Airway Hyperresponsiveness In A Rat Model Of Bleomycin-induced Pulmonary Fibrosis

Objective:To explore cyclosporin A aerosol for anti-airway hyperresponsiveness in bleomycininduced pulmonary fibrosis and discuss the potential implication of TGF-β₁ and TNF-αon the development of AHR in a rat model of bleomycin-induced pulmonary fibrosis.Method:Thirty-six male healthy wistar mice were divided equally into 3 groups:group A as con trol,group B treated with bleomycin,and group C treated with cyclosporin A aerosol.Hydroxyproline (HYP)in lung tissue,serum concentration of transforming growth factor-β(TGF-β₁)and tumor necrosis factor-α(TNF-α)and airway pressure time index(APTI)were measured.Result:Alveolar structure of group A was normal.On day 7 alveolar inflammation degree was less in group C than in group B,On day 28 Pulmonary fibrosis degree was less in group C than in group B.On day 28,HYP in lung tissue and TGF-β₁,TNF-αin serum were more in group B than in group s A and C.When the concentration of mACH is 0.05mg/kg,Compared with group A (0.508 mmHg/s)and group C(0.671mmHg/s),APTI was significantly higher in group B (0.841mmHg/s).When the co ncentration of mACH is 0.25mg/kg,Compared with group A(0.632 mmHg/s)and groupC(0.901mm Hg/s),APTI was significantly higher in group B(0.716mmHg/s). When the concentration of mACH is 0.5mg/kg,Compared with group A(0.677 mmHg/s)and gro up C(0.938mmHg/s),APTI was signif icantly higher in group B(0.800mmHg/s).Conclusion:Airway hyperresponsiveness exists in rats with bleomycin induced pulmonary fibrosis. TGF-β₁,TNF-αin serum increased in a rat model of bleomycin-induced pulmonary fibrosis and decreased after inhalation of CsA.Inhalation of CsA alleviates bleomycin induced pulmonary fibros is and reduces airway hyperresponsiveness through the reduce of TGF-β₁ and TNF-αin rats.