Effects of Different Doses of Methylprednisolone on Early Lung Injury in Paraquat Toxic Rats

Objective: To study the effect of different does of Methylprednisolone on early lung injury of rats with paraquat intoxi-cation.Methods: 114 Wistar rats were randomly divided into 5 groups : normal control group(A group),intoxication group(B group),5mg/kg Methylprednisolone group(C group)、15mg/kg Methylprednisolone group(D group) and 30mg/kg Methylprednisolone group(E group).The 22mg/kg paraquat dissolvent was injected by peritoneal injection in B,C,D,E group for once.Then sacrificing the rats in 5 groups at 3 time points(24h,72h,168h),describing lung tissue and observing oxygenation index and lung ratios and the lung pathologi-cal changes by light microscope.Results: C,D,E group compared with B group,the pathological changes of acute lung injury such as alveolar hemorrhage,exudation,inflammatory cell infiltration,alveolar septal infiltration of inflammatory cells are relatively mild.C and D Group are the lighter of pathological injury.In each group the same time in lung ratios: B group is the largest,group E in the24h and 72h points score was the lowest(P 0.05).oxygenation index: C,D,E group are increase(P 0.05).Conclusion: 30mg/kg Methylpred-nisolone has protective effect on lung injury of rats with paraquat intoxication and it is better than 5mg/kg and 15mg/kg Methylpred-nisolone.