title: A high-throughput LC-MS/MS screen for GHRP in equine and human urine, featuring peptide derivatization for improved chromatography.
abstract: The growth hormone releasing peptides (GHRPs) hexarelin, ipamorelin, alexamorelin, GHRP-1, GHRP-2, GHRP-4, GHRP-5, and GHRP-6 are all synthetic met-enkephalin analogues that include unnatural D-amino acids. They were designed specifically for their ability to stimulate growth hormone release and may serve as performance enhancing drugs. To regulate the use of these peptides within the horse racing industry and by human athletes, a method is presented for the extraction, derivatization, and detection of GHRPs from equine and human urine. This method takes advantage of a highly specific solid-phase extraction combined with a novel derivatization method to improve the chromatography of basic peptides. The method was validated with respect to linearity, repeatability, intermediate precision, specificity, limits of detection, limits of confirmation, ion suppression, and stability. As proof of principle, all eight GHRPs or their metabolites could be detected in urine collected from rats after intravenous administration.
authors.affiliation: Biological Research Unit, Racing Analytical Services Ltd, 400 Epsom Road, Flemington, Victoria, Australia, 3031.
authors.forename: Mark
authors.initials: M
authors.lastname: Timms
authors.forename: Nikki
authors.initials: N
authors.lastname: Hall
authors.forename: Vita
authors.initials: V
authors.lastname: Levina
authors.forename: John
authors.initials: J
authors.lastname: Vine
authors.forename: Rohan
authors.initials: R
authors.lastname: Steel
mesh_terms: D061605:Administration, Intravenous; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D004300:Doping in Sports / Q000517:prevention & control; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives / Q000032:analysis / Q000652:urine*; D057166:High-Throughput Screening Assays / Q000379:methods; D006736:Horses; D006801:Humans; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D013007:Growth Hormone-Releasing Hormone
keywords: GHRP; derivatization; mass spectrometry; solid-phase extraction; urine