Ⅲ型胶原纤维在实验性特发性肺纤维化早期的动态研究

Expression of type Ⅲ collagen in bleomycin-induced pulmonary fibrosis

目的 通过动物实验的方法 ,动态地观察Ⅲ型胶原在平阳霉素诱导的兔肺纤维化中的变化。方法 12只新西兰白兔 ,在经支气管内灌注平阳霉素诱导纤维化模型之后的第 7、14、2 1和 2 8天 ,分别随机取 3只处死 ,分离两侧肺组织取材进行免疫组化染色分析。结果 与正常对照组比较 ,尽管第 1、2周时肺内的改变均以炎性渗出和实变为主 ,但可在增厚的肺泡隔内发现散在的点状、线状红棕色增生Ⅲ型胶原。 3、4周后随炎性反应进行性减弱 ,被染色的Ⅲ型胶原反而显著地进行性增多 ,在病变区形成杂乱的网格样分布。而且Ⅲ型胶原免疫组化染色对胶原显示的敏感性显著高于VG染色。结论 纤维化的早期胶原沉积以Ⅲ型胶原的增生为主 ,大量Ⅲ型胶原的沉积表明纤维化处于活动阶段或早期状态 ,从此意义上这个观察过程均可称作早期阶段。这对于临床通过穿刺组织分析来评价疾病的发展是非常有价值的。

Objective To observe and analyze dynamically the changes of type Ⅲ collagen in experimental pulmonary fibrosis. Methods Pulmonary fibrosis was induced in 12 rabbits by intratracheal instillation of bleomycin, and other 8 were taken as control group. On day 7, 14, 21 and 28, respectively, the lungs from 3 rabbits chosen randomly underwent immunohistological DAB staining. Results As compared with the normal control group, in the 1st and 2nd week, the pulmonary lesions were mainly inflammation and consolidation, but within the thickened alveolar septum, there were presence of dot-like, linear brownish proliferation collagen type Ⅲ. After the 3rd and 4th week, the inflammatory reaction appeared progressively diminished, the stained type Ⅲ collagen increased significantly and became the predominant feature. Moreover, the immunohistologicaly stained type Ⅲ collagen showed a higher sensitivity over VG stain. Conclusion In the early stage of fibrosis, the collagen deposited is mainly type Ⅲ collagen, massive deposition of type Ⅲ collagen indicates the fibrosis is still in its early active stage,which can be evaluated through biopsied material and assessed the progression of the lesion or disease.