Quantitative Determination of Metabolic Products of 19-Norandrostenediol in Human Plasma Using Gas Chromatography/Mass Spectrometry

Abstract

ABSTRACT:Prohormones such as 19-norandrostenediol (estr-4-ene-3␤,17␤-diol) have been added to the list of prohibited substances of the World Anti-Doping Agency because they are metabolized to the common nandrolone metabolites norandrosterone and noretiocholanolone. So far, no studies on the metabolism and in vivo conversion of 19-norandrostenediol after oral or sublingual administration have been reported nor have had quantified data on resulting plasma nandrolone levels. In the present study, an openlabel crossover trial with eight healthy male volunteers was conducted. After application of capsules or sublingual tablets of 19-norandrostenediol plasma concentrations of 19-norandrostenediol, nandrolone as well as major metabolites (19-norandrosterone and 19-noretiocholanolone) were determined using a validated assay based on gas chromatography/mass spectrometry. The administration of 100-mg capsules of 19-norandrostenediol yielded maximum plasma total concentrations (i.e., conjugated plus unconjugated compounds) of 1.1 ng/ml (؎0.7) for 19-norandrostenediol, 4.0 ng/ml (؎2.6) for nandrolone, 154.8 ng/ml (؎130.8) for 19-norandrosterone, and 37.7 ng/ml (؎6.9) for 19-noretiocholanolone. The use of 25-mg sublingual tablets resulted in 3.3 ng/ml (؎1.0) for 19-norandrostenediol, 11.0 ng/ml (؎6.4) for nandrolone, 106.3 ng/ml (؎40.1) for 19-norandrosterone, and 28.5 ng/ml (؎20.8) for 19-noretiocholanolone. Most interestingly, the pharmacologically active unconjugated nandrolone was determined after administration of sublingual tablets (up to 5.7 ng/ml) in contrast to capsule applications. These results demonstrate the importance of prohibiting prohormones such as 19-norandrostenediol, in particular, since plasma concentrations of nandrolone between 0.3 to 1.2 ng/ml have been reported to influence endocrinological parameters.Nandrolone (NL; Fig. 1A) is an anabolic steroid usually administered as the decanoate ester in the form of oily intramuscular injections. Nandrolone has been used as an anabolic agent after debilitating illness and for the treatment of postmenopausal osteoporosis, postmenopausal metastatic breast carcinoma, anemia as a result of chronic renal failure, and aplastic anemia. In addition to these therapeutic applications, NL gained public recognition because of its abuse by athletes for the purpose of increasing muscle mass and muscular strength (Yesalis and Bahrke, 1995). As a result, NL, among others, was banned in 1974 by the International Olympic Committee. To provide evidence of NL doping, the main urinary metabolites 19-norandrosterone (NA; Fig. 1B) and 19-noretiocholanolone (NE; Fig. 1C) have been used as target analytes (Schänzer and

Mechanism of action of bolandiol (19-nortestosterone-3β,17β-diol), a unique anabolic steroid with androgenic, estrogenic, and progestational activities

“…A third possibility is conversion to 19-NT by 3β-HSD [2]. The first possibility was investigated in vivo using the castrate 22 day-old rat model in which the dual 5α-reductase inhibitor dutasteride was administered concurrently with maximal stimulatory doses of androgens.…”

“…Previously, we compared the activity of bolandiol in a castrated adult male Sprague Dawley rat model to that of 19-nortestosterone (19-NT: nandrolone), a proposed metabolite of bolandiol [2] and dihydrotestosterone (DHT), all administered in Silastic implants [3]. Long-term administration of bolandiol (20–24 wk) prevented the loss of lean body mass (LBM), bone mineral density (BMD), and levator ani (LA) muscle weight that occurs in castrate rats while inhibiting gonadotropin and endogenous T production.…”

“…It has been suggested that the anabolic activity of bolandiol is attributable to its conversion by 3β-hydroxysteroid dehydrogenase (3β-HSD) to 19-NT [2,4–6], a potent anabolic steroid [7–9], because increased urinary metabolites of 19-NT can be measured after oral dosing of men with bolandiol [10–12]. Interestingly, the prohormone of 19-NT, 19-norandrostenedione, has recently been shown to have tissue selectivity in castrate male rats [13] supporting the notion that precursors and metabolites of these steroids may have unique profiles of tissue activity.…”

Metabolism of Oral Turinabol by Human Steroid Hormone-Synthesizing Cytochrome P450 Enzymes

“…The cholesterol level in the inner mitochondrial membrane is controlled by StAR protein activity, which varies upon signaling via the hypothalamic-pituitary-adrenal axis and other steroidogenic stimuli. Plasma levels of the prohormone 19-norandrostenediol and its active metabolite nandrolone were reported to be in the range of several hundreds of nanograms per 100 ml after a single dose of 25-100 mg (Schrader et al, 2006), which is in excess of DOC and 11-deoxycortisol plasma levels (Mason and Fraser, 1975). Exact 19-norandrostenediol and metabolite plasma levels were, however, also dependent on the route of administration.…”

Detecting the abuse of 19‐norsteroids in doping controls: A new gas chromatography coupled to isotope ratio mass spectrometry method for the analysis of 19‐norandrosterone and 19‐noretiocholanolone

“…[4][5][6][7][8][9][10][11][12][13] It is usually administered by intramuscular injection as decanoate or phenyl propionate ester, even if several oral nandrolone prohormones (19-norandrostenedione and 19-norandrostenediol) formulations have been easily accessible for years as dietary supplements and are still freely available on Internet market. [14][15][16][17][18][19] 19-Norsteroids undergo a phase I metabolism similar to that of testosterone, through the oxidation of hydroxyl group on C17 (catalyzed by 17β-hydroxysteroid-dehydrogenase), reduction of double bound C4-C5 (by 5α-and 5β-reductase) and reduction of three keto-function (by 3α-and 3β-hydroxysteroiddehydrogenase) enzymatic steps. 20,21 Unlike dihydrotestosterone (DHT), the 5α-dihydro 19-norderivatives possess a weak binding affinity to the androgen receptors in prostate and hair follicles, reducing the incidence of prostatic growth and alopecia and justifying the beneficial effect of nandrolone in male hypogonadism therapy.…”