Figure 3. (A,B,C,D) Time-course and effect of IFN- and LPS on nitric oxide production induced by dentin extracts. Thioglycolate-elicited (A,C) or naïve macrophages (B,D) were treated with particulate (D-part), non-particulate (D-n-part) (5 mg/mL), and demineralized (d-Ext) (9 µg/mL) dentin extracts, and silica (30 particles/cell) in the presence or absence of AG (200 µM), IFN- (60 U/mL), LPS (500 ng/mL), or L-NMMA (200 µM) for 48 hrs or at indicated times. *Significantly different from respective control values at P < 0.05. In (A) and (B), ^# indicates the significance at P < 0.05 vs. condition without AG. In (C) and (D), ^# indicates the significance at P < 0.05 vs. condition without additional stimulation. (E,F) Effect of dentin treatment on hydrogen peroxide and TNF- production by thioglycolate-elicited macrophages. Cells were stimulated with D-n-part and D-part (5 mg/mL), d-Ext (9 µg/mL), or silica (30 particles/cell) in the presence or absence of PMA (400 ng/mL) and AG (200 µM), and H₂O₂ production was assessed after 48 hrs. *Significantly different from respective control values at P < 0.05. In E, # indicates the significance at P < 0.05 vs. condition without PMA. In F, # indicates the significance at P < 0.05 vs. condition without additional stimulation. Data are the mean + SEM of triplicates.