血管生成因子修复肺气肿病变的实验研究

目的 观察碱性成纤维细胞生长因子（bFGF）和血管内皮生长因子（VEGF）对大鼠肺气肿模型动脉血气和肺组织病理学的影响,探讨bFGF、VEGF修复肺泡的机制及肺气肿新的发病机制。方法 Wistar大鼠24只,随机分为bFGF组、VEGF组、对照组和健康对照组4组。bFGF组、VEGF组、对照组大鼠气管内一次性注入猪胰弹性蛋白酶（PPE）（250U／kg）复制肺气肿模型,健康对照组以生理盐水对照,4周后模型制成,bFGF组、VEGF组气管内分别注入bFGF（400U／只）和VEGF（2μg/只）,对照组和健康对照组注人生理盐水,每周1次,连续3次。4周后对比大鼠动脉血气和肺泡形态学变化,免疫组化法检测CD34’细胞个数确定肺毛细血管增生情况。结果各组血气分析差异均无统计学意义;bFGF组、VEGF组平均肺泡数（MAN）分别为（43±8）／视野、（44±9）／视野],均明显多于对照组（30±6）／视野]（P〈0．01）;平均肺泡面积（MAA）分别为（9856±1864）μm^2、（9804±1929）μm^2,均明显小于对照组（14525±3408）μm^2]（P〈0．01）;平均内衬间隔（MLI）分别为（196±38）μm、（194±38）μm,均明显小于对照组（288±68）μm]（P〈0．01）;CD34’阳性细胞相对面积分别为3．7％±1．3％、2．6％±1．2％,均明显多于对照组（0．8％±0．7％）（P〈0．05）。结论 bFGF和VEGF能促进肺毛细血管再生,修复肺气肿的病变。肺毛细血管的损伤可能在肺气肿的发生发展中扮演了重要角色。

Restoration of pathological changes of emphysema by angiogenesis factors: experiment of rats

OBJECTIVE: To investigate whether intratracheal administration of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) restore the pulmonary function and pathology in emphysema, and research the mechanism of they restored pulmonary emphysema, and the pathogenesis of pulmonary emphysema. METHODS: Twenty-four Wistar rats were randomized into the 4 equal groups: bFGF group receiving a single intratracheal instillation of porcine pancreatic elastase (PPE) 250 U/kg, and 4 weeks later receiving intratracheal instillation of bFGF 400 U once a week for 3 weeks), VEGF group (receiving a single intratracheal instillation of PPE 250 U/kg, and 4 weeks later receiving intratracheal instillation of VEGF 2 microg once a week for 3 weeks), control group receiving a single intratracheal instillation of PPE 250 U/kg, and 4 weeks later receiving intratracheal instillation of normal saline (NS) once a week for 3 weeks], and normal group (receiving intratracheal instillation of NS in above-mentioned pattern). Four weeks after treatment, arterial blood sample was collected from the abdominal aorta to undergo blood gas analysis for assessment pulmonary function, and then the rata were killed with their lungs taken out to undergo pathological examination. Immunohistochemistry was performed to detect the CD34, markers of pulmonary capillary endothelial cells. RESULTS: There were no significant differences in the artery blood gas analysis among the four groups (all P > 0.05). The levels of mean alveoli number (MAN) of the bFGF and VEGF groups were (43 +/- 8)/HP and (44 +/- 9)/HP] respectively, both significantly higher than that of the control group (30 +/- 6)/HP, both P < 0.01]. The levels of mean linear intercept (MLI) of the bFGF and VEGF groups were (196 +/- 38) microm and (194 +/- 38) microm respectively, both significantly lower than that of the control group (288 +/- 68) microm, both P < 0.01). the mean alveoli area (MAA) level of the bFGF and VEGF groups were (9856 +/- 1864) microm(2) and (9804 +/- 1929) microm(2) respectively, both significantly lower than that of the control group (14,525 +/- 3408) microm(2), both P < 0.01]. The percentages of CD34(+) cells of the bFGF and VEGF groups were (3.7 +/- 1.3)% and (2.6 +/- 1.2)% respectively, both significantly higher than that of the control group (0.8 +/- 0.7)%, both P < 0.05). CONCLUSION: bFGF and VEGF can restore the pathological changes of experimental emphysema. The damage of pulmonary capillary may play an important role in the pathogenesis of pulmonary emphysema.