VEGF和PCNA在慢性低氧性肺动脉及高压大鼠主动脉、肺动脉平滑肌细胞中表达

目的研究慢性低氧性肺动脉高压(PAH)发生过程中,血管内皮生长因子(VEGF)及细胞核增殖抗原(PCNA)在体循环血管、肺循环血管平滑肌细胞中的表达。方法利用低压缺氧舱建立大鼠缺氧性肺动脉高压模型。实验分为3组即正常氧组、缺氧2wk组和缺氧3wk组。用免疫组化染色和图像分析,检测主动脉、肺动脉主干及肺内小动脉平滑肌细胞中VEGF及PCNA的表达量。结果VEGF在正常氧组大鼠的主动脉、肺动脉主干及肺内小动脉平滑肌内均有表达;缺氧组大鼠肺动脉主干及肺内小动脉平滑肌细胞内VEGF的表达明显增强并随着缺氧时间的延长而增加;主动脉平滑肌内VEGF的表达量无明显变化。PCNA在正常氧组大鼠的主动脉、肺动脉主干及肺内小动脉平滑肌内均有微弱表达;但缺氧时只有肺小动脉平滑肌内其表达量增加;主动脉、肺动脉主干平滑肌内PCNA的表达量无明显差别。结论在缺氧性肺动脉高压的发生过程中,VEGF在体循环血管、肺循环血管平滑肌细胞中的表达量具有差异性,提示其可能在肺动脉高压形成过程中起重要作用。

Different expression and significance of VEGF and PCNA in aorta and pulmonary artery smooth muscle cells of rats with hypoxia pulmonary hypertension

AIM: To study the expression of vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA) in aorta and pulmonary artery smooth muscle cells of rats with hypoxia pulmonary hypertension (HPH). METHODS: The rat chronically HPH models were set up in the hypobaric hypoxia cabin. The experimental rats were divided into 3 groups: control group (rearing in a normoxia environment), two hypoxia groups (oxygen-deficient time being 2 weeks and 3 weeks, respectively). Expression of VEGF and PCNA were detected by immunohistochemical staining and image analysis. RESULTS: There was VEGF expression in vascular smooth muscle cells of aorta, pulmonary artery trunk and pulmonary arteriole in control group. In two hypoxia groups VEGF expression in vascular smooth muscle cells of pulmonary artery, trunk and pulmonary arteriole increased significantly, while no difference was found in smooth muscle cells of aorta. Expression of PCNA was very little in vascular smooth muscle cells of aorta, pulmonary artery trunk and pulmonary arteriole in control group. In two hypoxia groups, the PCNA expression increased only in vascular smooth muscle cells of pulmonary arteriole; there was no difference of PCNA expression in vascular smooth muscle cells of aorta and pulmonary artery trunk between hypoxia groups and control group. CONCLUSION: There is difference of VEGF expression in pulmonary artery trunk and aorta smooth muscle cells during the formation of chronic HPH, suggesting that VEGF expression may play very important role in the formation of chronic HPH.[