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Themistoklis Dabalis – One of the best experts on this subject based on the ideXlab platform.

  • determination of Anabolic Steroids in muscle tissue by liquid chromatography tandem mass spectrometry
    Journal of Chromatography A, 2009
    Co-Authors: George Kaklamanos, Georgios Theodoridis, Themistoklis Dabalis
    Abstract:

    Abstract A specific and sensitive multi-method based on liquid chrochromatography–tandem mass spectrometry using atmospheric pressure chemical ionization (LC–APCI–MS/MS) has been developed for the determination of 20 Anabolic Steroids in muscle tissue (diethylstilbestrol, β-estradiol, ethynylestradiol, α/β-boldenone, α/β-nortestosterone, methyltestosterone, β-trenbolone, triamcinolone acetonide, dexamethasone, flumethasone, α/β-zearalenol, α/β-zearalanol, zearalenone, melengestrol acetate, megestrol acetate and medroxyprogesterone acetate). The procedure involved hydrolysis, extraction with tert-butyl methyl ether, defattening and final clean-up with solid phase extraction (SPE) on Oasis HLB and Amino cartridges. The analytes were analyzed by reversed-phase LC–MS/MS, in positive and negative multiple reaction monitoring (MRM) mode, acquiring two diagnostic product ions from each of the chosen precursor ions for the unambiguous confirmation of the hormones. The method was validated at the validation level of 0.5 ng/g. The accuracy and precision of the method were satisfactory. The decision limits CCα ranged from 0.03 to 0.14 ng/g while the detection capabilities CCβ ranged from 0.05 to 0.24 ng/g. The developed method is sensitive and useful for detection, quantification and confirmation of these Anabolic Steroids in muscle tissue and can be used for residue control programs.

  • Determination of Anabolic Steroids in bovine urine by liquid chromatography-tandem mass spectrometry.
    Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2009
    Co-Authors: George Kaklamanos, Georgios Theodoridis, Themistoklis Dabalis
    Abstract:

    A liquid chrochromatography-tandem mass spectrometric (LC-MS/MS) multi-method has been developed for the determination of 15 Anabolic Steroids in bovine urine (diethylstilbestrol, dienestrol, hexestrol, beta-estradiol, ethynylestradiol, alpha/beta-boldenone, alpha-nortestosterone, alpha/beta-zearalenol, alpha/beta-zaeralanol, zearalenone, stanozolol and 16beta-OH-stanozolol). The procedure involved enzymatic hydrhydrolysis, extraction with tert-butyl methyl ether, a washing step with hexane and final clean-up with SPE with Oasis HLB and Amino cartridges. The analytes were quantified by liquid chrochromatography coupled to a tandem mass spectrometer (LC-TSQ Quantum AM) operating in both positive and negative atmospheric pressure chemical ionisation (APCI). Data acquisition was performed in multiple reaction monitoring (MRM) mode quantifying two diagnostic product ions from a chosen precursor. The method was validated according to the Commission Decision 2002/657/EC, for the detection and confirmation of residues in products of animal origin. The method specificity, sensitivity, accuracy and precision were evaluated. The decision limits CCalpha ranged from 0.06 to 0.26 ng/ml and the detection capabilities CCbeta ranged from 0.11 to 0.49 ng/ml. The developed method is sensitive and useful for detection, quantification and confirmation of these Anabolic Steroids in bovine urine and can be used for residue control programs.

David S Celermajer – One of the best experts on this subject based on the ideXlab platform.

  • androgenic Anabolic Steroids and arterial structure and function in male bodybuilders
    Journal of the American College of Cardiology, 2001
    Co-Authors: Mark A Sader, David S Celermajer, Kaye A Griffiths, Robyn J Mccredie, David J Handelsman
    Abstract:

    Abstract OBJECTIVES The study examined arterial and cardiac structure and function in bodybuilders using androgenic Anabolic Steroids (AAS), compared to non-steroid-using bodybuilder controls. BACKGROUND Adverse cardiovascular events have been reported in bodybuilders taking Anabolic Steroids. The cardiovascular effects of AAS, however, have not been investigated in detail. METHODS We recruited 20 male bodybuilders (aged 35 ± 3 years), 10 actively using AAS and 10 who denied ever using Steroids. Serum lipid and hormone levels, carotid intima-media thickness (IMT), arterial reactivity, and left ventricular (LV) dimensions were measured. Vessel diameter was measured by ultrasound at rest, during reactive hyperemia (an endothelium-dependent response, leading to flow-mediated dilation, FMD), and after sublingual nitroglycerin (GTN, an endothelium-independent dilator). Arterial reactivity was also measured in 10 age-matched non-bodybuilding sedentary controls. RESULTS Use of AAS was associated with significant decreases in high density lipoprotein cholesterol, sex hormone binding globulin, testosterone and gonadotrophin levels, and significant increases in LV mass and self-reported physical strength (p 0.2). The GTN responses were significantly lower and carotid IMT significantly higher in both bodybuilding groups, however, compared with the non-bodybuilding sedentary controls (p = 0.01). CONCLUSIONS Although high-level bodybuilding is associated with impaired vascular reactivity and increased arterial thickening, the use of AAS per se is not associated with significant abnormalities of arterial structure or function.

George Kaklamanos – One of the best experts on this subject based on the ideXlab platform.

  • determination of Anabolic Steroids in muscle tissue by liquid chromatography tandem mass spectrometry
    Journal of Chromatography A, 2009
    Co-Authors: George Kaklamanos, Georgios Theodoridis, Themistoklis Dabalis
    Abstract:

    Abstract A specific and sensitive multi-method based on liquid chromatography–tandem mass spectrometry using atmospheric pressure chemical ionization (LC–APCI–MS/MS) has been developed for the determination of 20 Anabolic Steroids in muscle tissue (diethylstilbestrol, β-estradiol, ethynylestradiol, α/β-boldenone, α/β-nortestosterone, methyltestosterone, β-trenbolone, triamcinolone acetonide, dexamethasone, flumethasone, α/β-zearalenol, α/β-zearalanol, zearalenone, melengestrol acetate, megestrol acetate and medroxyprogesterone acetate). The procedure involved hydrolysis, extraction with tert-butyl methyl ether, defattening and final clean-up with solid phase extraction (SPE) on Oasis HLB and Amino cartridges. The analytes were analyzed by reversed-phase LC–MS/MS, in positive and negative multiple reaction monitoring (MRM) mode, acquiring two diagnostic product ions from each of the chosen precursor ions for the unambiguous confirmation of the hormones. The method was validated at the validation level of 0.5 ng/g. The accuracy and precision of the method were satisfactory. The decision limits CCα ranged from 0.03 to 0.14 ng/g while the detection capabilities CCβ ranged from 0.05 to 0.24 ng/g. The developed method is sensitive and useful for detection, quantification and confirmation of these Anabolic Steroids in muscle tissue and can be used for residue control programs.

  • Determination of Anabolic Steroids in bovine urine by liquid chromatography-tandem mass spectrometry.
    Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2009
    Co-Authors: George Kaklamanos, Georgios Theodoridis, Themistoklis Dabalis
    Abstract:

    A liquid chromatography-tandem mass spectrometric (LC-MS/MS) multi-method has been developed for the determination of 15 Anabolic Steroids in bovine urine (diethylstilbestrol, dienestrol, hexestrol, beta-estradiol, ethynylestradiol, alpha/beta-boldenone, alpha-nortestosterone, alpha/beta-zearalenol, alpha/beta-zaeralanol, zearalenone, stanozolol and 16beta-OH-stanozolol). The procedure involved enzymatic hydrolysis, extraction with tert-butyl methyl ether, a washing step with hexane and final clean-up with SPE with Oasis HLB and Amino cartridges. The analytes were quantified by liquid chromatography coupled to a tandem mass spectrometer (LC-TSQ Quantum AM) operating in both positive and negative atmospheric pressure chemical ionisation (APCI). Data acquisition was performed in multiple reaction monitoring (MRM) mode quantifying two diagnostic product ions from a chosen precursor. The method was validated according to the Commission Decision 2002/657/EC, for the detection and confirmation of residues in products of animal origin. The method specificity, sensitivity, accuracy and precision were evaluated. The decision limits CCalpha ranged from 0.06 to 0.26 ng/ml and the detection capabilities CCbeta ranged from 0.11 to 0.49 ng/ml. The developed method is sensitive and useful for detection, quantification and confirmation of these Anabolic Steroids in bovine urine and can be used for residue control programs.

A. T. Kicman – One of the best experts on this subject based on the ideXlab platform.

  • Pharmacology of Anabolic Steroids
    British Journal of Pharmacology, 2008
    Co-Authors: A. T. Kicman
    Abstract:

    Athletes and bodybuilders have recognized for several decades that the use of Anabolic Steroids can promote muscle growth and strength but it is only relatively recently that these agents are being revisited for clinical purposes. Anabolic Steroids are being considered for the treatment of cachexia associated with chronic disease states, and to address loss of muscle mass in the elderly, but nevertheless their efficacy still needs to be demonstrated in terms of improved physical function and quality of life. In sport, these agents are performance enhancers, this being particularly apparent in women, although there is a high risk of virilization despite the favourable myotrophic-androgenic dissociation that many xenobiotic Steroids confer. Modulation of androgen receptor expression appears to be key to partial dissociation, with consideration of both intracellular steroid metametabolism and the topology of the bound androgen receptor interacting with co-activators. An anticatabolic effect, by interfering with glucocorticoid receptor expression, remains an attractive hypothesis. Behavioural changes by non-genomic and genomic pathways probably help motivate training. Anabolic Steroids continue to be the most common adverse finding in sport and, although apparently rare, designer Steroids have been synthesized in an attempt to circumvent the dope test. Doping with Anabolic Steroids can result in damage to health, as recorded meticulously in the former German Democratic Republic. Even so, it is important not to exaggerate the medical risks associated with their administration for sporting or bodybuilding purposes but to emphasize to users that an attitude of personal invulnerability to their adverse effects is certainly misguided.

F T Delbeke – One of the best experts on this subject based on the ideXlab platform.

  • Detection and characterization of Anabolic Steroids in doping analysis by LC-MS
    TrAC Trends in Analytical Chemistry, 2008
    Co-Authors: Oscar J Pozo, Koen Deventer, Peter Van Eenoo, F T Delbeke
    Abstract:

    Abstract The detection of target Anabolic Steroids in doping analysis has generally been performed by gas chromatography combined with mass spectrometry (GC-MS). However, liquid chrochromatography combined with tandem mass spectrometry (LC-MS2) is gradually becoming more important for this purpose. Also, since non-commercially available Anabolic Steroids have been found in some doping-control samples, detection and structural determination of unknown Steroids has become a challenge for doping-control laboratories. We discuss the potential of different LC-MS and LC-MS2 scan modes for detection of both target and unknown Anabolic Steroids. Several modes (e.g., selected reaction monitoring, full scan and product-ion scan) can be successfully used for the detection of target analytes. In order to detect and to characterize unknown Steroids and metabolites, the most powerful approach seems to be to combine several scan modes. We use a practical case to illustrate the potential of LC-MS and LC-MS2 for this purpose.

  • ionization of Anabolic Steroids by adduct formation in liquid chromatography electrospray mass spectrometry
    Journal of Mass Spectrometry, 2007
    Co-Authors: Oscar J Pozo, Peter Van Eenoo, Koen Deventer, F T Delbeke
    Abstract:

    The ionization of 46 Anabolic Steroids has been studied. The absence of basic or acidic moieties in most of these analytes makes their direct ionization as [M + H]+ by atmospheric pressure interfaces difficult. The formation of adducts with different components of the mobile phase has been found to be an efficient way to ionize Anabolic Steroids by electrospray. Different mobile phases using methanol (MeOH) or acetonitrile as organic solvent and HCOOH, Na+ or NH4+ as additives have been tested to favor the adduct formation. A direct correlation between the chemical structure of the Anabolic steroid and the possibility to ionize it in a particular chromatographic condition has been found. According to their ionization, Anabolic Steroids can be divided into seven different groups depending on both the nature and the relative position of their functional groups. The formation of different adducts such as [M + Na + MeOH]+ or [M + H + CH3 CN − H2O]+ is required in order to ionize some of these groups and the optimal mobile phase composition for each group of Anabolic Steroids is proposed. Despite the ionization limitations due to their chemical structure, most of tested Anabolic Steroids could be ionized using the adduct formation approach. Copyright © 2007 John Wiley & Sons, Ltd.