Transfusion of stored red blood cells (RBCs) is associated with a decrease in tissue oxygenation in animal models and with increased mortality and morbidity in patients. Recent studies have demonstrated that stored RBCs are deficient in vasodilatory ability and depleted of
S
-nitrosohemoglobin (SNO-Hb), and that renitrosylation
ex vivo
can increase SNO-Hb levels and restore vasoactivity. We have examined in a mouse model the extent to which transfusion impairs tissue oxygenation and whether SNO-Hb repletion can ameliorate that impairment. We report here that transfusion of (mouse) RBCs stored for 1 day or 1 week results in tissue hypoxia that is largely prevented by SNO-Hb repletion prior to transfusion (
1 day stored blood
: % decrease in oxygenation 58+/−10% untreated vs. 92+/−0.7% SNO-Hb repleted, p<0.05, n=3– 6;
1 week stored blood
: % decrease in oxygenation 66+/−10% untreated vs. 91+/−2.8% SNO-Hb repleted, p<0.05, n=3– 6). Storage of mouse blood beyond human expiration-equivalents (1 month) resulted in substantial lysis and the death of all mice transfused (native and SNO-Hb repleted blood, n=5). In conclusion, repletion of SNO-Hb ameliorates the decrease in tissue oxygenation that results from transfusion of untreated stored blood. Therefore, SNO-Hb repletion may provide a simple and efficacious method to reduce transfusion-related mortality and morbidity.
Pharmacologic Targeting of Red Blood Cells to Improve Tissue Oxygenation