[Purine metabolism in endothelial cells]

In human umbilical endothelial cells purine metabolism was studied: activities of some key-enzymes, concentrations of ATP, ADP, and creatine phosphate (CP), and the incorporation of labeled purine bases, purine nucleosides and glycine were measured. The results obtained show that endothelial cells are capable of degradation and synthesis of purine nucleotides. The rate of purine nucleotide synthesis via salvage pathways predominates that of de novo synthesis. Preincubation with phosphate resulted in increased nucleotide pools and incorporation of performed purines, whereas ribose showed the opposite effect. An explanation of these effects might be the limited availability of intracellular phosphoribosylpyrophosphate.