锰超氧化物歧化酶、细胞黏附分子-1和诱生型一氧化氮合酶在大鼠心肌缺血预适应中的意义

Significance of Mn-SOD,ICAM-1,iNOS in the ischemic preconditioning of rats

目的通过建立心肌梗死、心肌缺血预适应(ischemic precondition,IP)大鼠模型,并测定其血清中锰超氧化物歧化酶(Mn-SOD)、细胞黏附分子-1(ICAM-1)、诱生型一氧化氮合酶(iNOS)含量的变化来阐明其在IP过程中的作用。方法 Wistar大鼠90只,分为对照组、心肌梗死组、IP 1个循环组、IP 2个循环组、IP 3个循环组、IP 4个循环组。通过氯化三苯四唑(triphenyl tetrazolium chloride,TTC)染色方法来测定心肌梗死的面积;通过氧化还原酶法测定血清中的Mn-SOD的含量变化,通过酶联免疫法测定血清中ICAM-1、iNOS的含量。结果 (1)IP可以明显降低心肌梗死的面积,其保护作用并不随IP时间的增加而增加,而是在IP 3个循环以后维持在最高的水平,IP 4个循环之后心肌梗死面积反而有所下降,与3个循环组比较差异没有统计学意义。(2)心肌梗死以后血清中的Mn-SOD含量与对照组相比明显升高(P<0.05)。IP以后血清中的Mn-SOD含量亦有明显的升高,从第1个循环开始到第3个循环,随着循环次数的增加血清中的Mn-SOD含量依次增加,高峰在IP 3个循环的时间,达到了(169.69±23.35)g/L,与心肌梗死组比较差异有统计学意义(P<0.01);第4个循环的时间血清中Mn-SOD的含量较3个循环组反而稍有下降,但是两者之间差异没有统计学意义(P>0.05)。(3)心肌梗死以后血清中的ICAM-1含量与对照组相比明显升高(P<0.05)。IP以后血清中的ICAM-1含量亦有明显的升高,从第1个循环开始到第4个循环,随着循环次数的增加血清中的ICAM-1含量依次增加,高峰在IP 4个循环的时间,达到了(145.33±21.13)g/L,与心肌梗死组比较差异有统计学意义(P<0.01);第4个循环的时间血清中Mn-SOD的含量较3个循环组高,但是两者之间差异没有统计学意义(P>0.05)。(4)心肌梗死以后血清中的iNOS含量与对照组相比明显升高(P<0.05)。IP以后血清中的iNOS含量亦有明显的升高,从第1个循环开始到第3个循环,随着循环次数的增加血清中的iNOS含量依次增加,高峰在IP 4个循环的时间,达到了(218.00±11.43)g/L,与心肌梗死组比较差异有统计学意义(P<0.01)。结论 IP对缺血及梗死心肌具有保护作用,Mn-SOD、ICAM-1、iNOS在IP过程中有明显的变化,可能参与了心肌IP的过程。

Objective To develop a myocardial infarction and ischemic preconditioning（IP）model and try to explain the significance of Mn-SOD,ICAM-1 and nitric-oxide synthase（iNOS） in the ischemic preconditioning of rats,through the detection of changes in the levels of Mn-SOD,intercellular adhesion molecule-1（ICAM-1） and induced nitric oxide（iNOS） in blood plasma.methods Ninety adult Wistar rats were randomly divided into 6 groups： the control group,the myocardial infarction group,the first cycle IP group,the second cycle IP group,the third cycle IP group,and the fourth cycle IP group.The size in the area of myocardial infarction was measured with triphenyl tetrazolium chloride（TTC） method,changes in the levels of Mn-SOD in serum were detected with the oxidation reduction enzyme method,and contents of ICAM-1 and iNOS in serum were determined by ELISA.results （1） IP could obviously reduce the infarction area,however,the protective effect of IP was not increased with IP cycles,reaching the peak at the third cycle of IP and then decreased to some extent from the fourth cycle without statistical significance,when compared with the other 3 cycles.（2） The content of Mn-SOD in the serum was increased significantly following myocardial infarction,when compared with that of the control group（P0.05）.Following ischemic preconditioning（IP）,the content of Mn-SOD in the serum was also increased significantly,starting from the first cycle to the third cycle.The content of Mn-SOD in the serum was increased with the increase of cycles,reaching the peak level of（169.69±23.35）g/L at the third cycle,with statistical significance,when compared with that of the myocardial infarction group（P0.01）.The content of Mn-SOD in the serum was decreased in the fourth cycle,when it was compared with that of the third cycle group,but without statistical significance（P0.05）.（3） The content of ICAM-1 in the serum was increased after myocardial infarction,when compared with that of the control group（P0.05）.After IP,the content of ICAM-1 in the serum was also increased significantly.With the cycle increased,the content of Mn-SOD was also increased,beginning from the first cycle to the fourth cycle.The content of ICAM-1 in the serum was increased with the increase of cycles,reaching the peak level of（145.33±21.13） g/L at the fourth cycle,with statistical significance,when compared with that of the myocardial infarction group（P0.01）.The content of Mn-SOD in the serum at the fourth cycle was higher than that of the third cycle,but without statistical significance（P0.05）.（4） The content of iNOS in the serum was increased obviously after myocardial infarction,when compared with that of the control group（P0.05）.Following IP,the content of iNOS in the serum was increased obviously too.With the cycles increased,the content of iNOS was also increased,reaching the peak level of（218.00±11.43）g/L at the fourth cycle,with statistical significance,when compared with that of the myocardial infarction group（P0.01）.conclusionOur study indicates that IP seemed to have a protective effect on ischemic myocardium.Significant changes were noted in Mn-SOD,ICAM-1 and iNOS in the process of IP,which might play an important role in IP.