Intervention Effects of Methylprednisolone to Acute Lung Injury Model of Rats Induced by Oleic Acid / 医学研究杂志

ABSTRACT

Objective To observe the intervention effects of methylprednisolone (MPred) to acute lung injury(ALI) model of rats induced by oleic acid.Methods Thirty of Sprague-Dawley rats were randomly divided into three groups which were normal control group (NC,n =6),oleic acid model group (n =12),and MPred group (n =12).Rats were injected with oleic acid at dose of 0.1mg/ kg via caudal vein and then ALI model was established.The rats of NC group were injected with 0.1 mg/kg of normal saline instead of oleic acid.In NC group rats were sacrificed by blood collection at 6h after NS injection.Blood samples and tissues were collected and stored freezing.Samples of the other groups were collected at 2h and 6h after the last treatment.The observation indexes are histomorphology of lung tissue,the wet and dry weight of lung (W/D),index of quantitative assessment (IQA) score,partial pressure of oxygen in artery (PaO2),and SOD,MDA,MMP-9 and TIMP-1 levels in the blood plasma and lung tissue.Results Lung surface hyperemia relieved obviously and pink secretion from trachea of rats in MPred group decreased compared with oleic acid model group.In light microscope,compared with oleic acid model group,effusion of inflammatory cell in alveolar space of rats in MPred group eased.W/D of rats in oleic acid model group advanced obviously compared with that in NC group,W/D of rats in medrol group lowered obviously compared with that in oleic acid model group.IQA scores of rats in oleic acid model group advanced obviously compared with that in NC group,IQA score of rats in MPred group lowered obviously compared with that in oleic acid model group.PaO2 of rats in oleic acid model group lowered obviously compared with that in NC group,PaO2 of rats in MPred group advanced obviously compared with that in oleic acid model group.The level of SOD in plasma and lung tissue of rats in oleic acid model group lowered obviously compared with that in NC group,SOD level in plasma and lung tissue of rats in MPred group advanced obviously compared with that in oleic acid model group.The level of MDA in plasma and lung tissue of rats in oleic acid model group lowered obviously compared with that in NC group,MDA in plasma and lung tissue of rats in MPred group advanced obviously compared with that in oleic acid model group.Compared with the NC group,the level of MMP-9 in the plasma and lung tissue of oleic acid induced ALI rats increased and TIMP-1 levels decreased significantly.The level of MMP-9 in the plasma of rats decreased and TIMP-1 level increased significantly in MPred group at 2h and 6h.Conclusion MPred can improve lung pathological injury,increase PaO2 level,decrease lung W/D ratio and IQA scores by modulating the level or activity of the SOD and MDA and MMP-9 and TIMP-1 in the plasma and lung tissues.It is speculated that the effects of anti-inflammation and anti-exudation of sodium aescinate may due to affecting on oxidative stress response as well as the decomposition and remodeling of extracellular matrix during inflammatory lung injury of acute lung injury rats.