Storage Lesion in Banked Blood Due to Disruption of Nitric Oxide (NO) Homeostasis

The purpose of this study is to explore the impact of aged blood on endothelial function by measuring forearm blood flow during intra-arterial acetylcholine infusion in normal healthy human volunteers after infusion of autologous blood stored for 5-10 days or 35-42 days. Our hypothesis is that 1) the vasodilatory response to the infusion of acetylcholine will be reduced in the 35-42 day group compared with the 5-10 day group, because of scavenging of the NO released from the endothelium by the hemolytic process in the aged blood, 2) that the infusion of aged stored blood will produce vasoconstriction, measured by reduced forearm blood flow during infusion of the 35-42 day compared with the 5-10 day old blood, and that 3) there will be increases in venous levels of cell free plasma hemoglobin, red cell microparticles, red cell membrane damage, arginase levels and activity, decreased arginine levels, markers of oxidative stress (carbamylated proteins and nitrated tyrosine residues), and increases in plasma in vitro NO consumption during the infusion of 35-42 day old compared to 5-10 day old blood.