| Objective:To investigate the antioxidant effect and signal transduction mechan ism of naringenin（NAR）preconditioning on myocardial ischemia reperfusion（I/R）in rats.Methods:Thirty-two adult male SD rats were randomly divided into SHAM operation group（SHAM group）,ischemia reperfusion group（I/R group）,naringin preconditioning+I/R group（NAR group）,NAR preconditioning+I/R+（PI3K/AKT signaling channel inhibitor）LY294002 group（NL group）.7days before I/R treatment,NAR group and NL group were intraperitoneally injected with NAR(100mg.Kg-1.D-1),NL group was intraperitoneally injected with LY294002(0.3mg.kg-1),then I/R was performed by ligation of the anterior descending branch of the coronary artery.The SHAM group was not performed ligation,and the other three groups were performed ligation for 30min,and than reperfusion for 120min.After successful I/R,the rats in each group were sacrificed and samples were collected.HE staining was used to observe the pathological changes;TUNEL fluorescence staining was used to observe the apoptosis level of myocardial cells and the apoptosis rate was calculated by the corresponding formula;The kits were used to detect the activity levels of LDH,CK of serum and ROS,MDA value,SOD activity levels in the myocardial;protein expression levels of AKT,p-AKT,Nrf2,HO-1 and NQO1 in the myocardial were detected by Western blot;The transcription levels of Nrf2 and HO-1 genes were detected by RT-PCR.Results:（1）In the SHAM group,HE staining showed orderly arrangement of myocardial fibers,complete myocardial cell structure and no inflammatory cell infiltration;TUNEL staining showed almost no green fluorescent staining cells.（2）Compared with SHAM group,HE staining showed myocardial cell edema,fuzzy structure,rupture,disorderly arrangement of myocardial fibers,and a large number of inflammatory cell infiltration in the I/R group;TUNEL staining showed significantly green fluorescent staining cells were increased;the apoptosis rate of myocardial cells and activity levels of serum LDH,CK were significantly increased（P<0.05）;while ROS and MDA value of myocardial were significantly increased（P<0.05）,SOD activity was significantly decreased（P<0.05）;there was no significant difference in AKT expression of myocardial（P>0.05）,and the expression levels of P-AKT,Nrf2,HO-1 and NQO1 were slightly increased with no statistical significance（P>0.05）.（3）Compared with I/R group,HE staining showed myocardial cells edema and destruction were reduced,the myocardial fibers were more neatly arranged and Inflammatory cells was significantly decreased in the NAR group;TUNEL stai ning showed green fluorescent staining cells were decreased;the apoptosis rat e of myocardial cells and the activity levels of serum LDH,CK were significant ly decreased（P<0.05）;ROS and MDA value of myocardial were significantly d ecreased（P<0.05）,SOD activity was dramatically increased（P<0.05）;there wa s no significant difference in AKT expression of myocardial（P>0.05）,the expr ession levels of p-AKT,Nrf2,HO-1,NQO1 were significantly increased（P<0.05）.（4）Compared with NAR group,HE staining showed edema and destruction of myocardial cells were increased,Heart muscle fibers were more disorganized,and inflammatory cells were increased,Tunnel staining showed green fluorescent staining cells was significantly increased,The apoptosis rate of myocardial cells and the activity levels of serum LDH and CK were significantly increased（P<0.05）,ROS and MDA value of myocardial were significantly increased（P<0.05）,SOD activity was significantly decreased（P<0.05）;there was no significant difference in AKT expression of myocardial（P>0.05）,The expression levels of P-AKT,Nrf2,HO-1 and NQO1 were significantly decreased（P<0.05）.Conclusion:Oxidative stress is one of the causes of myocardial ischemia-repe rfusion injury,NAR has obvious protective effect on myocardial ischemia-reper fusion injury,which upregulated PI3K/AKT/Nrf2 pathway to develop the prote in expression levels of HO-1,NQO1,SOD and other antioxidant substances to scavene ROS,MDA... |
PDF Full Text Request