Anti-Inflammatory Effects of Adrenomedullin on Acute Lung Injury Induced by Carrageenan in Mice

Figure 3

Effect of adrenomedullin (AM) on iNOS expression and NO formation. Lung sections taken from CAR-treated mice treated with vehicle showed positive staining for iNOS, localized mainly in inflammatory cells (b). The degree of positive staining for iNOS was markedly reduced in tissue sections obtained from mice treated with AM (c). Lung sections taken from sham mice showed no staining for iNOS (a). The figure is representative of at least 3 experiments performed on different experimental days. A significant increase in iNOS (e, e1) quantification, assayed by Western blot analysis, was detected in lungs obtained from mice subjected to CAR-induced pleurisy, if compared with lung from sham mice (e, e1). Treatment with AM significantly attenuated this protein quantification in the lung tissues (e, e1). A representative blot of lysates obtained from 5 animals per group is shown and densitometry analysis of all animals is reported. The results in panel (e1) are expressed as mean ± s.e.m. from 𝑛=5/6 lung tissues for each group. *𝑃<0.01 versus sham group. ^∘𝑃<0.01 versus CAR. Nitrite and nitrate levels, stable NO metabolites, were significantly increased in the pleural exudates at 4 h after CAR (CAR) administration (d). AM significantly reduced the CAR-induced elevation of nitrite and nitrate in the exudates (d). Data are expressed as mean ± s.e.m. from 𝑛=10 mice for each group. ^∗𝑃<0.01 versus sham group. ^∘𝑃<0.01 versus CAR.