中文摘要：

目的：探讨血管内皮生长因子（VEGF）在低氧性肺动脉高压形成中的意义及多黏菌素B（PMB）对其的影响。方法：将30只SD大鼠分成正常对照组（N组）、低O2高CO24w组（F组）、低O2高CO24w＋PMB组（P组），观察各组大鼠肺动脉平均压（InPAP）、右心室重量比（RV／LV＋S）、肺小动脉管壁面积／管总面积（WA／TA）、中膜厚度（PAMT）及超微结构，用ELISA法检测血清和肺组织VEGF含量，免疫组化法检测肺组织VEGF、蛋白激酶C（PKC）表达的变化。结果：①F组大鼠mPAP、RV／LV＋S、血清和肺组织VEGF的含量明显高于N组（P〈0．01），P组则低于F组（P〈0．01）。②病理显示F组WA／TA、PAMT较N组增高（P〈3．01），内弹力板扭曲明显，胶原纤维增多，中膜平滑肌细胞增生。P组大鼠血管壁的改变明显减轻。③F组大鼠肺细小动脉VEGF蛋白及PKC的表达与N组比较明显增加（P〈0．01），而P组与F组比较，则明显降低（P〈0．05，〈0．01）。结论：低氧诱导肺动脉VEGF的增加，后者参与了慢性低氧性肺动脉高压的形成，PKC可能是低氧时上调VEGF表达的重要因素。

英文摘要：

To explore the roles of vascular endothelial growth factor （VEGF） in hypoxia pulmonary hypertension and effect of Polymyxin B（PMB）. Methods： Thirty SD rats were randomly divided into normal control group （N）, hypoxia hypercapnia group（F）, hypoxia hypercapnia ＋PMB group （P）. The levels of VEGF in serum and in lung tissue were measured with ELISA; the pathology of pulmonary arterioles was observed under light microscopy, electron microscopy and image analysor; the expression of VEGF,PKC were observed by immunohistochemistry. Results：①Mean pulmonary arterial pressure（mPAP）, weight ratio of RV to LV＋S, the leves of VEGF in serum and in lung tissue of group F were significantly higher than those of group N and group P （P〈0.01）.②Pathological changes showed that vessel wall area/total area（WA/TA）, thickness of tunica media of pulmonary arterioles （PAMT）were much higher in rats of group F than those of group N and group P （P〈0.01）; proliferation of smooth muscle cells and collagenous fibers of pulmonary arterioles in rats of group F and PMB could reverse the changes mentioned above.③VEGF and PKC in pulmonary arterioles were significantly higher in rats of group F than that of group N（p〈0.01）, they were significantly decreased in rats of group P than that of group F （p〈0.05,〈0.01）. Conclusion： Hypoxia strongly stimulates the production of VEGF in pulmonary arterial vascular,which plays an important role in the process of hypoxia pulmonary hypertension, and hypoxia-induced PKC activation is one kind of basic mechanisms in this course.