NSF PR 00-47 - June 20, 2000
This material is available primarily for archival
purposes. Telephone numbers or other contact information
may be out of date; please see current contact information
at media
contacts.
New Test For Presence of Nitric Oxide Could Improve
Medical Knowledge
Researchers supported by the National Science Foundation
(NSF) have developed a means to detect nitric oxide
that could help improve scientists' understanding
of this molecule's role in neurological signaling
and other biological functions.
Stephen Lippard, Katherine J. Franz and Nisha Singh
of the Massachusetts Institute of Technology synthesized
a nitric oxide sensing system that consists of a molecule
whose fluorescence switches on when nitric oxide is
present. They reported their findings in the June
16 international edition of the German publication
Angewande Chemie.
Nitric oxide plays a major role in the regulation of
blood pressure, the prevention of blood clotting,
the dilation of blood vessels and the destruction
of pathogens. It is used extensively in medical treatment;
for example, nitroglycerin ameliorates the pain of
angina by supplying nitric oxide to the blood vessels
that supply the heart. The popular drug Viagra controls
penile erection by regulating nitric oxide.
To understand the mechanism of nitric oxide's action
in the body, medical researchers needed a sensitive
means of detecting the molecule in vivo. An
effective sensor system had to be sensitive only to
nitric oxide, even in the presence of other chemically
active molecules such as oxygen, and able to measure
the minute concentrations normally found in living
cells.
The new sensor consists of a central cobalt atom surrounded
by two organic "arms." In the absence of nitric oxide,
the molecule fluoresces only very weakly. When nitric
oxide is present, it chemically bonds to the cobalt
atom, causing a molecular rearrangement that results
in a substantial, measurable increase in fluorescence.
This indicator does not respond to other molecules,
such as oxygen.
"Many of the nitric oxide detectors used today are
based on identification of its decomposition products,
nitrite and nitrate," said Lippard. "In contrast,
our fluorescence indicator reacts directly with nitric
oxide. It has the potential to track the formation
of nitric oxide in real time."
The scientists are now working on the development of
more sensitive, water-soluble sensors with a stronger
fluorescence response. "With this future generation
of sensors it should be possible to measure nitric
oxide in cell cultures. In the distant future, applications
to understand nitric oxide-triggered neurobiological
events in living organisms, and possibly even medical
applications, could emerge," Lippard adds.
NSF is an independent federal agency which supports
fundamental research and education across all fields
of science and engineering, with an annual budget
of about $4 billion. NSF funds reach all 50 states,
through grants to about 1,600 universities and institutions
nationwide. Each year, NSF receives about 30,000 competitive
requests for funding, and makes about 10,000 new funding
awards.
For instant information about NSF, sign up for the
Custom News Service. From the toolbar on NSF's home
page, (http://www.nsf.gov),
sign up to receive electronic versions of NSF news,
studies, publications and reports. Follow the simple
sign-on procedures that guide you to your choices.
Also see NSF news products at: http://www.nsf.gov:80/od/lpa/start.htm,
http://www.eurekalert.org/,
and http://www.newswise.com
|