Mechanism Of Uncoupling Protein 2 In Myocardial Protection Of Sevoflurane Postconditioning

Objective:To explore the mechanism of uncoupling protein 2(UCP2)in myocardial protection of sevoflurane postconditioning(SPost C)in male mice.Methods:A total of 45 healthy male mice were randomly divided into three groups(n=15).Sham group was sham-operated group.Ischemia-reperfusion group was established in vivo,and sevoflurane post-treatment group SPost C was given 1MAC sevoflurane on the basis of I/R group.The diameter of aorta and ejection fraction were recorded by echocardiography.The infarct size was measured by TTC+ Evans blue staining.Recording of myocardial tissue structure by HE staining method.Observation of mitochondrial structure under transmission electron microscope.Determination of energy metabolism of cardiomyocytes by ROS kits,and the expression of UCP2 protein in the three groups was detected by western blot method.Results:(1)The change rate of aortic diameter and ejection fraction in I/R+SPost C group was smaller than that in I/ R group(P< 0.05).The myocardial infarct size decreased in I/R+SPost C group(P < 0.05).(2)Compared with Sham group,the arrangement of myocardial tissue was more disordered in myocardial microstructure.Some myocardial fibers were broken and cardiomyocytes were swollen and vacuolated.Compared with I/R group,the degree of myocardial disorder,cardiomyocyte swelling,myocardial fiber rupture and inflammatory cell infiltration were alleviated in I/R+SPost C group.(3)Mitochondrial structure under electron microscope: The structure of mitochondria in I/R+SPost C group was better than that in I/R group.The morphology of mitochondria was basically intact with slight swelling and a small amount of myofilament was dissolved.(4)Compared with the I/R group,the ROS production in the I/R+SPost C group decreased(P < 0.05).(5)Compared with sham group,the expression of UCP2 protein in I/R group was higher,and the expression level of UCP2 in I/R+SPost C group was further up-regulated than the I/R group(P < 0.05).Conclusion:The up-regulation of UCP2 protein expression may be related to the protective effect of SPost C on myocardial ischemia-reperfusion injury.