摘要
目的:探讨低氧诱导因子-1α(hypoxia inducible factor-1α,HIF-1α)在心肌缺血后适应中对心肌的保护作用及机制。方法:健康成年SD大鼠40只,随机分为4组,每组10只。对照组(A组):仅在冠状动脉前降支穿线,不结扎,持续225 min;缺血再灌注组(B组):阻断前降支45 min后再灌注3 h;缺血后适应组(C组):阻断前降支45 min后,再灌注开始瞬间实施再灌注10 s-缺血10 s,共3个循环的干预,再灌注3 h;缺血后适应+HIF-1α抑制剂组(D组):阻断前降支45 min后,腹腔注射HIF-1α抑制剂AG490(3μg/g),再灌注瞬间实施再灌注10 s-缺血10 s,共3个循环的干预,再灌注3 h。在结扎冠状动脉前降支前、缺血45 min后、再灌注3 h后3个时间点,在大鼠股静脉处分别测定血清中的肌酸激酶、肌钙蛋白含量。再灌注3 h后,取大鼠心脏用2,3,5-氯化三苯基四氮唑染色法测定心肌梗死面积;Western blot法测定心肌组织中HIF-1α在各组中的表达情况。结果:(1)4组大鼠血清肌酸激酶、肌钙蛋白含量在结扎前(术前)差异无统计学意义(P>0.05);缺血45 min后,B组、C组及D组与A组比较差异有统计学意义(P<0.01);再灌注3 h后,B组、C组及D组与A组比较差异均有统计学意义(P均<0.01),且B组、D组显著高于C组(P<0.05)。(2)B组[(45.81±5.96)%]、C组[(37.17±4.99)%]及D组[(45.00±3.29)%]与A组[(2.46±1.13)%]心肌梗死面积比较,差异均有统计学意义(P<0.01);B组、D组与C组心肌梗死面积比较,差异有统计学意义(P<0.05)。(3)心肌组织中,A组HIF-1α蛋白微量表达;B组HIF-1α蛋白表达高于A组(P<0.05);C组HIF-1α蛋白显著高于B组(P<0.05);D组HIF-1α蛋白几乎不表达。结论:缺血后适应增加HIF-1α在心肌中的表达;HIF-1α表达增加可能参与大鼠心肌缺血后适应心肌保护的过程。
Objective To investigate the protective role and mechanism of hypoxia inducible factor(HIF)-1αin myocardial ischemia postconditioning.Methods Forty healthy adult SD rats were randomly divided into four groups with 10 rats in each group.The control group(group A)was sham operation group,and the rats underwent the same surgical procedures except that the suture passed under the left anterior descending branch(LAD)of the coronary artery was not tightened for 225 minutes.In the ischemia-reperfusion group(group B),the LAD was blocked for 45 minutes,and then reperfusion for 3 hours.In the ischemic postconditioning group(group C),45 minutes after blocking the LAD,reperfusion was performed for 10 seconds-ischemia for 10 seconds at the beginning of reperfusion,a total of 3 cycles of intervention,and reperfusion for 3 hours.Ischemic postconditioning+HIF-1αinhibitor group(group D):45 minutes after blocking the LAD,HIF-1αinhibitor AG490(3μg/g)was injected intraperitoneally,and reperfusion was performed for 10 seconds-ischemia 10 seconds at the moment of reperfusion.A total of 3 cycles of intervention,reperfusion for 3 hours.Blood samples were harvested from femoral vein at three time points(before ligation of the LAD,45 minutes after ischemia,3 hours after reperfusion)to analyze the serum levels of creatine kinase and cardiac troponin respectively.After 3 hours of reperfusion,myocardial tissue was used to measure the infarction size through 2,3,5-triphenyltetrazolium chloride staining method;and Western blot method was used to detect the expression of HIF-1αin each group.Results(1)There were no significant differences in the serum levels of creatine kinase and cardiac troponin among four groups before ligation(P>0.05);45 minutes after ischemia,there were significant differences between group B,group C,and group D compared with group A(P<0.01).After 3 hours of reperfusion,there were significant differences between group B,group C,and group D compared with group A(all P<0.01),and group B,group D were significantly higher than that in group C(P<0.05).(2)Compared with group A[(2.46±1.13)%],the area of myocardial infarction in group B was(45.81±5.96)%,in group C was(37.17±4.99)%,and group D was(45.00±3.29)%,and the differences were statistically significant(P<0.01).(3)The HIF-1αprotein in myocardial tissue in group A was slightly expressed;the expression of HIF-1αprotein in group B was higher than that in group A(P<0.05);and group C was significantly higher than that in group B(P<0.05);HIF-1αprotein was almost not expressed in group D.Conclusion After ischemic postconditioning,HIF-1αincreased in myocardium;the increased expression of HIF-1αmay be involved in the protective process of myocardial ischemic postconditioning in rats.
作者
梁延霄
李键芬
王文生
李东玉
Liang Yanxiao;Li Jianfen;Wang Wensheng;Li Dongyu(Department of Cardiac Surgery,Shengjing Hospital of China Medical University,Shenyang 110004,China)
出处
《中国小儿急救医学》
CAS
2021年第6期499-504,共6页
Chinese Pediatric Emergency Medicine
基金
辽宁省自然科学基金(20092107)。
