Figure 4: Effects of treatment with silica particles on G-CSF expression in mice. 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. (A) The plasma concentrations of G-CSF were determined by ELISA 24 h after treatment. (B) The concentration of G-CSF in livers of mice was determined by ELISA 24 h after nSP70 injection (0.8 mg/mouse). (C) Anti-G-CSF antibodies (50 µg/ mouse) or isotype controls were injected intraperitoneally into BALB/c mice 4 h prior to nSP70 injection (0.8 mg/mouse). Twenty-four hours after nSP70 treatment, the proportion of neutrophils in peripheral blood of each mouse was analyzed by flow cytometry. Data are presented as mean ± SEM; n = 5–6; **P < 0.01 vs saline-treated group; *P < 0.05 vs saline-treated group; ##P < 0.01 vs nSP70-treated group.