A high-throughput LC-MS/MS screen for GHRP in equine and human urine, featuring peptide derivatization for improved chromatography.
Drug testing and analysis
confidence
Key findings
LC-MS/MS method developed for extraction, derivatization, and detection of GHRPs (including ipamorelin) in urine; analytical method paper, no clinical/biological endpoints.
View source on PubMed (PMID 24574167) ↗
- Sample size
- Not reported
- Population
- Rats (proof of principle); equine and human urine samples
- Dosing
- Intravenous administration of eight GHRPs
- Duration
- Not reported
- Route
- Intravenous
- Blinding
- not_reported
- Controls
- none
- Drug class
- peptide
Full 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.