Introduction:
In utero exposure to particulate matter through perinatal development has been demonstrated to produce cardiac dysfunction during adulthood. It is unknown what effect exposure to air pollution during the in utero period alone has on cardiac dysfunction and electrical remodeling in adulthood. We tested the hypothesis that adult mice exposed to concentrated particulate matter in utero would demonstrate global cardiac dysfunction as well as cellular electrical remodeling at adulthood.
Methods:
Female FVB mice were exposed either to filtered air (FA) or particulate matter with diameter less than 2.5 μm (PM2.5) at a concentration of ~ 51.69 μg/m3 for 6 h/day, 7 days/wk (consistent with exposure in a large metropolitan city) beginning at plug formation throughout pregnancy. Cardiac function was assessed via ECHO in male offspring at 12 wks of age, followed by sacrifice and isolation of ventricular cardiomyocytes from both groups of mice for electrophysiological recordings.
Results:
ECHO identified increased LVESd (2.25 ± 0.20 FA, 2.61 ± 0.35 PM2.5, P=0.0001) and LVEDd (3.89 ± 0.03 FA, 3.99 ± 0.038 PM2.5, P=0.04) dimensions and reduced PWTs (1.40 ± 0.05 FA, 1.26 ± 0.04 PM2.5, P=0.04) in mice exposed in utero to PM2.5. Morphological alterations were associated with lower systolic function as indicated by reduced fractional shortening% (43.6 ± 2.1 FA, 33.2 ± 1.6 PM2.5, P=0.0009) in PM2.5 exposed mice compared to FA controls. Electrophysiological recordings revealed significant prolongation of the action potential at 90% repolarization (APD90) in PM2.5 exposed mice compared to FA. (FIGURE)
Conclusions:
In utero exposure to relevant levels of particulate matter results in dilated cardiomyopathy and electrical remodeling. Future studies are warranted to determine the causes of, and the exposure thresholds resulting in this adverse cardiac remodeling.
In Utero Exposure To Cigarette Smoke Promotes Cardiac Dysfunction In High‐fat Fed Mice