Significance of transforming growth factor β_1 expression in the lung of neonatal premature rats exposed to hyperoxia

Objective To study transforming growth factor β_1 (TGF-β_1) expression in the lung of neonatal premature rats exposed to hyperoxia at different time. Methods 99 neonatal premature rats were assigned to hyperoxic group and air group randomly They were sacrificed at the postnatal 3 rd ,7 th and 14 th day,then their lungs were achieved for H.E staining and immunohistochemistry to measure the expression of TGF-β_1. The difference of TGF β_1 expression were tested by rank-sum test. Results TGF-β_1 expression in hyperoxic group was always wider than that of air group at the corresponding period,and its expression in alveolar and bronchi epithelial cells as well as mesenchymal was stronger than that of control group(u respectively is: 49.0、14.0、63.0 at the 3 rd day;34.0、2.0、45.0 at 7 th day;and 32.0、13.5、33.0 at 14 th day (all P0.05). TGF-β_1 in alveolar macrophages could only be observed on the postnatal 14 th day hyperoxic group. The u between two groups was 13.0 and P0.05. Conclusion It is possible that stronger TGF-β_1 expression in the lung and its expression in alveolar macrophages has relationship with lung injury induced by hyperoxia.