Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Excess oxygen worsens lung inflammation in mice


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:

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>