Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study shows how spikes in nitrite can have a lasting impact on the heart

05.03.2009
A new study provides insight into how a short burst in nitrite can exert lasting beneficial effects on the heart, protecting it from stress and assaults such as heart attacks.

In this study, just published in Circulation Research, researchers at Boston University School of Medicine have demonstrated for the first time that short elevations in circulating levels of this simple anion are sufficient to have a lasting impact on the heart by modulating its oxidation status and its protein machinery.

Nitrite, an oxidation product of the ubiquitous short-lived cell signaling molecule, nitric oxide (NO), was until recently thought to be biologically inert at the relatively low levels found in the body. Traces of nitrite are present in our diet and significant amounts are continuously produced from nitrate, another oxidation product of NO and a constituent of green, leafy vegetables. The suspicion that high levels of nitrite and nitrate may cause cancer, as well as concerns about their risk to compromise the ability of red blood cells to deliver oxygen to tissues, have led to strict regulations aimed at limiting our exposure to these substances through drinking water and food products.

In the past few years, however, multiple research groups have shown that low concentrations of nitrite exert numerous beneficial effects, ranging from anti-bacterial activities to increases in local blood flow, and that they can somehow protect tissues from damage when oxygen is suddenly cut off and then rapidly restored, as occurs during heart attacks and strokes.

To study the molecular underpinnings of this protective effect of nitrite, the researchers at Boston University School of Medicine used a rat model in which they administered nitrite only once, causing a short spike in circulating levels, as a way to simulate the types of naturally occurring increases in nitrite that follow exercise or consumption of a meal rich in nitrate.

The researchers used a systems-biology approach in which changes in multiple biological and biochemical systems (e.g., the composition of a large number of proteins, the concentration of several small molecule metabolites, and functional outcomes) are simultaneously monitored and then integrated to produce one final picture in order to provide a broader view of the impact of this treatment on the heart. They tested their theory that following these changes over time and at different doses of nitrite might help to explain the protective effects of nitrite on the heart.

"What we found was that a single brief nitrite treatment elicited persisting changes in the heart's oxidation status together with lasting alterations to numerous proteins involved in the heart's energy metabolism, redox regulation, and signaling," said David H. Perlman, a post-doctoral research associate in the Cardiovascular Proteomics Center at Boston University School of Medicine, and lead author of the study. "These alterations were particularly striking because they persisted at least 24 hours after the actual nitrite levels had returned back to normal, and they were correlated strongly with the improvements in heart function observed at the same time."

He noted that this type of protection, called 'cardiac preconditioning', is a recently discovered phenomenon shown to be caused by numerous pharmacological agents.

"The proteins we have implicated include some key proteins, such as mitochondrial aldehyde dehydrogenase, that have been shown by others to be critical to cardiac protection afforded by other agents and triggers," added Perlman. "This is exciting because it ties nitrite-triggered cardioprotection into the broader preconditioning field. Our study complements and extends other work, and identifies new players of potential importance for protection of the heart."

Perlman explained that nitrite levels in our bodies change under a number of circumstances, such as when we run up a flight of stairs or eat a big serving of salad.

"For years, the resulting bursts in nitrite were considered to be of little if any physiological relevance. Now we have good reason to believe that even small spikes in nitrite concentration can alter protein function in the heart in ways that afford protection," noted Perlman.

"We are intrigued by the breadth and magnitude of the proteomic changes in heart mitochondria elicited by a single, short-lasting elevation in nitrite concentration and believe that our findings will have broad implications for mitochondrial signalling and cardiac energetics," commented Martin Feelisch, senior author of the study. "It looks as though nitrite is triggering an ancient program aimed at fine-tuning mitochondrial function. Although the present study focussed on the heart, our observations may extend to other tissues and translate into relevant changes in muscle function elsewhere. If true, this may help explain, for example, the training effects of very short periods of exercise, which are known to be associated with elevations in circulating nitrite concentrations."

Interestingly, only low and high doses of nitrite, but not those in-between, were found to be protective. Although further studies will be needed to fully delineate the mechanisms of nitrite-induced cardioprotection, this study informs ongoing basic and translational studies by highlighting the importance of the dose-effect relationship for nitrite and the broad array of downstream targets possibly involved in its cardioprotective efficacy, the researchers concluded.

Gina DiGravio | EurekAlert!
Further information:
http://www.bmc.org

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>