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Evaluation of Food and Food Contaminants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
In the present study, Langlois et al.363 investigated alternative mechanisms through which ATZ may induce estrogen-like effects in amphibians. These mechanisms include the induction of estrogen receptor α (eralpha), which is activated upon estrogen binding and has been recognized as an estrogenic biomarker of estrogenic exposure.364 Studies have shown that after treatment with estrogenic substances, eralpha expression increased in Rana pipiens tadpole brain (17α-ethinylestradiol [EE2]365), the whole body of Xenopus laevis tadpoles (bisphenol A366), and fish liver (EE2367). The 5β-reductase (srd5beta) pathway is also potentially involved in the feminization of developing amphibians.368 A member of the aldo-keto reductase superfamily, srd5beta can regulate androgen bioavailability by catalyzing the conversion of testosterone to 5β-dihydrotestosterone (5β-DHT) reviewed by Langlois et al.363 Therefore, they hypothesized that exposure to ATZ alters eralpha mRNA level and srd5beta activity in the target tissues of exposed tadpoles.
Indirect clinical markers for the detection of anabolic steroid abuse beyond the conventional doping control in athletes
Published in European Journal of Sport Science, 2019
Georgios A. Christou, Maria A. Christou, Lovro Žiberna, Konstantinos A. Christou
AAS elicit their androgenic and anabolic effects in the target tissues through the binding to the nuclear androgen receptors (Jin & Penning, 2001; Saudan et al., 2006). Dihydrotestosterone is converted from testosterone in the cytosol of cells of target tissues through the action of 5alpha-reductase and is inactivated by the action of 3alpha-hydroxysteroid dehydrogenase. Dihydrotestosterone is responsible for the androgenic effects of AAS, while AAS and particularly testosterone induce anabolic effects. Renal tissue responds to AAS administration similarly to muscle tissue with enhanced anabolic and low androgenic action, since both kidneys and muscles are characterized by high levels of 3alpha-hydroxysteroid dehydrogenase enzymes and little 5alpha-reductase (Jin & Penning, 2001; Saudan et al., 2006). In this respect, most AAS apart from dihydrotestosterone and mesterolone are at least moderately potent anabolics and thus are expected to be relatively effective in increasing RBC concentration.