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

- We observed the interactive effects of low temperature and Ambient Fine particulate matter to AMs.
- We reported the responses of AMs after an 8-h treatment with two factors.
- Possible interactive effect might enhance the release of inflammatory mediators and oxidative damage of AMs.

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, 100 μg/ml) under different temperature (18, 24, 30, 37 °C) for 8 h. 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 (100 μg/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.