A Method to Detect Remote Organ Injury after Intestinal Ischemia-Reperfusion in Mice.

Abstract

Intestinal ischemia and hypoperfusion appear to play key roles in the pathogenesis of multiple organ dysfunction syndrome (MODS). While various animal models have been used to elucidate what causes MODS, investigators have recently started to use mice since knockout and transgenic technologies emerged. However, definite methods to estimate systemic organ damage, especially endothelial injury, have not well been established in mice. We, therefore, attempted to establish simple methods that enable us to detect intestinal, pulmonary, and hepatic injury in a murine model of intestinal ischemia-reperfusion (I/R). Adult female BALB/c mice underwent 45 minutes of superior mesenteric artery occlusion and subcutaneously received 3ml of saline as fluid resuscitation. Two and 6 hours after reperfusion, whole blood was drawn from the inferior vena cava and the heart. Microvascular permeability and edema formation in the intestine, lung, and liver, were quantitated by Evans blue method (EB) and wet/dry ratio (W/D), respectively. Liver function was also measured by plasma alanine aminotransferase (ALT) and total bilirubin (T-Bil) concentrations. In the second set of experiments, the same methods were employed in C57BL/6 mice after 45 minutes of intestinal ischemia and 2 hours reperfusion. In BALB/c mice, intestinal injury was detected by EB and W/D and increased pulmonary permeability was measured by EB. Liver injury was quantitated by EB, W/D, and T-Bil. In C57BL/6 mice, intestinal injury was estimated by EB and W/D, lung leak by EB, and liver injury by W/D, ALT, and T-Bil. While slight difference was observed between those two strains of mice, the data indicate that intestinal, pulmonary and hepatic injury could be successfully estimated by the combination of EB, W/D, ALT and T-Bil in a murine model of intestinal I/R. These methods may become useful in mice not only to delineate the mechanisms linking intestinal I/R and remote organ injury but also in other fields of shock research.