氨茶碱和辛伐他汀对慢性阻塞性肺疾病大鼠气道炎症和气道黏液高分泌的影响

目的：观察氨茶碱和辛伐他汀对慢性阻塞性肺疾病(慢阻肺)的防治作用并从气道炎症和气道黏液高分泌角度探讨其作用机制。方法：采用烟熏和大鼠气管内注入脂多糖的方法建立慢阻肺模型。将40只雄性SD大鼠随机均分为对照组、慢阻肺组、氨茶碱组和辛伐他汀组。对照组和慢阻肺组用生理盐水1 mL/100 g灌胃，1次/d；氨茶碱组用氨茶碱溶液(5 g/L)1 mL/100 g灌胃，1次/d；辛伐他汀组用辛伐他汀溶液(0.5 g/L)1 mL/100 g灌胃，1次/d。用肺功能仪检测大鼠肺功能，HE染色观察大鼠支气管、肺组织病理变化，酶联免疫吸附(ELISA)法检测各组大鼠支气管肺泡灌洗液(BALF)中白细胞介素(IL)-8，IL-17及肿瘤坏死因子(TNF)-α含量，Western印迹法检测大鼠支气管肺组织中黏蛋白5AC和TLR4蛋白的表达，荧光实时定量(RT)-PCR检测大鼠支气管肺组织中黏蛋白5AC mRNA和TLR4 mRNA的表达。结果：慢阻肺组支气管、肺组织改变及肺功能变化符合慢阻肺病理生理特点。与对照组相比，氨茶碱组和辛伐他汀组支气管肺组织均出现不同程度的损伤，但损伤程度轻于慢阻肺组。慢阻肺组各项肺功能指标均明显低于对照组(均P<0.01)，而氨茶碱组和辛伐他汀组均明显高于慢阻肺组(均P<0.01)，辛伐他汀组呼气峰值流量明显高于氨茶碱组(P<0.01)。慢阻肺组BALF中IL-8，IL-17及TNF-α含量均明显高于对照组(均P<0.01)，而氨茶碱组和辛伐他汀组均明显低于慢阻肺组(均P<0.01)，氨茶碱组BALF中IL-8，IL-17及TNF-α含量均明显低于辛伐他汀组(均P<0.05)。慢阻肺组支气管肺组织黏蛋白5AC mRNA和TLR4 mRNA及其蛋白的表达水平均明显高于对照组(均P<0.01)；而氨茶碱组和辛伐他汀组均明显低于慢阻肺组(均P<0.05)，且两组间差异无统计学意义(均P>0.05)。结论：氨茶碱和辛伐他汀可降低慢阻肺模型大鼠BALF中IL-8，IL-17及TNF-α水平，抑制支气管肺组织中黏蛋白5AC和TLR4蛋白的表达，通过减轻气道炎症和气道黏液高分泌作用来达到防治慢阻肺的目的。

Effect of aminophylline and simvastatin on airway inflammation and mucus hypersecretion in rats with chronic obstructive pulmonary disease

Objective: To observe the role of aminophylline and simvastatin in preventing and curing chronic obstructive pulmonary disease (COPD), and to explore the underlying mechanisms based on airway inflammation and mucus hypersecretion. Methods: The rat model of COPD was established by combination of cigarette smoking with intratracheal lipopolysaccharide (LPS) injection. Male SD rats were randomly divided into 4 groups (n=10 per group): a control group, a COPD group, an aminophylline group and a simvastatin group. The rats in the control group and the COPD group were treated with normal saline once a day via intragastric administration, while the rats in the aminophylline group and the simvastatin group were treated with aminophylline (5 g/L) and simvastatin (0.5 g/L) 1 mL/100g once a day via intragastric administration, respectively. Pulmonary function and pathological changes in bronchus and lung were observed. The levels of IL-8, IL-17, and TNF-α in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). The mRNA and protein expressions of TLR4 and mucin 5AC (MUC5AC) in bronchi and lung tissues were detected by real-time PCR and Western blot, respectively. Results: Pulmonary function and the pathophysiologic changes in bronchi and lung tissues in the COPD rats were consistent with typical phenotype of COPD. Compared with the control group, lung function indexes were significantly attenuated in the COPD group, while the levels of IL-8, IL-17, and TNF-α in BALF as well as the mRNA and protein levels of MUC5AC and TLR4 were significantly increased. Compared with the COPD group, lung function indexes were significantly increased in the aminophylline group and simvastatin group (P<0.01), while pulmonary pathological damages, the levels of IL-8, IL-17, and TNF-α in BALF as well as the mRNA and protein levels of MUC5AC and TLR4 were significantly decreased (P<0.01). Compared with the aminophylline group, the peak expiratory flow as well as the levels of IL-8, IL-17, and TNF-α in the simvastatin group were elevated (P<0.05). There are no significant difference in the mRNA and protein levels of MUC5AC and TLR4 between the 2 groups (P﹥0.05). Conclusion: Aminophylline and simvastatin can decrease IL-8, IL-17, and TNF-α levels in BALF and inhibit the expression of MUC5AC and TLR4 in airway and lung tissues in COPD rats, suggesting that they may have a preventive and therapeutic effect on COPD through reducing the airway inflammation and mucus hypersecretion.