Ayotte Christiane

Biography

A graduate in chemistry from the University of Montreal , Prof. Christiane Ayotte has completed graduate studies in organic chemistry, also at the Université de Montréal. After a two-year postdoctoral training at the INRS-Santé in mass spectrometry, she joined the doping control laboratory as a research associate. It then focused on the characterization, by mass spectrometry, of the urinary metabolites of anabolic steroids. Her work has led to the development of the screening method used in the laboratory since 1991, which she has been responsible for.

Research Interest

Anabolic Steroids The detection of illegal use by athletes of anabolic androgenic steroids that may be endogenous in humans is complex. These steroids include testosterone and its precursors, 4-androstene-3,17-dione and dehydroepiandrosterone, as well as 19-nerosteroids, some of which are commercially available for self-administration in the United States and the Internet. We characterized the phase I and II metabolites excreted following oral administration of androstenedione and DHEA. The synthesis of authentic reference standards was carried out in collaboration with Prof. Donald Poirier of the CHUL. The normal steroid profile is altered especially for testosterone, but abnormally high concentrations of terminal metabolites are also observed as well as the presence of glucur and sulfoconjuated hydroxylated metabolites such as 6a-androstenedione, 6b-epiandrosterone. In some cases, normal excretion of some hydroxylated metabolites is suppressed while others are increased (JF Lévesque, J. Roy, P. Bérher). This work allowed us to propose markers of administration that can be measured by GC / MS analysis. We also studied and demonstrated the variation in the 13C content of urinary metabolites excreted as a result of the administration of these steroids as a direct reflection of the specific content of the steroids contained in the end-use products. For 19-nonsteroids, we also demonstrated the variation in the 13C content of urinary metabolites in relation to their endogenous (eg during pregnancy) or exogenous origin. We also studied the excretion (phase I and II metabolism) of 19-nonsteroids by ingestion of offsets from non-castrated animals in which nortestosterone is endogenous (project in collaboration with the Cologne laboratory and subsidized by the Agency World Anti-Doping Organization (Mr. Cléroux, C. Guay, A. Lajeunesse). Projects in collaboration with researchers from the Cologne and Tokyo laboratories (funded by the World Anti-Doping Agency) aim to validate the IRMS (Stable Isotope Mass Spectrometry) method when applied to the urinary metabolites of testosterone and nortestosterone, to determine the reference values ​​of 13C levels of urinary steroids in different populations and to document the applicability of the method for the purpose of the sport doping control. It should be mentioned that these methods can most certainly be applied to the control of the administration of "natural" steroids in slaughter animals.