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Inhalation of Simulated Smog Atmospheres Affects Cardiac Function in Mice
Citation:
Tong, H., Todd Krantz, J. Krug, C. King, M. McGee, Ian Gilmour, AND S. Gavett. Inhalation of Simulated Smog Atmospheres Affects Cardiac Function in Mice. Society of Toxicology Annual Meeting, San Antonio, TX, March 14 - 19, 2018.
Impact/Purpose:
This study demonstrates the cardiovascular effects of simulated smog exposure in an animal model.
Description:
The health effects of individual criteria air pollutants have been well investigated. However, little is known about the health effects of air pollutant mixtures that more realistically represent environmental exposures. The present study was designed to evaluate the cardiac effects of inhaled smog atmospheres (SA) generated from photochemically reacted mixtures of either gasoline and isoprene, producing high ozone (SA-O3) or isoprene alone (SA-Is) in mice. Four-month-old female mice were exposed for 4 h to filtered air (FA), SA-O3, or SA-Is. Immediately and 20 h after exposure, cardiac responses in isolated hearts were assessed with a Langendorff preparation using a protocol consisting of 20 min of global ischemia followed by 2 h of reperfusion. Cardiac function was measured by index of left-ventricular developed pressure (LVDP) and cardiac contractility (dP/dt) before ischemia. On reperfusion, recovery of post-ischemic LVDP and infarct size were examined. Pre-ischemic LVDP and dP/dt were lower in mice immediately after SA-Is exposure and 20 h after SA-O3 exposure compared to the FA control. In addition, SA-O3 reduced the coronary artery flow rate 20 h after exposure compared to the FA control. There was no statistically significant difference of post-ischemic recovery of cardiac function and infarct size between FA and SA-O3 or SA-Is groups at either time point. This study demonstrates that acute SA-O3 and SA-Is exposures decrease LVDP and cardiac contractility in mice, indicating that photochemically-altered atmospheres affect the cardiovascular system. THIS ABSTRACT OF A PROPOSED PRESENTATION DOES NOT NECESSARILY REFLECT EPA POLICY.