Mechanism of faster NO scavenging by older stored red blood cells

Abstract

The blood storage lesion involves morphological and biochemical changes of red blood cells (RBCs) that occur during storage. These include conversion of the biconcave disc morphology to a spherical one, decreased mean corpuscular hemoglobin concentration, varied mean corpuscular volume, reduced integrity of the erythrocyte membrane with formation of microparticles, and increased cell-free hemoglobin. We studied the extent that older stored red blood cells scavenge nitric oxide (NO) faster than fresher stored red blood cells. Using electron paramagnetic resonance spectroscopy and stopped-flow absorption spectroscopy to measure the rate of NO uptake and reaction with hemoglobin in red cells, we found that older stored red blood cells scavenge NO about 1.8 times faster than fresher ones. Based on these experimental data, we simulated NO scavenging by fresher or older stored red blood cells with a biconcave or spherical geometry, respectively, in order to explore the mechanism of NO scavenging related to changes that occur during blood storage. We found that red blood cells with a spherical geometry scavenges NO about 2 times slower than ones with a biconcave geometry, and a smaller RBC hemoglobin concentration or volume increases NO scavenging by red blood cells. Our simulations demonstrate that even the most extreme possible changes in mean corpuscular hemoglobin concentration and mean corpuscular volume that favor increased NO scavenging are insufficient to account for what is observed experimentally. Therefore, RBC membrane permeability must increase during storage and we find that the permeability is likely to increase between 5 and 70 fold. Simulations using a two-dimensional blood vessel show that even a 5-fold increase in membrane permeability to NO can reduce NO bioavailability at the smooth muscle.BackgroundTransfusion of older stored blood may be harmful.ResultsOlder stored red blood cells scavenge nitric oxide more than fresher cells.ConclusionAs stored red blood cells age, structural and biochemical changes occur that lead to faster scavenging.SignificanceIncreased nitric oxide scavenging by red blood cells as a function of storage age contributes to deleterious effects upon transfusion.

Established and theoretical factors to consider in assessing the red cell storage lesion

“…both theoretical and actual toxicology in the context of in vitro human and whole animal models. Such substances include: c scavengers of nitric oxide (NO) and inhibitors of NO generation that may result in lack of vascular relaxation (eg, hemoglobin, both free and in microparticles, 14 alterations in RBCs themselves, 15 and asymmetric dimethylarginine that may inhibit NO synthase 16,17 In some cases, the biological effects of stored/aged blood in whole animal models has resulted in profound pathology and pathophysiology, with substantial morbidity and mortality of recipients of the stored (but not fresh) units of blood.…”

Biochemistry of storage lesions of red cell and platelet concentrates: A continuous fight implying oxidative/nitrosative/phosphorylative stress and signaling

“…This findings has been confirmed very recently by fully exploring the extent of the storageassociated increase in NO scavenging (about 2 fold) and a satisfactory elucidation of the mechanism has also been provided [22]. The authors found that, due to the storage-induced damage to the red cell cytoskeleton, the RBC membrane permeability to NO increases 5-70 fold during storage [22].…”

Circulating Erythrocyte Microparticles and the Biochemical Extent of Myocardial Injury in ST Elevation Myocardial Infarction

“…in packed erythrocyte units) transfused in experimental models [10,14]. Moreover, there are data supporting the concept that after a longer duration of erythrocyte packing, the ‘associated' scavenging of nitric oxide by hemoglobin is faster [15]. RBCm in packed erythrocyte units are principally produced through a hemolytic process that occurs throughout collection, packing, and preservation - also described as the storage lesion [16] - while in vivo RBCm production is mediated through complex cell activation and apoptosis processes [17].…”