نتایج جستجو برای: 3α diol
تعداد نتایج: 5400 فیلتر نتایج به سال:
Previous studies suggest that male testosterone concentrations have declined over time. To explore this in a large US population, we examined testosterone and free testosterone concentrations in National Health and Nutrition Examination Surveys (NHANES) from 1988-1991 and 1999-2004. We also examined sex hormone-binding globulin (SHBG), estradiol, and androstanediol glucuronide (3α-diol-G) over ...
PURPOSE Polymorphisms in the genes SRD5A1 and SRD5A2 encoding androgen biosynthetic 5α-reductase enzymes have been associated with an altered risk of biochemical recurrence after radical prostatectomy in localized prostate cancer. EXPERIMENTAL DESIGN To gain potential insights into SRD5A biologic effects, we examined the relationship between SRD5A prognostic markers and endogenous sex-steroid...
Herein, we present a new strategy for the preparation of a broad range of brassinosteroid biosynthetic precursors/metabolites differing by the ring A fragment. The protocol is based on the use of readily available phytohormones of this class bearing a 2α,3α-diol moiety (epibrassinolide or epicastasterone) as starting materials. The required functionalities (Δ2-, 2α,3α- and 2β,3β-epoxy-, 2α,3β-,...
A simple spectrophotometric method for the assay of steroid 5α-reductase (5α-SR) was developed in which 5α-dihydrotestosterone (5α-DHT) and 5α-androstane-3α,17β-diol (5α-diol), metabolites formed in the NADPH-dependent reduction of testosterone with enzyme sources of 5α-SR, were measured by enzymatic cycling using 3α-hydroxysteroid dehydrogenase in the presence of excess thionicotinamide-adenin...
In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid-related compounds. Subsequent gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α- and 3β- isomers of the novel compound; 3-chloro-17α-methyl-5α-androstan-17β-ol. Synthesis of authentic reference materials followed by comp...
Background: The bioactive androgens testosterone (T) and dihydrotestosterone (DHT) regulate bone and fat mass in men. The effects of androgens are largely determined by the rate of their synthesis and inactivation. Irreversible conjugation of androgens or androgen metabolites by UDP glucuronosyltransferases (UGTs) into water-soluble glucuronidated androgen metabolites plays an important role in...
Acupuncture has been demonstrated to improve menstrual frequency and to decrease circulating testosterone in women with polycystic ovary syndrome (PCOS). Our aim was to investigate whether acupuncture affects ovulation frequency and to understand the underlying mechanisms of any such effect by analyzing LH and sex steroid secretion in women with PCOS. This prospective, randomized, controlled cl...
INTRODUCTION A historic belief was that testosterone was the "hormone of desire." However, recent data, which show either minimal or no significant correlation between testosterone levels and women's sexual desire, suggest that nonhormonal variables may play a key role. AIM To compare women with hypoactive sexual desire disorder (HSDD) and those with the recently proposed more symptomatic des...
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