Summary: Jon Lundberg of the Karolinska Institute in
Stockholm and his colleagues had set out to
study the importance of natural gut bacteria
in nitrate metabolism using mice bred to
harbour no microorganisms. But when these
germ-free mice were fed sodium nitrate, and
nitrite ions then showed up in their blood,
the team began hunting for enzymes to
explain the result.
They recorded nitrate-reducing activity
from xanthine oxidoreductase in the liver
tissue of both rodents and humans, and
found that NO2
­
can be further reduced
to NO. The pathway ramped up during an
experiment in which the researchers clamped
the abdominal aorta of rats -- perhaps
unsurprisingly, given that NO dilates blood
vessels.

Source: Alon, Uri - Departments of Molecular Cell Biology & Physics of Complex Systems, Weizmann Institute of Science
Tlusty, Tsvi - Department of Physics of Complex Systems, Weizmann Institute of Science

Collections: Biology and Medicine; Physics