Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry.
Level 5 - mechanism / opinion, no new human data
Non-clinical analytical chemistry method development and animal validation study
PubMed 23084823 · doi:10.1016/j.chroma.2012.09.043
What was done
Researchers developed a liquid chromatography-mass spectrometry (LC/MS) method to detect N-acetylated LKKTETQ (the active synthetic peptide in TB-500) and its metabolites for doping control in equine sports. Potential metabolites were first characterized via in vitro studies. Target analytes were extracted from equine plasma and urine using solid-phase ion-exchange cartridges and identified by LC retention times and major product ion relative abundances. The method was validated using plasma and urine samples collected from horses administered a single 10 mg dose of N-acetylated LKKTETQ.
What was found
The LC/MS method achieved detection and confirmation limits of 0.02 ng/mL in equine plasma and 0.01 ng/mL in equine urine. The assay successfully confirmed the presence of the parent peptide and its metabolites in post-administration equine biological samples.
Why it matters
This establishes the first validated analytical method capable of confirming the administration of the performance-enhancing peptide TB-500 in equine doping control.
Limits
The abstract does not state the sample size (number of horses tested), the duration of the detection window post-administration, or the pharmacokinetic clearance rates. The method was evaluated only in equines following a single administration, so performance after repeated dosing or in other species was not reported.
Cited by
- supports Thymosin beta-4 is utilized as a doping agent in horse racing.