Compounds enhancing oxygen delivery
For more than 25 years substances and methods enhancing oxygen delivery in the body have been of great concern in the fight against doping. The clear influence of an increased amount of red blood cells on physical performance, most obvious for endurance sports, has alerted the anti-doping authorities to put a high priority on efforts to disclose the administration of such doping practices.
The annually updated WADA-prohibited list mentions several erythropoiesis stimulating agents (ESA) as well as methods for the enhancement of oxygen transfer. The indicated substances include all different glycoprotein forms of erythropoietin preparations, synthetic peptidic compounds (Hematide/Peginesatide) as well as small molecular hypoxia-inducible factor (HIF) stabilizers. Prohibited methods like autologous and non-autologous blood transfusions are as well prohibited as haemoglobin-based oxygen carriers (HBOCs).
The analytical approaches to disclose these kinds of doping range from direct detection of the actual prohibited substance or its markers (metabolites) to indirect detection methods monitoring the effects of those doping practices through the establishment of the Athletes Biological Passport.
A broad selection of analytical techniques has been developed including among others chromatographic separation with mass spectrometric detection (LCMS), isoelectric focusing (IEF) and flow cytometry. For several of the discussed substances a possible performance enhancing effect lasts considerably longer than its presence in the body. Therefore, doping control measures have been extended by an indirect approach, monitoring an individual haematological profile over time documented as the Athletes blood passport. Comprehensive harmonized guidelines have been established through the world anti-doping agency (WADA) in order to describe pre-analytical, analytical and interpretational criteria for its application in doping control.