Protective effects of ulinastatin combined with dexamethasone on acute lung injury induced by endotoxin in rabbits

Objective To study the protective effects of ulinastatin(UTI) combined with dexamethasone(Dex) on endotoxin-induced acute lung injury in rabbits.Methods Forty New Zealand rabbits were randomly divided into five groups with 8 rabbits each:LPS group(L),UTI group(U),Dex group(D),UTI combined with Dex group(T),normal controls(C).Except group C,all rabbits of other groups were injected a dose of LPS 600μg/kg IV.Meanwhile group U,D and T received UTI100000U/kg or/and Dex 5mg/kg.The specimens were collected 4h later for detecting the levels of TNF-α and NO in serum and blood gas analysis,histological manifestations,the lung wet/dry weight ratio,lung tissue MPO and SOD activity,lung tissue MDA. Results Compared with group C, the lungs of the rabbits in group L had significant spotty hemorrhage.The inflammatory granulocyte infiltrating,diffused alveolar septum thickening and spotty hemorrhage were observed with pathological examinations.The histological changes of group U,D and T were better than those in group L.Compared with group L, the levels of TNF-α and NO,the lung wet/dry weight ratio,lung tissue MPO activity and MDA of group U,D and T decreased significantly, lung tissue SOD activity and blood gas analysis improved significantly. Compared with group U and D, group T improved more significantly.Conclusion Ulinastatin combined with dexamethasone has a better protective effect on acute lung injury induced by endotoxin, which is probably related to reducing the inflammation mediator and oxyradical release and inhibiting the reaction of enzymes.