| Summary: | Recombinant human erythropoietin (r-HuEPO) administration stimulates the increase in red blood cell (RBC) mass and ultimately the oxygen carrying capacity of the blood, which results in its ergogenic benefits. EPO and its related forms are banned by the World Anti-Doping Agency. The main aim of this thesis was to apply an untargeted liquid chromatography-mass spectrometry based approach to investigate a possible phenotypic response to r-HuEPO in the plasma, urine and RBC (from whole blood and centrifuged blood residue) metabolomes of twenty physically active non-smoking males, as a potential method to detecting abuse. Participants underwent a ten week sampling protocol consisting of two weeks of baseline, four weeks of treatment (50IU.kg-1 every second day) followed by four weeks of wash-out. Significant metabolites (p-value < 0.05) were identified from a diverse range of metabolic pathways. Most interesting are as follows: orotate from urine, as well as linoelaidyl and elaidic carnitines, glycine, ergothioneine, thymine, 2-oxoglutarate, L-arginine, homoarginine, deoxycholic acid 3-glucuronide, D-glucuronate, D-glucosamine, 4-aminobutanoate, muramic acid and [PR] tretinoin/all-trans retinoic acid from plasma. The whole blood investigation highlighted significant metabolites which could be responsible for the generation of glutathione (namely 2-oxoglutaramate) which is an essential component to RBCs, because of its antioxidant capacity. Whereas the RBC residue obtained following removal of plasma showed significant changes in L-carnitine and acyl-carnitines (linoelaidyl, elaidic, hydroxybutyryl, heptadecanoyl, stearoyl, tetradecanoyl carnitines). As a result of the absence in a control group as well as training frequency of the participants, in the primary study, a small pilot investigation was carried out with the same untargeted methodology to investigate the phenotypic response of an hour of aerobic exercise in the urine metabolome of three physically active non-smoking males. Main significant systems affected include: purine pathway, tryptophan metabolism, carnitine metabolism, cortisol metabolism, androgen metabolism, amino acid oxidation and the gastrointestinal microbiome. It was concluded that a more robust investigation into r-HuEPO abuse would require a placebo controlled cross-over study, in order to ensure that the findings were truly related to the administration itself and not to other external stimuli, such as training.
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