FRIDAY, Sept. 22 (HealthDay News) -- Carbon monoxide (CO) -- the colorless, odorless gas often dubbed the "silent killer" -- shows promise in treating pulmonary arterial hypertension (PAH), according to new research.

In a study published in the September issue of the Journal of Experimental Medicine, researchers from Beth Israel Deaconess Medical Center in Boston and the University of Pittsburgh tested the effects of treating PAH in mice with low, non-toxic doses of CO.

PAH is a condition in which blood vessel walls thicken so much that blood can no longer be effectively pumped through them, resulting in serious cardiopulmonary complications and, in many cases, heart attacks. There is currently no cure for PAH.

For the study, the researchers exposed mice with PAH to a short, daily regimen of CO.

They found the gas reversed the PAH in the animals, resulting in the restoration of normal blood pressures and heart weights -- indicating imminent heart failure was reversed.

Through further investigation, the researchers found that CO's benefits were due to the destruction of smooth muscle cells, which uncontrollably grow in the blood vessels of people with PAH. The CO dose destroyed the smooth muscle cells without affecting healthy cells.

"Our hope is that CO will find a place in the clinic as a therapeutic option for the treatment of disease," study author Leo Otterbein, an associate professor of surgery at Harvard Medical School, said in a prepared statement. "CO has been around since before life began on earth and, in fact, it is thought to have contributed to the origin of life. Perhaps this was a sign of its necessary role in biology."

More information

The National Heart, Lung, and Blood Institute has more about pulmonary arterial hypertension.