The determination of salivary oxypurines before and after exercise by combined liquid chromatography-field asymmetric waveform ion mobility spectrometry-time-of-flight mass spectrometry

Abstract

A method combining field asymmetric waveform ion mobility spectrometry with liquid chromatography-mass spectrometry (LC-FAIMS-MS) has been developed for the analysis of the oxypurine compounds hypoxanthine (HX) and xanthine (XA) in saliva. Separation of the oxypurines from interfering matrix components was investigated using FAIMS-MS. The selected FAIMS parameters were then applied to the rapid LC-FAIMS-MS analysis of HX and XA using a short chromatographic separation method (7 min). A comparison of the LC-MS method with and without FAIMS applied, resulted in improved discrimination from saliva matrix interferences and improved chromatographic peak integration for both HX and XA using a FAIMS separation. A quantitative evaluation of the LC-FAIMS-MS method was performed giving limits of detection of 2.0 ng mL-1 for HX and 1.8 ng mL-1 for XA, and limits of quantification of 6.6 ng mL-1 for HX and 6.0 ng mL-1 for XA. The developed LC-FAIMS-MS method was applied to the targeted analysis of the oxypurine metabolites in saliva collected from healthy male athletes (n=11) before and after exercise designed to induce oxidative stress; post-exercise collection time-points included immediately after exercise, one hour and twenty-four hours' post-exercise. The salivary concentrations of both HX and XA were lower after physical exercise, compared to the pre-exercise (rest) concentrations and returned to approximately pre-exercise levels after twenty-four hours. The method reported has the potential for monitoring the salivary oxypurines, HX and XA, as biomarkers of oxidative stress and in other clinical applications.

“Fuel for the Damage Induced”: Untargeted Metabolomics in Elite Rugby Union Match Play

“…Overall, the intensity and duration of elite rugby union match play cause acute metabolite perturbations indicative of both oxidative and metabolic stress whilst fulfilling the high energy demands. The reduced salivary purine profiles due to oxidative stress have been observed post exhaustive exercise in male athletes [ 39 ]. The increase in serum 2-hydroxybutyrate post-match is indicative of the cumulative stress upon energy systems [ 40 ] and may be due to increased catabolism of l -threonine [ 41 ] and glutathione synthesis [ 42 ] in response to oxidative stress.…”

Metabolomics in Exercise and Sports: A Systematic Review

“…Generally, exercise metabolomic studies identified more metabolites in urine relative to serum or plasma. The lowest number of metabolites identified having a significant change in any exercise metabolomic study was two as reported by Arthur et al (50) for a study looking at metabolic changes in saliva after 60 minutes of cycling ( 45minutes at an intensity of 70% of maximum power (Pmax) and greatest distance possible for a further 15 minute-period) in 11 healthy male athletes using targeted liquid chromatography flow injection analysis tandem mass/mass spectrometry (LC-FAIMS-MS).…”