Navigation Links
Powerful free radical causes lung damage from oxygen therapy
Date:10/5/2010

AUGUSTA, Ga. The most toxic free radical appears responsible for much of the lung damage that can result from oxygen therapy in the critically ill or injured, Medical College of Georgia researchers report.

Within just a few days, ventilators and oxygen chambers used to significantly increase oxygen levels can also dramatically increase levels of peroxynitrite, an oxidant powerful enough to break down DNA and cause proteins to malfunction, said Dr. Yunchao Su, pharmacologist in the MCG Schools of Medicine and Graduate Studies.

Oxygen toxicity is the most severe side effect of oxygen therapy in newborns and adults. The lungs take the brunt of the damage, which can include inflammation, hemorrhaging and swelling that may result in death or chronic lung problems, said Su, corresponding author of the study published in the Journal of Biological Chemistry.

"We knew it was bad but we did not know why," Su said. The good news is they may also have a solution.

Researchers found that within five days, mice placed in small oxygen chambers that mimic oxygen levels given in intensive care have dramatically elevated levels of peroxynitrite in their lungs. Free radicals, such as peroxynitrite, result from oxygen use and are safe at low levels. While it's a given that oxygen therapy produces free radicals, the significant increase in peroxynitrite was not known.

The trouble begins when high oxygen levels prompt endothelial cells that line blood vessels and tiny airs sacs in the lung to make more nitric oxide, the precursor of peroxynitrite. At high levels, nitric oxide, most often a helpful compound, combines with other free radicals produced by excess oxygen use to form the powerful peroxynitrite. "As oxygen levels increase, nitric oxide levels increase and so peroxynitrite levels do as well," Su said.

But he appears to have identified a break point in the destructive cycle. Su found that in the face of high oxygen levels, the enzyme that makes nitric oxide binds with the protein actin to produce more nitric oxide. So he developed a compound, peptide 326, that interferes with their binding and the excess peroxynitrite levels that typically follow. Su used the binding site itself as a cue for the peptide design after trying many existing compounds, including smoke, to break the bond.

Su's long term goal is for peptide 326, or something similar, to be used in patients likely after the first few days of oxygen therapy. Much as health care providers monitor blood oxygen long term to ensure sufficient levels, they could also monitor peroxynitrite levels. "It's only after several days of steady increases that the level becomes destructive," Su noted.

MCG scientists are already using peptide 326 in mice receiving oxygen therapy.


'/>"/>

Contact: Toni Baker
tbaker@mcg.edu
706-721-4421
Medical College of Georgia
Source:Eurekalert  

Related medicine news :

1. Breaching the blood-brain barrier to create powerful new tools for fighting cancer
2. doeLegal and Zapproved Sign Alliance to Add Legal Hold Pro to Suite of Powerful Online Legal Solutions
3. New Book Reveals the Powerful and Undermining Impact of Stress on Good Decision Making and What Leaders Can Do About It
4. Powerful People Often Too Optimistic About Task Time
5. Adapting to clogged airways makes common pathogen resist powerful drugs
6. American Council on Exercise (ACE) Study Reveals Kettlebells Provide Powerful Workout in Short Amount of Time
7. Plant compound resveratrol shown to suppresses inflammation, free radicals in humans
8. Lumenis Announced Today it is Sponsoring the Endometriosis Foundation of America's Symposium 'Advancing the Art and Science of Endometriosis: Stem Cells to Radical Excision Surgery'
9. Henry Ford Health System goes radical: Creating the hospital of the future
10. Cigarette smoke causes harmful changes in the lungs even at the lowest levels
11. Scientists closer to finding what causes the birth of a fat cell
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Powerful free radical causes lung damage from oxygen therapy
(Date:2/10/2016)... ... 10, 2016 , ... 10 Best Water is excited to announce ... brand owners that topped the list as a result of their commitment to offering ... brand was Tibet 5100, a top notch water company that specializes in providing the ...
(Date:2/10/2016)... , ... February 10, 2016 , ... ... organization, welcomes S.S. Nesbitt as the latest addition to its growing list of ... other locations throughout the Southeast, from Orlando to Huntsville and in between. , ...
(Date:2/10/2016)... ... February 10, 2016 , ... Pediatric ... in their patients. Research shows that the Goal Attainment Scale (GAS) captures 20% ... this challenge and learn more about the Goal Attainment Scale, Education Resources Inc. ...
(Date:2/10/2016)... ... February 10, 2016 , ... IDEX Health & ... PEEK-lined stainless steel (PLS) columns combine the strength of traditional stainless steel with ... of biological samples while operating at ultra-high pressures of 20,000 psi. The higher ...
(Date:2/10/2016)... Washington, DC (PRWEB) , ... February 10, 2016 , ... ... highest level since the start of Medicare Part D a decade ago, according to ... collecting comments from older adults on how they are coping with rapidly rising costs. ...
Breaking Medicine News(10 mins):
(Date:2/10/2016)... Feb. 10, 2016  Astellas Pharma Inc. (TSE: 4503, ... today that it has successfully completed, through its indirect ... to purchase all issued and outstanding shares of common ... CEO: Paul Wotton , "Ocata") for a price ... cash ("Tender Offer"). Astellas commenced the Tender Offer on ...
(Date:2/10/2016)... , Feb. 10, 2016  The ... Nursing received an in-kind gift from ... a VeinViewer® Vision vein finder for the ... help students as they learn how to ... technology with traditional technique. ...
(Date:2/10/2016)... , Feb. 10, 2016 ... synergistic confluence of various technologies that results ... previously unavailable. These opportunities create a cyclical ... in turn, drives the development of new ... is characterized by technology convergences, which are ...
Breaking Medicine Technology: