To evaluate the efficacy of a perflurocarbon emulsion (Fluosol: FC-43) for protecting preserved lungs from ischemic reperfusion injuries, we employed an isolated canine left lung reperfusion model. The left lung from 15 mongrel dogs was flushed and preserved in Euro-Collins solution for 24 hrs at 4 degrees C. The preserved lungs were rinsed through the pulmonary artery with a perflurocarbon emulsion (perfluorotributylamine: FC-43) or Carolina rinse solution II (CRS-II) and then reperfused with whole blood for 120 minutes. The lungs were divided into three groups; lungs reperfused without rinse (Group 1: n = 5), and lungs rinsed with oxygenated FC-43 (Group 2: n = 6) or CRS-II (Group 3: n = 4). Reperfusion was with whole blood warmed to 37 degrees C. The pulmonary vascular resistance was lower in the lungs in Group 1 than in those in Groups 2 and 3 (84.2 +/- 33.3 v.s. 322.3 +/- 190.5 and 474.1 +/- 219.0 mmHg/L/min, p < 0.01). There was no significant difference in the PaO2 among the 3 groups at the end of reperfusion. The extravascular lung water (dry/wet ratio) was lower in the lungs in Group 2 than Groups 1 and 3 (90.5 +/- 0.7% v.s. 86.8 +/- 2.1% and 92.1 +/- 2.1% p < 0.01). These data demonstrated that pulmonary function and structure were maintained well in lungs reperfused with FC-43. We conclude that a perfluorocarbon emulsion (FC-43) is useful for protecting ischemic canine lungs from reperfusion injury, but Carolina rinse solution II is not effective for minimizing reperfusion injury in canine lungs.