Detection of secondary biomarker of met-eGH as a strategy to screen for somatotropin misuse in horseracing

Abstract

Since the Australian commercialisation of the recombinant equine growth hormone (reGH) in 1998 (EquiGen-5), Bresagen), this reGH, which differs only from eGH by an additional methionine at the N-terminal end (met-eGH), is worldwide suspected to be administered to racehorses as a doping agent. Indeed, the use of this biological drug is considered as a threat to horseracing since it acts both on growth, development or reproductive functions, and on the improvement of performances. In this work, we describe two reliable techniques based on surface plasmon resonance biosensor immunoassay (SPR-BIA) and solid-phase enzyme-linked immunosorbent assay (ELISA) as new, rapid and efficient long-term screening methods applicable to horseracing antidoping analysis. The ELISA and SPR-BIA tests were applied to octanoic acid purified IgGs from serum/plasma samples collected on two thoroughbreds treated with recombinant equine growth hormone for a period of two weeks. The first kinetic study of serum/plasma antibodies raised as a consequence of recombinant equine growth hormone administrations, which allows the detection from eight days up to 200 days after the beginning of the treatment, was performed. In order to trace the occurrence of anti-reGH antibodies in routine analysis and to monitor the animal level exposure to this forbidden molecule, a random population study was conducted on 233 post-race horses.

Metabolism of Anabolic Steroids and Their Relevance to Drug Detection in Horseracing

“…The use of biomarker approaches is highly attractive and initial work carried out in detection of growth promoters in cattle appears promising [113]. Initial investgations into their application to equine sport have been carried out [114][115][116][117][118][119][120]. Similarly, the use of receptor assays has been extensively researched for application to meat residue ana lysis and also shows promise for future use in sports testing [91,121,122].…”

Generation and processing of urinary and plasmatic metabolomic fingerprints to reveal an illegal administration of recombinant equine growth hormone from LC-HRMS measurements

“…In order to check whether the regulation is fulfilled or not, controls have been organized and efficient methods based on mass spectrometry detection have been set up. To date, the screening of reGH administration focuses on specific biomarkers such as Insulin-like growth factor-1 or antibodies anti-reGH (Popot et al 2001;(Bailly-Chouriberry 2008a) whereas confirmation methods relies on LC-MS/MS measurement of the reGH itself in plasma (Bailly-Chouriberry 2008b).…”

Elimination kinetic of recombinant somatotropin in bovine

“…endogenous + recombinant forms), but therefore limited to screening [16,17]. Some methods based on the detection of biomarkers of somatotropin have been developed, but limited as well to screening [18,19].…”