Abstract: ObjectiveTo explore the changes of N-terminal propetide of typeⅢprocollagen(P Ⅲ NP),laminin(LN), and transforming growth factor-β1(TGF-β1)plasma in rats with pulmonary fibrosis induced by uranium dusts.MethodsSixty adult Wistar rats were divided randomly into control group(30 rats)and uranium dust group(30 rats).The intratracheal instillation method was used.Uranium dust group was exposed to 20mg/ml uranium dust suspension 1ml per rat,meanwhile control group was exposed to normal saline 1ml per rat.On the day of 7,14,21,30,and 60 after the exposure,6 rats in each group were killed and the peripheral blood samples were collected at same time.The levels of LN and P Ⅲ NP in plasma were detected by radioimmunoassay and the level of TGF-β1 in plasma was measured with enzyme-linked immunosorbent assay.ResultsIn the development of pulmonary fibrosis induced by uranium dust,the contents of P Ⅲ NP,LN,and TGF-β1 in plasma were increased significantly at 21,30,and 60 days after the uranium dust exposure.On the day of 21,30,and 60 after the uranium exposure,the contents of P Ⅲ NP were 17.90±1.55,19.06±1.62,and 20.09±1.65 ng/ml;the contents of LN were 81.81±1.32,83.64±1.52,and 84.73±2.20 ng/ml and the TGF-β1 were 34.03±3.21,46.65±3.09,and 40.95±3.18 pg/ml,respectively.The the contents of P Ⅲ NP,LN,and TGF-β1 were significantly higher compared with those in the control group(P<0.01).The changes of P Ⅲ NP and LN contents were associated with the development of pulmonary fibrosis.ConclusionIn uranium dust-induced lung fibrosis of rats,the contents of P Ⅲ NP,LN,and TGF-β1 in plasma increase significantly.