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:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... First ... United States, named Dr. Sesan Ogunleye, as the Medical Director of its new Mesquite-Samuell ... facility Medical Director of our new Mesquite location,” said Dr. James M. Muzzarelli, Executive ...
(Date:6/25/2016)... Oklahoma City, Oklahoma (PRWEB) , ... June 25, ... ... to helping both athletes and non-athletes recover from injury. Recently, he has implemented ... for the Oklahoma City area —Johnson is one of the first doctors to ...
(Date:6/25/2016)... ... 2016 , ... Conventional wisdom preaches the benefits of moderation, whether it’s a ... the bar too high can result in disappointment, perhaps even self-loathing. However, those who ... , Research from PsychTests.com reveals that behind the tendency to set ...
(Date:6/24/2016)... ... June 24, 2016 , ... Those who have experienced traumatic events ... turn to unhealthy avenues, such as drug or alcohol abuse, as a coping mechanism. ... tools for healthy coping following a traumatic event. , Trauma sufferers tend to feel ...
(Date:6/24/2016)... ... ... a crisis. Her son James, eight, was out of control. Prone to extreme mood shifts ... upset him, he couldn’t control his emotions,” remembers Marcy. “If there was a knife ... and say he was going to kill them. If we were driving on the ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... INDIANAPOLIS , June 23, 2016 ... Tomorrow,s Leaders Scholarship is any indication, the future is ... online at www.diabetesscholars.org by the Diabetes Scholars ... in the way of academic and community service excellence. ... program since 2012, and continues to advocate for people ...
(Date:6/23/2016)... 2016 Revolutionary technology includes multi-speaker ... , industry leaders in advanced audiology and hearing aid ... Opn ™, the world,s first internet connected hearing aid ... devices.      (Photo: http://photos.prnewswire.com/prnh/20160622/382240 ) ... of ,world firsts,: , TwinLink™ - the ...
(Date:6/23/2016)... 23, 2016 The vast majority of dialysis ... facility.  Treatments are usually 3 times a week, with ... including travel time, equipment preparation and wait time.  This ... grueling for patients who are elderly and frail.  Many ... and rehabilitation centers for some duration of time. ...
Breaking Medicine Technology: