哮喘大鼠气道细胞DNA合成和气道重塑关系的实验研究

目的研究哮喘动物气道细胞的DNA合成和气道重塑以及二者之间的关系。方法建立大鼠哮喘模型,采用双标免疫组化技术和计算机图像分析系统对气道细胞的DNA合成和气道重塑进行研究。结果 （1）哮喘组气道平滑肌细胞和上皮细胞的DNA合成BrdU阳性计数明显高于对照组（P<0.01,P<0.05）;（2）哮喘组气道平滑肌细胞和上皮细胞DNA合成Brdu阳性计数和气道直径呈高度正相关（P<0.01,P<0.05）,对照组无明显相关性（P<0.05,P<0.05）;（3）哮喘组气道上皮层厚度明显大于对照组（P<0.01）,平滑肌层厚度、气道直径和α-平滑肌肌动蛋白阳性区面积和对照组无显著性差异（P>0.05）。结论变态反应性炎症所导致的气道细胞DNA合成增加以及细胞增生,可能是引起气道重塑反应发生的重要原因。

Experimental study of DNA synthesis in the airway cells and airway remodeling in asthmatic rats

Objectives To study the DNA synthesis in the airway cells of asthmatic rats after allergen stimulation in association with airway remodeling. Methods Double staining immunohistochemical techniques was used to determine DNA synthesis of the airway cells of 12 asthmatic and 12 normal rats. BrdU incorporation into the airway smooth muscle (ASM) and epithelium was quantified by employment of computer-assisted image analysis. Results BrdU indices in both the ASM and the epithelium of asthmatic model group were higher than those of the control group (P<0.01, P<0.05), and positive linear correlation of the BrdU indices in the ASM and epithelium with the airway diameter was observed (7=0.7828, P<0.01; r=0.5 852, P<0.05), which was not found in the control group (r=-0.3755, P>0.05; r=-0.5208, P>0.05). The epithelial thickness of the model group was significantly greater than that of the control group (P<0.01). There was no significant difference in terms of airway diameter, thickness of the ASM and the area positive of a-smooth muscle actin between the 2 groups (P>0.05). Conclusion Increased DNA synthesis and accelerated proliferation of ASM and epithelial cells in sensitized SD rats following repeated allergen challenges may lead to airway remodeling.