Establishment of a Mouse Model of Pulmonary Fibrosis by Intravenous Administration of Bleomycin

Objective To establish a C57BL/6 mouse model of pulmonary fibrosis with bleomycin and observe the pathologic changes of lungs in the model mice.Methods Sixty six C57BL/6 mice(female,8 wk of age,17 to 20 g body weight) were randomly divided into BLM80 group,BLM150 group,BLM300 group and control group,which received intravenous injection of bleomycin in a dose of 80 mg/kg,150mg/kg,300mg/kg and normal saline via the tail vein,respectively.Results(1) The mice lost 16% and 35% of their body weight after 80 mg/kg and 150 mg/kg bleomycin injection,respectively.(2) The survival rate of BLM80 group,BLM150 group,BLM300 group and control group was 100%,43%,0 and 100%,respectively.(3) At 14 and 28 days after injection,the hydroxyproline content per lung in the BLM150 group was 738±46 nmol and 886±83 nmol,respectively,significantly increased than that in the control group(360±75 nmol)(P0.01).(4) At 28 days after bleomycin injection,fibrosis was widely and stably formed in the subpleura and perivascular area in the mouse lungs of BLM150 group.The pathological scores of pulmonary fibrosis in BLM150 group were significantly higher than those in BLM80 and normal groups(P0.001,respectively).Conclusions Pulmonary fibrosis model has been successfully established by intravenous injection of bleomycin once in a dose of 150 mg/kg in C57BL/6 mice.