This study was designed to compare the cardiovascular effects of inhaled photochemically altered diesel exhaust (aged DE) to freshly emitted DE (fresh DE) in female C57Bl/6 mice. Mice were exposed to either fresh DE, aged DE, or filtered air (FA) for 4 hr using an environmental irradiation chamber. Cardiac responses were assessed 8 hr after exposure utilizing Langendorff preparation with a protocol consisting of 20 min of perfusion and 20 min of ischemia followed by 2 hr of reperfusion. Cardiac function was measured by indices of left-ventricular-developed pressure (LVDP) and contractility (dP/dt) prior to ischemia. Recovery of post-ischemic LVDP was examined on reperfusion following ischemia. Fresh DE contained 460 µg/m3 of particulate matter (PM), 0.29 ppm of nitrogen dioxide (NO2) and no ozone (O3), while aged DE consisted of 330 µg/m3 of PM, 0.23 ppm O3 and no NO2. Fresh DE significantly decreased LVDP, dP/dtmax, and dP/dtmin compared to FA. Aged DE also significantly reduced LVDP and dP/dtmax. Data demonstrated that acute inhalation to either fresh or aged DE lowered LVDP and dP/dt, with a greater fall noted with fresh DE, suggesting that the composition of DE may play a key role in DE-induced adverse cardiovascular effects in female C57Bl/6 mice.

中文翻译：

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吸入柴油机废气的心血管作用：小鼠体内光化学变化与新鲜释放相比。

这项研究旨在比较雌性C57Bl / 6小鼠吸入的光化学改变的柴油机排气（老化的DE）与新鲜散发的DE（新鲜的DE）对心血管的影响。使用环境照射室将小鼠暴露于新鲜的DE，老化的DE或经过滤的空气（FA）中4小时。暴露后8小时，使用Langendorff制剂评估心脏反应，该方案包括20分钟的灌注和20分钟的缺血，再进行2小时的再灌注。在缺血之前，通过左心室发育压力（LVDP）和收缩力（dP / dt）的指数来测量心脏功能。缺血后在再灌注时检查缺血后LVDP的恢复。新鲜的DE包含460 µg / m3的颗粒物（PM），0.29 ppm的二氧化氮（NO2）且不含臭氧（O3），而老化的DE包含330 µg / m3的PM，0。O3为23 ppm，无NO2。与FA相比，新鲜DE显着降低了LVDP，dP / dtmax和dP / dtmin。老年DE也显着降低LVDP和dP / dtmax。数据表明，新鲜或老化的DE的急性吸入会降低LVDP和dP / dt，新鲜DE的下降更大，这表明DE的组成可能在DE诱导的雌性C57Bl / 6心血管不良反应中起关键作用老鼠。