Effect Of Intermittent Hypoxia On The Expression Of Different Subtypes Of SOD In Rat Lung Tissue And The Intervention Effect Of Edaravone

Objective: To explore the expression changes of different subtypes of SOD in lung tissue of rats after intermittent hypoxia exposure and the intervention effect of Edaravone.Methods: 36 rats were randomly divided into 4 groups: normal control group（NC group）,intermittent hypoxia group（IH group）,intermittent hypoxia+Edaravone group（IH+NE group）and intermittent hypoxia+normal saline group（IH+NS group）,with 9rats in each group.After 56 days of IH exposure,the lung tissue of rats was stained with HE and Masson to observe the morphological changes of lung tissue and the deposition of collagen fibers;The expression levels of SOD1,SOD2,and SOD3 in each group were detected by ELISA;The expression levels and sites of SOD1,SOD2,and SOD3 were detected by immunohistochemistry;The random alveolar septal thickness was used to quantify the degree of injury,and the correlation with SOD1,SOD2,and SOD3 was analyzed.Results: Compared with NC group,the expression of SOD1,SOD2,and SOD3 in IH group and IH+NS group decreased（P<0.05）.The intervention of Edaravone increased the expression of SOD1,SOD2,and SOD3 in different degrees after IH,and the changes of SOD1 and SOD2 were statistically different（P<0.01）;On HE staining,the alveolar structure of NC group was complete and the morphological changes were the lightest;In IH group and IH+NS group,the alveolar structure was destroyed,the alveoli were slightly swollen,the alveolar cavity was narrow,the alveolar septum was widened,there were a large number of red blood cell infiltration and a small amount of inflammatory cells;Compared with IH group and IH+NS group,the alveolar structure of IH+NE group was complete and the morphological changes were slightly lighter;Masson staining,IH group ang IH+NS group had more blue staining area and fiber content;The IH+NE group took second place.The NC group had smaller blue staining area and less fiber content;Immunohistochemical SOD1,SOD2,and SOD3 proteins were mainly deposited in pulmonary vascular endothelium and alveolar septum.From the positive expression results,the positive expression of lung NC group was stronger than that of lung IH+NE group,and the positive expression of lung IH group and IH+NS group was slightly weaker,which was consistent with the quantitative results of SOD detected by ELISA;Compared with the NC group,the mean value of alveolar septum in the IH group and IH+NS group increased significantly（P<0.01）,and the mean value of alveolar septum after Edaravone intervention was lower than that in the IH group and IH+NS group（P<0.01）.The results of correlation analysis showed that SOD1,SOD2,and SOD3 were negatively correlated with mean alveolar septum,including SOD1（r =-682 P = 0.000）,SOD2（r=-843 P = 0.000）and SOD3（r =-387 P = 0.020）.Conclusion: 1.IH exposure can down regulate the expression of different subtypes of SOD in lung tissue,cause lung tissue injury through inflammatory oxidative stress,and increase lung fiber deposition at the same time;2.The expression of different subtypes of SOD in the lung tissue of IH rats was negatively correlated with the degree of lung injury,and the correlation of SOD2 was the strongest,SOD1 was the second,and SOD3 was the weakest;3.The intervention of Edaravone injection under IH exposure can up regulate the expression of SOD of different subtypes to a certain extent,mainly SOD2 and SOD1,and reduce the lung tissue injury and fiber deposition caused by IH.