Abstract: Objective To investigate the effects of dexamethasone on vascular endothelial growth factor(VEGF) in the early stage of acute lung injury(ALI).Methods 24 male New Zealand rabbits were divided into three groups randomly:N:the control group(n=9);L:the ALI group(n=8) receiving intervenous lipopolysaccaride(LPS) to achieve the degree of ALI;E:the early-intervention group(n=7),treated with 2 mg dexamethasone immediately after injection of LPS.Results In group ALI,blood pressure,heart rate,pH and buffer excess(BE) were markedly decreased.VEGF in serum and bronchoalveolar lavage fluid(BALF) were both higher than those in the sham ones.In group E,the blood pressure and heart rate decrease were diminished,the increase of VEGF in serum and BALF were inhibited significantly and the extent of lung pathological changes were mitigated.Conclusion Dexamethasone could improve the permeability of endothelium by inhibiting of VEGF in the early stage of ALI.

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