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.