Reduction of Acute Lung Injury by Administration of Spironolactone After Intestinal Ischemia and Reperfusion in Rats

Multiple organ failure, including acute lung injury, is a common complication of intestinal ischemia and reperfusion (I/R) injury and contributes to its high mortality rate. Activated polymorphonuclear neutrophils and reactive oxygen species contribute to the lung injury caused by intestinal I/R. Mineralocorticoid receptor antagonist spironolactone has a protective effect against I/R injury in animal models of retina, kidney, heart, and brain. The aim of the present study is to investigate the effect of aldosterone receptor blocker spironolactone on lung injury induced by intestinal I/R.

Wistar albino rats were divided into four groups: (1) sham control; (2) intestinal I/R (30 min of ischemia by superior mesenteric artery occlusion followed by 3 h of reperfusion); (3) spironolactone pretreatment (20 mg/kg) + I/R; and, (4) spironolactone pretreatment without I/R. Spironolactone was given orally 3 days prior to intestinal I/R. A marker for lipid peroxidation (malondialdehyde; MDA), an indicator or oxidation state (reduced glutathione; GSH), an index of polymorphonuclear neutrophil sequestration (myeloperoxidase; MPO), inducible nitric oxide synthase (iNOS) immunoreactivity, and the histopathology of the lung tissue were analyzed.

Spironolactone pretreatment markedly reduced intestinal I/R-induced lung injury as indicated by histology and MDA and MPO levels. Moreover, the pretreatment decreased the iNOS immunoreactivity.

The present study strongly suggests that spironolactone pretreatment decreased neutrophil infiltration, iNOS induction, oxidative stress, and histopathological injury in an experimental model of intestinal I/R induced-lung injury of rats.