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Verrières-le-Buisson, France

Bailly-Chouriberry L.,Laboratoire des Courses Hippiques LCH | Cormant F.,Laboratoire des Courses Hippiques LCH | Garcia P.,Laboratoire des Courses Hippiques LCH | Kind A.,Ames Laboratory | And 2 more authors.
Analytical Chemistry | Year: 2013

Cobra venom (Naja kaouthia) contains a toxin called α-cobratoxin (α-Cbtx). This toxin is a natural protein containing 71 amino acids (MW 7821 Da) with a reported analgesic potency greater than morphine. In 2007, in USA, this substance was found in the barns of a thoroughbred trainer and since then till date, the lack of a detection of this molecule has remained a recurring problem for the horseracing industry worldwide. To solve this problem, the first method for the detection of α-cobratoxin in equine plasma has now been developed. Plasma sample (3 mL) was treated with ammonium sulfate at the isoelectric point of α-Cbtx, and the pellet was dissolved in a phosphate buffer and mixed with methanol for precipitation. The supernatant was then concentrated prior to its extraction on WCX SPE cartridges. The eluate was concentrated with two consecutive filtration steps before the trypsin digestion. The samples were analyzed using a LC-MS/MS Q Exactive instrument at 70,000 resolution on the product ions of the doubly charged precursor of the target peptide (24TWCDAFCSIR33). The method was validated (n = 18) at 5 μg/L (640 pmol/L) according to the Association of Official Racing Chemists (AORC) requirements. The lower limit of detection was 1 μg/L (130 pmol/L). The present method has made it possible for us to confirm the presence of α-Cbtx in a horse plasma sample 24 h post the administration of α-Cbtx. Thus, the present method provides the first sensitive, specific, and reliable analytical method to confirm the presence of α-Cbtx in equine plasma. © 2013 American Chemical Society. Source


Bailly-Chouriberry L.,Laboratoire des Courses Hippiques LCH | Cormant F.,Laboratoire des Courses Hippiques LCH | Garcia P.,Laboratoire des Courses Hippiques LCH | Lonnberg M.,Uppsala University | And 4 more authors.
Analyst | Year: 2012

Recombinant human erythropoietin (rHuEPO) is a 30-34 kDa glycoprotein banned by the racing authorities. For some years this molecule has been detected in race horses in USA and in Europe, and even in racing camels. Although direct methods to differentiate horse endogenous EPO and rHuEPO have been developed either by LC-MS/MS or by isoelectric focusing (IEF) with double-blotting, the short confirmation time of such prohibited hormone in plasma remains a problem for horseracing doping control laboratories. In order to improve the rHuEPOs confirmation process in horse plasma or urine in terms of reliability and delay, a small anti-EPO monolith membrane contained in a disposable column (anti-EPO monolith column) has been successfully used and validated (n = 10). This new sample preparation, combined with LC-FAIMS-MS/MS, has been performed on plasma and urine samples collected from one horse which received an Eprex® treatment during six consecutive days and a second one with a single injection of Aranesp®. This inventive technology allowed the possibility to confirm the presence of rHuEPO within one day with a limit of detection validated for both urine and plasma at 250 pg mL -1 by means of a disposable, ready to use immunoaffinity column. The lower limit of detection (LLOD) obtained for each matrix was 100 pg mL -1. These results provide an important improvement for rHuEPO doping control in horseracing especially the possibility to confirm these banned molecules in both matrices, urine and plasma, with a confidence of two specific target peptides. © 2012 The Royal Society of Chemistry. Source


Kaabia Z.,University of Nantes | Kaabia Z.,Laboratoire des Courses Hippiques LCH | Dervilly-Pinel G.,University of Nantes | Popot M.A.,Laboratoire des Courses Hippiques LCH | And 4 more authors.
Drug Testing and Analysis | Year: 2014

Nandrolone (17β-hydroxy-4-estren-3-one) is amongst the most misused endogenous steroid hormones in entire male horses. The detection of such a substance is challenging with regard to its endogenous presence. The current international threshold level for nandrolone misuse is based on the urinary concentration ratio of 5α-estrane-3β,17α-diol (EAD) to 5(10)-estrene-3β,17α-diol (EED). This ratio, however, can be influenced by a number of factors due to existing intra- and inter-variability standing, respectively, for the variation occurring in endogenous steroids concentration levels in a single subject and the variation in those same concentration levels observed between different subjects. Targeting an efficient detection of nandrolone misuse in entire male horses, an analytical strategy was set up in order to profile a group of endogenous steroids in nandrolone-treated and non-treated equines. Experiment plasma and urine samples were steadily collected over more than three months from a stallion administered with nandrolone laurate (1mg/kg). Control plasma and urine samples were collected monthly from seven non-treated stallions over a one-year period. A large panel of steroids of interest (n=23) were extracted from equine urine and plasma samples using a C18 cartridge. Following a methanolysis step, liquid-liquid and solid-phase extractions purifications were performed before derivatization and analysis on gas chromatography-tandem mass spectrometry (GC-MS/MS) for quantification. Statistical processing of the collected data permitted to establish statistical models capable of discriminating control samples from those collected during the three months following administration. Furthermore, these statistical models succeeded in predicting the compliance status of additional samples collected from racing horses. © 2013 John Wiley & Sons, Ltd. Source

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