注射用心肌肽预处理对大鼠未成熟心肌缺血再灌注损伤的保护作用及其机制  

Protective effect of cardiomypeptidin for injection preconditioning on immature myocardial ischemia-reperfusion injury in young rats and its mechanism

作　　者：杨立平[1] 陈良万[1] 张贵灿[1] 张志强 陈道中[1] 董疑[1] 杜剑之[1] 戴小福[1] 

机构地区：[1]福建医科大学协和临床学院心外科,福建福州350001 [2]福建医科大学药学院新药研究所,福建福州350001

出　　处：《吉林大学学报（医学版）》2011年第6期1037-1042,1176,共7页Journal of Jilin University：Medicine Edition

基　　金：教育部博士点基金资助课题(200803920001)

摘　　要：目的:探讨注射用心肌肽预处理对幼鼠未成熟心肌缺血再灌注损伤的保护作用,阐明其相应的作用机制。方法:通过结扎SD幼鼠冠状动脉左前降支建立缺血再灌注损伤模型。SD大鼠随机分为假手术组、模型对照组及注射用心肌肽预处理组(CMP组)。检测血清乳酸脱氢酶(LDH)、肌酸磷酸激酶同工酶(CK-MB)、肌钙蛋白T(Tn-T)和心肌组织匀浆丙二醛(MDA)、总超氧化物歧化酶(SOD)、总一氧化氮合酶(TNOS)、诱导型一氧化氮合酶(iNOS)、内皮型一氧化氮合酶(eNOS)含量,免疫组织化学法检测NOS2(iNOS)、NOS3(eNOS)含量及Caspase-3蛋白表达水平;光学显微镜观察心肌梗死范围,透射电镜检测心肌组织结构改变;TUNEL法观察心肌凋亡细胞。应用实时荧光定量PCR分析心肌组织iNOS、eNOS、Caspase-3mRNA表达。结果:CMP组大鼠LDH、CK-MB、Tn-T含量低于模型对照组(P<0.05或P<0.01),MDA、SOD、TNOS、iNOS含量以及Caspase-3、iNOS表达水平较假手术组增高,但低于模型对照组(P<0.05或P<0.01)。CMP组与模型对照组大鼠比较,坏死(AN)/缺血危险面积(AAR)下降52%(P<0.01),心肌梗死范围缩小。模型对照组大鼠心肌片状出血,炎性细胞浸润,心肌细胞严重变性坏死,心肌细胞凋亡显著;而CMP组心肌细胞变性坏死程度较轻,血管结构正常,心肌凋亡细胞水平介于假手术组和模型对照组之间。结论:注射用心肌肽预处理对大鼠未成熟心肌缺血再灌注损伤具有保护作用,其作用机制可能与减少NO生成,抑制心肌细胞Caspase-3mRNA和蛋白表达,从而减少细胞凋亡有关。Objective To investigate the protective effect of cardiomyopeptidin(CMP) for injection preconditioning on the immature myocardial ischemia-reperfusion injury in young rats,and clarify its mechanism.Methods 30 young healthy SD rats were randomly divided into sham-operated group,model control group and CMP group(n=10).The levels of serum lactic dehydrogenase(LDH),creatine kinase MB(CK-MB),troponin Tn-T were detected;the contents of superoxide dismutase(SOD),malondialdehyde(MDA),nitric oxide(NO),total nitric oxide synthase(TNOS),inducible nitric oxide synthase(iNOS)and endothelial nitric oxide synthase(eNOS)in myocardium tissue were measured;the expression levels of iNOS,eNOS and Caspase-3 protein in myocardial tissue were detected by immunohistochemical method.The expressions of iNOS,eNOS and Caspase-3 mRNA in myocardial tissue were measured by real-time fluorescence quantitative PCR.The changes of myocardial structures were observed with optical microscope and transmission electron microscope.The apoptosis of myocytes was observed by TUNEL.Results Compared with model control group,the levels of LDH,CK-MB,Tn-T in CMP group were decreased(P<);Compared with sham-operated group,the contents of MDA,SOD,TNOS,and iNOS were increased and the expression levels of iNOS and caspase-3 mRNA were significantly down-regulated in CMP group,but less than those in model control group(P<0.01 or P<0.05).Several pieces of myocardial hemorrhage and inflammatory cell infiltration were observed in model control group,severe degeneration and necrosis of myocytes could be found,the apoptotic myocytes were significantly increased;while in CMP group,the myocardial pathological injuries were mitigated,only mild degeneration and necrosis of myocardial cells could be found,the vascular structure was near-complete,the number of apoptotic myocytes between sham operation group and control group.Conclusion Cardiomyopeptidin for injection preconditioning can protect immature myocardium against ischemia-reperfusion injury in young rats.The mechanism

关 键 词：未成熟心肌 心肌肽 再灌注损伤 缺血预处理 细胞凋亡 

分 类 号：R96[医药卫生—药理学]