Topic
Pregnenolone
About: Pregnenolone is a research topic. Over the lifetime, 3539 publications have been published within this topic receiving 126444 citations. The topic is also known as: (3b)-3-hydroxy-Pregn-5-en-20-one & 3-Hydroxypregn-5-en-20-one.
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TL;DR: 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.
42 citations
TL;DR: In this article, the synthesis from smilagenin, progesterone, and pregnenolone of Δ14-3β-hydroxy-5β-etienic acid and some of its ester derivatives, as well as of β-anhydrodigitoxigenin acetate is described.
Abstract: The synthesis, from smilagenin, progesterone, and pregnenolone, of Δ14-3β-hydroxy-5β-etienic acid and some of its ester derivatives, as well as of β-anhydrodigitoxigenin acetate, is described. Sinc...
42 citations
TL;DR: It is clear that extra-adrenal factors such as insulin and T have some adrenal regulatory capacity, and insulin stimulated DHEAS and decreased DHEA production, suggesting that it increases adrenocortical sulfotransferase activity.
42 citations
TL;DR: This study shows that an early removal of CHOL from brain extracts coupled to well-validated extraction and fractionation procedures are prerequisites for reliable measurements of free and conjugated PREG and DHEA by GC-MS or other indirect methods.
42 citations
TL;DR: RT-PCR analysis revealed that gene expression of three steroidogenic enzyme show distinctly different tissue-specific patterns of expression in the Japanese eel, suggesting that some steroidogenic enzymes are also expressed in non-endocrine tissues and could potentially regulate the local and/or circulating steroid levels in teleosts, as they do in mammals.
42 citations