Extended storage of human platelets at 22 C: changes in glycogen and adenine nucleotide metabolism.

The energy metabolism of human platelets stored at 22 C with continuous agitation has been studied. Freshly prepared platelets contain 9.7 mg of glycogen, 9.1 mu moles of ATP, 3.7 mu moles of ADP, 0.9 mu moles of AMP per 10(11) platelets and have an adenylate charge of 0.8. In the first 72 hours of storage there is no appreciable change in the glycogen content, adenylate charge and rate of ATP pool labeling. Therefore, on the basis of these results, the early impairment of function reported by others cannot be ascribed to alterations in the platelet energy metabolism. Upon further storage, however, there is a progressive loss of adenylate and glycogen while hypoxanthine accumulates extracellularly.