Researchers at Beth Israel Deaconess Medical Center (BIDMC), Boston, and the University of Pittsburgh have released the results of animal studies that show that carbon monoxide (CO) has proven effective in treating the symptoms of pulmonary arterial hypertension (PAH).

The paradoxical theory that CO, “the silent killer,” could be used to prevent the onset of certain inflammatory conditions was first proposed in 1998, and numerous studies since then have shown that when administered at low, nontoxic concentrations prior to certain procedures it offers protection against organ rejection or blockage of the carotid arteries.

These newest findings, however, demonstrate that CO can also be used to treat and reverse existing disease, according to Leo Otterbein, PhD, senior author.

“Our results offer the exciting possibility that in extremely low concentrations and for brief intermittent exposures of 1 hour per day, CO gas might be effectively used as a therapy to treat PAH in a clinical setting,” says Otterbein, an investigator in the Transplantation Center at BIDMC and associate professor of surgery at Harvard Medical School.

The researchers found that CO reversed PAH in the study animals by arresting growth of the vessels’ smooth muscle cells and inducing apoptosis. As the smooth muscle cells died, both the pulmonary blood vessels and right heart were restored to their normal size. CO did not induce the death of all of the smooth muscle cells in the blood vessels, however, only the population that was problematic.

Otterbein and colleagues are hopeful that CO will find a place in the clinic as a therapeutic option for the treatment of PAH. 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,” concludes Otterbein.

Source: Beth Israel Deaconess Medical Center