THURSDAY, July 22 (HealthDay News) -- Chronic ozone exposure may increase sensitivity to myocardial dysfunction, according to an animal study presented at the American Heart Association's Basic Cardiovascular Sciences 2010 Scientific Sessions, held from July 19 to 22 in Rancho Mirage, Calif.
To assess the effect of chronic ozone exposure on myocardial dysfunction, Rajat Sethi, Ph.D., of Texas A&M Health Science Center-Rangel College of Pharmacy in Kingsville, and colleagues studied rats that had been isolated and exposed to filtered air or 0.8 parts per million ozone.
The researchers found in vivo cardiac functions were significantly lower in the ozone-exposed rats compared to the rats exposed to filtered air, which suggested that ozone enhanced sensitivity to cardiac dysfunction. Examination of the hearts of sacrificed rats revealed increased levels of tumor necrosis factor-alpha in the ozone-exposed rats, as well as decreased levels of cardioprotective caveolin-1 (Cav1) and decreased pro-apoptotic p38MAPK alpha, which, with Cav1, has been associated with enhanced death signaling.
"This clinically significant study is timely and will help better understand the mechanisms underlying the pathology of ozone-induced cardiac injury. The long-term goal is to contribute relevant data useful in guiding regulatory policies to establish air quality standards that will better protect populations living in urban air polluted environments around the world," the authors write.
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