Abstract：Objective To observe the effects of hyperoxia exposure on pulmonary inflammatory response and fibrosis in new born mice. Methods 40 Kunming mice aged 2 days were randomly divided into air group (n = 20) and hyperoxia group (n = 20), reared in air or (60±5)% oxygen respectively. The mice were examined daily and the weight was recorded the next day. At the 3rd, 7th, 14th, 21st day of the experiment, 5 mice of each group were sacrificed respectively, then the appearance of lung tissue, lung wet/dry weight ratio were observed; the pathological structure of lung tissue was examination by HE staining; collagen fiber of lung tissue was examination by Sirius red staining. Results ①No mouse died in the two groups during the experiment. The weight of mousein hyperoxia group was significantly was lower than that of air group at the 7th day after exposured to oxygen, the difference was statistically significant (P < 0.01). ②The ratio of lung wet/dry weight in hyperoxia group was higher than that in air-group begin the 7th day after hyperoxia exposured, the difference was statistically significant (P < 0.05 or P < 0.01). ③In hyperoxia group, with the time of exposured to oxygen increasing, lung structure showed typical BPD: alveoli showed irregular structure, interstitial was large, partial alveoli fused, alveolar count decreased, partial region occured inflammatory closed; at the 14th, 21st day after hyperoxia exposured, RAC in hyperoxia group was lower than air group, the difference was statistically significant (P < 0.01). ④Compared with air group, collagen area in hyperoxia-group increased at yhe 7th, 14th, 21st day after hyperoxia exposured. Conclusion BPD micemodels were successfully produced by sustained hyperoxia exposure. Sustained hyperoxia exposure may increase lung inflammation and fibrosis in neonatal mice, which may be an important mechanism for the development of BPD.
2017, Vol. 14 
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