The relationship of granulocyte ATP to chemotactic response during storage

During the storage of granulocytes, bactericidal activity declines more slowly than does chemotactic response (CTR). Bacterial killing involves increased activity of the hexose monophosphate shunt, oxygen utilization and the generation of toxic products of oxygen. Chemotaxis is probably a contractile process involving myosin and actin filaments and possibly ATP as a source of energy. Thus, maintainance of ATP may be important in granulocyte preservation. During storage at 1 to 6 C of granulocytes collected by continuous and intermittent flow centrifuge leukapheresis, both CTR and ATP decreased approximately 33 percent. Decreases in CTR and ATP were 12 and 10 percent respectively when cells were stored at 20 to 24 C. Further decreases in CTR and ATP occurred between 24 and 48 hours of storage, although levels of both were higher in cells stored at 20 to 24 C compared with those stored at 1 to 6 C. When the results from all storage conditions were combined, the overall coefficient of correlation between CTR and ATP was 0.71 (p less than .05). Although ATP is probably not the only important variable in granulocyte preservation, granulocytes may resemble red blood cells in that a minimal level of ATP may be necessary for adequate function.