雾化吸入布地奈德干预肺纤维化大鼠及其机制的实验研究

Experimental study of inhaling budesonid in treating pulmonary fibrosis in rats and the possible mechanism

目的:探讨雾化吸入布地奈德对博莱霉素诱导的大鼠肺纤维化的影响及其可能机制。方法:45只SD雌性大鼠随机分为3组(各组15只):对照组、模型组和干预组,肺纤维化模型行气管内滴入博莱霉素造模。干预组造模后第7天雾化吸入布地奈德,模型组和对照组雾化吸入等量生理盐水,雾化后第7天、第14天、第28天各组随机处死5只动物并分别保存肺组织,HE和Masson染色判断肺组织肺泡炎及肺纤维化程度;免疫组化染色测定肺组织转化生长因子-β(transforming growth factor-β,TGF-β)、结缔组织生长因子(connective tissue growth factor,CTGF)的表达水平;RT-PCR检测Ⅰ、Ⅲ型胶原mRNA的表达水平。结果:肺组织病理学观察显示对照组肺泡炎和肺纤维化程度明显轻于模型组和干预组,干预组较模型组有明显改善;模型组和干预组肺组织中TGF-β和CTGF水平较对照组均有明显增高(P<0.05),但干预组较模型组表达减少(P<0.05);模型组Ⅰ、Ⅲ型胶原表达明显高于对照组(P<0.05),而干预组较模型组表达明显减少(P<0.05)。结论:布地奈德具有明显的抗纤维化作用,机制可能为通过抑制细胞因子的表达而减少肺组织中Ⅰ、Ⅲ型胶原的生成,最终抑制肺纤维化。

Objective：To investigate the effects and the possible mechanism of inhaling budesonid in treating bleomycin-induced pulmonary fibrosis in rats. Methods：Forty-five SD rats were randomly divided into three groups（15 in each group）：control group,model group and intervention group. Rats in intervention group inhaled budesonid every two days from the 7th d after intratracheal instillation while those in model group and control group inhaled the same volume of 0.9% normal saline. Five rats in each group were randomly killed on the 7th,14 th,28th d after atomizing inhalation and the pulmonary tissues were preserved respectively. HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis. Immunohistochemical technique was used to evaluate the level of transforming growth factor-β（TGF-β）and connective tissue growth factor（CTGF）in lung tissues. RT-PCR was used to detect the level of type Ⅰ and Ⅲ collagen in pulmonary tissues. Results：Pulmonary tissue pathology showed that the extent of alveolus inflammation and pulmonary fibrosis was less intense in control group than in model group and intervention group and was better in intervention group than in model group. Significant over-expressions of CTGF and TGF-β were shown in pulmonary tissues of rats in model group and intervention group（higher expressions in model group than in intervention group,P〈0.05）compared with those in control group（P〈0.05）. Expressions of type Ⅰ and Ⅲ collagen were significantly higher in model group than in control group（P〈0.05）,but lower in intervention group than in model group（P〈0.05）. Conclusion：Budesonid has anti-fibrosis potency,the mechanism of which may be reducing the production of type Ⅰ and Ⅲ collangen through inhibiting the expressions of cytokines such as TGF-β and CTGF.