Effects of Shengmai drink(生脉饮) on nitric oxide and inducible nitric oxide synthase in rats with acute lung injury induced by lipopolysaccharide

Objective: To investigate the effects of Shengmai drink(生脉饮) on nitric oxide(NO) and inducible nitric oxide synthase(iNOS) in rats with acute lung injury(ALI) induced by lipopolysaccharide(LPS).Methods: The male Wistar rats were randomly divided into four groups: control group,ALI group,Shengmai drink group and dexamethasone group.LPS was injected into the sublingual vein of rats to prepare ALI models.Macroscopic and histopathological examinations were performed and biological indexes including lung wet weight/dry weight,the ratio of neutrophils and protein content in the bronchoalveolar lavage fluid((BALF),) pulmonary vascular permeability and pulmonary alveolar permeability index were detected.(Meanwhile),the activities of serum NO and lung tissue homogenate iNOS were measured.Results: Lung histopathological examination showed the injury and cellular infiltration in the pulmonary stroma and alveoli were more prominent in the ALI group than that in the control group.Lung wet weight/dry weight,the(ratio) of neutrophils and protein content in BALF,pulmonary alveolar(permeability) index,pulmonary vascular(permeability) were significantly increased,NO and iNOS were also markedly elevated in the ALI group((P0.05) or(P0.01)). Compared with ALI group,in the dexamethasone and Shengmai drink groups,the histopathological changes were significantly milder,and the above biological indexes of lung injury and the contents of NO and iNOS were correspondingly(decreased)(P0.05 or P0.01).Conclusion: (Dexamethasone) and Shengmai drink have protective effect on LPS induced ALI and theirtherapeutic mechanism is possibly via inhibiting the activities of NO and iNOS.