中文摘要：

目的 研究联合使用血管内皮生长因子（VEGF）和地塞米松对胎鼠肺泡Ⅱ型细胞发育和肺泡表面活性物质结合蛋白B（SP-B）表达的影响，为防治早产儿呼吸窘迫综合征寻找新途径。方法 取孕20d的Wistar大鼠剖腹取胎鼠，原代培养肺泡Ⅱ型细胞，将所得肺泡Ⅱ型细胞分成4组，分别加入VEGF、地塞米松、VEGF＋地塞米松、空白培养液（即时照组），孵育后测定各组胎鼠肺泡Ⅱ型细胞VEGF及其受体Flt-1、Flk-1和SP-B。结果 VEGF组、地塞米松组与VEGF＋地塞米松组SP-B均阳性表达，对照组SP-B阴性表达；VEGF组与VEGF＋地塞米松组VEGF、Flt-1、Flk-1阳性表达，地塞米松组VEGF、Flt-1、Flk-1阴性表达。结论 VEGF能促进肺泡发育和肺表面活性物质SP-B的合成与分泌。拮抗地塞米松下调肺泡Ⅱ型细胞受体表达的作用。

英文摘要：

Objective To study t-he effects of vascular endothelial growth factor （VEGF） combined with dexamethasone on expression of pulmonary surfactant protein B so as to explore a new route to prevent and cure respiratory distress syndrome （RDS） in premature infants. Methods Rat embryos were got from Wistar rats at 20 days gestation period. Primary cuhure of AEC Ⅱ was done. The experiment was divided into VEGF group, dexamethasone group, VEGF plus Dexamethasone group and control group to determine the amount of VEGF with its receptors Flt-1 and Flk-1 and expression of pulmonary surfactant protein B by immunology histochemistry. Results SP-B showed prositive expression in VEGF group, dexamethasone group and VEGF plus dexamethasone group. Control group showed negative expression of SP-B. VEGF group and VEGF plus dexamethasone group showed positive expression of VEGF, Flt-1 and Flk-1. Dexamethasone group showed negative expression of VEGF, Flt-1 and Flk-l. Conclusion VEGF can promote the synthesis and secretion of pulmonary surfactant protein B and antagonise the underregulation of AEC Ⅱ receptors expression by dexamethasone. VEGF and dexamethasone can improve the function of pulmonary epithelial ＇ceils through promoting the expression of pulmonary suffactant protein B.