The changes of transforming growth factor-β1 in pulmonary fibrosis induced by paraquat in mice1 / 中华急诊医学杂志

ABSTRACT

Objective To study the changes of transforming growth factor-β1(TGF-β1) in pulmonary fibrosis induced by paraquat (PQ) with immunohistochemistry method. MethodsA total of 58 C57BL/6J male mice were randomly (random number) divided into the experimental group and control group. Pulmonary fibrosis was induced by intra-peritoneal injection of PQ in dose of 10 mg/kg into the mice of experimental group (n = 48), while physiological saline was used instead in mice of control group (n = 10). The mice of experimental group were sacrificed 2, 5, 7 and 14 days after PQ poisoning and the mice of control group were sacrificed on the 7th day after saline administration. Lungs of mice were taken and histological changes in lungs were evaluated by haematoxylin-eosin stain, and TGF-β1 was determined with immunohistochemistry method. The integrated optical density (iOD) value of TGF-β1 was measured and analyzed. ResultsThe TGF-β1 was markedly increased in macrophages during the genesis of pulmonary fibrosis induced by PQ. As the course of fibrosis progressed, the positive staining of TGF-B1 was mainly seen in macrophages and neutrophil's cytoplasm. On the 14th day after PQ poisoning, TGF-β1-positive cells were also detected in the fibroblast and myo-fibroblast inside the fibroblastic foci. Compared with the control group, the iOD value of TGF-β1 increased in experimental group (P ＜ 0. 01 ) and it gradually upgraded during the course of fibrosis. Conclusions The TGF-β1 significantly increased during the course of pulmonary fibrosis induced by PQ and played an important role in the pathogenesis of the disease.