Hypoxanthine is a purine base, which is produced with hydrolysis of adenosine triphosphate. Hypoxanthine efflux from muscles into blood, but it can be recycled via salvage pathway with hypoxanthine-guanine phosphoribosyltransferase, both in muscle and blood. Hypoxanthine-guanine phosphoribosyltransferase convertes hypoxanthine to inosine monophosphate, which is then used to synthetise adenosine triphosphate. This system is very important for adenosine triphosphate energy regeneration during and post exercise. High activity of hypoxanthine-guanine phosphoribosyltransferase is monitored after high intensity exercise. Hypoxanthine can be used as a metabolic indicator of training status and can tell us how well is individual organism adaptated to specific exercise. Because of this, measurement of hypoxanthine and hypoxanthine-guanine phosphoribosyltransferase activity can be used as a aid to track and field and other sport coaches to monitor their athletes adaptation to trainings.
We examined ten track and field athletes who competes in 100 meters and 400 meters. We took venous blood samples in different periods of one year competition cycle of athletes. Whole concentrations of hypoxanthine and xanthine were assessed by specific oxidation, and hypoxanthine-guanine phosphoribosyltransferase activity with sandwich ELISA. We also performed other tests to assessed parameters of physical performance of athletes, which helped us to better understand results of concentrations of hypoxanthine and xanthine and hypoxanthine-guanine phosphoribosyltransferase measurements.
The results shows that group of athletes who competes in 100 meters have higher values of hypoxanthine and xanthine pre and post exercise during all periods of one year competition cycle. Comparing this results with results of test on the special bike, we find out that higher values of maximal relative peak power leads to lower hypoxanthine and xanthine concentrations and vice versa, for athletes who compete in 100 meters. This also came out in squat jump test for winter competition period. In group of athletes who competes on 400 meters, results of test did not vary so much between competition periods, and then also whole concentrations of hypoxanthine and xanthine are almost the same in whole year.
We might conclude that maybe there is possible correlation between hypoxanthine and xanthine concentrations and athletics performance and therefore it can be metabolic indicator that show us how well the human organism is adapted to physical exercise.