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Ho HSM, Farrington AF, Bond AJ, Ho ENM, Wong WT. Doping control of estra-4,9-diene-3,17-dione in horses. Drug Test Anal 2024. [PMID: 38926502 DOI: 10.1002/dta.3756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/14/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024]
Abstract
Estra-4,9-diene-3,17-dione (dienedione) is an anabolic-androgenic steroid (AAS) available on the market as a dietary supplement for bodybuilding. It is prohibited in both human and equine sports due to its potential performance-enhancing effect. With the rare presence of the 4,9-diene configuration in endogenous steroids, dienedione has been considered as a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in entire male horse urine samples led to the investigation of its possible endogenous nature in horses, and its endogenous nature in entire male horses has been recently confirmed and reported by the authors' laboratory. While dienedione is not detected in castrated horses (geldings), it is essential to study its elimination and identify its metabolites for its effective control. To study the elimination and biotransformation of dienedione, administration experiments were performed by giving three castrated horses (geldings) each single oral dose of 1500 mg of dienedione powder for seven consecutive days. The postulated in vivo metabolites included 17-hydroxyestra-4,9-dien-3-one (M1a and M1b), hydroxylated dienedione (M2a, M2b, M3a, M3b, M4, M5) and hydroxylated M1 (M6a, M6b, M7a, M7b, M8a and M8b), formed from hydroxylation and reduction of dienedione. To control the misuse of dienedione in geldings, M3a and M3b are the potential targets that gave the longest detection time, which could be detected for up to 2-5 days in urine and 0.4-4 days in plasma.
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Affiliation(s)
- Helen S M Ho
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Adrian F Farrington
- Department of Veterinary Clinical Services, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China
| | - Amanda J Bond
- Department of Equestrian Affairs, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China
| | - Emmie N M Ho
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China
| | - Wing-Tak Wong
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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Ho HSM, Ho ENM, Wong WT. Endogenous nature of estra-4,9-diene-3,17-dione in entire male horses. Drug Test Anal 2024. [PMID: 38532598 DOI: 10.1002/dta.3685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/29/2024] [Accepted: 03/07/2024] [Indexed: 03/28/2024]
Abstract
Estra-4,9-diene-3,17-dione (dienedione) is an anabolic androgenic steroid (AAS) sold as a bodybuilding supplement. It is prohibited in both human and equine sports. With no report of 4,9-diene configuration in endogenous steroids, dienedione has long been considered a synthetic AAS. Nevertheless, the reoccurring detection of dienedione in colt (entire male horse) urine samples lead to the investigation of its possible endogenous nature in horses. This paper describes (i) the detection of naturally occurring dienedione in colts, (ii) the conjugation study of dienedione and (iii) the population study of free and glucuronide-conjugated dienedione in colt urine. Qualitative and quantitative analyses of dienedione content in colt urine were performed, employing liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Qualitative analyses showed that dienedione was endogenous in colt urine and mainly in the form of glucuronide conjugates. Glucuronidation of dienedione was believed to happen at 3-enol leading to dienedione-3-glucuronide. Upon the population study of free and glucuronide-conjugated dienedione in colt urine samples (n = 175), the mean ± SD was determined to be 2.5 ± 3.5 ng/ml. The population data fitted a normal distribution after a fifth root transformation with the exclusion of one outlier by Grubb's test. A possible in-house threshold was proposed at 30 ng/ml of free and glucuronide-conjugated dienedione in colt urine associated with a risk factor of 1 in 14,269 (with a degree of freedom of 173). This is the first report of endogenous dienedione in entire male horses and the approach for controlling its potential misuse by using a threshold is also presented.
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Affiliation(s)
- Helen S M Ho
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hong Kong, China
| | - Emmie N M Ho
- Racing Laboratory, The Hong Kong Jockey Club, Hong Kong, China
| | - Wing-Tak Wong
- Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hong Kong, China
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Viljanto M, Love C, White D, Habershon-Butcher J, Hincks P, Gray B, Scarth J. Detection of methandienone and its metabolites in equine urine, plasma and hair following a multidose oral administration. Drug Test Anal 2024. [PMID: 38234065 DOI: 10.1002/dta.3633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024]
Abstract
Methandienone is an anabolic-androgenic steroid that is prohibited in equine sports due to its potential performance enhancing properties. Metabolism and detection of methandienone in equine urine have been investigated comprehensively in literature; however, there is a limited knowledge about its metabolites in equine plasma and no information about its detection in equine hair. Following a multi-dose oral administration of methandienone to two Thoroughbred horses, 17-epimethandienone, methyltestosterone, two mono-hydroxylated, two di-hydroxylated and three 17α-methylandrostanetriol metabolites were detected in plasma. The majority of these were present as free analytes, whilst the mono-hydroxylated metabolites and one isomer of 17α-methylandrostanetriol were partially conjugated. Estimated peak concentrations of methandienone were 6,000 and 11,100 pg/ml; meanwhile, they were 25.4 and 40.5 pg/ml for methyltestosterone. The most abundant analyte in the post-administration plasma samples of both horses was the mono-hydroxylated metabolite; however, the parent compound provided the longest detection (up to 96 h). Screening analysis of hair enabled the detection of methandienone in mane hair samples only, for up to 3 months. Its mono- and di-hydroxylated metabolites were detected with greater peak responses for up to 6 months post-administration in both mane and tail samples, showing that these metabolites could be better analytical targets for hair analysis when administered orally. A follow-up methodology with an extensive wash procedure confirmed the presence of methandienone and its metabolites in a number of post-administration hair samples. Final wash samples were also analysed to assess the degree of internal incorporation (via bloodstream) against possible external deposition (via sweat/sebum).
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Harding C, Viljanto M, Cutler C, Habershon-Butcher J, Biddle S, Scarth J. In vitro and in vivo metabolism of the anabolic-androgenic steroid oxandrolone in the horse. Drug Test Anal 2021; 14:39-55. [PMID: 34378336 DOI: 10.1002/dta.3139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/29/2021] [Accepted: 07/31/2021] [Indexed: 11/09/2022]
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Choi TL, Wong JK, Kwok WH, Curl P, Mechie S, Wan TS. Metabolic study of methylstenbolone in horses using liquid chromatography-high resolution mass spectrometry and gas chromatography-mass spectrometry. J Chromatogr A 2018; 1546:106-118. [DOI: 10.1016/j.chroma.2018.02.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/12/2018] [Accepted: 02/20/2018] [Indexed: 02/07/2023]
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6
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Waller CC, McLeod MD. A review of designer anabolic steroids in equine sports. Drug Test Anal 2016; 9:1304-1319. [DOI: 10.1002/dta.2112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/05/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Christopher C. Waller
- Research School of Chemistry; Australian National University; Canberra ACT Australia
| | - Malcolm D. McLeod
- Research School of Chemistry; Australian National University; Canberra ACT Australia
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Wong ASY, Leung GNW, Leung DKK, Wan TSM. Doping control analysis of anabolic steroids in equine urine by gas chromatography-tandem mass spectrometry. Drug Test Anal 2016; 9:1320-1327. [DOI: 10.1002/dta.2090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 12/20/2022]
Affiliation(s)
- April S. Y. Wong
- Racing Laboratory; The Hong Kong Jockey Club, Sha Tin Racecourse; Hong Kong China
| | - Gary N. W. Leung
- Racing Laboratory; The Hong Kong Jockey Club, Sha Tin Racecourse; Hong Kong China
| | - David K. K. Leung
- Racing Laboratory; The Hong Kong Jockey Club, Sha Tin Racecourse; Hong Kong China
| | - Terence S. M. Wan
- Racing Laboratory; The Hong Kong Jockey Club, Sha Tin Racecourse; Hong Kong China
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Metabolic studies of oxyguno in horses. Anal Chim Acta 2015; 891:190-202. [DOI: 10.1016/j.aca.2015.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 07/29/2015] [Accepted: 08/08/2015] [Indexed: 12/17/2022]
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Kwok WH, Kwok KY, Leung DKK, Leung GNW, Wong CHF, Wong JKY, Wan TSM. In vitro metabolism studies of desoxy-methyltestosterone (DMT) and its five analogues, and in vivo metabolism of desoxy-vinyltestosterone (DVT) in horses. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:994-1005. [PMID: 28338272 DOI: 10.1002/jms.3613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/13/2015] [Accepted: 05/04/2015] [Indexed: 06/06/2023]
Abstract
The positive findings of norbolethone in 2002 and tetrahydrogestrinone in 2003 in human athlete samples confirmed that designer steroids were indeed being abused in human sports. In 2005, an addition to the family of designer steroids called 'Madol' [also known as desoxy-methyltestosterone (DMT)] was seized by government officials at the US-Canadian border. Two years later, a positive finding of DMT was reported in a mixed martial arts athlete's sample. It is not uncommon that doping agents used in human sports would likewise be abused in equine sports. Designer steroids would, therefore, pose a similar threat to the horseracing and equestrian communities. This paper describes the in vitro metabolism studies of DMT and five of its structural analogues with different substituents at the 17α position (RH, ethyl, vinyl, ethynyl and 2 H3 -methyl). In addition, the in vivo metabolism of desoxy-vinyltestosterone (DVT) in horses will be presented. The in vitro studies revealed that the metabolic pathways of DMT and its analogues occurred predominantly in the A-ring by way of a combination of enone formation, hydroxylation and reduction. Additional biotransformation involving hydroxylation of the 17α-alkyl group was also observed for DMT and some of its analogues. The oral administration experiment revealed that DVT was extensively metabolised and the parent drug was not detected in urine. Two in vivo metabolites, derived respectively from (1) hydroxylation of the A-ring and (2) di-hydroxylation together with A-ring double-bond reduction, could be detected in urine up to a maximum of 46 h after administration. Another in vivo metabolite, derived from hydroxylation of the A-ring with additional double-bond reduction and di-hydroxylation of the 17α-vinyl group, could be detected in urine up to a maximum of 70 h post-administration. All in vivo metabolites were excreted mainly as glucuronides and were also detected in the in vitro studies. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Wai Him Kwok
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - Karen Y Kwok
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - David K K Leung
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - Gary N W Leung
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - Colton H F Wong
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - Jenny K Y Wong
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
| | - Terence S M Wan
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, NT, Hong Kong, China
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Evaluation of horse urine sample preparation methods for metabolomics using LC coupled to HRMS. Bioanalysis 2014; 6:785-803. [DOI: 10.4155/bio.13.324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background: Horse urine is the medium of choice for the implementation of metabolomic approaches aimed at improving horse doping control. However, drug analysis in this biofluid is a challenging task due to the presence of large amounts of interfering compounds. Methodology & Results: A comparative study of sample preparation has been conducted to evaluate five sample-preparation methods, namely acetonitrile precipitation, proteinase K hydrolysis, membrane filtration and sample dilution with water by factors of five and 20, for metabolome analysis using liquid chromatography coupled to high resolution mass spectrometry. Assessment was performed at both global and targeted levels, by using a few thousand features obtained from peak detection software, and internal standards and 100 annotated or identified metabolites. Conclusion: By considering the number of detected signals, their intensity and their detection repeatability, acetonitrile precipitation was selected as the most efficient sample-preparation method for the analysis of horse urine metabolome in liquid chromatography coupled to high resolution mass spectrometry conditions.
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Schmitz A, Zielinski J, Dick B, Mevissen M. In vitro
metabolism of testosterone in the horse liver and involvement of equine CYPs 3A89, 3A94 and 3A95. J Vet Pharmacol Ther 2014; 37:338-47. [DOI: 10.1111/jvp.12106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 12/24/2013] [Indexed: 02/03/2023]
Affiliation(s)
- A. Schmitz
- Division of Veterinary Pharmacology and Toxicology; Vetsuisse Faculty; University Bern; Bern Switzerland
| | - J. Zielinski
- Division of Veterinary Pharmacology and Toxicology; Vetsuisse Faculty; University Bern; Bern Switzerland
| | - B. Dick
- Department of Nephrology, Hypertension and Clinical Pharmacology; Inselspital; Bern Switzerland
| | - M. Mevissen
- Division of Veterinary Pharmacology and Toxicology; Vetsuisse Faculty; University Bern; Bern Switzerland
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12
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Oxidative stress and myocardial dysfunction in young rabbits after short term anabolic steroids administration. Food Chem Toxicol 2013; 61:101-5. [DOI: 10.1016/j.fct.2013.03.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 03/16/2013] [Indexed: 01/01/2023]
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13
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Kwok WH, Ho ENM, Leung GNW, Tang FPW, Wan TSM, Wong HNC, Yeung JHK. Metabolic studies of 1-testosterone in horses. Drug Test Anal 2012; 5:81-8. [DOI: 10.1002/dta.1380] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/09/2012] [Accepted: 05/10/2012] [Indexed: 12/13/2022]
Affiliation(s)
- W. H. Kwok
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse; Sha Tin, N.T.; Hong Kong; China
| | - Emmie N. M. Ho
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse; Sha Tin, N.T.; Hong Kong; China
| | - Gary N. W. Leung
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse; Sha Tin, N.T.; Hong Kong; China
| | - Francis P. W. Tang
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse; Sha Tin, N.T.; Hong Kong; China
| | - Terence S. M. Wan
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse; Sha Tin, N.T.; Hong Kong; China
| | - Henry N. C. Wong
- Department of Chemistry; The Chinese University of Hong Kong; Sha Tin, N.T.; Hong Kong; China
| | - John H. K. Yeung
- School of Biomedical Sciences; The Chinese University of Hong Kong; Sha Tin, N.T.; Hong Kong; China
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Abstract
Historically, dope-testing methods have been developed to target specific and known threats to the integrity of sport. Traditionally, the source of new analytical targets for which testing was required were derived almost exclusively from the pharmaceutical industry. More recently, the emergence of designer drugs, such as tetrahydrogestrinone that are specifically intended to evade detection, or novel chemicals intended to circumvent laws controlling the sale and distribution of recreational drugs, such as anabolic steroids, stimulants and cannabinoids, have become a significant issue. In this review, we shall consider the emergence of designer drugs and the response of dope-testing laboratories to these new threats, in particular developments in analytical methods, instrumentation and research intended to detect their abuse, and we consider the likely future impact of these approaches.
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Metabolism of anabolic steroids and their relevance to drug detection in horseracing. Bioanalysis 2011; 2:1085-107. [PMID: 21083210 DOI: 10.4155/bio.10.57] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The fight against doping in sport using analytical chemistry is a mature area with a history of approximately 100 years in horseracing. In common with human sport, anabolic/androgenic steroids (AASs) are an important group of potential doping agents. Particular issues with their detection are extensive metabolism including both phase I and phase II. A number of the common AASs are also endogenous to the equine. A further issue is the large number of synthetic steroids produced as pharmaceutical products or as 'designer' drugs intended to avoid detection or for the human supplement market. An understanding of the metabolism of AASs is vital to the development of effective detection methods for equine sport. The aim of this paper is to review current knowledge of the metabolism of appropriate steroids, the current approaches to their detection in equine sport and future trends that may affect equine dope testing.
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Wong JKY, Tang FPW, Wan TSM. In vitro metabolic studies using homogenized horse liver in place of horse liver microsomes. Drug Test Anal 2011; 3:393-9. [DOI: 10.1002/dta.273] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 12/10/2010] [Accepted: 01/16/2011] [Indexed: 11/08/2022]
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The use of in vitro technologies and high-resolution/accurate-mass LC-MS to screen for metabolites of ‘designer’ steroids in the equine. Drug Test Anal 2011; 3:74-87. [DOI: 10.1002/dta.250] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Leung DK, Tang FP, Wan TS, Wong JK. Identification of cryptorchidism in horses by analysing urine samples with gas chromatography/mass spectrometry. Vet J 2011; 187:60-4. [DOI: 10.1016/j.tvjl.2009.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 10/08/2009] [Accepted: 10/10/2009] [Indexed: 10/20/2022]
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Scarth JP, Teale P, Kuuranne T. Drug metabolism in the horse: a review. Drug Test Anal 2010; 3:19-53. [DOI: 10.1002/dta.174] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/02/2010] [Accepted: 08/02/2010] [Indexed: 12/13/2022]
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20
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Bratoeff E, García P, Heuze Y, Soriano J, Mejía A, Labastida AM, Valencia N, Cabeza M. Molecular interactions of progesterone derivatives with 5 alpha-reductase types 1 and 2 and androgen receptors. Steroids 2010; 75:499-505. [PMID: 20359488 DOI: 10.1016/j.steroids.2010.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/19/2010] [Accepted: 03/22/2010] [Indexed: 11/20/2022]
Abstract
The aim of this study was to ascertain the inhibitory effect of several progesterone derivatives for 5 alpha-reductase types 1 and 2 isozymes and to determine the binding to the androgen receptor. The 3,20-dioxopregna-4-ene-17 alpha-yl acetate 4 containing an acetoxy group in C-17 and steroid 17 alpha-hydroxypregn-4-ene-3,20-dione 5 having a hydroxyl group in the same position inhibited both isozymes. On the other hand, 17 alpha-hydroxy-4,5-epoxypregnan-3,20-dione 6 with an epoxy function at C-4, inhibited only the type 1 enzyme. Steroid 4-chloro-17 alpha-hydroxypregn-4-ene-3,20-dione 7a and 4-bromo-17 alpha-hydroxypregn-4-ene-3,20-dione 7b having the C-4 conjugated system and a chlorine or a bromine atom at C-4 respectively, inhibited both types of 5 alpha-reductase. These results indicate that an increase in the electronegativity of ring A produces a major inhibitory activity for 5 alpha-reductase type 1; however this increase was not observed for type 2 enzyme. When the free hydroxyl group of 7a or 7b was esterified, compounds 3,20-dioxo-4-chloropregn-4-ene-17 alpha yl-4-ethylbenzoate 8a and 3,20-dioxo-4-bromopregn-4-ene-17 alpha yl-4-ethylbenzoate 8b were obtained; these steroids inhibited only the 5 alpha-reductase type 2 enzyme. Finasteride and steroids 4, 5, 7b, 8a showed a comparable in vivo pharmacological activity, however the IC(50) values of these compounds were higher as compared to that of finasteride. These results indicated also that steroids 4, 5, 7a, and 7b bind to the androgen receptor whereas compounds 6, 8a and 8b failed to do so. The overall data from this study showed that steroids 5 and 7b bind to the AR and decreased of the growth of prostate and seminal vesicles. Moreover, 4 decreased also the growth of seminal vesicles.
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Affiliation(s)
- Eugene Bratoeff
- Department of Pharmacy, Faculty of Chemistry, National University of Mexico City, Mexico, D.F., Mexico
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Scarth JP, Spencer HA, Hudson SC, Teale P, Gray BP, Hillyer LL. The application of in vitro technologies to study the metabolism of the androgenic/anabolic steroid stanozolol in the equine. Steroids 2010; 75:57-69. [PMID: 19854209 DOI: 10.1016/j.steroids.2009.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/07/2009] [Accepted: 10/08/2009] [Indexed: 10/20/2022]
Abstract
In this study, the use of equine liver/lung microsomes and S9 tissue fractions were used to study the metabolism of the androgenic/anabolic steroid stanozolol as an example of the potential of in vitro technologies in sports drug surveillance. In vitro incubates were analysed qualitatively alongside urine samples originating from in vivo stanozolol administrations using LC-MS on a high-resolution accurate mass Thermo Orbitrap Discovery instrument, by LC-MS/MS on an Applied Biosystems Sciex 5500 Q Trap and by GC-MS/MS on an Agilent 7000A. Using high-resolution accurate mass full scan analysis on the Orbitrap, equine liver microsome and S9 in vitro fractions were found to generate all the major phase-1 metabolites observed following in vivo administrations. Additionally, analysis of the liver microsomal incubates using a shallower HPLC gradient combined with various MS/MS functions on the 5500 Q trap allowed the identification of a number of phase 1 metabolites previously unreported in the equine or any other species. Comparison between liver and lung S9 metabolism showed that the liver was the major site of metabolic activity in the equine. Furthermore, using chemical enzyme inhibitors that are known to be selective for particular isoforms in other species suggested that an enzyme related to CYP2C8 may be responsible the production of 16-hydroxy-stanozolol metabolites in the equine. In summary, the in vitro and in vivo phase 1 metabolism results reported herein compare well and demonstrate the potential of in vitro studies to compliment the existing in vivo paradigm and to benefit animal welfare through a reduction and refinement of animal experimentation.
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Affiliation(s)
- James P Scarth
- HFL Sport Science, Newmarket Road, Fordham, Cambridgeshire, CB7 5WW, UK.
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Scarth JP, Spencer HA, Timbers SE, Hudson SC, Hillyer LL. The use ofin vitrotechnologies coupled with high resolution accurate mass LC-MS for studying drug metabolism in equine drug surveillance. Drug Test Anal 2010; 2:1-10. [DOI: 10.1002/dta.88] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Abstract
This chapter reviews drug and medication control in equestrian sports and addresses the rules of racing, the technological advances that have been made in drug detection and the importance of metabolism studies in the development of effective drug surveillance programmes. Typical approaches to screening and confirmatory analysis are discussed, as are the quality processes that underpin these procedures. The chapter also addresses four specific topics relevant to equestrian sports: substances controlled by threshold values, the approach adopted recently by European racing authorities to control some therapeutic substances, anabolic steroids in the horse and LC-MS analysis in drug testing in animal sports and metabolism studies. The purpose of discussing these specific topics is to emphasise the importance of research and development and collaboration to further global harmonisation and the development and support of international rules.
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Affiliation(s)
- Ed Houghton
- HFL Sport Science, Newmarket Road, Fordham, Cambridgeshire, UK.
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Leung GNW, Tang FPW, Wan TSM, Wong CHF, Lam KKH, Stewart BD. In vitro and in vivo studies of androst-4-ene-3,6,17-trione in horses by gas chromatography-mass spectrometry. Biomed Chromatogr 2009; 24:744-51. [DOI: 10.1002/bmc.1358] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Modern techniques for the determination of anabolic–androgenic steroid doping in the horse. Bioanalysis 2009; 1:785-803. [DOI: 10.4155/bio.09.52] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Control of the use of performance-affecting substances in the horse is critical to the integrity of a wide range of equine sports, with major implications for both animal welfare and revenue streams. One class of medications enjoying particular public notoriety is the anabolic–androgenic steroid group, as highlighted by the recent ‘Big Brown’ affair and Congressional inquiries into the use of steroids in professional sports, including horse racing, in the USA. This review examines the latest developments pertaining to the analytical detection of these substances in equine biological samples and the supporting regulatory environment. Consideration is given to the full variety of sample matrices available, together with modern sample preparative approaches and instrumental techniques. Issues concerning the regulation of endogenous steroids, including thresholds where applicable, are also discussed.
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