Effect of NO donor sodium nitroprusside on lipopolysaccharide induced acute lung injury in rats

The effects of LPS on arterial oxygen tension (PaO₂). 8h after intratracheal administration of LPS a 20% decrease in PaO₂ was induced (#P<0.01 vs. before treatment, n=8). Co-treatment of haemin or SNP with LPS ameliorated the reduction in PaO₂ (^*P<0.05 vs. LPS group, n=8, respectively) and there is no difference between control (before LPS treatment) and HM or SNP groups in PaO₂ (P>0.05 vs. control, n=8, respectively).

Immunohistochemical analysis for HO-1 expression in rat lung (SABC and haematoxylin and eosin (HE), original magnification ×400). (A) sham-operation group, no staining of HO-1 was detected in the alveolar region. (B) LPS group, some of the inflammatory cells and alveolar epithelia were stained positive for HO-1. In the HM+LPS (C) and SNP+LPS group (D), intense positive staining for HO-1 was seen in quite a number of inflammatory cells and alveolar epitheliums. All figures are representative of at least three experiments performed on different days, respectively.

Immunohistochemical analysis for iNOS expression in rat lung (SABC and haematoxylin and eosin (HE), original magnification ×400). (A) In the sham-operation group iNOS expression was barely detectable in the alveolar region. (B) In the LPS group intensive staining of iNOS was found in macrophages, some inflammatory cells, and alveolar epitheliums. There was light staining for iNOS in some inflammatory cells and alveolar epitheliums in the haemin+LPS group (C) and the SNP+LPS group (D). All figures are representative of at least three experiments performed on different days, respectively.