DURHAM, N.C. -- Duke University Medical Center researchers have found that
nitric oxide, combined with hemoglobin, is a major regulator of gas exchange,
as well as blood pressure, in the circulatory system. The finding appears
to have solved the long-standing mystery of how blood carries oxygen to
body tissues and extracts waste carbon dioxide while keeping vessels open
and blood pressure steady.
Scientists say the discovery, detailed in the March 21 issue of the British journal Nature, could quickly pay off in developing the first effective blood substitute, and may ultimately change the way many diseases are treated.
"We now know that nitric oxide is involved in the blood's major functions," said cardiologist and pulmonologist Dr. Jonathan Stamler in an interview. "Oxygen delivery is essential to life and a deficiency in oxygen is associated with diseases of every organ. The same picture is gradually emerging for nitric oxide (NO). Understanding delivery of both in concert could have profound therapeutic implications.
"The duet of hemoglobin and NO is fantastically symbiotic in carrying out the machinery of life," he said. "Hemoglobin uses a spritz of the NO it carries to help get oxygen into tissues. And NO helps hemoglobin carry away the trash of carbon dioxide. It's fantastic."
The work was funded by the National Institutes of Health and the Pew Charitable Trusts. Working with Stamler was first author, Duke research associate Li Jia, and Joseph Bonaventura and Celia Bonaventura, from Duke's Nicholas School of the Environment and the Marine Biomedical Center.
Nitric oxide, long known as a noxious gas in the atmosphere, has been found over the past several years to play a major role in numerous biological systems. For example, scientists discovered that NO worked in the circulatory system to dilate blood vessels. "Free" NO is released by endothelial cells on the inside of
Contact: Renee Twombly