Fig. 5. Effect of low-dose lipopolysaccharide on the plasma concentrations of nitrite/nitrate in different mouse strains. Mice were treated with normal saline or 0.1 mg/kg lipopolysaccharide (LPS) intraperitoneally. 1400W (20 mg/kg) was given to wild-type C57BL/6J (WTBL/6) mice 2 h before saline or LPS administration. Twenty-four hours later, blood was collected and plasma prepared. Nitrite and nitrate were measured using a fluorometric assay. Each error bar represents the mean ± SE. The number shown in each bar represents the sample size in the group. *P < 0.05, **P < 0.01, ***P < 0.001. iNOS−/−= inducible nitric oxide synthase knockout; 1400W =N -(3-(aminomethyl)benzyl)acetamidine; MyD88−/−= myeloid differentiation factor 88 knockout; sGC−/−= soluble guanylate cyclase knockout; TLR4−def= Toll-like receptor 4-deficient; WTBL/10 = wild-type C57BL/10ScSn.