Banked Blood May Lose Key Gas
Loss May Make It Harder for Banked Blood to Deliver Oxygen to Tissues
Oct. 9, 2007 -- Banked blood quickly loses a gas that's needed to deliver
oxygen to tissues, new research shows.
The gas is called nitric oxide.
In two new studies, scientists report that when blood is stored under
normal conditions, nitric oxide's ability to do its job fades rapidly.
Treating banked blood with nitric oxide may fix that problem, according to
the researchers, who included Duke University's Jonathan Stamler, MD.
"This data is of considerable interest," the American Red Cross
tells WebMD. "We anticipate it may eventually lead to a better
understanding of how to preserve red cell properties during storage."
In lab tests, Stamler's team tested banked blood's ability to deliver oxygen
to heart tissue in dogs.
The researchers focused on SNO-Hb (S-nitrosohemoglobin), which is the blood
protein hemoglobin tweaked by nitric oxide.
Banked blood was better at delivering oxygen to heart tissue in dogs when
the blood had been treated with nitric oxide, compared with banked blood
In other experiments, another team of researchers -- including Duke
University's Timothy McMahon, MD, PhD -- found that red blood cells in banked
blood lost some of their flexibility in storage. That process happened more
slowly than SNO-Hb loss in banked blood.
Red blood cells need to be flexible to travel through tiny blood vessels;
otherwise, they could block or take longer to navigate through those blood
vessels, McMahon's team notes.
Replenishing SNO-Hb may help keep stored red blood cells flexible, according
to McMahon and colleagues.
Both studies were partly funded by Nitrox/N30, a company which is developing
ways to treat oxygen delivery disorders. Several of the researchers report
financial ties to Nitrox/N30, and McMahon is the co-inventor of a patent
related to red blood cells and SNO gases.