龙血竭总黄酮对新西兰兔心肌缺血/再灌注损伤作用的研究

目的研究龙血竭总黄酮对新西兰兔心肌缺血/再灌注损伤的保护作用。方法将30只新西兰兔随机分为三组,每组10只。采用结扎新西兰兔左冠状动脉前降支法,建立心肌缺血/再灌注损伤模型。观察心肌组织HE染色的结构变化,测量左心室内压最大上升速率(+dp/dtmax),检测心肌肌酸激酶同工酶(CK-MB)。结果龙血竭处理组心肌组织结构明显好于缺血/再灌注组;缺血/再灌注组和龙血竭处理组+dp/dtmax均明显低于假手术组(P0.01),龙血竭处理组+dp/dtmax高于缺血/再灌注组(P0.01);缺血/再灌注组CK-MB水平明显高于假手术组(P0.01),龙血竭处理组CK-MB水平高于假手术组(P0.05),并低于缺血/再灌注组(P0.01)。结论龙血竭总黄酮能够改善心肌缺血/再灌注损伤,保护心肌组织结构,稳定细胞膜结构,减少心肌CK-MB漏出,提高缺血/再灌注损伤模型心肌的收缩功能。     

CARD6通过调控ASK1表达抑制炎症反应和细胞凋亡保护心肌缺血再灌注损伤

目的:探讨胱天蛋白酶募集域蛋白6(CARD6)对心肌缺血再灌注损伤(MIRI)中炎症反应和细胞凋亡的影响,并分析其相关分子机制。方法:将60只SD大鼠随机分为假手术组(Sham组)、模型组(MIRI组)、MIRI+空载慢病毒(LV-NC)组、MIRI+CARD6过表达慢病毒组(MIRI+LV-CARD6组),每组15只。除Sham组外,其他各组大鼠采用手术结扎冠状动脉左前降支的方法构建MIRI模型。采用全自动生化分析仪检测心肌损伤指标含量,酶联免疫吸附法(ELISA)检测炎性细胞因子水平,苏木精-伊红(HE)染色观察大鼠心肌组织形态学变化,原位末端标记测定(TUNEL)染色法检测大鼠心肌细胞凋亡情况,蛋白免疫印迹法(Western Blot)检测大鼠心肌组织中凋亡相关蛋白表达,实时定量聚合酶链式反应(RT-qPCR)法和Western Blot法检测大鼠心肌组织中CARD6、细胞凋亡信号调节激酶1(ASK1)mRNA和蛋白表达。结果:与Sham组比较,MIRI组大鼠心肌细胞水肿变性,大量间质炎性细胞浸润,存在明显心肌组织病理损伤;大鼠血清中乳酸脱氢酶(LDH)、肌酸激酶(CK)、肌酸激...     

从线粒体膜稳定作用探讨线粒体K(MITO-KATP)通道开放剂改善老年冠心病大鼠心肌缺血再灌注损伤的机制

目的从线粒体膜稳定作用探讨线粒体K+ATP(MITO-KATP)通道开放剂尼可地尔(Nicorandil,Nic)改善老年冠心病大鼠心肌缺血再灌注损伤的机制。方法选取60只健康雄性SD老年大鼠(18～20个月),体重400～600 g,随机分为3组:假手术(Sham)组、模型(Model)组和尼可地尔(Nic)组,每组10只。建立老年冠心病大鼠心肌缺血再灌注(MI/R)模型,尼可地尔(Nic)组在再灌注之前,股静脉注射尼可地尔5 mg/kg,假手术组和模型组注射等量的生理盐水。3组大鼠在术后24 h进行腹主动脉取血,分别检测大鼠血清中,肌酸磷酸激酶同工酶(CK-MB)和乳酸脱氢酶(LDH)的水平变化;采用流式细胞仪测定大鼠心肌细胞线粒体膜电位的变化情况;采用Western Blot法测定心肌细胞线粒体中p-Cx43蛋白变化情况,心肌组织中Bcl-2和Bax蛋白表达情况的变化。结果与Sham组相比,模型组大鼠血清中CK-MB和LDH的含量增加(P0.05),说明心肌缺血再灌注会导致心肌细胞损伤;与模型组相比,尼可地尔组大鼠血清中CK-MB和LDH的含量下降(P0.05),说明尼可地尔有抗心肌缺血的作用。采用阳离子绿色荧光染料罗丹明123对线粒体的膜电位进行检测,与Sham组相比,模型组大鼠心肌线粒体膜电位降低(P0.05),而尼可地尔组大鼠心肌线粒体膜电位高于模型组(P0.05),说明心肌细胞凋亡时会导致线粒体膜电位降低以及功能变化,而线粒体K+ATP通道开放剂尼可地尔可以缓解线粒体的损伤情况。Western Blot结果表明,与Sham组相比,模型组大鼠心肌线粒体p-Cx43的蛋白表达下调,而尼可地尔组大鼠心肌线粒体p-Cx43的蛋白表达高于模型组,说明尼可地尔能够上调心肌线粒体p-Cx43的蛋白表达,维持线粒体的稳定性。与Sham组相比,模型组大鼠心肌组织中Bcl-2的蛋白表达下调,Bax蛋白表达上调;而尼可地尔组大鼠心肌组织中Bcl-2的蛋白表达上调,Bax蛋白表达下调,说明线粒体K+ATP通道开放剂尼可地尔可有效抑制心肌缺血再灌注导致的心肌细胞凋亡。结论线粒体K+ATP通道开放剂尼可地尔对心肌缺血再灌注损伤有保护作用,其机制可能是通过降低大鼠血清中CK-MB和LDH的含量,维持线粒体膜稳定性,抑制心肌细胞的凋亡。     

曲美他嗪后处理与缺血后处理对大鼠再灌注心肌保护作用的对比

目的 对比观察曲美他嗪(TMZ)后处理与缺血后处理(IPOC)对大鼠心肌缺血再灌注损伤(MIRI)的保护作用.方法40只Wistar 大鼠随机分为4组(n=10):假手术组、模型组、曲美他嗪组(TMZ组)、缺血后处理组(IPOC组).结扎左冠状动脉前降支,建立大鼠心肌缺血/再灌注损伤模型,记录各组心肌梗死面积,光镜HE染色观察心肌组织细胞形态,透射电镜观察心肌细胞微观结构,测定血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、谷草转氨酶(AST)活性变化.结果 TMZ组、IPOC组与模型组比较:①心肌梗死面积减少(P＜0.05);②心肌细胞损伤程度相当,较模型组有明显改善;③心肌细胞超微结构损伤程度相当,较模型组有明显改善;④心肌酶CK、LDH、AST活性较模型组均有明显降低(P＜0.05).结论 TMZ后处理与IPOD对MIRI心肌均有明显的保护作用,二者作用差异不明显.     

腺苷后处理对大鼠心肌缺血再灌注损伤后HSP70表达及心肌细胞凋亡的影响

目的 通过观察腺苷后处理对大鼠心肌缺血再灌注损伤后热体克蛋白70(HSP70)表达及凋亡的影响,探讨腺苷后处理对心肌缺血再灌注损伤的保护机制.方法 24只成年雄性Wistar大鼠随机分为假手术对照组(Sham组)、缺血再灌注组(I/R组)、腺苷后处理组(AD组),采用结扎大鼠左冠状动脉前降支法制备大鼠心肌缺血再灌注模型;免疫组化SABC法检测HSP70表达;采用DNA原位末端缺口标记法(TUNEL)检测心肌细胞凋亡.结果 与假手术组比较,I/R组与AD组HSP70表达水平均升高(P＜0.05),且AD组明显高于I/R组(P＜0.05).心肌细胞凋亡率,I/R组与AD组较假手术组增高(P＜0.05),且AD组明显低于I/R组(P＜0.05).结论 腺苷后处理可增加心肌缺血再灌注损伤大鼠HSP70的表达,减轻心肌细胞凋亡,有效保护心肌缺血再灌注损伤.     

6-姜酚抑制氧化应激减轻大鼠心肌缺血/再灌注损伤

目的:研究6-姜酚抑制氧化应激减轻心肌缺血/再灌注损伤(MIRI)的作用与机制。方法:雄性Wistar大鼠40只,按随机原则分为随机分为4组(每组10只):假手术组、6-姜酚组(6-G组)、MIRI组、6-G+MIRI组。6-G组大鼠不行手术,在6-G+MIRI组手术前30min同时经尾静脉给药(6mg/kg)。各组大鼠经ELISA法检测血清丙二醛(MDA)、超氧化物岐化酶(SOD)、心肌酶(CK、CK-MB、TnT、TnI)水平,TUNEL法检测心肌细胞凋亡并计算凋亡指数,TTC双染色法测量心肌梗死面积,ELISA法检测血清Bcl-2、Bax、Caspase-3等水平。结果:与MIRI组比较,6-G+MIRI组MDA水平降低(P0.05)、SOD水平升高(P0.05);心肌酶水平下降(P0.05);心肌细胞凋亡减轻,凋亡指数降低(P0.05);心肌梗死面积缩小(P0.05);血清Bcl-2水平升高(P0.05)、Bax水平下降(P0.05)、Bcl-2/Bax比值升高(P0.05)、Caspase-3水平下降(P0.05)。结论:6-G可减轻MIRI,其机制可能是通过抑制氧化应激减轻心肌细胞凋亡。     

参附注射液对心肌缺血再灌注损伤模型大鼠的保护作用

目的探讨参附注射液(SFI)对心肌缺血再灌注损伤(MIRI)模型大鼠的保护作用。方法 60只健康SD大鼠随机均分为假手术组,缺血再灌注模型组以及SFI处理低、中、高剂量组(分别5、10、20 ml/kg)。建立大鼠MIRI模型,记录心电图中T波及S-T段电压变化,测定各组肌酸激酶(CK)、CK同工酶(CK-MB)、乳酸脱氢酶(LDH)和基质金属蛋白酶(MMP)-9的活性和肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6的浓度,并观察心肌组织病理学改变,分析SFI对MIRI的保护作用。结果与假手术组比较,模型组心电图中的ST段和T波均出现了不同程度的偏移,且心室脏器系数、心肌梗死区重量以及梗死百分比增大(P<0.05);SFI处理后,心电图中的ST段和T波偏移较小,心室脏器系数、心肌梗死区的重量和百分比明显降低,且高剂量组改善最明显(P<0.05)。与假手术组相比,模型组大鼠心肌酶谱CK-MB、CK、LDH、MMP-9活性及TNF-α、IL-6浓度明显升高(P<0.05),与模型组相比,给药后SFI处理组以上指标均明显下降,且随着剂量增加下降越明显(P<0.05)。结论 SFI对大鼠MIRI有明显的保护作用,可能与改善CK-MB、CK、LDH、MMP-9活性及TNF-α、IL-6浓度有关,且使用高剂量的SFI对大鼠MIRI保护作用更显著。     

阿芬太尼调节SphK1/S1P信号通路保护心肌缺血再灌注损伤大鼠

[目的]探究阿芬太尼对心肌缺血再灌注损伤(MIRI)大鼠的作用及在该过程中对鞘氨醇激酶1(SphK1)/鞘氨醇-1-磷酸(S1P)信号通路的调节机制。[方法]将SPF级SD雄性大鼠随机分为假手术组、模型组、阳性药物组(复方丹参组)和阿芬太尼低剂量组、阿芬太尼高剂量组、阿芬太尼高剂量+SphK1激动剂组(阿芬太尼+PMA组),每组20只。除假手术组,其余组均利用结扎左前降支冠状动脉后再灌注复制MIRI模型。全自动生物化学分析仪检测血清乳酸脱氢酶(LDH)、肌酸激酶(CK)和谷草转氨酶(AST)的活性;TTC检测大鼠心肌梗死面积;HE染色观察大鼠心肌组织形态学特征;TUNEL染色检测大鼠心肌细胞凋亡;ELISA检测血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、白细胞介素1β(IL-1β)及S1P的水平;试剂盒检测心肌组织中丙二醛(MDA)含量和超氧化物歧化酶(SOD)的活性;Western blot检测心肌组织SphK1蛋白表达。[结果]相较于假手术组,模型组大鼠心肌组织病理损伤严重,血清中心肌损伤标志物LDH、CK和AST的活性,心肌梗死面积和心肌细胞凋亡率,TNF-α、I...     

复发木尼孜其颗粒对大鼠心肌缺血/再灌注损伤的保护及其与核因子NF-κB信号通路的相关性

目的 探讨复方木尼孜其颗粒（Munziq）对大鼠模型心肌缺血/再灌注损伤（MIRI）的影响及其机制。方法 选择70只SD大鼠随机分为4组:正常假手术组（简称Con组）10只、正常缺血再灌注组（简称IR组）20只、复方木尼孜其颗粒组（5.06g/kg）20只、阿托伐他汀组（AT,20 mg/kg）20只,灌胃干预21天。检测各组心肌组织NIK, IKKα,pIKKα,及 p65表达及血清CTN-T、CK-MB、LDH、MDA IL-1β, IL-6, TNF-α, IL-10 及 ICAM-1含量。结果：心肌HE染色中复方木尼孜其组和阿托伐他汀组心肌细胞出现轻度颗粒变性和空泡变性。红细胞和淋巴细胞浸润,血管扩张和充血几乎没有观察到。同样这两组损伤心肌细胞的病理学特征均明显减轻。心肌细胞肿胀减少。cTn-T, CK-MB, LDH, 及 MDA水平变化：MIRI组的CTN-T、CK-MB、LDH、MDA水平显著高于假手术组（P＜0.05）。与MIRI组比较,复方木尼孜其颗粒和阿托伐他汀组的CTN-T、CK-MB、LDH、MDA含量显著降低（P＜0.05）。NIK, IKKα, pIKKα,及p65水平的变化：与假手术组相比,MIRI组的NIK、IKKα、PIKKα、P65水平显著高于对照组（P＜0.05）。而复方木尼孜其组和阿托伐他汀组的上述蛋白含量明显低于MIRI组（P＜0.05）。IL-1β, IL-6, TNF-α, IL-10 及 ICAM-1.水平变化： MIRI组IL-1β、IL-6、TNF-α、IL-10水平均高于假手术组（P＜0.05）。假手术组与MIRI组比较有显著性差异（P＜0.05）。复方木尼孜其与MIRI组、阿托伐他汀组和MIRI组比较差异有统计学意义（P＜0.05）。结论 复方木尼孜其颗粒在缺血再灌注损伤中具有心脏保护作用。这种作用可能通过抑制NF-κB信号通路来发挥作用。复方木尼孜其颗粒可能作为保护心脏围手术期心肌缺血再灌注损伤的干预药物。     

罗格列酮对大鼠心肌缺血再灌注损伤的保护作用

目的 观察罗格列酮对大鼠在体心肌缺血再灌注损伤及心肌细胞凋亡的影响.方法 采用结扎大鼠左冠状动脉前降支30 min,再灌注60 min的方法 ,复制大鼠心肌缺血再灌注损伤模型.实验动物随机分为罗格列酮组(3 mg·kg-1·d-1)、模型组(生理盐水2ml/d)和假手术组(生理盐水2ml/d).再灌注后观察血清酶学改变,Evans blue、TTC双重染色检测心肌梗死面积,流式细胞术测定心肌细胞凋亡指数,免疫组化检测凋亡蛋白Bcl-2、Bax表达.结果 与模型组比较,罗格列酮显著降低血清酶CK、LDH水平(P＜0.01),缩小心肌梗死面积(P＜0.01),增加Bcl-2、减少Bax表达(P＜0.01),减少心肌细胞凋亡(P＜0.01).结论 罗格列酮对心肌缺血再灌注损伤有保护作用.     

心肌缺血预适应对急性心肌梗死影响的观察

目的:探讨心肌缺血预适应对急性心肌梗死(AMI)临床表现及其预后的影响。方法:根据AMI前有无心绞痛发作分为预缺血组和无预缺血组,分组观察AMI患者血清肌酸磷酸激酶(CPK)峰值,住院期间并发症(心衰、心源性休克、严重心律失常),以及住院期间心性病死率。结果:预缺血组血清CPK峰值明显低于无预缺血组(P<0.05),住院期间心源性休克及严重心律失常发生率明显低于无预缺血组(P<0.05)。结论:心肌缺血预适应可减轻心肌坏死程度,缩小梗死面积,并减少AMI并发症的产生。     

Effects of myocardial hypoxia and ischemia on myocardial scintigraphy

The effect of regional myocardial ischemia and hypoxia on myocardial scintigraphy was studied in patients and dogs after intravenous administration of cesium-129. Seven men with angiographically proved ischemic heart disease underwent exercise testing and ¹²⁹Cs was given immediately when ischemia was manifested in the electrocardiogram. Defects were not evident in the scintigrams of any patient. Failure to visualize a defect might be related to delayed uptake of ¹²⁹Cs by the myocardium (maximal uptake in 45 minutes). The ischemic state was dissipated before the disparity in uptake between normal and ischemic myocardium could be visualized. Cesium-129 is useful for identifying acute myocardial infarcts but should not be used to visualize transient exercise-induced regional ischemia.Six dogs were given ¹²⁹Cs after induction of regional myocardial hypoxia by perfusion of the anterior descending coronary artery with venous blood. In each, scintigraphy revealed a defect that resolved after reperfusion with arterial blood. Two other dogs were given ¹²⁹Cs before perfusion with hypoxemic blood; neither dog manifested a defect. Since perfusion was maintained by a pump these results suggest that the major cause of the scintigraphically observed defect was inadequate cellular uptake of ¹²⁹Cs rather than excessive cellular loss. Since regional myocardial hypoxia produced a reversible defect, scintigraphic studies might overestimate the size of an acute myocardial infarct in man by including the ischemic zone surrounding the infarct.     

Effect of nitrates on myocardial remodeling after acute myocardial infarction

Nitrates are effective for the therapy of acute coronary syndromes, including acute myocardial infarction. Their application in acute infarction has established that vasodilators are beneficial provided hypotension is avoided. Nitrates limit early ventricular remodeling in infarction. New dosing strategies and formulations that permit chronic use after infarction with less tolerance might limit late remodeling. Over the last decade, the demonstrated effectiveness of angiotensin-converting enzyme (ACE) inhibitors in limiting ventricular dilation postinfarction has generated controversy over the usefulness of nitrates for that indication. The uncertainty has been intensified by 2 large mortality trials that tested both agents as adjuncts to conventional therapy. These trials were not designed to test whether nitrates might limit remodeling. Mechanistic experimental and clinical studies that tested whether nitrates or ACE inhibitors could effectively limit ventricular remodeling showed that both improved remodeling endpoints. However, experimental studies raise some concern about the decrease in infarct collagen associated with ACE inhibition and emphasize the fact that final outcome represents a balance of effects. That nitrates do not decrease infarct collagen could be important. Nitrate-induced early recruitment of ventricular function after late reperfusion of acute infarction might also be important. In the mortality trials, > 50% of patients received open-label nitrates as per indication. Thus, the trial results to date do not suggest that nitrates are ineffective for remodeling, but rather that ACE inhibitors can confer added benefit. There has been no large clinical trial to test the efficacy of nitrates for remodeling as there has been for ACE inhibitors.     

冠状动脉心肌桥研究现状

正常情况下,冠状动脉及其分支走行于心外膜下心肌表面。当冠状动脉或其分支的某个节段行走于室壁心肌纤维之间,被形似桥的心肌纤维覆盖,在心脏收缩时出现暂时性管腔狭窄甚至闭塞,则被心肌纤维覆盖的动脉段称为壁冠状动脉,这段心肌纤维称为冠状动脉心肌桥（简称心肌桥,myocardial bridging,MB）。早在1922年Grainicanu首先描述了心肌桥的存在,但直到1960年Portmann和1wig才率先报道了心肌桥的影像学表现——“收缩期狭窄”,即冠状动脉某一节段收缩期变得狭窄、模糊或显影不清,而舒张期显影正常。本介绍了心肌桥的发生、解剖特点、病理生理机制、临床表现、诊断及治疗现状。     

Effects of myocardial edema on the development of myocardial interstitial fibrosis

OBJECTIVE: The mechanism by which chronic myocardial edema causes cardiac dysfunction is poorly understood. We hypothesized that myocardial edema triggers cardiac fibrosis development resulting in cardiac dysfunction. Since collagen is the most abundant constituent of the interstitial matrix, we examined the effects of edema development on cardiac collagen metabolism. METHODS: We utilized a chronic pulmonary artery banded rat model that produces right ventricular hypertrophy with myocardial edema and left ventricular edema without hypertrophy or hyperplasia. Wet to dry ratios (index of edema), collagen type I and III concentrations, prolyl 4-hydroxylase (P4-H) and collagen type I and III mRNA levels, collagenase activity and transforming growth factor-beta were measured in both ventricles. RESULTS: Right and left ventricular wet to dry ratios were significantly elevated from 1 to 28 days after pulmonary artery banding compared to sham rats. Right and left ventricular collagen types I and III and P4-H mRNA levels increased significantly at 3 days followed by significant increases in right and left ventricular collagen concentration 7 days after pulmonary artery banding. Right ventricular collagenase activity increased at 3 days while left ventricular collagenase activity decreased 7 days after PA banding. CONCLUSIONS: We conclude that myocardial edema preceded the observed increase in collagen deposition and that edema may have triggered increased collagen synthesis by fibroblasts. leading to fibrosis development.     

Effect of statin therapy before Q-wave myocardial infarction on myocardial perfusion

Recent studies emphasized the non-lipid-lowering effects of hydroxymethylglutaryl coenzyme A reductase inhibitors on endothelial function, inflammation, and platelet activation in patients with stable atherosclerosis. This study sought to evaluate the impact of statin pretreatment in patients with acute myocardial infarction (AMI) on level of systemic inflammation and myocardial perfusion. A total of 253 consecutive patients undergoing primary angioplasty on a native vessel within 12 hours of AMI were divided into a group with statin pretreatment (n = 86) and control patients (n = 167). Angiographic myocardial blush grade (MBG) after revascularization of the infarct-related artery was determined to evaluate myocardial perfusion. Statin pretreatment was associated with a lower frequency of increased C-reactive protein (>or=5 mg/L) on admission compared with the control group (48% vs 64%; p = 0.019). The frequency of normal perfusion (MBG 3) was higher in the statin-pretreatment group than the control group (45% vs 26%, respectively; p <0.001). Statin pretreatment was an independent predictor of normal myocardial perfusion (MBG 3; odds ratio 2.53, 95% confidence interval 1.15 to 9.53, p = 0.022) in addition to age 相似文献   

心肌灌注断层显像对急性心肌梗死再灌注的研究

目的　通过心肌灌注断层显像研究急性心肌梗死 (AMI)患者经尿激酶或冠状动脉介入治疗前后心肌梗死面积的变化。方法　用99m锝甲氧基异丁基异腈心肌灌注断层显像测定 12 0例AMI患者心肌再灌注前后的心肌梗死面积。结果　再灌注组 (n =81)和无再灌注组 (n =36 )首次心肌显像心肌缺损面积无显著性差异 (P >0 0 5 ) :再灌注组再次显像心肌缺损面积明显小于首次显像 (2 2 3± 3 1%和 31 9± 5 6 % ,P <0 0 5 ) ;无再灌注组再次显像心肌缺损面积与首次显像无明显差异 (2 9 6± 2 8%和 32 4± 5 l% ,P >0 0 5 ) ;预后不良组心肌缺损面积明显高于预后较好组 (35 8± 6 1% ,n =32和2 0 6± 4 0 % ,n =88,P <0 0 5 )。结论　心肌灌注断层显像可作为AMI再灌注疗效评价较准确的手段