Adrenomedullin Prevents Lung Injury after Hepatic Ischemia-Reperfusion Damage

Objective: Acute lung injury is a complication after hepatic ischemia/reperfusion (I/R) and might be responsible for high mortality rate. The aim of this study was to demonstrate that adrenomedulline administration may prevent lung injury after hepatic I /R by downregulation of proinflammatory cytokines. Materials and Methods: This study was performed by using 54 male Wistar rats. The rats were randomly allocated into 3 groups and in groups were randomly allocated into 1st, 2nd, and 4th hour subgroups. After I/R, AM (12 mu g/kg) was infused for 30 minute via portal vein. Blood and tissue samples were collected 1, 2 and 4 hour after reperfusion. Hepatic I/R induced lung injury, as characterized by lung edema, histopathologic changes and proinflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels were evaluated. Results: The TNF-alpha enzyme activity in the first hour was found to be significantly higher in the I/R group than in the Sham and AM group (p= 0.027 and p= 0.041, respectively). The levels of TNF-alpha in the sham-operated group were similar in the AM group (p= 0.310). Significant differences were found only in the second hour IL-6 measurements (p= 0.038). Similar differences in caspase-9 enzyme activity in the sham-operated and AM group (p=0.291). Treatment with AM decreased lung injury after hepatic I/R as demonstrated by reduction in histologic damage. Conclusions: Acute lung injury was decreased by AM treatment after hepatic I/R injury.