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目的探讨高浓度氧暴露致新生大鼠急性肺损伤时血管内皮生长因子(VEGF)的表达及其对肺发育的影响,为临床防治支气管肺发育不良提供理论依据。方法生后2~3日龄新生Sprague-Dawley(SD)大鼠48只随机分为空气组和高氧组各24只,分别置于空气及常压氧气(≥95%)喂养,采用荧光定量PCR和Western Blot方法检测第1、3、7天时各组大鼠肺组织VEGF mRNA和蛋白表达水平,HE染色动态观察新生大鼠肺组织形态结构变化。结果两组大鼠肺组织第1、3、7天VEGF mRNA和蛋白表达水平均逐渐降低,高氧组明显低于空气组,第1天差异无统计学意义(P>0.05),第3、7天差异有统计学意义(P<0.05)[VEGF mRNA:1天(0.86±0.35)比(1.00±0.28),3天(0.54±0.26)比(0.92±0.34),7天(0.32±0.20)比(0.61±0.12);VEGF蛋白:1天(0.78±0.33)比(1.00±0.16),3天(0.60±0.08)比(0.85±0.27),7天(0.34±0.12)比(0.56±0.18)]。与空气组相比,高氧组肺组织显著发育不良,肺泡结构简单,肺泡数目减少,肺微血管发育受阻。结论 VEGF对肺发育起重要作用,其确切作用机制有待进一步研究。
Objective To investigate the expression of vascular endothelial growth factor (VEGF) and its effect on lung development in neonatal rats with acute lung injury induced by hyperoxia and to provide a theoretical basis for clinical prevention and treatment of bronchopulmonary dysplasia. Methods 48 neonatal Sprague-Dawley (SD) rats, 2 to 3 days after birth, were randomly divided into two groups: air group and hyperoxia group, each of which was fed with air and atmospheric oxygen (≥95%). Fluorescence quantitative PCR and Western Blot were used to detect the expression of VEGF mRNA and protein in the lung tissue on the 1st, 3rd, 7th day. The morphological changes of the lung tissue were observed by HE staining. Results The expression of VEGF mRNA and protein in the lung tissue of rats in both groups decreased gradually on the 1st, 3rd and 7th day, the levels in the hyperoxia group were significantly lower than those in the air group, with no significant difference on the first day (P> 0.05) The difference between the two groups was statistically significant (P <0.05) at 7 days (P <0.05) ) (0.61 ± 0.12), VEGF protein (0.78 ± 0.33) vs (1.00 ± 0.16), 3 days (0.60 ± 0.08) vs 0.85 ± 0.27 (7 days vs 0.34 ± 0.12 vs 0.56 ± 0.18)]. Compared with the air group, the lung tissue in the hyperoxia group developed significantly dysplasia, the alveolar structure was simple, the number of alveoli was reduced, and the development of pulmonary microvascular was blocked. Conclusion VEGF plays an important role in lung development. The exact mechanism remains to be further studied.