Intestinal
ischemia and reperfusion (I/R) is encountered in various clinical conditions and contributes to multiorgan failure and mortality as high as 60% to 80%. Intestinal I/R not only injures the intestine, but affects remote organs such as the lung leading to
acute lung injury. The development of novel and effective
therapies for intestinal I/R are critical for the improvement of patient outcome.
AICAR (5-aminoimidazole-4-carboxyamide ribonucleoside) is a cell-permeable compound that has been shown to possess antiinflammatory effects. The objective is to determine that treatment with
AICAR attenuates intestinal I/R injury and subsequent
acute lung injury (ALI). Male Sprague Dawley rats (275 to 325 g) underwent intestinal I/R injury with blockage of the superior mesenteric artery for 90 min and subsequent reperfusion. At the initiation of reperfusion, vehicle or
AICAR (30 mg/kg BW) was given intravenously (IV) for 30 min. At 4 h after reperfusion, blood and tissues were collected for further analyses. Treatment with
AICAR significantly decreased the gut damage score and the water content, indicating improvement in histological integrity. The treatment also attenuated tissue injury and proinflammatory
cytokines, and reduced bacterial translocation to the gut.
AICAR administration after intestinal I/R maintained lung integrity, attenuated neutrophil chemotaxis and infiltration to the lungs and decreased lung levels of
tumor necrosis factor (TNF)-α and
interleukin (IL)-6. Inflammatory mediators, lung-
inducible nitric oxide synthase (iNOS) and
cyclooxygenase-2 (COX-2)
proteins, were decreased in the lungs and lung apoptosis was significantly reduced after
AICAR treatment. These data indicate that
AICAR could be developed as an effective and novel therapeutic for intestinal I/R and subsequent ALI.