The roles of nuclear factor-κB,inducible nitric oxide synthase,and nitric oxide in the mechanism of acute lung injury in rats

Objective To explore the roles of nuclear factor-κB (NF-κB),inducible nitric oxide synthase (iNOS),and nitric oxide (NO) in the mechanism of acute lung injury (ALI).Methods Lipopolysaccharide (LPS,5 mg/kg) was used to copy ALI rat models.Thirty-two adult SD rats were randomly divided into four groups:control group (NS group),ALI model group (LPS group), N-acetyl cysteine (NAC) pretreatment group (NAC group) and Dexamethasone (DXM) pretreatment group (DXM group).In the later two groups,NAC (200 mg/kg) or DXM (70 mg/kg) was injected intraperitoneally respectively 1 hour before LPS was given intravenously.Four hours after LPS injection,the animals were killed.Then the pathological manifestation of lungs was observed,the lung index was calculated,while the intension of NF-κB expression and iNOS expression in the lung,the concentration of NO and malondialdehyde (MDA) in serum was detected.Results Obvious ALI pathological manifestation in the lungs of LPS group rats was observed.Compared with NS group,the expression of NF-κB and iNOS in lungs and concentration of NO in serum increased significantly in LPS group (P0.05)as well as lung index and concentration of MDA in serum (P0.05).Compared with LPS group,the pathological manifestation in the lung was ameliorated and the expression of NF-κB and iNOS,the concentration of NO and MDA,and lung index decreased significantly in NAC group and DXM group (P0.05).Conclusion NF-κB and iNOS-NO pathway were involved the pathogenesis of ALI in rat model and could be novel target molecules in prevention and treatment of ALI/ARDS.