Bloody revelation

HAEMOGLOBIN, the blood's red pigment which was until now thought to transport only oxygen to and bring out carbon dioxide from the body's tissues, has now been credited with yet another major function. In a finding that could mean a new look at treating disorders like blood pressure and a possible development of artificial blood, it has been found to distribute another gas during its rounds - nitric oxide.

Another part of haemoglobin, known as cysteine residue, can apparently hold and release nitric oxide, thereby regulating the levels of the gas in the body's circulatory system. Nitric oxide, long considered a toxic gas, may turn out to be as important as oxygen, contends Jonathan Stamler of the Duke University Medical Centre in Dufham, North Carolina, who is also a senior author of the report on baemoglobin's latest function, which appeared in March 21 issue of Nature.

While the phenomenon has been observed in rats, Stamler and his colleagues at Duke University are confident that the, same results will be found in the human body on account of its similarity to rat physiology.