Reperfusion of ischemic dog lung results in fever, leukopenia, and lung edema.

Pulmonary artery obstruction results in minimal parenchymal abnormalities in normal lung and diminishes edema formation in dog lungs injured by oleic acid. We tested the hypothesis that reperfusion of ischemic regions would result in significant injury in normal lung and would ablate the protective effect of ischemia in oleic acid injury. The pulmonary artery of the left diaphragmatic lobe was occluded for 48 h in 12 oleic-acid-injured and 10 normal animals. Observations made immediately before reperfusion and for 4 h after reperfusion in the awake dogs indicated that reperfusion resulted in systemic abnormalities in both groups of animals, including a rise in temperature, a fall in cardiac output, and a marked drop in circulating leukocytes. In uninjured animals, the reperfused lobe demonstrated an elevated wet-to-dry weight ratio of 5.70 +/- 0.13 compared with 4.42 +/- 0.06 for the right diaphragmatic lobe (p less than 0.05). Histologic examination revealed edema and white cell infiltrates in the alveoli of the reperfused lobe in uninjured animals. In injured animals, there was no difference in either wet-to-dry ratios or morphologic aspects between the lobes. The results demonstrate both a local and systemic toxic effect of reperfusion in normal animals and ablation of the partial protective effect of pulmonary artery occlusion in oleic-acid-injured animals.