Secretion Defect in Platelets Stored at 4°C

Abstract

To understand the functional changes induced by storage, we have examined the adenine nucleotides of platelets stored for 72 hr at 22 degrees C and 4 degrees C. Ten platelet concentrates (PC) were stored at each temperature with five in each group having a final volume of 50 ml and 30 ml. The total ATP and ADP content of platelets decreased following storage in all 4 groups of PC, with the decrease being greater in the PC stored at 22 degrees C than those at 4 degrees C. The mean thrombin secretable ATP + ADP content of platelets from PC stored at 22 degrees C and 4 degrees C were 29.7% and 19.7% of the total content, respectively (p less than 0.001). Thus, cold stored platelets have a higher total content of ATP + ADP but secrete distinctly lesser amounts than 22 degrees C stored platelets. Labeling of the metabolic pool adenylates with 14C-adenine revealed a greater decrease in the adenylate energy charge of the platelets stored at 4 degrees C. The secretion defect demonstrated in cold stored platelets may be related to the inability of these platelets to maintain ATP homeostasis.