Determination of growth hormone releasing peptides (GHRP) and their major metabolites in human urine for doping controls by means of liquid chromatography mass spectrometry.
2011
Abstract
A family of small protein peptides have been the focus of doping controls representing a comparably new strategy for sportsmen. These growth hormone releasing peptides (GHRP) are orally active and induce an increased production of endogenous growth hormone (GH). While the established test for exogenous GH fails, the misuse of these prohibited substances remains unrecognizable. The present study provides data for the efficient extraction of a variety of known drug candidates namely GHRP-6, GHRP-2, GHRP-5, alexamorelin, ipamorelin and hexarelin from urine with subsequent mass spectrometric detection after liquid chromatographic separation. Method potentially enables the retrospective evaluation of the acquired data for unknown metabolites by means of a non-targeted approach with high-res/highly accurate full-scan w/ additional higher energy dissociation experiments. This is of great importance due to the currently unknown metabolism of most of the targets and, thus, the method is focused on the intact peptide drugs. Only the already characterized major metabolite of GHRP-2 (D-Ala-D-2-naphthylAla-L-Ala, as well as its stable isotope-labelled analogue) was synthesized and implemented in the detection assay. Method validation for qualitative purpose was performed with respect to specificity, precision (<20%), intermediate precision (<20%), recovery (47-95%), limit of detection (0.2-1 ng/mL), linearity, ion suppression and stability. Two stable isotope-labelled internal standards were used (deuterium-labelled GHRP-2 metabolite). The proof was obtained by the analysis of excretion study urine samples obtained from a single oral administration of 10 mg of GHRP-2. Here, the known metabolite was detectable over 20 h after administration while the intact bodybuilding peptides free from observation.
Wait. I noticed something. You are posting abstract here. Is your posts coming from a research study? I am just really curious as I am also very interested in the products.
Reply With Quote