Ischemia-reperfusion injury is one of the significant problems in clinical lung transplantation. We investigated the effect of lung preservation with Euro-Collins solution (EC group) or low-potassium dextran solution (LPD group) on lipid peroxidation and ischemia-reperfusion injury in a pig model of lung allotransplantation. The donor lungs were preserved at 4 degrees C for 18 h. Left-sided single lung transplantation was performed, followed by 6 h of reperfusion. Lipid peroxidation was measured as thiobarbituric acid-reactive materials (TBARM) in bronchoalveolar lavage (BAL) fluid and effluent solutions from pulmonary artery (Effluent). After 18 h of ischemia, the LPD group showed lower TBARM in BAL and Effluent than the EC group (p < 0.05). After ischemia plus reperfusion, lung wetto-dry weight ratios and TBARM levels in BAL in the LPD group were lower than those of the EC group (p < 0.05). Lung wet-to-dry weight ratios correlated with TBARM levels in BAL (p < 0.05, r = 0.50). We conclude lipid peroxidation in BAL and Effluent may reflect the degree of ischemia-reperfusion injury, and lung preservation with LPD can reduce lipid peroxidation and lung injury as compared with EC.