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Synthetic cathinones are recreational drugs that mimic the effects of illicit stimulants like cocaine, amphetamine or Ecstasy. Among the available synthetic cathinones in the United States, 3,4-methylenedioxypyrovalerone (MDPV) is commonly abused and associated with dangerous side effects. MDPV is a dopamine transporter blocker 10-fold more potent than cocaine as a locomotor stimulant in rats. Previous in vitro and in vivo studies examining MDPV metabolism reported 3,4-dihydroxypyrovalerone (3,4-catechol-PV) and 4-hydroxy-3-methoxypyrovalerone (4-OH-3-MeO-PV) as the two primary metabolites. We developed and validated a liquid chromatography-high resolution mass spectrometry method to quantify MDPV and its primary metabolites in 100 μL human and rat plasma. Plasma hydrolysis was followed by protein precipitation before analysis. Limits of detection were 0.1 μg L(-1), with linear ranges from 0.25 to 1000 μg L(-1). Process efficiency, matrix effect, total imprecision (%CV) and accuracy (%target) were 36-93%, from -8 to 12%, 2.1 to 7.3% and 86 to 109%, respectively. MDPV and metabolites were stable at room temperature for 24 h, 4 °C for 72 h and after 3 freeze-thaw cycles with less than 10% variability. Human-rat plasma cross validation demonstrated that rat plasma could be accurately quantified against a human plasma calibration curve. As proof of this method, rat plasma specimens were analyzed after intraperitoneal and subcutaneous dosing with MDPV (0.5 mg kg(-1)). MDPV, 3,4-catechol-PV and 4-OH-3-MeO-PV concentrations ranged from not detected to 107.5 μg L(-1) prior to and up to 8h after dosing. This method provides a simultaneous quantification of MDPV and two metabolites in plasma with good selectivity and sensitivity., (Published by Elsevier B.V.)

Administration of hormonal compounds as growth promoters in livestock farming was banned by Council Directive 93/22/EC, however, this kind of substances are sometimes reported within the framework of European monitoring residue plans. Various analytical methods have been previously developed to screen for their misuse, and they are now especially efficient for monitoring the illegal administration of synthetic and semi-synthetic hormones. Nevertheless, proving an exogenous administration of hormones from natural origin (i.e. estradiol-17β or progesterone) still remains a challenging task for European authorities. As a result of their origin, these target compounds are indeed always present in the analytical matrix, and because the concentration levels of natural steroids are extremely variable from one animal to another, the establishment of reference thresholds appears very difficult. During this preliminary study, metabolomic data was acquired on a high performance liquid chromatography system coupled to high resolution mass spectrometer (HPLC-LTQ-Orbitrap). Serum samples were collected from dairy cows treated or not with sex steroid hormones commonly employed in animal husbandry: estradiol-17β (or its ester estradiol benzoate) and progesterone. After appropriate data processing and multivariate statistical analyses (OPLS-DA), it was possible to highlight significant metabolic modifications in serum consecutively to the administration of estradiol and/or progesterone. Those differences were used to build predictive models able to suspect illegal administration of these hormones in cattle. Potential biomarker candidates of estradiol and/or progesterone were pointed out, that remains to be structurally elucidated., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The use of steroid hormones as growth promoters in cattle is banned within the European Union since 1988 but can still be fraudulently employed in animal breeding farms for anabolic purposes. While efficient targeted confirmatory methods have been implemented in control laboratories for many years, fast and reliable screening methods are still required, especially in the case of natural hormones abuse, but more globally for new "fishing" strategies allowing to reveal the use of even unknown anabolic agents. The development of focused profiling or untargeted metabolomic approaches is thus emerging in this context. The present study was a focused profiling study using steroids phase II metabolites, with the aim to get a better understanding of the steroid metabolism disruptions after exogenous administration of androstenedione and finally reveal potential biomarkers signing its administration. A sample preparation procedure was first developed, based on a separation of 31 glucuronide and sulphate conjugate compounds using an anion exchange SPE system. Each fraction was then analysed by UPLC-MS/MS in MRM mode showing a rapid (between 4h and 4 days after treatment) and huge excretion of several direct metabolites of androstenedione such as etiocholanolone-glucuronide or epiandrosterone-sulphate., (Copyright © 2010 Elsevier B.V. All rights reserved.)