Figure 1.

Concentration-dependent production of NO by macrophages stimulated with LPS and IFNγ. Macrophages were stimulated with LPS (A) or LPS (20 ng/mL) plus IFNγ (B) for 48 h, after which the cells were harvested and the NO released was measured as nitrite using the Griess reagent. The columns represent the means ± SE of three independent experiments, each done in quadruplicate. *P < 0.05 (by Student's t test).