Chemiluminescence and nitrite determinations by the MALU macrophage cell line

The MALU macrophage cell line is an in vitro coculture of mesothelial cells and alveolar macrophages from mice. During the culture, macrophages in a preactivated state can be collected in the supernatant (Lombard et al., 1988). We describe here two methods to measure reactive oxygen intermediate (ROI) and reactive nitrogen intermediate (RNI) production by the MALU macrophages. We measured ROI by the chemiluminescence assay with a luminometer and RNI was measured colorimetrically in a spectrophotometer with the Griess reagent. Different parameters (cell number, incubation time, temperature and activating substance) which can interfere with the cell response were analysed. Our results show that the MALU macrophage cell line produces large amounts of ROI and RNI after activation. This cell line is a good model for investigating the effect of pharmacological drugs on ROI and RNI production.