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  • Metabolism of anabolic androgenic steroids: evaluation of sulfate conjugated metabolites to improve detection capabilities

    Metabolism of anabolic androgenic steroids: evaluation of sulfate conjugated metabolites to improve detection capabilities

    By

    Investigateur principal
    R. Ventura

    Institut Municipal d’Investigacio Medica (IMIM)

    Espagne   ―   2009   ―   Complété

    Sommaire

    Code: 09A20RV 

    There is a need for doping control laboratories to improve the detection capabilities of the administration of anabolic androgenic steroids (AAS). Most AAS are extensively metabolized. Studies on steroid metabolism have been traditionally performed using GC-MS methods. Recently, LC-MS systems have demonstrated wide possibilities for the elucidation of new phase I metabolites and the use of this technology has resulted in the detection of previously unreported metabolites. Phase II metabolic reactions of AAS have been normally studied by using specific hydrolysis of the conjugated metabolites present in urine extracts. In most cases, enzymes with –glucuronidase activity were used, thus mainly conjugates with glucuronic acid have been studied up to now using both GC-MS and LC-MS/MS approaches.
    Sulfate metabolites are known to be important for some endogenous steroids and they have also been described for exogenous AAS. However, the study of sulfates has been limited by the difficulties of their efficient hydrolysis to the phase I metabolites detected by GC-MS or LC-MS/MS. In spite of this, long-term sulfated metabolites have been reported for some AAS.
    The objective of the project will be the evaluation of the phase II metabolism of AAS to look for sulfate conjugates of steroid metabolites that could be used as long-term markers of AAS misuse. A methodology based on the direct analysis of sulfate conjugates by LC-MS/MS will be developed. The different scan methods will be developed to identify unknown sulfate metabolites in administration study samples of different AAS. The excretion profiles of the identified sulfate metabolites will be compared with those of other steroid metabolites targeted in conventional screening procedures, in order to evaluate their interest as long-term markers of steroid misuse. Finally, a methodology addressed to the reliable detection of identified sulfate metabolites in routine antidoping analysis will be developed.

    Main Findings: 

    The objective of the project was to study the phase II metabolism of anabolic androgenic steroids (AAS) to look for sulphate conjugated metabolites that could be used to improve detection capabilities of AAS misuse. A methodology based on the direct analysis of sulphate conjugates by LC-MS/MS was developed. A liquid-liquid extraction with ethyl acetate was used to extract steroid sulphates from urine samples. Based on the common mass spectrometric behavior of steroid sulphates, precursor ion and neutral loss scan methods, and selected reaction monitoring methods including theoretical transitions of potential metabolites, were used to detect new sulphate metabolites in post-administration samples. AAS studied were boldenone, boldione, methyltestosterone and metandienone. Boldenone sulphate and epiboldenone sulphate were identified as minor metabolites of boldenone in humans. These metabolites were detected in urine during the same time as the main metabolites (boldenone and 5β-androst-1-en-17β-ol-3-one, BM1, detected in the glucuronide fraction). The analysis for the absence of these sulphates could be used as additional criterion of the endogenous origin of boldenone and BM1 in samples with low concentrations of these metabolites before going to GC/C/IRMS analysis. For boldione, seven metabolites conjugated with sulphate were detected. Three novel sulphate metabolites of methyltestosterone were identified and one of them was detected in urine for long time after administration, increasing the retrospectivity of the detection between two and three times with respect to other metabolites described. For metandienone, seven sulphate metabolites were detected in post-administration samples and one of them, was detected in urine for long time after administration, doubling the detection time compared to the last long-term metabolite described (the same phase I metabolite excreted in the glucuronide fraction). 
    The results of the project demonstrate the importance of sulphatation as a phase II metabolic pathway for AAS and the interest to study this metabolic fraction to look for new metabolites of AAS to improve the capabilities (e.g. long-term metabolites) of the detection of these compounds in doping controls.

    Voir le projet à propos de Metabolism of anabolic androgenic steroids: evaluation of sulfate conjugated metabolites to improve detection capabilities
  • Optimization of the method for the detection of erythropoietin and its analogues

    Optimization of the method for the detection of erythropoietin and its analogues

    By

    Investigateur principal
    F. Garribba

    Federazione Medico Sportiva Italiana

    Italie   ―   2009   ―   Complété

    Sommaire

    Code: 09B8FG 

    Erythropoietin (EPO) is an hormone regulating the synthesis of red blood cells, thus increasing the ability of blood to carry oxygen. Its analogues could be used by athletes in endurance sport and therefore appear in the WADA list of banned substances. Nowadays there are direct and indirect methods for the detection of erythropoietin. 
    The direct method developed by Lasne, is divided into four steps: urine concentration, isoelectric focusing separation, double blotting and detection by chemiluminescence. The development of other forms of recombinant EPO, and the need to increase the window of detectability of EPO administration, led to the need of updating the Lasne method to ensure the highest efficacy and efficiency of the anti-doping analysis. For instance, due to the differences in the apparent molecular mass of recombinant and endogenous erythropoietins, the administration of some recombinant EPOs can also be detected by SDS PAGE, another tool to clarify the profile of the suspicious samples. 
    The overall aim of the project is to study the effect of some specific modifications of the Lasne method, in order to (i) reduce the overall time of the analysis, (ii) simplify the sample treatment process, (iii) improve the limit of detection, and (iv) increase the robustness of the results.  Particularly, we plan to evaluate the effect of some modification at the level of (i) the preparation of the gel, (ii) the incubation steps respective to the blotting process, and (iii) the antibody incubations following the second blotting step. The effectiveness of the proposed solutions will be tested on a significant number of reference samples, of spiked urines and of negative and positive samples coming from our routine activity.

    Main Findings: 

    In the first part of this project we focused on the possibility of reducing the overall analytical times of the method for the detection of erythropoietins (EPOs), possibly completing the procedure in less than one working day from the start of the analytical process. The method is basically the same originally proposed by Lasne et al. and presently implemented by the WADA accredited laboratories, with few significant modifications involving the use of a novel blotting system based on vacuum technologies (namely, the SNAP i.d.® system). The system allows in principle a significant shortening of the time required for blocking, washing and antibody incubations, and we have considered its potential effectiveness if used after the first blotting step of the isoelectrofocusing (IEF) procedure. By applying a vacuum to actively drive reagents through the blotting membrane, the time of incubation for the blocking step and the washing step are indeed drastically shortened. 
    Furthermore, since the differences between the apparent molecular masses of endogenous and recombinant erythropoietins and analogues make possible to discriminate the endogenous and some exogenous EPOs by SDS-PAGE, the utility of the SNAP i.d.® system was verified also for this procedure. Finally, due to the recent developments in the field of electrophoretic EPOs detection, the utility for the SDS/Sarcosyl-PAGE procedure was also investigated.  The alternative procedures involving the SNAP i.d.® system in the IEF and SDS/Sarcosyl-PAGE methods were validated in terms of sensitivity, specificity and robustness using blank urine samples spiked with biological reference preparation of exogenous erythropoietin (BRP, rEpo) or darbepoetin α (NESP) or epoetin δ (Dynepo) or CERA and urine samples from antidoping controls found to be negative during the screening analysis. The effectiveness of the newly developed approach has been also evaluated analyzing urine samples from excretion studies. 
    The results showed that even if the time of each step is drastically reduced (the use of SNAP i.d.® system reduces the time for the complete analysis five to six hours) the limits of detection, the specificity and the robustness of the newly developed procedure are very similar to those obtained by the method currently used by the WADA accredited laboratory of Rome.  We have validated both the IEF method and the SDS/Sarcosyl-PAGE method with the use of the SNAP i.d.® system.  The shortening of the time required to complete the procedure may reveal particularly valuable especially on the occasion of major international events, where the analytical workload drastically increase and, in parallel, the reporting times are very compressed. 
    In the second part of the study we have evaluated the effect of some specific modifications of the procedure, in particular different reagents: a secondary antibody goat anti-mouse IgG (H+L) biotin conjugated different from the one currently in use in our laboratory purchased from Pierce/Thermo, two different streptavidin-peroxidase adducts (one complexed and one conjugated) and a specific monoclonal antibody anti-hEPO from mouse (Clone 23H2) on a gelatinous support inside a column to purify the urine samples were tested.  The results obtained showed no significant advantage with respect to the reference procedure, although the results obtained the monoclonal antibody anti-hEPO used for immunopurification step is not good to purify urine samples but we have preliminarily obtained good results using it as primary antibody. 

    Voir le projet à propos de Optimization of the method for the detection of erythropoietin and its analogues
  • Pharmacological characterization of nucleosides as potential modulators of erythropoietin production and effects

    Pharmacological characterization of nucleosides as potential modulators of erythropoietin production and effects

    By

    Investigateur principal
    P.A. Borea

    Italie   ―   2009   ―   Complété

    Sommaire

    Code: 09D3PB

    In the last years the WADA has founded studies of our groups aiming to develop in vitro test systems for the structure independent identification of anabolic substances. Our test system is a stable transfected yeast transactivation system for the identification of substances with affinity to the androgen receptor. Using this test system we could identify and characterise several designer steroids. In the last funding period we further characterized SC and started with the construction of a new reporter gene system in Schizosaccharomyces pombe. SC was able to detect anabolic steroids and their metabolites with a high specificity and sensitivity in urine of abusers (Zierau et al. 2008). Even selective androgen receptor modulators (SARMs) could be detected with SC. In excretion studies with Methyltestosterone in close cooperation with the doping control lab cologne SC was able to detect 1-Testosterone abuse up to 307 hours (GCMS detection limit was 118 hours). Treatment of the urine (concentration, purification) further increases the sensitivity of SC. Using new reporter gene plasmids we could reduce the duration time of the test from 2 days down to 18 h. In addition SP was successfully generated and is now ready to be further characterized. Reaching these milestones, our future aim is to use the SC to supplement GCMS techniques in routine doping analytics. Therefore we want to develop a standard routine procedure protocol to use the system in routine analysis. We also want to further enhance the sensitivity of the system by validation the newly generated SP system. In addition our SC system will be used to identify new long-term metabolites of anabolic steroids. So SC will in addition further improve the sensitivity of the GCMS detection systems.

    Main findings

    The results of this research Project present biologic and pharmacological “in vitro” and “in vivo” evidence that increases of EPO secretion during limited oxygen availability may be affected by extracellular adenosine generation and signaling. Therefore, we suggest that adenosine may be a doping agent “in vivo” since bone marrow is an hypoxic tissue. The A3 receptor does not appear to be involved in these direct effects of adenosine in HeL023 differentiation. On the contrary, the A3 receptor appears to be the mediator for the increase in EPO production induced by Adenosine.

    The molecular signaling induced by Adenosine to increase EPO release by A3 receptors promotes HIF-1 expression. In particular, Adenosine can affect hematopoiesis at three levels: 1) increasing EPO concentration; 2) increasing ET-differentiation and 3) impairing MK-commitment. Adenosine, through A1 and A3 receptors, improves ET differentiation, accelerating the early commitment signaling. Adenosine may impair MK differentiation tuning PM fate toward the ET commitment. The mechanism appeared to involve the distal molecular effectors of EPO signaling pathway. Moreover, Adenocard increases EPO blood levels. Even if the increase was of modest entity, it is possible that adenosine, given as a unique bolo, has been rapidly degraded in few hours “in vivo”. We suggest that a chronic Adenocard treatment may generate a greater EPO increase with relevant physiological effects on PM cells

    Voir le projet à propos de Pharmacological characterization of nucleosides as potential modulators of erythropoietin production and effects
  • Pharmacological manipulation of the central nervous system: Evidence of performance benefits and implications for the list of prohibited substances

    Pharmacological manipulation of the central nervous system: Evidence of performance benefits and implications for the list of prohibited substances

    By

    Investigateur principal
    R. Maughan

    Royaume-Uni   ―   2009   ―   Complété

    Sommaire

    Code: 09E12RM

    The fatigue that accompanies prolonged exercise in most often ascribed to events occurring in the periphery (glycogen depletion, dehydration). Recent evidence, however, suggests that the central nervous system plays a critical role, especially during exercise in the heat. This is an important consideration, as many major championships take place during the summer, often in countries with warm climates.

    Many stimulants acting on the CNS are included in the WADA Prohibited List; they can enhance performance and may pose a risk to health. Pharmacological manipulation of the CNS function can influence mood, the sensation of effort and/or thermal stress, cognitive function and tolerance to pain and discomfort. Drugs that manipulate brain neurotransmitters, in particular serotonin, dopamine and noradrenaline, have been shown to influence exercise performance, but many of these agents are not currently included on the Prohibited List. Many of these drugs are used in the treatment and management of a wide variety of psychiatric disorders, so the pharmaceutical industry is constantly producing novel, more selective and more powerful agents, with the potential for marked effects on exercise performance. Athletes may have legitimate reasons for their use (under Therapeutic Use Exemption; TUE), but the inappropriate use of these agents by athletes to enhance performance is a distinct possibility.

    These drugs, which are readily accessible over the internet, may also pose a risk to health as the normal limits to body temperature may be exceeded. At least one high profile death during the Tour de France has been ascribed to hyperthermia consequent upon amphetamine use.

    This project will investigate the performance effects of drugs affecting the CNS, and will also consider the various factors (gender, environment etc) that may influence their efficacy. These findings will help determine the suitability of this class of drugs for future inclusion on the Prohibited List.

    Main findings

    Stimulant medications enhance the activity of the central and peripheral nervous systems, producing a variety of effects including increased alertness, motivation and arousal, elevated heart rate and blood pressure, altered mood and the perception of a diminished requirement for food and sleep. Since these responses are likely to influence athletic performance, the aim of this project was to examine evidence that pharmacological manipulation of the central nervous system can produce improvements in exercise performance. Anecdotal reports, evidence from screening procedures used by WADA-accredited laboratories, as well as TUE application statistics, provide some evidence that athletes may be increasingly turning drugs of this nature. Of course, athletes may have legitimate reasons for the use of these drugs, but these agents may also be used with the sole aim to enhance performance. Of particular concern would be medications employed in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy.

    The present series of studies provide clear evidence to support the inclusion of Bupropion on future Prohibited Lists. The findings of the studies presented here, along with our previously published work, demonstrate that bupropion can produce a significant, measureable and consistent improvement in exercise performance in warm conditions when taken at the maximal therapeutic dose (+7-9% vs a placebo condition). This response is apparent in both male and female participants, and does not appear to be influenced by pre-exercise nutritional intake. Increased exercise performance following administration of bupropion was associated with the attainment of higher core temperatures and heart rates during the later stages of exercise. This occurs without any apparent change in the subjects’ perceived exertion or thermal stress. It is distinctly possible that the use of bupropion and methylphenidate by athletes competing in warm conditions will increase susceptibility to heat illness and potentially fatal heat stroke.

    Contrary to the findings of a recently published report, ingestion of tyrosine (the precursor of dopamine) produced no effect on physical performance during an exhaustive cycle test; this response may be due to rate limiting steps in catecholamine synthesis from tyrosine. The administration of the Parkinson’s drug, Sinemet (containing L-Dopa), also failed to significantly influence exercise performance, but performance may have been limited by side effects reported by some participants. S-adenosylmethionine (SAM) has become popular as an alternative therapy for the treatment/management of depression and other related disorders. Despite some effects on the physiological response to exercise, there was no evidence of a benefit to exercise performance following a 7 days of administration.

    In conclusion, it appears that bupropion can produce a measureable and consistent improvement in exercise performance in warm conditions when taken at the maximal therapeutic dose. With this in mind, inclusion of bupropion on future Prohibited Lists appears to be warranted. Substances that alter catecholamine production do not appear to consistently influence performance, but further investigation is justified.

    Voir le projet à propos de Pharmacological manipulation of the central nervous system: Evidence of performance benefits and implications for the list of prohibited substances
  • Precursor ion scanning for the detection of new stroids markers. Evaluation of population factors in the detectability of these markers. Routine application of precursor ion scanning for the open detection of anabolic steroids

    Precursor ion scanning for the detection of new stroids markers. Evaluation of population factors in the detectability of these markers. Routine application of precursor ion scanning for the open detection of anabolic steroids

    By

    Investigateur principal
    O.J Pojo Mendoza

    Institut Municipal d’Investigacio Medica (IMIM)

    Espagne   ―   2009   ―   Complété

    Sommaire

    Code: 09A05DP 

    This project aims at four goals: 
    A. Interpretation and evaluation of precursor ion scanning chromatograms (urine profile recognition) 
    In the field of anti-doping control, chromatograms from target steroid-analysis are generally evaluated and interpreted visually by the analyst which is trained for this purpose. 
    A similar approach will be adopted for evaluating the precursor scanning chromatograms. To get acquainted with the chromatograms, around 50 blank samples will be analysed.  In a second step precursor ion scan chromatograms obtained from controlled administration studies (e.g. methyltestosterone, methanedienone,…) and from adverse analytical findings from routine target screening will also be investigated to get acquainted with positive samples. The applicability of instrument software for this purpose will be evaluated.  
    B. Application to real samples
    Urine-samples will be analysed. These samples will include all out of competition samples and both out of competition samples and in competition samples   
    C. Study of the influence of different population factors in the detectability of different markers for several anabolic steroids 
    A single dose of the previously studied steroids (stanozolol and methyltestosterone) will be administered to six volunteers belonging to different population groups. Urine will be collected for three weeks and a method including all feasible markers will be applied. The best marker(s) will be selected based on the results obtained. This procedure will also be followed if promising new markers are found in the re-evaluated steroids. 
    D. Re-evaluation of the metabolism of additional steroids by LC-MS/MS looking for alternative markers for the detection of steroid misuse 
    Three or four additional steroids will be re-evaluated via the analysis by LC-MS. These steroids will be selected based on the availability of excretion studies in both laboratories.  
    Appropriate precursor scan and/or neutral loss scan methods will be applied for each steroid depending on their structure. Feasible metabolites will be characterized by MS techniques. The metabolic nature of these metabolites will be determined, if necessary, by the analysis of chimeric mouse urine after the drug administration. A full excretion study will be analyzed in order to determine the long term metabolites. 

    Main Findings: 

    Anabolic steroids with a 3-keto-4-ene structure have in common that they fragment by LC-ESI-MS/MS at high collision energy in tree common ions: methyltropylium (m/z 105), tropylium (m/z 91) and phenyl ion (m/z 77). The use of a precursor ion scan method for these 3 ions would allow to detect new/unknown AAS and metabolites with 3-keto-4-ene structures. 
    In this project, the potential of approaches based on precursor ion scan for doping control purposes have been evaluated in two scenarios: (i) routine application and (ii) metabolic studies of AAS.
    In the routine application, the potential use of the approach in two laboratories (Gent and Barcelona) was explored. The analysis of a common set of 12 samples allowed for the confirmation of the suitability of the method for the detection of positive samples for known steroids. The analysis of this common set of samples also revealed several limitations in the harmonization between laboratories regarding relative retention times and the precursor ions observed. 
    During the whole project, a total of 1911 routine-samples were analyzed using the established precursor scan protocol by the two laboratories. These samples covered both samples from athletes from high-risk sports (strength sports) and urines samples from athletes who tested positive for known steroids. Seven suspicious samples were detected. Despite the application of several analytical strategies such as product ion scan in both positive and negative ionization mode with accurate mass measurements and GC-MS, none of them could be clearly assigned to belong to the AAS family. Regarding metabolic studies, the method allowed for the detection of several metabolites for boldione, 4-chloro-methanedienone and clostebol. Several previously unreported metabolites were detected and characterized.  
    Finally, the effect of population factors in the detectability of long-term metabolites was evaluated in two different scenarios: stanozolol and clostebol. Results showed that both 17-epistanozolol-N-Glucuroinide and 4-chloro-5-androst-3β-ol-17-one 3β-sulfate are the long-term metabolites for stanozolol and clostebol irrespective of the ethnicity of the volunteer. 

    Voir le projet à propos de Precursor ion scanning for the detection of new stroids markers. Evaluation of population factors in the detectability of these markers. Routine application of precursor ion scanning for the open detection of anabolic steroids
  • Preparation and characterisation of new immunopurified urinary and plasmatic EPO standards. Acronym: REFEPOS

    Preparation and characterisation of new immunopurified urinary and plasmatic EPO standards. Acronym: REFEPOS

    By

    Investigateur principal
    J. Pascual

    Institut Municipal d’Investigacio Medica (IMIM)

    Espagne   ―   2009   ―   Complété

    Sommaire

    Code: 09B3JP

    The analytical strategy of doping control relies on the availability of reference standards against which compare the results obtained after the application of any procedure. The situation with the endogenous urinary EPO standard (NIBSC 2nd international reference preparation) needs careful attention: - the urinary standard (uEPO) from NIBSC is coming to an end and according to the correspondence held with NIBSC, there are no plans to produce a new batch.
    - At this stage, only 2 vials (20 IU) per laboratory and year will be provided.
    - The NIBSC uEPO standard was produced by unspecific protein concentration from urine of anaemic patients. Hence it contains very high concentrations of proteins other than uEPO.
    - Despite all efforts devoted so far, there has not been an appropriate characterisation of the origin of the charges responsible for its IEF behaviour.
    - The comparison between any standard obtained from patients and a standard obtained from healthy volunteers has to be performed.
    - An appropriate analytical standard of serum or plasma EPO is needed and has to be developed.               The technology for EPO immunopurification has already been developed and the members of the research team have first-hand experience in the field. However, its up-scaling for large volume processing (e.g. ten litres or urine per day) has to be developed tested properly. 
    With this background, the aim of the project is: - developing the methodology for producing a urinary EPO standard by processing urine from patients and healthy volunteers.
    - producing immunopurified urinary and serum EPO standards, available for doping control purposes.              As secondary objectives, the daily variation of their urinary EPO profiles will be studied and, using EPO from patients producing elevated concentrations of the structural characterisation of EPO will be approached.

    Main Findings: 

    The general aim of the project was the development of a large scale inmunopurification procedure and its application for the preparation of a relatively large scale batch of endogenous EPO standard in urine and, if feasible, plasma from healthy volunteers and patients producing large amounts of this glycoprotein.
    The immunopurification procedure developed implied a sample pretreatment includingdissolution under alcaline conditions of the sediment/precipitates present in urine, followed by a thorough multi‐step filtration (first, a filtration through a triple glass fibre filter AP25 (Millipore), 2 µm AP20 (Millipore) and 0.5 µm RW06 (Millipore); second a 0.22 µm Millipak filter unit).  
    Immunopurification of urinary volumes between 1.5 and 2 L was achieved using 2 mL Sepharose columns containing as much as 12 mg of anti‐EPO monoclonal antibody. Columns needed to be used at 4ºC, overnight at a 2‐3 mL/min flow rate. Recovery, during the development phase showed to be roughly around 50% for solutions of up to 80 IU/L.  
    However when real urine samples were treated, it soon became evident that the urinary matrix was able to block the columns, even after substantial filtration. Tamm‐Horsfall protein, the most abundant glycoprotein in urine, could have been part of the problem. Extensive washing of the immunoaffinity columns, changing of filtering procedures as well as heating the urine samples seemed to delay the problem, but did not solve it.
    On the other hand, it was impossible to find proper patients or volunteers with elevated EPO excretion. Patients from clinical hematology, pneumology or oncology resulted in depleted EPO concentrations. Finally it was decided to use urine from healthy volunteers with serious implications regarding the amount of EPO that could be reached.  Immunopurified EPO was very sensitive to preparation conditions with significant losses due to irreversible adsorption on glass or plastic vials.
    Overall, recovery was below 5% and only a very small, symbolic, batch of 15 vials of 1.6 IU/vial of liophylized material could be obtained in a buffer composition compatible with electrophoretic or mass spectrometric methods.
    Obtaining reasonable amounts of this glycoprotein standard, and at a reasonable cost, would imply an international approach with access to a number of high EPO excreting individuals under proper long term conditions.

    Voir le projet à propos de Preparation and characterisation of new immunopurified urinary and plasmatic EPO standards. Acronym: REFEPOS
  • Salbutamol metabolism, How to differentaite oral vs inhaled administrations: Looking outside the box

    Salbutamol metabolism, How to differentaite oral vs inhaled administrations: Looking outside the box

    By

    Investigateur principal
    X. de la Torre

    Federazione Medico Sportiva Italiana

    Italie   ―   2009   ―   Complété

    Sommaire

    Code: 09E24XD

    Salbutamol belongs to the class of beta-2-agonists, and its use is prohibited by the WADA if administered for reasons different than the pharmacological treatment of respiratory diseases (i.e. asthma , broncospasm).  At present, discrimination between the therapeutic and illicit use of salbutamol is based on concentration thresholds, being the urinary concentration of non-sulfated drug mainly, but not exclusively, related to the administered dose and to the route of administration.  Small differences in metabolism can be observed due to the difficulty of avoiding a partial oral administration during inhalation administration where a fraction of the dose is swallowed. It appears that investigation of the location of the majority of salbutamol metabolism is of great interest and may add additional knowledge for better discrimination of salbutamol route of administration. 
    It seems adequate in terms of analytical and metabolic reasons to develop a LC/MS/MS method for the simultaneous detection of the free, glucuronoconjugated and sulphated forms of salbutamol. In addition, an evaluation of the spontaneous urinary salbutamol hydrolysis could be estimated (stability test).  The combination of chiral liquid chromatography coupled to mass spectrometry will add a dimension to salbutamol metabolism assessment.  The determination of the well accepted S/R ratio of the free + glucuronated salbutamol to differentiate oral vs. inhaled administation would be complemented by the determination of the S/R ratio of the sulphated fraction. The determination of the sulphated fraction will offer the possibility to better understand and discriminate between different routes of administration. 
    The genotypic characterization of selected sulfotransferases (SULT’s) of the individuals participating to the study (coming from two different ethnic groups) will also be performed, in order to correlate the genotypic expression of the sulfotransferases (SULT), that are the enzymes responsible for salbutamol metabolism with the phenotypic data obtained from the experiments described in the previous step. 

    Main Findings: 

    Salbutamol is one of the most used β2-adrenoceptor agonists by athletes for relieving bronchospasm and for prevention of exercise-induced-asthma. Inhalation is the preferred route of administration, but also the oral route is recommended, in particular for populations where inhalation presents practical problems (i.e. young children). Since salbutamol, similar to other β2-adrenoceptor agonists, produces an anabolic effect when sufficiently high doses are administered orally, its use is approved by the World Anti-Doping Agency (WADA) only after inhaled administration. Currently, sport authorities monitor salbutamol use in and out of competition: urine concentrations greater than the Decision Limit of 1200 ng/mL (free + glucuronated salbutamol) are considered adverse analytical finding unless the non- inhaled administration could be excluded by other means. Previous studies have demonstrated that after oral administration, the majority of salbutamol is found in the urine either as the parent compound (24-33%) or as conjugated sulfate metabolite (48%).On the contrary, no significant biotransformation occurs in the lungs, thus the percentage of salbutamol metabolite depends mainly on the percentage of the dose that is swallowed and absorbed from the gastrointestinal tract.
    Salbutamol is administered as a mixture of two enantiomers: S(+)-and R(-)-salbutamol and enantioselective disposition studies have demonstrated that after oral administration the enantiomers are conjugated at a different rate by the body tissues. The active R(-) enantiomer undergoes a higher rate of sulfation, and therefore, after oral intake the non metabolized S(+) enantiomer is excreted in a greater level than the non metabolized R(-) enantiomer. For the above reasons the ratio between S(+) and R(-) of the unchanged salbutamol was proposed as marker of oral administration.
    Based on the above evidence, an analytical method involving a solid-phase clean-up procedure followed by a chiral HPLC separation and a mass spectrometric detection to quantify separately the enantiomers of salbutamol and it sulphate conjugates has been developed and validated according to ISO17025 and WADA requirements.
    The urinary results confirmed that after inhalation the enantiomeric ratio between S(+) and R(-) of the non metabolized and of the metabolized salbutamol strongly depends on the percentage of the dose that is swallowed.  The sulphotransferases (SULT’s) responsible for the conjugation of salbutamol in different tissues, and for the different excretion of S(+) and R(-) enantiomers depending on the route of administration, are polymorphic and then large differences between individuals may be expected. In some specific cases, this may be the reason for reaching elevated concentrations of salbutamol after inhaled therapeutic administrations (permitted). To access to the information of the genotyping of this SULT’s may be crucial for the correct interpretation of the phenotypic data. To obtain genomic DNA from blood or saliva samples is a common practice in forensic investigations. In doping analysis urine still being the unique biological specimen available in more than 80-90% of the cases. Then it demonstrated the feasibility of obtaining genomic DNA from urine samples of the adequate quality for the genotyping of the sulfotranferases of interest.  A method for the extraction and amplification of genomic DNA form blood, urine and saliva samples was developed and validated, permitting to obtain genomic DNA of adequate quality starting from 2-5 μL of serum, 1-10 mL of urine or 2-5 μL of saliva respectively.

    Voir le projet à propos de Salbutamol metabolism, How to differentaite oral vs inhaled administrations: Looking outside the box
  • Steroid metabolism & the chimeric mouse model

    Steroid metabolism & the chimeric mouse model

    By

    Investigateur principal
    P. Van Eenoo

    Ghent University

    Belgique   ―   2009   ―   Complété

    Sommaire

    Code: 09E26PV 

    Anabolic steroids are amongst the most misused substances in doping control and are intensively metabolized in humans. Adequate screening for misuse of these substances therefore relies on the detection of metabolites in urine samples collected from athletes. 
    Most of the studies investigating the metabolism of pharmaceutically available steroids were performed in the 1980’s via gas chromatography mass spectrometry (GC-MS). This research resulted in the selection of appropriate metabolites for the detection of steroid misuse. Over the years the selection of metabolites was further elaborated to include several metabolites that can result in prolonged detection times. Recent reinvestigation of metabolism via LC-MS resulted in more appropriate metabolites for this technology, than those detected via GC-MS. 
    Over the last decade, a high number of non-pharmaceutical steroids have been introduced on the market as “nutritional supplements” or as black market designer steroids, while most of the pharmaceutical preparations have been retracted.  For both types, approval of administration by an Ethical Committee has become almost impossible. The UPA+/+SCID mouse model with humanized liver has proven to be the best appropriate model to mimic human steroid metabolism in the liver and application of this model to the metabolism of methandienone and methyltestosterone has contributed to the detection of new and long-term metabolites detectable via liquid chromatography tandem mass spectrometry (LC-MSn). 
    The current project would (re)investigate metabolism of several groups of steroids: 1. Substances currently listed on the prohibited list, but with limited knowledge on metabolism
    2. Substances currently not explicitly listed.

    Main Findings: 

    The aim of the project was to study the metabolism of different steroid compounds by means of a humanized chimeric mouse model. This uPA+/+-SCID mouse model has its liver transplanted with functional human hepatocytes. In the past the chimeric mouse model has proven to be a valuable tool in elucidating the urinary steroid metabolism, especially for those steroids for which it is difficult to obtain ethical approval for human excretion studies.

    In this project the metabolism of 7 steroid compounds was investigated:
    * methyl-1-testosterone
    * oxabolone
    * prostanozol
    * 6-bromo-androstenedione
    * 3α-androstanol
    * 17-methyldrostanolone
    * 4-chloro-17-methylandrostenediol (promagnon and methylclostebol)

    The metabolism of these 7 steroids was investigated by use of administration studies to the chimeric mouse model. The analyses of the mouse urine samples were performed on a combination of GC-MS and LC-MS/MS instruments. Comparing the pre- and post-administration
    mouse urine samples allowed us to obtain a urinary metabolic profile for all of the steroids. From all the detected metabolites, the most appropriate markers were selected based on their usefulness as target markers for steroid abuse. Those metabolites were implemented where possible in our routine screening methods for anti-doping screening, making our methods even more complete and comprehensive. Additionally, within the scope of the project, also the in vitro technique of human liver microsomes was optimized to assist this research.

    In the future this promising mouse model will be used to further encourage the fight against doping by evaluating some prohormones and food supplements based on the urinary results
    of the chimeric mice.

    Voir le projet à propos de Steroid metabolism & the chimeric mouse model
  • Storage contamination as a potential diagnostic test for autologous blood transfusion

    Storage contamination as a potential diagnostic test for autologous blood transfusion

    By

    Investigateur principal
    Dr. Ashenden

    SIAB & AFLD

    Australie   ―   2009   ―   Complété

    Sommaire

    Code: 09A13MF 

    Autologous blood transfusion is banned; however currently no test exists to detect this form of blood doping. Anecdotal reports suggest that elite athletes have been using autologous transfusions since at least the 1980s, and the Operacion Puerto scandal in Spain has revealed that some athletes continue to utilise transfusions. Blood must be withdrawn, then stored for several weeks prior to reinfusion (in the meantime the body replenishes the depleted blood so that there will be a corresponding boost in the total quantity of blood cells in circulation when the blood is finally reinfused). Blood is either refrigerated or frozen in specially designed blood storage bags. 
    Whilst the blood is in contact with the storage bag, it is known that there is an exchange of material between the plastic storage bag and the blood. Since the storage bags are man-made, the synthetic compounds that find their way into the blood are not normally found in the body. 
    Their presence in a doping control sample may therefore be used as a diagnostic test for the prior use of autologous transfusion.  This project will investigate whether the presence of plastic compounds in blood samples are sufficiently distinct to enable their use as a diagnostic. Pending the successful outcome from this first stage, we will extend our studies to document the persistence of these markers in volunteers after they have received blood transfusion to establish the likely window of detection associated with this type of testing. 

    Main Findings: 

    Two approaches were investigated to detect the presence of DEHP in reinfused red blood cells (RBC). The first approach was indirect and based on the hypothesis that DEHP was antigenic and that development of a suitable antibody could allow the flow cytometric detection of DEHP-contaminated cells. Substantial efforts were made to develop a monoclonal antibody against DEHP, however these attempts were unsuccessful. Because of the lack of these antibodies, this component of the research had to be abandoned. 
    The second approach was direct and turned on the ability of GC-MS to detect trace amounts of DEHP in lysed RBC membranes. Provided that rigorous measures were taken to avoid contamination during sample preparation and analysis, we demonstrated that the DEHP levels found in the membranes of stored RBC could be easily distinguished from background levels. However DEHP levels in RBC fell rapidly once the cells had been reinfused into circulation.

    Voir le projet à propos de Storage contamination as a potential diagnostic test for autologous blood transfusion
  • The impact of gender, race and hydration status on the ergogenic and pharmacokinetic impact of short acting β2-Agonists

    The impact of gender, race and hydration status on the ergogenic and pharmacokinetic impact of short acting β2-Agonists

    By

    Investigateur principal
    G. Whyte

    Liverpool John Moores University

    Royaume-Uni   ―   2009   ―   Complété

    Sommaire

    Code: 09E18GW 

    In 2002 The International Olympic Committee (IOC) established the requirement for athletes to present evidence of current asthma, exercise induced asthma (EIA), exercise-induced bronchoconstriction (EIB) or airway hyperresponsiveness (AHR) through the therapeutic use exemptions (TUE) process. The World Anti-Doping Agency (WADA) introduced the IOC policy on inhaled short acting 2-agonists in January, 2009. The inclusion of inhaled short acting 2-agonists is based upon health concerns rather than anti-doping concerns; however, evidence is only available for the performance enhancing effect of inhaled short acting 2-agonists in endurance sports at low doses. 
    The initial aim of this study is to examine the impact of inhaled short acting 2-agonists on team game performance and examine higher doses that remain within The WADA anti-doping upper limit. Hydration status has recently been used in the defence of a positive anti-doping test.  This has highlighted the lack of knowledge associated with potential confounding factors affecting urine analysis for short acting 2-agonists. 
    The second aim of this study is to examine the impact of gender, race and hydration status on urine concentrations of short acting 2-agonists at varying doses. The results of these studies will improve our understanding of the impact of inhaled short acting 2-agonists on performance, support The WADA in the implementation of regulations on the use of inhaled short acting 2-agonist and assist in the resolution of contested doping violations. 

    Main Findings: 

    Part A: Seven male runners (mean + SD; age 22.4 + 4.3 years; height 179.7 + 7.0 cm; body mass 76.6 + 8.6 kg) completed 6, 5 km running time-trials (3 in a temperate environment: 20OC, 40% RH; and 3 in a hot environment: 30OC, 40% RH) following the inhalation of 800 μg or 1600 μg of Salbutamol, or a placebo.  
    This is the first study to examine the impact of inhaled salbutamol at a dose 1600 µg versus 800 µg and placebo on time-trial endurance running performance. Furthermore, this study is the first to examine the pharmacokinetics of inhaled salbutamol at a dose of 1600 µg and 800 µg following a competitive endurance performance in temperate (20oC; 40% RH) and hot (30oC; 40% RH) environments. Results demonstrate no significant effect of Salbutamol on 5 km running time-trial performance in temperate or hot environments. Urine concentration of Salbutamol was below the WADA upper limit (1000 ug.ml-1) in all participants across all trials with the exception of one participant in the 1600 μg, hot trial (below the decision limit). The results of this study suggest that the current WADA guidelines, which allows athletes to inhale up to 1600 µg of Salbutamol is sufficient to avoid pharmaceutical induced performance enhancement. However, such high doses not only suggest poor management of asthma but also mean that an athlete may be at risk of contravening the current urinary threshold, particularly in hot environments. 
    Part B: Eighteen male and 14 female athletes (9 Caucasian males, 9 Caucasian Females, 2 Afro-Caribbean males, 2 Afro-Caribbean females, 6 Asian [Indian sub-continent] males and 4 Asian females) were recruited for this study. Participants were required to exercise in a hot, controlled environment (35oC, 40% relative humidity) at a self-selected pace until a target weight loss (2% or 5%) was achieved in the following trials: (i) 2% reduction in in body mass (BM), following inhalation of 800μg short acting β2-agonist; (ii) 2% reduction in in BM, following inhalation of 1600μg short acting β2-agonist; (iii) 5% reduction in in BM, following inhalation of 800μg short acting β2-agonist; (iv) 5% reduction in in BM, following inhalation of 1600μg short acting β2-agonist. The results of this study demonstrate that following the inhalation of 1600 µg it is possible to present with urine Salbutamol concentrations above the current WADA limit (1000 ng.ml-1) and decision limit (1200 ng.ml-1) for salbutamol resulting in an adverse analytical finding (AAF; WADA, 2010) and warrant further investigation. There were no differences according to sex or ethnic origin however; a large inter-individual variation existed. In conclusion, a BM loss greater than 2% concomitant to the acute inhalation of 1600 µg of Salbutamol may result in a urine concentration above the current WADA upper limit and decision limit leading to a positive test finding. This finding is independent of gender or ethnic origin. Hydration status per se is a critical factor in relation to doping control. The results of this study suggest that WADA consider the role of normalising drug concentrations to urine specific gravity in an attempt to negate the impact of hydration status on doping control tests. Data from this study will assist WADA in the implementation of regulations on the use of inhaled short acting β2-agonist and assist in the resolution of contested doping violations. 
    Part C: Seven male (mean + SD; age 23.1 + 3.9 years; weight 72.9 + 4.3 kg; height 177.0 + 4.7 cm) and six female (21.3 + 1.4 years; 63.9 + 5.8 kg; height 162.3 + 4.7 cm) football players completed a 52 minute football specific running protocol followed by twelve, 17.5 m sprints on three occasions following the inhalation of 800 μg or 1600 μg of Salbutamol, or a placebo. 
    This is the first study to examine the impact of inhaled salbutamol at a dose of 1600 µg versus 800 µg and a placebo on simulated association football (soccer) and multiple sprint performance in male and female players. Furthermore, this study is the first to examine the pharmacokinetics of inhaled salbutamol at a dose 1600 µg and 800 µg following a simulated association football performance in male and female players. Results demonstrated no significant effect of high dose (up to 1600 µg) Salbutamol on association football (soccer) specific performance or multi-sprint performance in male or female players. Following inhalation of 1600 µg of Salbutamol, Five players (2 male; 3 female) presented with concentrations of Salbutamol in urine above the WADA upper limit (1000 ng.ml-1) with three players (1 male; 2 female) attaining a concentration above the decision limit (1200 ng.ml-1). The results of this study suggest that the current WADA guidelines, which allows athletes to inhale up to 1600 µg of Salbutamol is sufficient to avoid pharmaceutical induced performance enhancement in association football (soccer) in male and female players. However, inhalation of 1600 µg may result in a urine concentration above the current WADA upper limit and decision limit. 

    Voir le projet à propos de The impact of gender, race and hydration status on the ergogenic and pharmacokinetic impact of short acting β2-Agonists
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