According to the Department of Health and Human Services news release, a study done by scientists with Duke University Medical Center in Durham, N.C., have found that blood that is donated is less effective than blood that is fresh.
Researchers have found a chemical deficiency in blood that is stored in blood banks, instead of fresh blood, and at the same time may have found a way to fix the problem. With these new studies coming about, explanations of why some blood transfusions do more harm then good are finally clearer. Dr. Jonathan Stamler, one of the senior researchers, explained that “Overall, the [previous clinical] trials have shown that while bleeding is bad, and while decreases in blood count is bad, giving blood back is not good — that’s the paradox,”
The information found will provide a molecular rationale for these observations. Dr Jonathan Stamler and Timothy McMahon, the lead researchers at Duke University Medical Center, examined the ability of fresh and banked blood. The results show that the activity is based on two separate parameters, one, how much oxygen, two, how much nitric oxide the red blood cells hold.
According to Stamler and McMahon, nitric oxide scientifically known as NO is a vasodilator, which dilates blood vessels. It is carried in red blood cells by hemoglobin. When the hemoglobin comes in contact with a tissue with little oxygen, it releases the nitric oxide, therefore allowing the blood vessels to open and ease the red cell’s entry into the tissue where oxygen can be released.
The researchers found that the blood which is stored loses the bulk of it’s nitric oxide within three house of collection, and it’s ability to induce vasodilation also diminishes. It was also found that the stored red blood cells gradually lose their “membrane flexibility” which is a physical attribute of the red blood cells that allow them to squeeze into narrow capillaries. Dr. Stamler says that “Everybody thinks if you give back oxygen-carrying red blood cells, you will get more oxygen to tissues, no, that’s not the case. The blood we give cannot open vessels, and thus cannot deliver oxygen, and we think that’s because it’s missing nitric oxide gas.”
According to the American Red Cross, someone in the United States needs blood every two seconds. Unfortunately only five percent of people in the United States donates blood in one year. Blood is needed for many reasons, cancer patients, blood disorders, sickle cell anemia, and some people need blood just to live their everyday lives. To learn how you can donate blood, please visit the American Red Cross.
SOURCE : Studies Probe Weaknesses in Donated Blood
SOURCE : American Red Cross – Donating Blood