FRIDAY, Jan. 6 (HealthDay News) -- The blood pressure medicine losartan [Cozaar] helped prevent lung damage in mice that were exposed to cigarette smoke for two months, researchers say.

Specifically, the drug prevented lung tissue breakdown, airway wall thickening, inflammation and lung overexpansion in the animals, according to the Johns Hopkins researchers.

The findings have led to a clinical trial of losartan in people with smoking-related chronic obstructive pulmonary disease (COPD). About 12 million Americans have COPD, which is the third leading cause of death in the United States.

The study, published in the Jan. 3 issue of the Journal of Clinical Investigation, was funded by drugmaker Merck & Co. and the U.S. National Heart, Lung, and Blood Institute.

"The results of our study in mice suggest that losartan or similar drugs could serve as an effective treatment for smoking-related lung diseases in humans," senior investigator Dr. Enid Neptune, a pulmonologist and assistant professor at the Johns Hopkins University School of Medicine, said in a Hopkins news release.

"And because these drugs are already approved for use in the United States as safe and effective treatments for hypertension, incorporating them into our treatment regimen for COPD would be quite rapid," Neptune added.

"It is very exciting that an existing medication has proven capable in an animal model of not only treating the problems of COPD, but also disrupting the biological pathway that precipitated them," pulmonologist Dr. Robert A. Wise, a Johns Hopkins professor who is leading the human clinical studies, said in the news release.

"If our tests in people prove successful, we could help restore lung health to millions of people who have suffered from tobacco addiction," Wise added.

Existing therapies for smoking-related COPD mainly provide relief of symptoms, such as shortness of breath, coughing and mucus production, Wise said. Blood pressure-lowering drugs may also help and some patients have surgery to remove damaged sections of the lung or undergo lung transplants.

While the findings of the new study are promising, scientists note that research involving animals often fails to produce similar results in humans.

More information

The American Academy of Family Physicians has more about chronic obstructive pulmonary disease.