Figure 3: Effects of treatment with silica particles on plasma MPO levels. (A) BALB/c mice were intravenously injected with nSP70 (0.2, 0.4, or 0.8 mg/mouse), nSP300 (0.8 mg/mouse), mSP1000 (0.8 mg/mouse), or saline. BALB/c mice with no treatment were divided into untreated group. Plasma concentrations of MPO were determined by ELISA. (B) BALB/c mice were injected intraperitoneally with anti-Ly-6G antibodies (50, 100, or 150 μg/mouse), isotype controls (150 μg/mouse), or PBS 24 h prior to nSP70 injection (0.8 mg/mouse). Twenty-four hours after nSP70 injection, plasma concentrations of MPO were determined by ELISA. Data are presented as mean ± SEM; n = 5–6; **P < 0.01 vs saline-treated group; ##P < 0.01 vs nSP70-treated group.