[Effects of melatonin on anti-oxidative function of lung injury induced by lipopolysaccharide in rats and ICAM-1 expression].

Aim:To investigate the protective effect of melatonin(MT)on lung tissues during acute lung injury(ALI)in rats and its possible mechanism.Methods:All rats were randomly divided into four groups:control group,lipopolysaccharide(LPS)group,dexamethasone(DEX)and MT treatment group.Myeloperoxidase(MPO)activity,superoxide dismutase(SOD)activity and malonaldehyde(MDA)content of lung tissues were detected at 3、6 and 12 h after intratracheal instillation in each group.In addition,the expression of intercellular adhesion molecule-1(ICAM-1)were observed through immunohistochemistry staining in lung tissues.Results:Compared with control group,SOD activity decreased significantly in LPS group(P0.01),but MPO activity,MDA content and the expression of ICAM-1 increased obviously(P0.01).The administration of MT and DEX mitigated above changes significantly(P0.05 or P0.01).Conclusion:MT possessed protective effect on lung tissues during ALI through scavenging free radicals and inhibiting the expression of ICAM-1 probably.