肺间质纤维化大鼠肺组织α平滑肌肌动蛋白及Ⅰ型胶原的表达

Expression of α-smooth muscle actin and Ⅰ-collagen in lung tissues of pulmonary interstitial fibrosis rats

目的探讨α平滑肌肌动蛋白（α-smooth muscle actin，α—SMA）在肺间质纤维化中的意义。方法将64只Wistar大鼠随机分为对照组和博莱霉素模型组。在第3天、第7天、第14天和第28天，HE染色观察大鼠肺组织结构的改变，免疫组织化学法测定肺组织α—SMA和Ⅰ型胶原的表达，同时用流式细胞术检测肺组织单细胞悬液α—sMA的相对含量。结果博莱霉素模型组大鼠肺组织α—SMA和Ⅰ型胶原的表达在各时间段均高于对照组（P〈0．05），并且两种因子表达呈正相关。同时，博莱霉素模型组各时间段两种因子测定结果均结果的差异有统计学意义（P〈0．05）。结论肺间质纤维化大鼠肺组织α—SMA表达增高，预示肌纤维母细胞的形成，导致Ⅰ型胶原堆积。从而引起肺纤维化。

Objective To investigate the expression of α-smooth muscle actin （α-SMA） and Ⅰ -cgllagen（col- Ⅰ） in pathogenesis of pulmonary interstitial fibrosis. Methods Sixty-four Wistar rats were divided into two groups, control group： instilled normal saline into trachea and bleomycin（BM） group： instilled BM into trachea. The course was sacrificed 3,7,14,28 days and at each time-point, the lung tissue morphological changes were examined by histopathology, α-SMA and col-Ⅰexpressions were studied by immunohistochemistry. Flow cytometry was utilized to quantitatively detect the precision of α-SMA in a cell suspension of lung tissues. Results At all time-points, lung tissues of α-SMA and col-Ⅰ increased significantly in BM group than that in control group （ P 〈 0.05）. Expression of col- Ⅰwas positively correlated with that of α-SMA. There was significant difference between expression of α-SMA and that of col- Ⅰ in BM group at all time-points（ P 〈0.05）. Conclusions The increase of α-SMA in pulmonary tissues of BM-indueed pulmonary fibrosis rats suggests the formation of myofibroblast, which may be involved in accumulation of col Ⅰand contributed to pulmonary fibrosis.