Objective To construct a rat model of chronic obstructive pulmonary disease (COPD) by smoking method, protease infusion and a combination of the two methods, and evaluate the effect of the model from the aspects of inflammation, imaging and pathology. Three modeling methods are compared.
Method Using smoking, protease instillation and a combination of the two methods to make COPD rats, each group of rats were 60, 30, and 30 rats, and a control group was set up with 20 rats. The weight of the rats is measured weekly. Rats in the smoked group and control group were modeled for 24 h, 1, 2, 4, 8, 12, 16, 20, and 24 weeks, and rats in the protease group and protease + smoked group were modeled for 24 h, 1, 2 , 4, 8, 12 weeks to receive cytokine testing, Micro-CT examination and pathological examination. Analysis of variance or Kruskal-Wallis H test was used for statistical analysis.
Results From the 7th week, the weight gain of the rats in the smoking group and the protease + smoking group was significantly slower than that in the control group (P<0.05). The levels of interleukin-10 in the protease group and the protease + smoking group at 24 h, 1, 2, and 4 weeks were significantly lower than those of the control group (P<0.05). The concentration of matrix metalloproteinase-9 in the protease group and the protease+smoke group at 24 h was significantly higher than that of the control group (P<0.05). In the protease group, protease+smoke group at the 4th week and the smoked group at the 8th week, the changes of emphysema can be observed on the Micro-CT images and pathological images.
Conclusion The use of smoking, protease and protease + smoking methods can successfully construct a rat COPD model. Micro-CT can sensitively and truly reflect the pathological changes of the lungs.