PROJECT REVIEW “Analysis of 19-Norsteroids, Testosterone and Precursors Metabolites
ثبت نشده
چکیده
Detecting the use of androgenic anabolic steroids, potentially endogenous in humans, and which are prohibited substances in sport doping control programmes, still represents a major challenge to the analysts. These steroids include testosterone, its precursors androstenedione and dehydroepiandrosterone, and the 19-norsteroids equivalents, some of which are commercially available for oral self-administration.
منابع مشابه
PROJECT REVIEW “Endogenous Testosterone, Testosterone Precursors And Metabolites; 19-Nor-Steroids and Establishment of Normal Urinary Levels Of These And Related Compounds”
Recently, a sizeable number of urine samples analysed by official laboratories tested positive (>2ngIml) for the nandrolone metabolites 1 9nortestosterone (19-NT), 1 9-norandrosterone (19-NA) and 19noretiocholanolone (19-NE) (1-6). The large number of positive tests in such a short period of time, combined with the fact that some sports involved had not previously been associated with the abuse...
متن کاملTestosterone and its precursors and metabolites enhance guanylate cyclase activity.
Both testosterone and cyclic GMP stimulate DNA synthesis. Because cyclic GMP and testosterone seem to have similar actions, the objective of this investigation was to determine if testosterone and its precursors might have part of their mechanism of action through stimulation of guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2], the enzyme that catalyzes the formation of cycli...
متن کاملUrinary metabolic profile of 19-norsteroids in humans: glucuronide and sulphate conjugates after oral administration of 19-nor-4-androstenediol.
19-Nor-4-androstenediol (NOL) is a prohormone of nandrolone (ND). Both substances are included in the WADA List of Prohibited Classes of Substances and their administration is determined by the presence of 19-norandrosterone (NA) with the urinary threshold concentration of 2 ng mL(-1). Routine analytical procedures allow the determination of NA excreted free and conjugated with glucuronic acid,...
متن کاملIntracrine androgen biosynthesis, metabolism and action revisited
Androgens play an important role in metabolic homeostasis and reproductive health in both men and women. Androgen signalling is dependent on androgen receptor activation, mostly by testosterone and 5α-dihydrotestosterone. However, the intracellular or intracrine activation of C19 androgen precursors to active androgens in peripheral target tissues of androgen action is of equal importance. Intr...
متن کاملIdentification of neuroactive steroids and their precursors and metabolites in adult male rat brain.
Steroids in the brain arise both from local synthesis and from peripheral sources and have a variety of effects on neuronal function. However, there is little direct chemical evidence for the range of steroids present in brain or of the pathways for their synthesis and inactivation. This information is a prerequisite for understanding the regulation and function of brain steroids. After extract...
متن کامل