血管内皮细胞生长因子在急性肺损伤大鼠中的表达及意义

目的探讨血管内皮细胞生长因子(VEGF)在脂多糖所致急性肺损伤大鼠中的表达及意义,为临床防治急性肺损伤提供参考依据。方法将40只SD大鼠随机分为LPS(脂多糖)组和NS(生理盐水)组,麻醉后气管插管,LPS组吸入LPS(3 mg/kg),NS组吸入等量NS。0h、2h、4h、6h时每组分别处死5只大鼠,抽血行血气分析,同时进行血浆VEGF水平、肺泡灌洗液(BALF)蛋白定量和VEGF水平、肺组织病理学、免疫组化以及VEGF mRNA表达水平检测。结果 LPS组2h、4h、6h时间点p H和Pa O2均明显低于NS组相应时间点,Pa CO2和肺损伤评分均明显高于NS组相应时间点(P0.05)。LPS组2h、4h、6h时间点BALF蛋白定量均明显高于NS组相应时间点(P0.05),LPS组2h、4h、6h时间点BALF和血浆VEGF定量均明显高于NS组相应时间点(P0.05)。LPS组BALF和血浆中VEGF水平与肺损伤评分均呈正相关(r=0.682和r=0.613,P0.001),BALF中VEGF水平与蛋白定量呈正相关(r=0.715,P0.001)。LPS组2h、4h、6h时间点肺组织中VEGF mRNA的表达均明显高于NS组相应时间点表达(P0.05)。结论 ALI大鼠血浆、BALF和肺组织中VEGF水平明显升高,血浆和BALF中VEGF水平与肺损伤程度呈正相关,BALF中VEGF水平与蛋白定量呈正相关,提示VEGF可能通过增加呼吸膜的通透性参与急性肺损伤发生过程。

Expression and significance of vascular endothelial growth factor in rats with acute lung injury

Objective To investigate the expression and significance of vascular endothelial growth factor in rats with acute lung injury caused by lipopolysaccharide in order to provide the reference for the prevention and treat-ment of acute lung injury. Methods 40 SD rats were randomly divided into the LPS group ( LPS) and the NS ( phosphate buffer) group. All animals were anesthetized and given tracheal intubation, the LPS group inhaled LPS (3mg/kg) and the NS group inhaled the same amount of NS. 5 rats in each group were sacrificed at 0h, 2h, 4h and 6h. Blood gas analysis and VEGF level in plasma and BALF were measured and protein in BALF, pathological and immunohistochemical change and VEGF mRNA expression levels in lung tissue were detected. Results The value of pH and PaO2 in the LPS group at 2h, 4h and 6h time-points were significantly lower than that in the NS group, and PaCO2 and lung lesion scores were significantly higher than those in the NS group ( P<0. 05 ) . BALF quantitative protein in the LPS group at 2h, 4h and 6h point was significantly higher than that in the NS group (P<0. 05). The VEGF of BALF and plasma in the LPS group at 2h, 4h and 6h were significantly higher than those in the NS group (P<0. 05). The VEGF levels in BALF and plasma were positively correlated with lung injury score (r=0. 682 and r=0. 613, P<0. 001) and BALF level was positively correlated with VEGF protein quantification in the LPS group (r=0. 715, P<0. 001). The expression of VEGF mRNA in lung tissues in the LPS group at 2h, 4h and 6h were significantly higher than that in the NS group (P<0. 05). Conclusion The VEGF expression in plasma, BALF and lung tissue of ALI rats increase significantly, and the VEGF level in plasma and BALF are positively correlated with the degree of lung injury and VEGF level in BALF is positively related with protein, which indicates that VEGF is probably in the process of ALI by increasing respiration and membrane permeability.