Increased levels of vascular endothelial growth factor in BALF in asthmatic rats

Objective To investigate the relationship between vascular endothelial growth factor (VEGF) levels and eosinophilic inflammatory profiles,and the degree of airway vascular permeability in the asthmatic rats. We evaluated the effect of inhaled dexamethasone on VEGF levels in BALF. Methods Eighteen SD rats were randomly divided into three groups: the control group, the asthma model group and the dexamethasone group. Asthmatic model was established by sensitization and challenge with ovalbumin and rats were inhaled dexamethasone before challenge in dethamethasone group. The VEGF levels, the percentage of eosinophils,the airway vascular permeability index in BALF and the PC50 were examined.Results The VEGF levels,the percentage of eosinophils,the PC50 and the airway vascular permeability index in asthma model group were higher than that in control group( P <0.05 orP <0.01). After 6-week inhaled dexamethasone therapy,the VEGF levels, the percentage of eosinophils, the PC50 and the airway vascular permeability index in dexamethasone group were decreased compared to asthma model group( P<0.05 or P<0.01). The VEGF levels were negatively correlated with PC50, the percentage of eosinophils, the airway vascular permeability index( r = - 0. 68,0. 76,0. 84, P <0. 01). Conclusions The VEGF levels in BALF were increased in asthmatic rats and its levels were associated with airway percentage of EOS,airway responsiveness and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in pathogenesis of asthma. Key words: Bronchial asthma;  Vascular endothelial growth factor