NEW YORK (Reuters Health) - A chemical that naturally occurs in the body may help scientists find better treatments for asthma.

The chemical, called lipoxin A4 (LXA4), appears to quiet hyper-responsive airways, researchers report this week in the advance online publication of the journal Nature Medicine.

In the new study, researchers gave asthmatic mice a synthetic compound that is similar to LXA4, but longer lasting, study co-author Dr. Charles N. Serhan explained in an interview with Reuters Health.

People with asthma often experience attacks during which airways narrow. Attacks can range from occasional periods of wheezing, mild coughing and slight breathlessness to more severe episodes that can lead to total blockage of the airways.

"LXA4 is rapidly formed and rapidly broken down by the body as a way of regulating cellular traffic," according to Serhan, director of the Center for Experimental Therapeutics at Brigham and Women's Hospital and a professor of anesthesia, perioperative and pain medicine, biochemistry and molecular pharmacology at Harvard Medical School, both in Boston, Massachusetts.

Basically, Serhan said, LXA4 acts to quiet inflammation by knocking down levels of cells that cause it.

In the new study, Serhan and his colleagues looked at the effect of LXa, a substance that mimics the naturally occurring molecule, but doesn't break down as quickly, in mice with asthma.

An hour after the mice were given LXa, they were exposed to substances that might normally cause airways to narrow and become inflamed. LXa not only kept the airways open, but also appeared to reduce inflammation, Serhan said.

To further test to see if LXA4 might be the key to new medications in humans, Serhan and his colleagues used genetic engineering techniques to produce mice that expressed the human version of the LXA4 receptor. Again, LXa kept airways from narrowing and reduced inflammation.

Serhan is hoping that the new research will catch the eye of a pharmaceutical company looking to develop new therapies for asthma.

"That would not be something we do," Serhan said. "But we're hoping that this research will be encouraging enough to draw that kind of attention."

With asthma on the rise, especially in children, new treatments are needed, Serhan said. "The agents available today have limited use and they don't work for everyone," he added. "A lot of testing needs to be done to figure out which medication is best for which patient. And that takes a long time. Besides, some of the classic therapies have side effects."

Serhan suspects that because LXA4 is produced by the body, that an analog to the molecule will have fewer side effects than drugs developed in other ways.

The new study was funded, in part, by grants from the National Institutes of Health.

SOURCE: Nature Medicine 2002;10.1038/nm748.

Reference Source 89

For more information on how to prevent other diseases, use
PreventDisease.com's "Quick Prevention Resources".