Energy Metabolism in Washed Human Platelets Responsive to ADP: Comparison with Platelets in Plasma

Summary. The effect of the presence of albumin and apyrase on the metabolic rate of suspensions of washed platelets was examined. Albumin and apyrase reduced platelet glycolytic rate and oxidation of [6‐14C]glucose. Albumin significantly reduced the leakage of platelet LDH, β‐glucuronidase, serotonin and nucleotide which occurred during the resuspension procedures. This indicates that albumin provides a degree of protection to the platelets during resuspension. Apyrase produced a slight reduction in the accumulation of total nucleotide in the medium during incubation and its effect on metabolism was considered to be due to its ADPase activity. Assay of levels of key glycolytic intermediates indicated that the washing procedure stimulated metabolism. Recovery of resting metabolic rates was more rapid and more complete in the presence of albumin and apyrase. It was concluded that the inclusion of these agents in the suspending medium of washed platelets is an effective way of obtaining washed platelets with a metabolic rate similar to that of unwashed platelets in plasma.