β-内啡肽在RVLM吗啡预处理减轻大鼠心肌缺血再灌注损伤中的变化  

Changes of β-endorphin in the reduction of myocardial ischemia-reperfusion injury in rats by morphine preconditioning in RVLM

作　　者：徐凯生 张丽 张野[1,2] Xu Kaisheng;Zhang Li;Zhang Ye(Dept of Anesthesiology,The Second Afilitled Hospital of Anhui Medical University,Hefei 230601;Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes,Anhui Medical University,Hefei 230032)

机构地区：[1]安徽医科大学第二附属医院麻醉与围术期医学科,合肥230601 [2]麻醉与围术期医学安徽普通高校重点实验室,安徽医科大学,合肥230032

出　　处：《安徽医科大学学报》2020年第4期557-562,共6页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金(编号:81471145)。

摘　　要：目的探讨头端延髓腹外侧区(RVLM)吗啡预处理(MPC)对大鼠心肌缺血再灌注损伤(IRI)的作用以及该过程中T2-5脊髓与左心室肌内β-内啡肽(β-EP)含量的变化。方法成年雄性SD大鼠72只,RVLM置管模型建立成功后随机均分为4组,假手术组(Sham组)、缺血再灌注组(IR组)、RVLM吗啡预处理组(MPC组)和缺血预处理组(IPC组)。缺血再灌注模型采用冠状动脉左前降支结扎30 min再灌注120 min,缺血预处理方法为心肌缺血5 min再灌注5 min,重复处理3次。Sham组、IR组和IPC组预先通过导管注射0.9%生理盐水。之后IR组进行缺血再灌注;IPC组在IR前进行IPC;MPC组在IR前核团注射吗啡。观察心电图,于再灌注30 min内记录室性心律失常[室性早搏(PVCs)及室速/室颤(VT/VF)]发生次数。心脏标本进行氯化三苯基四氮唑(TTC)染色,测量左心室(LV)、右心室(RV)、梗死区(IS)、缺血危险区(AAR)体积并计算IS/AAR比值。Western blot法检测RVLM核团c-Fos蛋白表达,ELISA法与免疫组化染色法分别定量和定性检测T2-5脊髓与左心室肌中β-EP的表达。结果与Sham组比较,IR组的IS体积、IS/AAR增高(P<0.01),PVCs、VT/VF发生次数增加(P<0.01),c-Fos表达水平增高(P<0.01),脊髓和心肌中β-EP表达水平增高(P<0.01);与IR组比较,IPC组和MPC组的IS体积、IS/AAR降低(P<0.05),PVCs、VT/VF发生次数减少(P<0.01),c-Fos表达水平降低(P<0.01),心肌和脊髓中β-EP表达水平增高(P<0.01)。结论 RVLM吗啡预处理可减轻大鼠心肌IRI,该作用可能与降低IR后RVLM核团内c-Fos表达水平有关,β-EP可能作为递质参与了中枢RVLM MPC产生的心肌保护效应。Objective To investigate the effect of morphine preconditioning in rostral ventrolateral medullar(RVLM) on myocardial ischemia-reperfusion(I/R) injury in rats and the changes of β-endorphin(β-EP) contents in T2-5 spinal cord and left ventricular muscle during the process. Methods 72 adult male SD rats were randomly divided into 4 groups(18 in each group):sham-operated group(Sham group), ischemia-reperfusion group(IR group), ischemic preconditioning group(IPC group), and RVLM morphine preconditioning group(MPC group). The ischemia reperfusion(I/R) model was treated with coronary artery left anterior descending branch ligation for 30 min and then reperfusion for 120 min. The ischemic preconditioning(IPC) was myocardial ischemia for 5 min, reperfusion for 5 min, and repeated the above operations for 3 times. Sham group, IR group and IPC group were injected 0.9% saline through the catheter. Then I/R was performed in the IR group, and IPC was performed before I/R in the IPC group. In the MPC group,morphine was injected before I/R. The numbers of ventricular arrhythmias [premature ventricular contraction( PVCs) and ventricular tachycardia/ventricular fibrillation( VT/VF) ]were recorded within 30 min of reinfusion by electrocardiogram monitoring. Cardiac specimens were stained with TTC.Left ventricle( LV),right ventricle( RV),infarct area( IS),ischemic risk area( AAR) volume were measured,and the IS/AAR ratio was calculated. Western blot assay was used for RVLM nucleus c-fos protein expression detection. ELISA assay and immunohistochemical staining assay were used for quantitative and qualitative detection the levels of β-EP expression in T2-5 spinal cord and left ventricular muscle,respectively. Results Compared with the Sham group,the IS volume,IS/AAR,the numbers of PVCs,VT/VF,and expression of c-Fos in RVLM and β-EP in spinal cord and myocardium were increased in IR group( P < 0. 01). Compared with. IR group,the IS volume,IS/AAR,the numbers of PVCs,VT/VF,and the levels of c-Fos expression were significantly decre

关 键 词：缺血预处理 心肌保护 吗啡 缺血再灌注损伤 Β-内啡肽 

分 类 号：R541.4[医药卫生—心血管疾病]