Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Excess oxygen worsens lung inflammation in mice

03.05.2005


Research performed at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, has revealed that oxygen therapy aimed at helping mice with acute lung inflammation breathe paradoxically worsened their illness. The researchers say excess oxygen appears to thwart a natural process that limits lung tissue damage. They overcame this deleterious side effect, however, by adding an inhaled anti-inflammatory drug to the oxygen therapy.



"This research illustrates, in an animal model, a delicate balance between supplemental oxygen therapy and an innate tissue-preserving process that appears to operate best in low-oxygen conditions," says NIAID Director Anthony S. Fauci, M.D.

Michail Sitkovsky, Ph.D., senior author of the paper published this week in the journal PLoS Biology, believes the findings could have clinical implications. Supplemental oxygen is a life-saving therapy for patients with breathing problems, but it can harm the lungs if it is used for long periods. While the problem of oxygen-induced lung damage is well known, the biochemical processes leading to this damage have not been fully explained. Dr. Sitkovsky’s research reveals a possible mechanism behind this oxygen-induced damage and also provides evidence of a simple way to prevent it.


The current study extends research published in 2001 by Dr. Sitkovsky and colleagues into the role played by the molecule adenosine in regulating inflammation. Inflammatory chemicals produced by the immune system in response to infection or injury must eventually be switched off so that excessive tissue damage can be avoided. Dr. Sitkovsky and his colleagues have shown that inflammation leads to a drop in oxygen levels in the inflamed tissues. This, in turn, triggers the release of adenosine from surrounding cells. When adenosine binds to cell receptors in the inflamed region, it serves as a tissue-protecting stop signal, slowing the flood of damaging inflammatory molecules, the scientists found.

From these findings, they reasoned that oxygen therapy given to patients with acute lung inflammation might "short-circuit" this protective pathway by preventing oxygen levels from dropping enough to trigger the inflammation stop signal.

To explore this possibility in an animal model, Dr. Sitkovsky and his colleagues induced lung inflammation in three groups of mice. The first group of 15 mice did not receive any supplemental oxygen. While they sustained moderate lung damage, only two died. Another group of 15 mice with acute lung inflammation were treated with either 100 percent or 60 percent oxygen for 48 hours. These mice suffered very extensive lung damage, and 11 of 15 died. Finally, the scientists treated another 15 mice with acute lung inflammation with a combination of 100 percent oxygen and an adenosine-like drug to compensate for the oxygen-induced loss of natural adenosine. Only two mice in this group died, and exacerbation of lung inflammation by oxygen was prevented.

The investigators conclude that in this small animal model highly pure oxygen therapy without the addition of an adenosine substitute worsens pre-existing lung inflammation. "We suggest that these adenosine substitutes be evaluated for their possible usefulness in settings of acute lung inflammation due to infection or other causes, such as asthma or surgical trauma," says Dr. Sitkovsky.

Dr. Sitkovsky is now continuing his research at the newly established New England Inflammation and Tissue Protection Institute, a consortium at Northeastern University in Boston.

NIAID is a component of the National Institutes of Health, an agency of the U.S. Department of Health and Human Services. NIAID supports basic and applied research to prevent, diagnose and treat infectious diseases such as HIV/AIDS and other sexually transmitted infections, influenza, tuberculosis, malaria and illness from potential agents of bioterrorism. NIAID also supports research on transplantation and immune-related illnesses, including autoimmune disorders, asthma and allergies.

Anne A. Oplinger | EurekAlert!
Further information:
http://www.niaid.nih.gov

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>