血管内皮生长因子对急性肺损伤大鼠的影响及地塞米松干预效果

Study of vascular endothelial growth factor in acute lung injury and effect of dexamethasone on it

目的探讨血管内皮生长因子（VEGF）在急性肺损伤（ALI）中的动态变化和地塞米松的干预效果。方法通过静脉注射脂多糖（LPS）2h、4h、6h和气管内滴人大肠杆菌（E．coli）12h、24h、36h复制大鼠ALI模型，观察不同时间点两种ALI模型血清和支气管肺泡灌洗液（BALF）中VEGF、肺组织VEGF阳性百分率、阳性目标积分光密度值的变化，以及地塞米松干预的影响。结果LPS组血清VEGF随着时间延长表达增加，与E．coli组比较差异无统计学意义；给予激素后LPS组和E．coli组血清中VEGF表达变化均无统计学意义。BALF中VEGF在LPS模型中随着时间延长表达逐渐增多，但4h与6h相比差异无统计学意义；在E．coli模型中随着时间延长逐渐增多；给予激素后两模型BALF中VEGF均下降。VEGF阳性率、阳性目标积分光密度值在LPS组中开始表达降低，6h表达升高，给予激素后均下降；在E．coli组随着时间延长表达增多，给予激素后24h下降。结论在LPS和E．coil诱导AL1模型中肺组织和BALF中VEGF表达均升高，表明VEGF参与ALI肺水肿的形成，地塞米松能够降低肺组织和BALF中VEGF的表达，减轻肺水肿。

Objective To explore the dynamic changes of vascular endothelial growth factor （VEGF） and significance of dexamethasone treatment. Methods Acute lung injury rat models were duplicated by intravenous injection of lipopolysaccharide （LPS） 2 h, 4 h, 6 h and tracheal instillation of Escherichia coli （E. coli） 12 h,24 h, 36 h. The changes of VEGF in the serum and hronchoalveolar lavage fluid （BALF）, VEGF-positive percentage of lung tissue, the positive goal of integrated optical density at different time points, and the impact of dexamethasone intervention were observed. Results The serum VEGF expression increased with time in the LPS model, there was no statistical significance between LPS model and E. coli model. The serum VEGF after given hormone was not statistically significant between the two models. The BALF VEGF expression gradually increased with time in the LPS model, but there was no significant difference between 4 h and 6 h. The BALF VEGF expression gradually increased with time in E. coli model, and decresed after given hormone in the two models. VEGF positive rate, positive goal of integrated optical density began to decrease in the LPS model,increased at 6th hour,and decreased after given hormone. They were increased with lime in E. coli model, and decreased at 24th hour after given hormone. Conclusions LPS and E. coli can induce expression of VEGF increased in lung tissue and BALF of acute lung injury model. It is indicated that VEGF participates in the formation of pulmonary edema in acute lung injury. Dexamethasone can reduce VEGF expression in lung tissue and BALF, and relieve pulmonary edema.