Abstract: Objective To explore changes and significance of vascular endothelial growth factor(VEGF) in the early period of acute lung injury(ALI).Methods Seventeen male New Zealand rabbits were randomly divided into two groups,the control group(n=9) and the ALI group(n=8).The ALI was induced by intravenous injection of lipopolysaccaride(LPS).Blood pressure,heart rate,blood gas contents and VEGF concentration in serum and bronchoalveolar lavage fluid(BALF) were measured 3 h and 6h after LPS injection.Specimens for pathological exams were obtained at the end of each experiment.Results In ALI group,blood pressure,heart rate and pH decreased significantly,compared to control group(P<0.05).Serum and BALF VEGF concentrations were increased significantly(P<0.01).The main pathological changes observed by microscopic examination were inflammatory granulocyte infiltration,disseminated thickening of alveolar septa and local hemorrhages.There was a significant correlation between BALF VEGF concentration and the grades of pathological changes 6 h after intravenous LPS administration(r²=0.850,Y=0.070X+4.598).Conclusion LPS up-regulated serum and BALF VEGF.BALF VEGF concentration shows a high degree of correlation with pathological changes in the lung,and may serve as a useful marker for monitoring ALI.

Key words: acute lung injury, endotoxin, vascular endothelial growth factor