The NO concentration in the culture medium was evaluated by measuring the NO2− accumulation with a nitric oxide analyzer (NOATM 280; Sievers Inc., Boulder, CO, USA) that is based on a gas-phase chemiluminescence reaction between NO and ozone. In brief, BMDMs (2 × 106 cells) were treated for 24 h with 100 μg/mL LDL (−), P1A3 or P2C7, and 100 μL of culture supernatants were injected into a reflux chamber containing vanadium (III) in 3N HCl heated to 90 °C. The NO produced was detected by gas phase chemiluminescence after reaction with ozone. A calibration curve was then created using a sodium nitrate standard solution.