矽肺大鼠肺内淋巴管增生与纤维化进程的关系
Relationship Between Lymphatic Hyperplasia and Fibrosis Process in Silicotic Rats
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摘要:
目的 探讨矽肺发病过程中肺内淋巴管增生与纤维化进程的关系。
方法 56只Wistar大鼠随机分为矽肺模型组和对照组,模型组又按动物处死时间分为1、7、14、28、42和56 d 6个亚组,每组8只大鼠。采用墨汁-硝酸银染色观察淋巴管增生情况,实时荧光定量PCR方法检测VEGFR-3 mRNA转录水平,免疫组化法、比色法检测肺组织中Ⅰ型胶原表达及羟脯氨酸含量。
结果 与对照组相比,矽肺大鼠肺组织中Ⅰ型胶原从染尘后1 d、羟脯氨酸含量从染尘后7 d即开始升高(
P < 0.05或P < 0.01);从染尘7 d开始发现增生的淋巴管,且随着染尘时间的延长,淋巴管增生呈现先增多后减少的趋势;VEGFR-3 mRNA表达在染尘后7 d开始增加(P < 0.01)。Pearson相关性分析显示在染尘早期,即28 d以前,Ⅰ型胶原含量、羟脯氨酸含量与VEGFR-3水平呈正相关(r =0.974 4,P =0.025 6;r =0.998 5,P =0.001 5),染尘28 d后Ⅰ型胶原含量、羟脯氨酸含量与VEGFR-3水平呈负相关(r =-0.975 1,P =0.024 9;r =-0.974 4,P =0.025 7)。结论 矽肺大鼠发病过程中出现肺组织淋巴管增生,其增生程度与矽肺纤维化具有相关性。
Abstract:Objective To assess relationship between lymphatic hyperplasia and fibrosis process in silicosis pathogenesis.
Methods Fifty-six Wistar rats were randomly divided into control and silicosis model group. The silicosis model group was further divided into subgroups as 1, 7, 14, 28, 42, and 56 d by animal neutralization time, eight rats in each group. Ink-silver nitrate staining was used to observe lymphatic hyperplasia. The level of mRNA transcription of vascular endothelial growth factor receptor-3(VEGFR-3) was determined by real-time quantitative PCR; the levels of collagen Ⅰ and hydroxyproline(HYP) were detected by fluorescence and immunohistochemistry staining.
Results Compared with the control group, collagen Ⅰ in the lung tissue rose up significantly from 1 d(
P < 0.05) and HYP from 7 d(P < 0.01) after silica exposure. Pulmonary lymphatics hyperplasia was found in the silicotic rats after 7 d of silica exposure, and along with the extension of exposure time, it was increased first and then decreased. The mRNA expression of VEGRF-3 was increased significantly from 7d(P < 0.01) after silica exposure. The results of Pearson correlation analysis showed that the contents of collagen Ⅰ and HYP were positively correlated with the level of VEGRF-3 before 28 d of silica exposure(r =0.974 4,P =0.025 6;r =0.998 5,P =0.001 5) and negatively after 28 d(r =-0.975 1,P =0.024 9;r =-0.974 4,P =0.025 7).Conclusion Lymphatic hyperplasia occurs in lung tissue during the process of silicosis, and the severity is associated with silicotic fibrosis process.