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

Objective: 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 (r=0.7828, P<0.01; r=0.5852, 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 alpha-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.