高氧致新生鼠肺结构及VEGF的变化及相关分析

Change of lung structure and expression of vascular endothelial growth factor protein in neonatal rats with hyperoxia

目的探讨新生大鼠高氧肺损伤后肺组织结构,血管密度及VEGF蛋白的表达变化及相关性。方法新生Sprague-Dawley大鼠72只随机分为高氧实验组和空气对照组,高氧组吸入95%高氧建立高氧肺损伤模型。分别采用HE染色和免疫组化法观察新生大鼠3d、7d、14d肺组织形态改变并作肺泡辐射状记数(Radial alveolar countsRAC),检测Ⅷ因子及VEGF蛋白表达。结果对照组大鼠生后随着肺发育,肺泡化逐渐完善,RAC计数、VEGF蛋白及Ⅷ因子表达逐渐增加。高氧组随着吸氧时间延长RAC计数、肺组织VEGF蛋白及Ⅷ因子表达均出现降低,并出现肺泡化阻滞,VEGF与Ⅷ因子始终具有相关性。结论 VEGF促进新生大鼠肺发育,新生大鼠高氧可抑制VEGF及Ⅷ因子在鼠肺内的表达,致肺泡化阻滞,出现类似早产儿支气管肺发育不良的肺组织形态学特征,VEGF在新生鼠肺发育和高氧肺损伤机制中起重要作用。

Aim To explore the changes of lung structure and expression of VEGF protein and factor Ⅷ, density of blood vessels and the correlation. Methods Seventy-two Sprague-Dawley neonatal rats were randomly continually exposed to hyperoxia （FIO2=95%） or room air （FiO2=21%,eontrol group） 30 minutes after birth. Histological study of the lung tissue and radical alveo]i count （RAC） were carrided out, and VEGF protein and factor Ⅷ expressed in the lungs were determindod by immunohistochemical methods respectively 3,7 and 14 days after birth. Results Alveolarization gradually makes progress,radical alveolar counts and VEGF protein and factor Ⅷ expression increased with increasing postnatal age in the control group. In the hyperoxia exposure group alveolarization were arrested,The expression of RAC and VEGF protein and factor Ⅷ was significantly reduced. The level of VEGF was correlated with that of factor Ⅷ . Conclusions VEGF is associated with lung development in neonatal rats. The expression of VEGF protein and factor Ⅷ in lungs of neonatal rats is inhibited after exposed to hyperoxia.