Inducible nitric oxide synthase (iNOS) immunoreactivity in lung parenchyma induced by silica instillation.

<p>Photomicrographs of lung parenchyma of wild-type (WT; <i>A, C, E</i>) and P2X7 receptor knockout (KO; <i>B, D, F</i>) mice 14 days after intratracheal instillation of silica particles (<i>C-F</i>) or saline (<i>A, B</i>). Arrows: mononuclear cells. Asterisk: aggregates of reactive cells. Bars: 1250 µm (<i>A, B</i>); 600 µm (<i>C, D</i>); 90 µm (<i>E, F</i>). <i>G:</i> quantification of iNOS immunoreactivity. Box plots represent median of 6-9 animals per experimental group with a statistical cut of ± 10-90%, with respective SD (15 random non-coincident fields/animal). **p <0.01 and ***p <0.001 in relation to the respective control; ⁺⁺p <0.01 in relation to Silica WT.