Effects of neutrophil elastase inhibitor (ONO-5046) on lung injury after intestinal ischemia-reperfusion

The underlying mechanisms of lung endothelial injury after intestinal ischemia-reperfusion (I/R) injury are not fully known. Here we investigated the effects of posttreatment with a neutrophil elastase inhibitor (NEI; ONO-5046) on lung injury after intestinal I/R injury in a rat model. Intestinal I/R was produced by 90 min of ischemia followed by either 60 or 240 min of reperfusion. For all experimental groups, the endothelial permeability index increased, neutrophil H2O2 production increased in the pulmonary vasculature blood, neutrophil counts increased in bronchoalveolar lavage fluid (BALF), and the cytokine-induced neutrophil chemoattractant (CINC)-1 and CINC-3 levels were increased in BALF after 240 min ( P < 0.01). In rats treated with NEI from 60 min after reperfusion, the lung endothelial permeability index was significantly reduced ( P < 0.05), whereas neutrophil H2O2 production in pulmonary vasculature blood and neutrophil count in BALF were significantly suppressed by NEI ( P < 0.05 and P < 0.01, respectively). In addition, NEI significantly suppressed the increase of CINC-1 and CINC-3 levels in BALF ( P < 0.05). Our study clearly indicates that posttreatment with NEI reduces neutrophil activation in the pulmonary vessels and neutrophil accumulation in the lungs and suggests that ONO-5046, even when administered after the primary intestinal insult, can prevent the progression of lung injury associated with intestinal I/R.