Effect of muscular exercise on the concentration of uridine and purine bases in plasma - Adenosine triphosphate consumption-induced pyrimidine degradation

To identify whether muscular exercise increases the plasma concentration of uridine and of purine bases, the effect of rigorous muscular exercise was determined in five healthy men with a bicycle ergometer. Twenty-five-minute muscular exercise at 65% maximum O-2 consumption increased the concentration of uridine, purine bases, and inorganic phosphate in plasma and of NH3 and lactic acid in blood, These results suggest that exercise-induced excessive adenosine triphosphate (ATP) consumption enhanced not only purine degradation but also pyrimidine degradation (uridine triphosphate [UTP] --> uridine diphosphate [UDP] --> uridine monophosphate [UMP] --> uridine) in exercising muscles. Copyright (C) 1997 by W.B. Saunders Company.