Increased nitric oxide production by airway cells of sensitized and challenged IL-10 knockout mice

The anti‐inflammatory cytokine interleukin (IL)‐10 suppresses induciblenitric oxide synthase (iNOS); therefore, NO production should increasein the absence of IL‐10. Production of NO (as nitrite) bybronchoalveolar lavage cells of IL‐10 knockout (−/−) micewas assessed after ovalbumin sensitization and airway challenge (S/C)and was compared with the IL‐10‐sufficient, wild‐type (WT) C57Bl6.Eosinophil recruitment occurred in S/C WT and IL‐10−/−mice, suggesting allergic airway inflammation. Alveolar macrophages(per g mouse) were unchanged (∼3×104 cells) with theexception of a doubling in the S/C IL‐10−/− mice(∼6×104 cells, P