Duke University Medical Center other research news
Duke University researchers reported in Nature that hemoglobin is involved in the control of blood pressure. They have identified a site in hemoglobin that reacts with nitric oxide (NO) to form S-nitrosohemoglobin. Hemoglobin, they write, is S-nitrosylated in the lung when red blood cells are oxygenated. As blood flows through the capillaries, NO is released, which then acts on the muscles surrounding the small blood vessels in tissues, enabling the vessels to relax, increasing the blood flow and delivery of oxygen to tissues.
This research helps explain why hemoglobin without red blood cells induces hypertension, when used as a blood substitute. That effect has been attributed to NO scavenging by the iron in hemoglobin, which prevents NO from exerting its modulating effect on blood pressure. ...