory animals, such as the rat and rabbit.
Journal ArticleDOI
Immunocytochemical localization of estradiol and progesterone receptors in the monkey ovary throughout the menstrual cycle.
TL;DR: Data from this study are consistent with the concept of a receptor-mediated autocrine or paracrine role for progestins, but not estrogens in the gametogenic and endocrine functions of the primate ovary throughout the menstrual cycle.
Journal ArticleDOI
Human placental Δ5-3β hydroxysteroid dehydrogenase activity (Δ5-33 HSDH): Intracellular distribution, kinetic properties, retroinhibition and influence of membrane delipidation
Françoise Ferre,M. Breuiller,Lise Cedard,Marie-Josèphe Duchesne,M. Saintot,Bernard Descomps,AndréCrastes de Paulet +6 more
TL;DR: The delta5-3beta HSDH activity, optimal pH, specific activity and sensitivity to the inhibitory action of various steroids are different when C19 and C21 steroids are used as substrates.
Journal ArticleDOI
Expression of estrogen receptor alpha and beta in the rhesus monkey corpus luteum during the menstrual cycle: regulation by luteinizing hormone and progesterone.
TL;DR: To reevaluate ER expression in the primate luteal tissue, semiquantitative RT-PCR based assays and Western blotting were used to assess ERα and β messenger RNA (mRNA) and protein levels in corpora lutea and to determine if ERβ mRNAexpression in the corpus luteum is regulated by LH.
Journal ArticleDOI
Progesterone receptor, but not estradiol receptor, messenger ribonucleic acid is expressed in luteinizing granulosa cells and the corpus luteum in rhesus monkeys
TL;DR: PR mRNA detection supports the hypothesis of progesterone action via classical receptor-mediated pathways in the luteinizing follicle and corpus luteum of the primate ovary.