高氧致慢性肺疾病新生大鼠肺泡损伤及肺泡上皮细胞的变化

Objective To explore the changes of alveolar morphology and alveolar epithelial cells in rats with hyperoxia-induced chronic lung diseases (CLD). Methods CLD model in neonatal rats was established by inhalation of high concentration oxygen(85%～90% ). Eighty neonatal rats were randomly exposed to hyperoxia (model group) and to room air (control group) (n =40 each). Radical alveolar counts and the alveolar septum thickness were used to evaluate alveolar development. The site and intensity of expression of SPC,AQP5 protein were detected by immunohistochemical staining,the dynamic expression of SPC mRNA,AQP5mRNA was detected by RT-PCR on day 1,3,7,14 and 21 after exposure. Results There were no significant differences about alveolar wall thickness and RAC between experimental groups and control group on day 1～3 ( P > 0. 05 ). But there was significant difference between the model group and the control groups on day 7 and 14 (P <0. 01 ). For model group,alveolar septum thickness peaked on day 21, the difference was significant compared with control group ( 10. 62±5.01 vs 3.62±0. 88, P < 0. 001 ), but RAC decreased to the lowest level, the difference was significant compared with control group ( 3.57±1.24 vs 10. 47±0. 88,P <0. 001 ). The expression of SPC decreased on day 3 manifestedly but increased on day 7 and the levels of SPC were higher than that in the control group. Experimental group showed gradual decrease in AQP5 expression as the lung impairment devastated. Conclusion Alveolar development was delayed and alveolar epithelial cell (AEC) was damaged in the neonatal CLD rats. The changes of SPC,AQP5 expression suggested AECI was severely damaged and failed in full recovery, meanwhile the quantity of AEC Ⅱ was increased but the ability of its differentiation and transformation was decreased.

Alveolar damage and the alveolar epithelial cell change in neonatal rats with chronic lung disease induced by hyperoxia