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1.
Drug Test Anal ; 3(1): 68-73, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21254454

RESUMEN

Methods have been developed to screen for and confirm darbepoetin alfa, recombinant human EPO, and methoxy polyethylene glycol-epoetin ß (PEG-epoetin ß) in horse plasma. All three methods screen samples with an enzyme-linked immunosorbent assay (ELISA) and confirm by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This report focuses on PEG-epoetin ß. The ELISA assay was able to detect PEG-epoetin ß at 0.02 ng/mL in 50 µL of horse plasma. Many samples had high background levels of immunoreactivity; however, introducing polyethylene glycol 6000 (PEG 6000) into the samples before the ELISA assay removed the high background and increased the apparent concentrations of PEG-epoetin ß. In samples collected following the administration of 100 µg of PEG-epoetin ß by the intravenous (IV), intramuscular (IM) and subcutaneous (SC) routes, PEG-epoetin ß was detectable up to 72, 144, and 120 h, respectively. The samples were prepared for LC-MS/MS analysis by extraction with anti-rHuEPO-antibodies-coated Dynabeads followed by digestion with trypsin. The LC-MS/MS confirmation method used the multiple reaction monitoring (MRM) scan mode to monitor four precursor-product ion transitions of the EPO-derived peptide T6. All four transitions of T6 were detectable with S/N > 3. The limit of confirmation for PEG-epoetin ß was 1.0 ng/mL in 2 mL of horse plasma. The method successfully confirmed the presence of PEG-epoetin ß in a sample collected from a Mircera®-treated horse. Compared to PEG-epoetin ß, better sensitivity was achieved for darbepoetin alfa and recombinant human EPO. Darbepoetin alfa was detected in horse plasma four days after IM administration of 100 µg.


Asunto(s)
Doping en los Deportes , Eritropoyetina/sangre , Caballos/sangre , Sustancias para Mejorar el Rendimiento/sangre , Polietilenglicoles/análisis , Detección de Abuso de Sustancias/veterinaria , Administración Oral , Animales , Cromatografía Liquida/veterinaria , Darbepoetina alfa , Ensayo de Inmunoadsorción Enzimática/veterinaria , Eritropoyetina/administración & dosificación , Eritropoyetina/análogos & derivados , Eritropoyetina/farmacocinética , Humanos , Inyecciones Intramusculares , Inyecciones Intravenosas , Inyecciones Subcutáneas , Sustancias para Mejorar el Rendimiento/administración & dosificación , Sustancias para Mejorar el Rendimiento/farmacocinética , Polietilenglicoles/administración & dosificación , Polietilenglicoles/farmacocinética , Proteínas Recombinantes , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray/veterinaria , Espectrometría de Masas en Tándem/veterinaria
2.
Drug Test Anal ; 1(9-10): 441-6, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20355229

RESUMEN

Approaches to detect whether an athlete has used growth hormone have been intensely investigated by sport organizations for 20 years. This effort has led to a human growth hormone (hGH) isoform ratio test in serum that has been approved by WADA and deployed at three Olympic Games, although a positive case has yet to be reported. We set out to determine whether the ratio test could be applied to urine. First we investigated various ways to extract hGH from spiked urine. We were able to recover 95% using selective centrifugal concentration. This fraction was then subjected to four different commercially available immunoprecipitation kits. The highest yield was obtained with the Invitrogen Dynabeads Protein G kit. Nevertheless it is apparent that these methods do not recover enough hGH for subsequent analysis by mass spectrometry. With further effort greater recovery of the 22 kDa isoform might be achieved, however it is very unlikely that the 20 kDa isoform could be detected. This method may be significantly improved by the application of both nanoparticle and aptamer technology.


Asunto(s)
Doping en los Deportes , Hormona de Crecimiento Humana/orina , Inmunoprecipitación/métodos , Isoformas de Proteínas/orina , Detección de Abuso de Sustancias/métodos , Humanos , Modelos Inmunológicos , Juego de Reactivos para Diagnóstico
3.
J Intern Med ; 264(2): 99-114, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18702750

RESUMEN

The fight against doping in sports commenced as a result of the death of a Danish cyclist during the Rome Olympic Games in 1960. The International Olympic Committee (IOC) established a Medical Commission (IOC-MC) which had the task of designing a strategy to combat the misuse of drugs in Olympic Sport. Some International Sport Federations (IF) and National Sports Federations followed suit, but progress was modest until the world's best male sprinter was found doped with anabolic steroids at the Olympic Games in Seoul in 1988. Further progress was made following the cessation of the cold war in 1989 and in 1999 public authorities around the world joined the Olympic Movement in a unique partnership by creating WADA--the 'World Anti-Doping Agency'. The troubled history of the anti-doping fight from the 1960s until today is reviewed. In particular, the development of detection methods for an ever increasing number of drugs that can be used to dope is described, as are the measures that have been taken to protect the health of the athletes, including those who may need banned substances for medical reasons.


Asunto(s)
Doping en los Deportes/prevención & control , Ética Médica , Detección de Abuso de Sustancias/métodos , Anabolizantes/farmacología , Análisis Químico de la Sangre , Doping en los Deportes/ética , Quimioterapia/normas , Eritropoyetina/farmacología , Femenino , Citometría de Flujo/métodos , Hormona de Crecimiento Humana/farmacología , Humanos , Agencias Internacionales/organización & administración , Cooperación Internacional , Masculino , Espectrometría de Masas/métodos , Proteínas Recombinantes , Deportes/ética , Detección de Abuso de Sustancias/tendencias
4.
Endocrinology ; 146(10): 4472-8, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15976054

RESUMEN

The discovery of tetrahydrogestrinone (THG) abuse by several elite athletes led the U.S. Congress to declare it a controlled substance, although conclusive evidence of its anabolic/androgenic activity is lacking. We determined whether THG affects myogenic differentiation and androgen receptor (AR)-mediated signaling, whether it binds to AR, and whether it has androgenic and anabolic effects in vivo. Accordingly, we measured the dissociation constant for THG with a fluorescence anisotropy assay using recombinant AR-ligand binding domain. The AR nuclear translocation and myogenic activity of androstenedione were evaluated in mesenchymal, multipotent C3H10T1/2 cells. We performed molecular modeling of the THG:AR interaction. The androgenic/anabolic activity was evaluated in orchidectomized rats. THG bound to AR with an affinity similar to that of dihydrotestosterone. In multipotent C3H10T1/2 cells, THG upregulated AR expression, induced AR nuclear translocation, dose dependently increased the area of myosin heavy chain type II-positive myotubes, and up-regulated myogenic determination and myosin heavy chain type II protein expression. The interaction between AR and the A ring of THG was similar to that between AR and the A ring of dihydrotestosterone, but the C17 and C18 substituents in THG had a unique stabilizing interaction with AR. THG administration prevented the castration-induced atrophy of levator ani, prostate gland, and seminal vesicles and loss of fat-free mass in orchidectomized rats. We conclude that THG is an anabolic steroid that binds to AR, activates AR-mediated signaling, promotes myogenesis in mesenchymal multipotent cells, and has anabolic and androgenic activity in vivo. This mechanism-based approach should be useful for rapid screening of anabolic/androgenic agents.


Asunto(s)
Gestrinona/análogos & derivados , Mesodermo/fisiología , Músculo Esquelético/citología , Receptores Androgénicos/fisiología , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Gestrinona/farmacología , Masculino , Mesodermo/citología , Mesodermo/efectos de los fármacos , Ratones , Músculo Esquelético/efectos de los fármacos , Orquiectomía , Ratas
5.
Clin J Sport Med ; 11(4): 254-9, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11753063

RESUMEN

OBJECTIVE: To determine if steroids containing over-the-counter (OTC) dietary supplements conform to the labeling requirements of the 1994 Dietary Supplement Health and Education Act (DSHEA). DESIGN: 12 brands of OTC supplements containing 8 different steroids were randomly selected for purchase in stores that cater to athletes. There are two androstenediones (4- and 5-androstene-3,17-dione), two androstenediols (4- and 5-androstene-3beta, 17beta-diol), and 4 more are 19-nor cogeners (19-nor-4- and 5-androstene-3,17-dione and 19-nor-4- and 5-androstene-3beta, 17beta-diol). MAIN OUTCOME MEASURES: 12 brands of OTC anabolic-androgenic supplements were analyzed by high-pressure liquid chromatography. RESULTS: We found that 11 of 12 brands tested did not meet the labeling requirements set out in the 1994 Dietary Supplement Health and Education Act. One brand contained 10 mg of testosterone, a controlled steroid, another contained 77% more than the label stated, and 11 of 12 contained less than the amount stated on the label. CONCLUSIONS: These mislabeling problems show that the labels of the dietary steroid supplements studied herein cannot be trusted for content and purity information. In addition, many sport organizations prohibit OTC steroids; thus, athletes who use them are at risk for positive urine test results. In this article we provide the details of the analyses, a summary of the steroids by name and structure, and information on the nature of the positive test results. Athletes and their physicians need this information because of the potential medical consequences and positive urine test results.


Asunto(s)
Suplementos Dietéticos/análisis , Suplementos Dietéticos/normas , Medicamentos sin Prescripción/análisis , Medicamentos sin Prescripción/normas , Etiquetado de Productos/legislación & jurisprudencia , Esteroides/análisis , Esteroides/normas , Doping en los Deportes/métodos , Humanos , Legislación Alimentaria , Etiquetado de Productos/normas , Vigilancia de Productos Comercializados , Control de Calidad , Esteroides/química , Esteroides/orina , Estados Unidos , Urinálisis/normas
6.
Rapid Commun Mass Spectrom ; 15(24): 2379-82, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11746905

RESUMEN

RSR13 (2-[4-[[(3,5-dimethylanilino)carbonyl]methyl]phenoxyl]-2-methylpropionic acid) is a synthetic allosteric modifier of hemoglobin that is currently in a phase III clinical trial as a radio-enhancing agent. RSR13 has been shown to increase maximum oxygen uptake (VO(2max)) in a canine skeletal model, which makes it a potential performance-enhancing agent for endurance athletes, since VO(2max) is an index of aerobic capacity. In this study we present a method for the detection of RSR13-bis-TMS in human urine by gas chromatography/electron impact ionization mass spectrometry (GC/EI-MS) suitable for doping control laboratories. The presence of RSR13 is detected by monitoring the ions m/z 485 ([M](+.)) and 470 ([M - CH3](+)). The limit of detection (LOD) is less than 2 ng/mL in urine. Urine samples collected from clinical trial subjects immediately prior to receiving an infusion of RSR13 showed no evidence of RSR13, whereas post-infusion urine samples contained up to 1181 microg/mL. A urine sample collected 36 h after administration of a small dose (10 mg/kg) and diluted 100-fold showed a signal 80 times higher than the LOD. Urine samples obtained from 100 randomly selected athletes in our routine testing program did not show any traces of RSR13. Sport authorities may wish to add RSR13 to the list of prohibited substances.


Asunto(s)
Compuestos de Anilina/orina , Doping en los Deportes , Propionatos/orina , Detección de Abuso de Sustancias/métodos , Calibración , Cromatografía de Gases , Glucurónidos/orina , Humanos , Indicadores y Reactivos , Sensibilidad y Especificidad , Espectrometría de Masa por Ionización de Electrospray
7.
J Clin Endocrinol Metab ; 86(8): 3654-8, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11502792

RESUMEN

Androstenedione is a steroid hormone and the major precursor to testosterone. It is available without prescription and taken with the expectation that it will be converted to testosterone endogenously and increase strength and athletic performance. The metabolism of orally administered testosterone has not been well studied. We randomly assigned 37 healthy men to receive 0, 100, or 300 mg oral androstenedione in a single daily dose for 7 d. Single 8-h urine collections were performed on the day before the start of the androstenedione administration and on d 1 and 7 to assess excretion rates of free and glucuronide- conjugated testosterone, androsterone, etiocholanolone, and dihydrotestosterone. Serum testosterone glucuronide concentrations were measured by frequent blood sampling over 8 h on d 1 in 16 subjects (5 each in the 0 and 100 mg group and 6 in the 300 mg group). In the control group, mean (+/-SE) d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 3 +/- 1, 215 +/- 26, 175 +/- 26, and 0.4 +/- 0.1 microg/h, respectively. In the 100 mg group, mean d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 47 +/- 11, 3,836 +/- 458, 4,306 +/- 458, and 1.6 +/- 0.2 microg/h, respectively. In the 300 mg group, mean d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 115 +/- 39, 8,142 +/- 1,362, 10,070 +/- 1,999, and 7.7 +/- 1.5 microg/h, respectively. Urinary excretion rates of all metabolites were greater in both the 100 and 300 mg groups than in controls (P < 0.0001). Urinary excretion rates of testosterone (P = 0.007), androsterone (P = 0.009), etiocholanolone (P = 0.0005), and dihydrotestosterone (P < 0.0001) were greater in the subjects who received 300 mg androstenedione than in those who received 100 mg. In the treated groups, excretion of free testosterone accounted for less than 0.1% of the total excreted testosterone measured. Serum testosterone glucuronide levels increased significantly during frequent blood sampling in both the 100 and 300 mg groups compared with controls (P = 0.0005 for the 100 mg group; P < 0.0001 for the 300 mg group). The net mean changes in area under the curve for serum testosterone glucuronide were -18 +/- 25%, 579 +/- 572%, and 1267 +/- 1675% in the groups receiving 0, 100, and 300 mg/d androstenedione, respectively. We conclude that the administration of both 100 and 300 mg androstenedione increases the excretion rates of conjugated testosterone, androsterone, etiocholanolone, and dihydrotestosterone and the serum levels of testosterone glucuronide in men. The magnitude of these increases is much greater than the changes observed in serum total testosterone concentrations. These findings demonstrate that orally administered androstenedione is largely metabolized to testosterone glucuronide and other androgen metabolites before release into the general circulation.


Asunto(s)
Androstenodiona/metabolismo , Administración Oral , Adulto , Androstenodiona/sangre , Androstenodiona/orina , Androsterona/orina , Pueblo Asiatico , Población Negra , Dihidrotestosterona/orina , Etiocolanolona/orina , Glucurónidos/sangre , Glucurónidos/orina , Humanos , Masculino , Testosterona/sangre , Testosterona/orina , Estados Unidos , Población Blanca
8.
Clin Chem ; 47(2): 292-300, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11159778

RESUMEN

BACKGROUND: Carbon isotope ratio methods are used in doping control to determine whether urinary steroids are endogenous or pharmaceutical. METHODS: Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) was used to determine the delta(13)C values for 5 beta-androstane-3 alpha,17 beta-diyl diacetate (5 beta A), 5 alpha-androstane-3 alpha,17 beta-diyl diacetate (5 alpha A), and 5 beta-pregnane-3 alpha,20 alpha-diyl diacetate (5 beta P) in a control group of 73 healthy males and 6 athletes with testosterone/epitestosterone ratios (T/E) >6. RESULTS: The within-assay precision SDs for 5 beta A, 5 alpha A, and 5 beta P were +/- 0.27 per thousand, +/- 0.38 per thousand, and +/- 0.28 per thousand, respectively. The between-assay precision SDs ranged from +/- 0.40 per thousand to +/- 0.52 per thousand. The system suitability and batch acceptance scheme is based on SDs. For the control group, the mean delta(13)C (SD) values were -25.69 per thousand (+/- 0.92 per thousand), -26.35 per thousand (+/- 0.68 per thousand), and -24.26 per thousand (+/- 0.70 per thousand), for 5 beta A, 5 alpha A, and 5 beta P, respectively. 5 beta P was greater than 5 beta A and 5 alpha A (P <0.01), and 5 beta A was greater than 5 alpha A (P <0.01). The means - 3 SD were -28.46 per thousand, -28.39 per thousand, and -26.37 per thousand for 5 beta A, 5 alpha A, and 5 beta P, respectively. The maximum difference between 5 beta P and 5 beta A was 3.2 per thousand, and the maximum 5 beta A/5 beta P was 1.13. Three athletes with chronically elevated T/Es had delta(13)C values consistent with testosterone administration and three did not. CONCLUSIONS: This GC-C-IRMS assay of urine diols has low within- and between-assay SDs; therefore, analysis of one urine sample suffices for doping control. The means, SDs, +/-3 SDs, and ranges of delta(13)C values in a control group are established. In comparison, testosterone users have low 5 beta A and 5 alpha A, large differences between 5 beta A or 5 alpha A and 5 beta P, and high 5 beta A/5 beta P and 5 alpha A/5 beta P ratios.


Asunto(s)
Androstano-3,17-diol/orina , Doping en los Deportes , Epitestosterona/orina , Pregnanodiol/orina , Detección de Abuso de Sustancias/métodos , Testosterona/orina , Isótopos de Carbono , Cromatografía de Gases y Espectrometría de Masas , Humanos , Masculino
9.
Rapid Commun Mass Spectrom ; 14(23): 2294-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11114040

RESUMEN

A gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) method is described and validated for measurement of delta(13)C values of the acetate derivatives of urinary etiocholanolone and androsterone. The analysis was performed with only 2 mL of urine. The sample preparation consisted of deconjugation with beta-glucuronidase, solid phase extraction, and derivatization with acetic anhydride and pyridine. The within-assay precision of two quality control (QC) urine samples ranged from 0.5 to 2.1 CV%. The between-assay precision in the same QC urines ranged from 1.7 to 3.4 CV%. Administration of testosterone enanthate to a subject resulted in a 6 per thousand decrease in delta(13)C values from -25 per thousand (baseline) to -31 per thousand. Two weeks after testosterone administration was discontinued, the delta(13)C values remained abnormally low while the urine testosterone/epitestosterone (T/E) ratio returned to less than 6. This relatively simple method is useful for rapidly screening a large number of urine samples, including those with T/E <6.


Asunto(s)
Androsterona/orina , Etiocolanolona/orina , Cromatografía de Gases y Espectrometría de Masas/métodos , Adulto , Isótopos de Carbono , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
10.
JAMA ; 284(20): 2618-21, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11086369

RESUMEN

CONTEXT: Several anabolic steroids are sold over-the-counter (OTC) in the United States, and their production is not regulated by the US Food and Drug Administration. Reports have suggested that use of these supplements can cause positive urine test results for metabolites of the prohibited steroid nandrolone. OBJECTIVES: To assess the content and purity of OTC androstenedione and to determine if androstenedione and 19-norandrostenedione administration causes positive urine test results for 19-norandrosterone, a nandrolone metabolite. DESIGN: Randomized controlled trial of androstenedione, open-label trial of 19-norandrostenedione, and mass spectrometry of androstenedione preparations, conducted between October 1998 and April 2000. SETTING: Outpatient facility of a university hospital. PARTICIPANTS: A total of 41 healthy men aged 20 to 44 years. INTERVENTION: Participants were randomly assigned to receive oral androstenedione, 100 mg/d (n = 13) or 300 mg/d (n = 11) for 7 days, or no androstenedione (n = 13); in addition, 4 patients received 10 microg of 19-norandrostenedione. MAIN OUTCOME MEASURES: Content of OTC androstenedione preparations; level of 19-norandrosterone in urine samples, determined by mass spectrometry, compared among the 3 randomized groups at day 1 and day 7, and among the participants who received 19-norandrostenedione from October 1998 to April 2000. RESULTS: All urine samples from participants treated with androstenedione contained 19-norandrosterone, while no samples from the no-androstenedione group did. Urinary concentrations were averaged for day 1 vs day 7 measurements; mean (SD) 19-norandrosterone concentrations in the 100-mg/d and 300-mg/d groups were 3.8 (2.5) ng/mL and 10.2 (6.9) ng/mL, respectively (P =. 006). The 19-norandrosterone content exceeded the cutoff for reporting positive cases (>2.0 ng/mL) in 20 of 24. The androstenedione preparation used was pure at a sensitivity of 0.1%, but at 0.001% 19-norandrostenedione was found. For the 4 participants to whom 10 microg of 19-norandrostenedione was administered, 19-norandrosterone was found in all urine samples. Of 7 brands of androstenedione analyzed at the 1% level, 1 contained no androstenedione, 1 contained 10 mg of testosterone, and 4 more contained 90% or less of the amount stated on the label. CONCLUSION: Our study suggests that trace contamination of androstenedione with 19-norandrostenedione is sufficient to cause urine test results positive for 19-norandrosterone, the standard marker for nandrolone use. Oral steroid doses as small as 10 microg are absorbed and excreted in urine. Some brands of androstenedione are grossly mislabeled. Careful analysis of androstenedione preparations is recommended in all studies of its biological effects. JAMA. 2000;284:2618-2621.


Asunto(s)
Anabolizantes/metabolismo , Androstenodiona/análogos & derivados , Androstenodiona/metabolismo , Contaminación de Medicamentos , Estranos/orina , Nandrolona/metabolismo , Medicamentos sin Prescripción , Adulto , Androstenodiona/química , Androstenodiona/farmacología , Suplementos Dietéticos , Humanos , Masculino , Espectrometría de Masas , Detección de Abuso de Sustancias , Estados Unidos , Urinálisis
11.
JAMA ; 283(6): 779-82, 2000 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-10683057

RESUMEN

CONTEXT: Androstenedione, a steroid hormone and the major precursor to testosterone, is available without prescription and is purported to increase strength and athletic performance. The hormonal effects of androstenedione, however, are unknown. OBJECTIVE: To determine if oral administration of androstenedione increases serum testosterone levels in healthy men. DESIGN: Open-label randomized controlled trial conducted between October 1998 and April 1999. SETTING: General clinical research center of a tertiary-care, university-affiliated hospital. PARTICIPANTS: Forty-two healthy men aged 20 to 40 years. INTERVENTION: Subjects were randomized to receive oral androstenedione (either 100 mg/d [n = 15] or 300 mg/d [n = 14]) or no androstenedione (n = 13) for 7 days. MAIN OUTCOME MEASURES: Changes in serum testosterone, androstenedione, estrone, and estradiol levels, measured by frequent blood sampling, compared among the 3 treatment groups. RESULTS: Mean (SE) changes in the area under the curve (AUC) for serum testosterone concentrations were -2% (7%), -4% (4%), and 34% (14%) in the groups receiving 0, 100, and 300 mg/d of androstenedione, respectively. When compared with the control group, the change in testosterone AUC was significant for the 300-mg/d group (P<.001) but not for the 100-mg/d group (P = .48). Baseline testosterone levels, drawn 24 hours after androstenedione administration, did not change. Mean (SE) changes in the AUC for serum estradiol concentrations were 4% (6%), 42% (12%), and 128% (24%) in the groups receiving 0, 100, and 300 mg/d of androstenedione, respectively. When compared with the control group, the change in the estradiol AUC was significant for both the 300-mg/d (P<.001) and 100-mg/d (P = .002) groups. There was marked variability in individual responses for all measured sex steroids. CONCLUSIONS: Our data suggest that oral androstenedione, when given in dosages of 300 mg/d, increases serum testosterone and estradiol concentrations in some healthy men.


Asunto(s)
Androstenodiona/farmacología , Testosterona/sangre , Administración Oral , Adulto , Androstenodiona/administración & dosificación , Androstenodiona/sangre , Área Bajo la Curva , Estradiol/sangre , Estrona/sangre , Humanos , Masculino , Testosterona/metabolismo
12.
J Clin Endocrinol Metab ; 84(8): 2705-11, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10443664

RESUMEN

Short term administration of testosterone stimulates net protein synthesis in healthy men. We investigated whether oxandrolone [Oxandrin (OX)], a synthetic analog of testosterone, would improve net muscle protein synthesis and transport of amino acids across the leg. Six healthy men [22+/-1 (+/-SE) yr] were studied in the postabsorptive state before and after 5 days of oral OX (15 mg/day). Muscle protein synthesis and breakdown were determined by a three-compartment model using stable isotopic data obtained from femoral arterio-venous sampling and muscle biopsy. The precursor-product method was used to determine muscle protein fractional synthetic rates. Fractional breakdown rates were also directly calculated. Total messenger ribonucleic acid (mRNA) concentrations of skeletal muscle insulin-like growth factor I and androgen receptor (AR) were determined using RT-PCR. Model-derived muscle protein synthesis increased from 53.5+/-3 to 68.3+/-5 (mean+/-SE) nmol/min.100 mL/leg (P < 0.05), whereas protein breakdown was unchanged. Inward transport of amino acids remained unchanged with OX, whereas outward transport decreased (P < 0.05). The fractional synthetic rate increased 44% (P < 0.05) after OX administration, with no change in fractional breakdown rate. Therefore, the net balance between synthesis and breakdown became more positive with both methodologies (P < 0.05) and was not different from zero. Further, RT-PCR showed that OX administration significantly increased mRNA concentrations of skeletal muscle AR without changing insulin-like growth factor I mRNA concentrations. We conclude that short term OX administration stimulated an increase in skeletal muscle protein synthesis and improved intracellular reutilization of amino acids. The mechanism for this stimulation may be related to an OX-induced increase in AR expression in skeletal muscle.


Asunto(s)
Anabolizantes/farmacología , Proteínas Musculares/biosíntesis , Músculos/efectos de los fármacos , Oxandrolona/farmacología , Adulto , Aminoácidos/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Masculino , Músculos/metabolismo , ARN Mensajero/análisis , Receptores Androgénicos/genética
13.
J Chromatogr B Biomed Sci Appl ; 727(1-2): 95-105, 1999 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-10360427

RESUMEN

We propose a new screening method for testosterone (T) doping in sport. The current method for detecting T administration is based on finding a T to epitestosterone ratio (T/E) in urine that exceeds six. The difficulties with T/E are that T administration does not always result in a T/E>6 and that a rare individual will have T/E>6 in the absence of T administration. Our previous studies reveal that carbon isotope ratio helps to determine the origin of the urinary T because the values for T and its metabolites decrease after the administration of exogenous T. In this study, we present a rapid and efficient screening sample preparation method based on three successive liquid-solid extractions, deconjugation with E. coli beta-glucuronidase after the first extraction, acetylation after the second extraction, and a final extraction of the acetates. The 13C/12C of two T metabolites (5beta-androstane-3alpha,17beta-diol and 5alpha-androstane-3alpha,17beta-diol) and one pregnanediol as endogenous reference (5beta-pregnane-3alpha,20alpha-diol) was measured by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) on 10 ml of urine collected from 10 healthy men before and after T administration. Following T administration, the 13 C/12C of 5beta-androstane-3alpha,17beta-diol diacetate and 5alpha-androstane-3alpha,17beta-diol diacetate declined significantly from -26.2 per thousand to -30.8 per thousand and from -25.2 per thousand to -29.9 per thousand, respectively and the 13C/12C of 5beta-pregnane-3alpha,20alpha-diol diacetate was unchanged. In addition, the ratio of androstanediols to pregnanediol increased in the post-T urines.


Asunto(s)
Androstano-3,17-diol/orina , Doping en los Deportes , Espectrometría de Masas/métodos , Pregnanodiol/orina , Testosterona/orina , Adulto , Androstano-3,17-diol/análogos & derivados , Biomarcadores , Humanos , Isótopos , Masculino , Persona de Mediana Edad , Estándares de Referencia , Valores de Referencia
14.
Clin Chem ; 43(7): 1280-8, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9216475

RESUMEN

Over the last decade the number of laboratories accredited by the International Olympic Committee (IOC) has grown to 25. Nearly half of the approximately 90,000 samples tested annually are collected on short notice-the most effective means to deter the use of anabolic androgenic steroids (AAS). The major urinary metabolites of AAS have been characterized and are identified by their chromatographic retention times and full or partial mass spectra. The process of determining if an athlete has used testosterone (T) begins with finding a T to epitestosterone (E) ratio > 6 and continues with a review of the T/E-time profile. For the user who discontinues taking T, the T/E reverts to baseline (typically approximately 1.0). For the extremely rare athlete with a naturally increased T/E ratio, the T/E remains chronically increased. Short-acting formulations of T transiently increase T/E, and E administration lowers it. Among ancillary tests to help discriminate between naturally increased T/E values and those reflecting T use, the most promising is determination of the carbon isotope ratio.


Asunto(s)
Anabolizantes/orina , Doping en los Deportes , Deportes , Detección de Abuso de Sustancias , Testosterona/orina , Epitestosterona/orina , Reacciones Falso Negativas , Humanos , Masculino
15.
JAMA ; 276(3): 231-7, 1996 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-8667569

RESUMEN

Drug control has become an important component of Olympic sport. At the Atlanta Centennial Olympic Games, urine samples will be tested for prohibited substances, including stimulants, narcotics, anabolic agents, diuretics, peptides, and glycoprotein hormones as well as prohibited methods of enhancing performance, including blood doping and pharmacological, chemical, and physical manipulation of the urine. Drug testing programs must address short-acting stimulants, beta-blockers, and diuretics; training drugs such as anabolic steroids; and drugs affecting the detectability of other drugs. Programs include short- or no-notice testing during training periods, testing at qualifying competitions, and testing at the Olympic Games. Procedures and disposition that occur when a prohibited substance is found in an athlete competing in an Olympic sport are discussed. An analysis of the ethics of the use of performance-enhancing drugs in sports and of drug control in terms of fair competition and the impact of enhancement technologies of the meaning of sports also is presented.


Asunto(s)
Doping en los Deportes , Deportes , Detección de Abuso de Sustancias , Antagonistas Adrenérgicos beta , Anabolizantes , Anestésicos Locales , Antiasmáticos , Cannabis , Estimulantes del Sistema Nervioso Central , Diuréticos , Eritropoyetina , Etanol , Ética , Glucocorticoides , Hormonas , Humanos , Exámenes Obligatorios , Narcóticos , Medicamentos sin Prescripción , Deportes/normas
16.
J Mass Spectrom ; 31(4): 397-402, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8799284

RESUMEN

Six laboratories in six countries collaborated to investigate the analytical method for estimating the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry in the context of detecting the application of T as a doping agent in sport. The protocol specified many but not all details of reagents and instrument conditions. The design included the distribution and analysis of four urines with different T/E values, three replicates per value, and one standard. The ranges of mean T/E values for the four urines estimated by peak area (PA) were 0.32-0.42, 0.72-0.94, 0.91-1.14 and 3.19-5.48. The analyses of variance for these data and for the peak height (PH) data were significant for the laboratory factor (p < 0.0001). In addition there was a significant interaction between the urine factor and the laboratory factor which indicates the complexity of the analysis. T/E calculated using PA was not significantly different from that using PH. For within-laboratory precision all values for PH and PA were < 8.3%, and for between-laboratory precision all values were < 11.7% except for one (20.1%). The data represent a baseline for future experiments designed to elucidate the sources of within-and between-laboratory variance, and to harmonize estimates of T/E.


Asunto(s)
Epitestosterona/orina , Testosterona/orina , Análisis de Varianza , Doping en los Deportes , Cromatografía de Gases y Espectrometría de Masas , Humanos , Indicadores y Reactivos , Laboratorios , Estándares de Referencia , Reproducibilidad de los Resultados
17.
J Mass Spectrom ; 31(2): 169-76, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8799270

RESUMEN

The current approach to detection of doping with testosterone is based on measuring the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry. The median T/E for healthy males who have not used T is about 1.0. In a single urine, a T/E lower than six leads to a negative report even though it does not exclude T administration. A value greater than six indicates possible T administration or a naturally elevated ratio. It has been shown previously that the carbon isotope ratio of urinary T changes after T administration. In this study a potential confirmation method for T abuse was optimized. Gas chromatography/combustion/carbon isotope ratio mass spectrometry (GC/C/IRMS) was used to analyze two T precursors (cholesterol and 5-androsten-3 beta, 17 beta-diol) and two T metabolites (5 alpha- and 5 beta-androstane-3 alpha, 17 beta-diol) in addition to T itself in each of 25 blind urines collected from eight healthy men before, during or after T administration. The carbon isotope ratios of T and the metabolites were lower after T administration. The relationships among the variables were studied using multivariate analysis and beginning with principal components analysis; cluster analysis revealed that the data are composed of two clusters, and classified the samples obtained after T administration in one cluster and the remainder in the other; discriminant analysis correctly identified T users. The measurement of carbon isotope ratios of urinary androgens is comparable to the T/E > 6 test and continues to show promise for resolving cases where doping with T is suspected.


Asunto(s)
Doping en los Deportes , Cromatografía de Gases y Espectrometría de Masas/métodos , Detección de Abuso de Sustancias/métodos , Testosterona/orina , Adulto , Isótopos de Carbono , Estudios Cruzados , Método Doble Ciego , Epitestosterona/orina , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante
20.
Metabolism ; 42(4): 446-50, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8487666

RESUMEN

Stanozolol, an oral 17 alpha-alkylated androgen, increases hepatic triglyceride lipase activity (HTGLA) and decreases high-density lipoprotein cholesterol (HDL-C) levels, whereas intramuscular testosterone has comparatively little effect. In the present study, we tested the hypothesis that aromatization of androgen to estrogen blunts the lipid and lipase effects of exogenous testosterone. Fourteen male weightlifters received testosterone enanthate (200 mg/wk intramuscularly), the aromatase inhibitor testolactone (250 mg four times per day), or both drugs together in a randomized cross-over design. Serum testosterone level increased during all three drug treatments, whereas estradiol level increased only with testosterone alone (+47%, P < .05), demonstrating that testolactone effectively inhibited testosterone aromatization. Testosterone decreased HDL-C(-16%, P < .05), HDL2-C(-23%, NS), and apoprotein (apo) A-I (-12%, P < .05) levels, effects that were consistently but not significantly greater with simultaneous testosterone and testolactone administration (HDL-C, -20%; HDL2-C, -30%; apo A-I, -15%; P < .05 for all). In contrast, both testosterone regimens decreased HDL3-C levels by 13% (P < .05 for both). HTGLA increased 21% during testosterone treatment and 38% during combined testosterone and testolactone treatment (P < .01 for both). Lipoprotein lipase activity (LPLA) increased only during combined testosterone and testolactone treatment (+31%, P < .01), suggesting that estrogen production may counteract the effects of testosterone on LPLA. Testolactone alone had little effect on any lipid, lipoprotein, apoprotein, or lipase concentration.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Aromatasa/metabolismo , HDL-Colesterol/sangre , Heparina/farmacología , Lipólisis , Testosterona/sangre , Adulto , Inhibidores de la Aromatasa , Estradiol/sangre , Hormona Folículo Estimulante/sangre , Humanos , Lipasa/sangre , Lipoproteína Lipasa/sangre , Hormona Luteinizante/sangre , Masculino , Testolactona/farmacología , Testosterona/farmacología , Levantamiento de Peso
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