Impact of probable interaction of low temperature and ambient fine particulate matter on the function of rats alveolar macrophages.

The present study aimed to explore the probable interaction of low temperature and ambient fine particulate matter (PM2.5) on rat alveolar macrophages (AMs). AMs were separated from rat BALF and exposed to PM2.5 (0, 25, 50, 100μg/ml) under different temperature (18, 24, 30, 37°C) for 8h. Results indicated that viability and phagocytosis function of AMs decreased with the decline of temperature and the rise of PM2.5 dose, and the strongest toxicity was shown in the highest PM2.5 (100μg/ml) exposure group at 18°C. Both PM2.5 and lower temperature increased the releasing of tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein 1α (MIP-1α) and interleukin-6 (IL-6), while significant interaction was only found in MIP-1α production. No obvious change was found in granulocyte-macrophage colony-stimulating factor (GM-CSF) detection. These results indicated that both the two factors are harmful to rat AMs and lower temperature could increase the toxicity of PM2.5 on the AMs.