Acute cardiovascular effects of inhaled ambient particulate matter: Chemical composition-related oxidative stress, endothelin-1, blood pressure, and ST-segment changes in Wistar rats

Short-term increases in particulate matter (PM) are associated with heightened morbidity and mortality from cardiovascular causes. Inhalation of PM is known to increase endothelin (ET)-1 levels. Yet, less is known about particle composition-related changes at the molecular level including the endothelinergic system and relationship with cardiovascular function changes. In this work, adult Wistar male rats were exposed for 4 h by nose-only inhalation to clean air, Ottawa urban particles (EHC-93, 48 mg/m3) and water-leached (EHC-93L, 49 mg/m3) particles, to examine the effect of particle compositional changes on oxidative stress, circulating ETs, blood pressure, and heart electrophysiology. Particle deposition in the respiratory compartment was estimated at 85 μg (25 ng/cm2). Lung cell proliferation was low in both treatment groups, indicating absence of acute injury. Inhalation of EHC-93 caused statistically significant elevations (p