"One important aspect of our study is the insight that knowledge of banked blood's SNO-Hb status may be used to judge the efficacy of a transfusion," Stamler said.
This information would allow physicians to discriminate between blood donations that may cause harm versus those that will have restorative effects following transfusion.
The research team hypothesized that the loss of NO compromises the ability to dilate blood vessels and thereby deliver oxygen to tissues, which is critical for survival. Red blood cells lacking NO instead would plug small blood vessels and cause heart attacks and kidney failure. In contrast, restoration of NO would ensure oxygen delivery.
The study, funded by the National Heart Lung and Blood Institute (NHLBI), found that mice, rats and sheep transfused with untreated banked blood had decreased oxygen levels in skeletal muscle and other tissuesexactly the opposite of what would have been predicted. By contrast, in animals transfused with renitrosylated (NO repleted) red blood cells, tissue oxygenation improved. In addition, researchers applied the same treatment to anemic animals and found improved blood flow, tissue oxygenation, and kidney function.
Stamler explained that these results demonstrate that restoration of blood NO levels may be useful in treating and preventing a wide variety of conditions, including heart attacks and strokes, and kidney damage following surgery. The findings also may offer new promise for patients with sickle disease, malaria and other blood disorders. In addition, the data suggest that Stamler's therapeutic is a simple way to reverse the potential toxicity of regular blood transfusions.
The Food and Drug Administration considers a transfusion successful if 75 percent of the banked red blood cells are circulating in the body of the recipient 24 hours after admi
|Contact: Jessica Studeny|
Case Western Reserve University