首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
温血停搏液术终灌注对缺血再灌注心肌的保护作用   总被引:2,自引:0,他引:2  
利用猫体外循环模型观察含甘露醇的温血停搏液术终灌注对缺血再灌注心肌的保护作用。心肌缺血恢复正常血液灌注前,从主动脉根部以5~6kPa的压力注入37℃含甘露醇的低钾温血停搏液50ml。结果显示用含甘露醇的温血停搏液术终灌注可保护缺血后再灌注心肌的功能,提高心肌能量储备,降低线粒体丙二醛含量。结论:含甘露醇的温血停搏液术终灌注,可提高心肌对氧自由基的清除能力,减轻线粒体膜脂质过氧化,提高心肌能量储备,有利于再灌注后心肌功能的恢复  相似文献   

2.
目的 利用猫体外循环模型对比观察间断冷血、持续冷血及持续温血心脏停搏液灌注对长时间停搏心肌保护的作用。方法 健康猫24只,随机分成4组:Ⅰ组为正常对照组,取正常猫心测定有关指标做为正常对照;Ⅱ-Ⅳ组为心脏停搏组,停搏时间3小时,用不同心肌保护方法保护心肌。结果 心脏停搏3小时后心肌线粒体呼吸功能、氧化磷酸化能力及心肌三磷酸腺苷(ATP0含量在间断冷血组明显下降,持续冷血组呈轻度下降,持温血组保持正  相似文献   

3.
目的利用猫体外循环模型对比观察间断冷血、持续冷血及持续温血心脏停搏液灌注对长时间停搏心肌的保护作用。方法健康猫24只,随机分成4组:Ⅰ组为正常对照组,取正常猫心测定有关指标做为正常对照;Ⅱ~Ⅳ组为心脏停搏组,停搏时间3小时,用不同心肌保护方法保护心肌。结果心脏停搏3小时后心肌线粒体呼吸功能、氧化磷酸化能力及心肌三磷酸腺苷(ATP)含量在间断冷血组明显下降,持续冷血组呈轻度下降,持续温血组保持正常。结论持续灌注温血停搏液技术可使心脏在停搏期间有充足的血液供应,是一种理想的心肌保护方法,特别适用于需长时间停搏和高危病例。  相似文献   

4.
利用猫体外循环模型,观察心肌缺血再灌注过程中MDA、SOD的变化,及开放主动脉前灌注含甘露醇的温血停搏液对其影响。结果见缺血心肌再灌注后线粒体MDA含量明显增加;缺血心肌复灌前从主动脉根部注入含甘露醇温血停搏液,使心脏在有氧环境下停搏,可降低心肌线粒体MDA含量,提高心肌SOD活性。表明缺血心肌在恢复正常血供前灌注含甘露醇温血停搏液,可减轻膜脂质的过氧化,保护自由基清除系统,减轻心肌的再灌注损伤。  相似文献   

5.
卡托普利心脏停搏液对缺血再灌注心肌NOS活性和NO产?…   总被引:1,自引:0,他引:1  
目的:探讨卡托普利心脏停搏液对缺血再灌注心肌保护作用的机制。方法:12只绵羊,随机均分为对照组和卡托普利组。常规建立体外循环,心脏停搏60分钟,再灌注30分钟。Ⅰ组采用仁济医院冷晶体停搏液,Ⅱ组在停搏液中加入卡托普利23μmol/L。观察冠状窦血中一氧化氮,肌酸磷酸激酶,环磷酸鸟苷,心肌丙二醛含量及心肌NO合酶同功酶活性的变化,监测心肌功能。  相似文献   

6.
开放主动脉前灌注含甘露醇的温血停搏液对心肌MDA和SOD…   总被引:2,自引:0,他引:2  
利用猫体外循环模型。观察心有缺血再灌注过程中MDA,SOD的变化,开放主动脉再灌注含甘露醇的温血停搏液对其影响。结果见缺血心肌再灌注后线粒体MDA含量明显增,缺血心肌复灌前从主动脉根部注入含甘露醇温血停搏液,使心脏在有氧下停搏,可降低心肌线粒体MDA含量,提高心肌SOD活性,表明缺血心肌在恢复正常血供前灌注含甘露醇温血停搏液,可减轻膜脂质的过氧化,保护自由基清除系统,减轻心肌的再灌注损伤。  相似文献   

7.
目的研究缺血预处理(IP)对大鼠离体心脏缺血再灌注损伤的保护作用机制。方法 Wistar大鼠48只,其中40只随机分为缺血再灌注组(I/R组)、IP组、二氮嗪组(DZ组)、5-羟葵酸(选择性线粒体ATP敏感性钾通道阻滞剂)拮抗IP组(5-HD IP组)、5-羟葵酸拮抗二氮嗪组(5-HD DZ 组),每组8只,另外8只用作正常心肌线粒体电镜检查对照组。应用Langendorff离体心脏灌注系统建立心脏缺血再灌注模型,平衡灌注20 min后,30 min预处理期间各组进行以下处理,IP组进行2次缺血再灌注,灌注压8.5 kPa,灌注速率8.5 ml/min。每次IP缺血5 min再灌注5 min;DZ组灌注50 μmol ·L-1二氮嗪;5-HD IP组灌注100 μmol·L-1 5-羟葵酸10 min,然后给予2次IP;5-HD DZ组灌注5-羟葵酸100μmol-L-1 10min,再灌注二氮嗪50μmol·L-1 10min。然后各组全心缺血40min,再灌注30min。持续测定心功能指标[心率、左心室发展压(INDP)、左心室舒张末压(INEDP)和冠脉流量(CF)],再灌注末取心肌,提取线粒体,电镜下观察其病理学改变,并进行线粒体Flameng评分。结果与I/R组比较,IP和二氮嗪预处理能明显提高再灌注期间LVDP,降低LVEDP,降低心肌线粒体Flameng评分(P< 0.01),减轻心肌病理学损伤;5-羟葵酸能部分拮抗IP、完全拮抗二氮嗪预处理对心肌缺血再灌注损伤的保护作用。结论 IP对心肌缺血再灌注损伤的保护作用与线粒体ATP敏感性钾通道的激活有关。  相似文献   

8.
低温对脑缺血再灌注所致线粒体功能损伤的影响   总被引:3,自引:0,他引:3  
脑缺血再灌注可引起电子传递链障碍、氧自由基生成增加,导致线粒体功能损害。而低温可促进缺血再灌注线粒体功能的恢复,减少氧自由基的生成,其机制可能与低温能够抑制脂质过氧化、保护电子传递链酶的活性有关。  相似文献   

9.
目的观察缺血后处理对小肠缺血再灌注损伤的保护作用。方法30只大白兔随机分为3组,每组8只:A组,假手术组;B组,肠缺血再灌注损伤模型组;C组,肠缺血再灌注损伤模型肠缺血后处理组,实验结束后取小肠标本进行小肠上皮细胞形态和呼吸功能指标测定。结果A、C两组线粒体的数目、周长均大于B组,A、C两组问比较,A组较大(P〈0.05)。A、C两组线粒体的面积、最大直径、最小直径、等效直径均小于B组(P〈0.05),A、C两组间比较差异无统计学意义(P〉0.05)。B组线粒体的体积密度小于A组,面积密度、比表面和粒子数密度均小于其余两组(P〈0.05)。A、C两组间三维平面形态计量学各参数比较差异无统计学意义(P〉0.05);B、C组线粒体呼吸控制比率(RCR)低于A组差异有统计学意义(P〈0.05),与C组比较,B组下降更为明显(P〈0.05)。结论小肠缺血后处理对缺血再灌注损伤肠上皮细胞线粒体形态和功能均有保护作用。  相似文献   

10.
缺血再灌注时心肌线粒体的变化与保护研究进展   总被引:2,自引:1,他引:2  
线粒体是真核细胞中重要和独特的细胞器,在细胞凋亡和坏死过程中都至关重要。线粒体功能受损是导致缺血再灌注(I/R)心肌不可逆损伤的重要原因之一。因此,针对线粒体的心肌保护措施受到越来越多的关注。一、线粒体在缺血再灌注过程中的改变1.自由基的产生:在I/R过程中氧自由基的生成主要有两个来源,其一是黄嘌呤氧化酶途径。线粒体呼吸链是自由基的另一来源。Vandenhoek等[1] 在离体心肌的I/R模型中证实线粒体电子转移与自由基的生成有关。氧自由基在线粒体中的产生部位被确认为在辅酶Q(泛醌)。当缺氧抑制呼吸链时,辅酶Q被还原成半泛醌,…  相似文献   

11.
BACKGROUND: Gender differences exist in the myocardial response to acute ischemia/reperfusion (I/R) injury and may be attributed to the effects of the sex hormones estrogen and testosterone. The role of estrogen in myocardial injury has been extensively studied but little information exists regarding the myocardial involvement of testosterone. Based on the deleterious effects of chronic endogenous and acute testosterone exposure observed in our previous studies, we postulated that chronic exogenous testosterone administration would also exhibit deleterious effects on myocardial function following I/R. METHODS: Langendorff perfused rat hearts were subjected to 25 min ischemia, 40 min reperfusion, and left ventricular developed pressure (LVDP) was recorded. Control and 5alpha-dihydrotestosterone (DHT) treated groups each consisted of normal males, castrated males, ovariectomized (OVX) females, and senescent females. P < 0.05 = significant. RESULTS: Chronic DHT replacement therapy showed no difference in functional ischemic recovery as measured by LVDP after 40 min reperfusion in castrated males (65.1 +/- 8.13% versus 66.3 +/- 4.54%), OVX females (64.5 +/- 10.6% versus 50.2 +/- 5.97%), and senescent females (42.1 +/- 0.04% versus 41 +/- 0.05%). Interestingly, LVDP was greater in DHT treated males than control males after I/R (65.2 +/- 8.20% versus 47.6 +/- 5.19%). Also, DHT treatment resulted in significantly increased recovery of LVDP after only 10 min reperfusion in castrated males, OVX females, and senescent females compared with their untreated counterparts (54.8 +/- 11.9% versus 32.9 +/- 5.75%, 66.7 +/- 11.5% versus 43.1 +/- 8.15%, 53.4 +/- 10.1% versus 32.9 +/- 5.75%, respectively). CONCLUSION: Contrary to the adverse effects we observed in earlier studies with both endogenous and brief exogenous testosterone in myocardium injured by I/R, the present study revealed that chronic exogenous testosterone neither improved nor worsened myocardial functional recovery following 25 min ischemia and 40 min reperfusion.  相似文献   

12.
目的探讨采用线粒体ATP敏感性钾通道(mitoKATP通道)选择性开放剂二氮嗪(DE)进行预处理能否模拟缺血预处理(IP)对硬化肝脏缺血再灌注损伤的保护作用及其可能的作用机制。方法雄性肝硬化SD大鼠随机分为5组(每组8只)。IP组以肝缺血5 min作预处理;DE组以静脉注射DE作为预处理;DE 5-HD组是在DE组基础上再予静注mitoKATP通道选择性阻滞剂5-hydroxydecanoate(5-HD)进行预处理;对照组(C组)以静注等量生理盐水作为预处理;上述4组均在预处理后行肝缺血45 min再灌注60 min;缺血方式均为70%肝脏热缺血。假手术组(S组)仅行开腹,不作任何其他处理。完成预定实验操作后分别取血用于血清谷丙转氨酶(ALT)与乳酸脱氢酶(LDH)检测,切取肝组织用于测定ATP酶活力、湿重/干重(W/D)的测定及观察显微、超微结构变化。结果C组ALT,LDH,ATP酶及W/D的水平明显高于S组(P<0.01),肝脏的显微及超微结构损伤明显;IP组与DE组的各项肝组织损伤指标均明显好于C组,ATP酶活性低于C组(P<0.05及P<0.01);而DE 5-HD组的肝损伤指标均差于DE组,ATP酶活性高于DE组(P<0.05及P<0.01)。结论使用DE进行药物预处理能够模拟出IP效应,对肝硬化大鼠肝脏I/R损伤具有保护作用,其作用可能与下调肝组织ATP酶活性,减少ATP大量分解,使肝组织ATP含量升高,改善肝能量代谢,增加能量储备;改善肝组织微循环,减轻肝脏水肿有关。  相似文献   

13.
OBJECTIVE: To examine whether propofol protects against postischemic myocardial dysfunction and apoptosis during reperfusion after prolonged cold ischemia in isolated rat hearts. DESIGN: A prospective, randomized, controlled study. SETTING: A university laboratory. PARTICIPANTS: Animals. INTERVENTIONS: The isolated hearts of 40 Sprague-Dawley male rats were perfused with modified Krebs-Hennseleit solution for 15 minutes for a stabilization period and 15 minutes for a perfusion period and then underwent 4 hours of global cold ischemia followed by 60 minutes of reperfusion. Four groups were studied (n = 10 for each group). Ten hearts served as an untreated control group. Propofol (2 micromol/L) treatment was performed only before ischemia in the PRE group, only during reperfusion in the POST group, and both before and after ischemia in the ALL group. MEASUREMENTS AND MAIN RESULTS: Infusion of propofol during reperfusion improved recovery of left ventricular-developed pressure (LVDP) from 61.2% +/- 8.5% (control) to 86.3% +/- 12.1% (POST) and 74.9% +/- 13.2% (ALL, both p < 0.05), whereas preischemic infusion of propofol (64.3% +/- 9.7%, PRE) did not improve recovery of LVDP. Infusion of propofol during reperfusion significantly reduced the number of apoptotic cells and led to a smaller infarct size than control and PRE groups (p < 0.05, respectively). CONCLUSIONS: Propofol infusion during the reperfusion period produced a cardioprotective effect and inhibited apoptosis of cardiomyocytes in the ischemia-reperfusion model, with prolonged cold ischemia, in isolated rat hearts.  相似文献   

14.
BACKGROUND: Hemodilution reduces hematocrit (Hct) and blood oxygen content. Tissue oxygenation is mainly preserved by increased cardiac output. As myocardial O2-demands increase, coronary vasodilatation becomes necessary to increase myocardial blood flow. Myocardial ischemia occurs at a critical Hct-value (Hctcrit), with accompanying exhaustion of coronary reserve. Hyperoxic ventilation is known to both reverse peripheral tissue hypoxia at Hctcrit and also to induce coronary vasoconstriction. This study aimed to determine whether hyperoxic ventilation at Hctcrit further exacerbates myocardial ischemia and dysfunction. METHODS: Nine anesthetized pigs ventilated on room air were hemodiluted by 1:1 exchange of blood with pentastarch (6%HES) to Hctcrit, defined as onset of myocardial ischemia (ECG changes). At Hctcrit, hyperoxic ventilation was started. Measurements were performed at baseline, at Hctcrit, and after 15 min of hyperoxic ventilation. We determined myocardial blood flow (microsphere method), arterial O2-content, subendocardial O2-delivery and myocardial function (left ventricular pressure increase). RESULTS: At Hctcrit 7 (6;8)%, O2-content was reduced [3.7 (3.1;3.9) ml dl(-1)]. Despite a compensatory increase of myocardial blood flow [531 (449;573), ml min(-1)100 g(-1)], all pigs displayed myocardial ischemia and compromised myocardial function (P < 0.05). Hyperoxic ventilation produced increased coronary vascular resistance secondary to vasoconstriction, and reduced myocardial blood flow [426 (404;464), ml min(-1)100 g(-1); P < 0.05]. Myocardial oxygenation was found to be maintained by increased O2-content [4.4 (4.2;4.8), ml dl(-1); P < 0.05], the contribution of dissolved O2 to subendocardial O2-delivery increased (32 vs. 8%; P < 0.05), which preserved myocardial function. CONCLUSION: Hyperoxic ventilation at Hctcrit is followed by coronary vasoconstriction and reduction of coronary blood flow. However, myocardial oxygenation and function is maintained, as increased O2-content (in particular dissolved O2) preserves myocardial oxygenation.  相似文献   

15.
RDepartmentofAnesthesiology ,RenminHospital,WuhanUniversity,Wuhan 4 30 0 6 0 ,China (ChenXJ,WangX ,XiaZYandLuoT)DepartmentofCardiacSurgery ,RenminHospital,WuhanUniversity ,Wuhan 4 30 0 6 0 ,China (TuZF) Correspondingauthor:Tel:86 2 7 880 82 4 78,E mail:xue0 30 8@mail.tom .com .cnecentlyischemiapreconditioninghasprovedtoamelioratethesubsequentsustainedmyocardiumischemia reperfusioninjury .1,2 Someexperimentsreportedthatremoteorgansischemiapreconditioning(RPC) ,suchasinkidney ,can…  相似文献   

16.
BACKGROUND: This study tested the hypothesis that induction and reperfusion with warm substrate-enriched (IRWSE) blood cardioplegia improves postoperative left ventricular (LV) function in patients undergoing elective coronary bypass surgery (CABG). METHODS: After giving informed consent, 67 patients scheduled for CABG surgery were randomized to either IRWSE + cold blood (CB) or CB alone. IRWSE cardioplegia consisted of 37 degrees C substrate-enriched (glutamate, aspartate, hyperkalemic) anterograde and retrograde blood cardioplegic solution followed by non-substrate-enriched cardioplegic solution given at 4 degrees C to 8 degrees C. LV function was measured with ventriculograms, volume conductance catheters, echocardiography, and multiple gated (image) acquisition. RESULTS: The end-systolic pressure-volume relationship was improved postbypass in the IRWSE + CB group (CB, 1.5 +/- 0.74 mm Hg/mL vs IRWSE + CB, 2.1 +/- 1.2 mm Hg/mL; p = 0.042). The postoperative ejection fraction (EF%) was better preserved in the CB group (CB, 65 +/- 11.53% vs IRWSE + CB, 58.62 +/- 11.75%; p < 0.04). CONCLUSIONS: Our results demonstrate a transient improvement in LV systolic function in the immediate postbypass period in CABG patients in the IRWSE + CB group. The intraoperative benefits of the IRWSE + CB technique did not persist in the postoperative period.  相似文献   

17.
BACKGROUND: Coenzyme Q10 (CoQ10) protects myocardium from ischemia-reperfusion (IR) injury as evidenced by improved recovery of mechanical function, ATP, and phosphocreatine during reperfusion. This protection may result from CoQ10's bioenergetic effects on the mitochondria, from its antioxidant properties, or both. The purpose of this study was to elucidate the effects of CoQ10 supplementation on mitochondrial function during myocardial ischemia-reperfusion using an isolated mitochondrial preparation. METHODS: Isolated hearts (n = 6/group) from rats pretreated with liposomal CoQ10 (10 mg/kg iv, CoQ10), vehicle (liposomal only, Vehicle), or saline (Saline) 30 min before the experiments were subjected to 15 min of equilibration (EQ), 25 min of ischemia (I), and 40 min of reperfusion (RP). Left ventricular-developed pressure (DP) was measured. Mitochondria were isolated at end-equilibration (end-EQ), at end-ischemia (end-I), and at end-reperfusion (end-RP). Mitochondrial respiratory function (State 2, 3, and 4, respiratory control index (RCI, ratio of State 3 to 4), and ADP:O ratio) was measured by polarography using NADH (alpha-ketoglutarate, alpha-KG)- or FADH (succinate, SA)-dependent substrates. RESULTS: CoQ10 improved recovery of DP at end-RP (67 +/- 11% in CoQ10 vs 47 +/- 5% in Vehicle and 50 +/- 11% in Saline, P < 0.05 vs Vehicle and Saline). CoQ10 did not change preischemic mitochondrial function. IR decreased State 3 and RCI in all groups using either substrate. CoQ10 had no effect in the mitochondrial oxidation of alpha-KG at end-I. CoQ10 improved State 3 at end-I when SA was used (167 +/- 21 in CoQ10 vs 120 +/- 10 in Saline and 111 +/- 10 ng-atoms O/min/mg protein in Vehicle, P < 0.05). Using alpha-KG as a substrate, CoQ10 improved RCI at end-RP (4.2 +/- 0.2 in CoQ10 vs 3.2 +/- 0.2 in Saline and 3.0 +/- 0.3 in Vehicle, P < 0.05). Using SA, CoQ10 improved State 3 (181 +/- 10 in CoQ10 vs 142 +/- 9 in Saline and 140 +/- 12 ng-atoms O/min/mg protein in Vehicle, P < 0.05) and RCI (2.21 +/- 0.06 in CoQ10 vs 1.85 +/- 0.11 in Saline and 1.72 +/- 0.08 in Vehicle, P < 0.05) at end-RP. CONCLUSIONS: The cardioprotective effects of CoQ10 can be attributed to the preservation of mitochondrial function during reperfusion as evidenced by improved FADH-dependent oxidation.  相似文献   

18.
Chronic rejection (CR) remains an unsolved hurdle for long‐term heart transplant survival. The effect of cold ischemia (CI) on progression of CR and the mechanisms resulting in functional deficit were investigated by studying gene expression, mitochondrial function, and enzymatic activity. Allogeneic (Lew→F344) and syngeneic (Lew→Lew) heart transplantations were performed with or without 10 h of CI. After evaluation of myocardial contraction, hearts were excised at 2, 10, 40, and 60 days for investigation of vasculopathy, gene expression, enzymatic activities, and mitochondrial respiration. Gene expression studies identified a gene cluster coding for subunits of the mitochondrial electron transport chain regulated in response to CI and CR. Myocardial performance, mitochondrial function, and mitochondrial marker enzyme activities declined in all allografts with time after transplantation. These declines were more rapid and severe in CI allografts (CR‐CI) and correlated well with progression of vasculopathy and fibrosis. Mitochondria related gene expression and mitochondrial function are substantially compromised with the progression of CR and show that CI impacts on progression, gene profile, and mitochondrial function of CR. Monitoring mitochondrial function and enzyme activity might allow for earlier detection of CR and cardiac allograft dysfunction.  相似文献   

19.
背景 中国针灸用于中风等神经系统疾病的治疗有悠久的历史和丰富的临床经验.电针是传统针灸与现代电学技术相结合的治疗方式,它对脑缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)的病理演变有重要影响.目的 探讨电针的神经保护及其机制.内容 依照脑I/RI的病理生理机制,分析与总结电针对脑I/RI的保护作用及其机制. 趋向 电针在运用补充与替代疗法预防、治疗或辅助治疗脑I/RI方面有良好的发展前景.  相似文献   

20.
目的 研究缺血预处理(IPC)对大鼠肝脏缺血/再灌注损伤的延迟保护作用,并探讨线柱体ATP敏感性钾通道(mitoKATP通道)在这种保护机制中的作用. 方法 SD大鼠随机分为5组(每组8只).IPC组以肝缺血5 min作预处理;DE组以静脉注射mitoKATP通道选择性开放剂二氮嗪(DE)作为预处理;IPC+5-HD组是在IPC组基础上再予静注mitoKATP通道特异性阻滞剂5-hydroxydecanoate(5-HD)进行预处理;对照组(C组)仅以静注等量生理盐水作为预处理;上述4组均在预处理24 h后行肝缺血1 h再灌注3 h,缺血方式均为70%肝脏热缺血.假手术组(S组)仅行两次开腹手术,不作其它处理.完成预定实验操作后取血用于血清谷丙转氨酶(ALT)与乳酸脱氢酶(LDH)检测,切取肝组织用于测定超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、湿重/干重(W/D)及观察显微及超微结构变化. 结果 C组ALT,LDH,MDA及W/D值明显高于S组(P<0.01),而SOD活性明显低于S组(P<0.01),肝脏的显微及超微结构损伤明显;IPC组与DE组的各项肝损伤指标均明显好于C组(P<0.05及P<0.01);IPC+5-HD组的肝损伤指标均差于IPC组(P<0.05及P<0.01). 结论 缺血预处理对正常大鼠肝脏I/R损伤具有延迟保护作用,肝细胞mitoKATP通道的开放在其中发挥了重要作用,作用途径可能与诱导肝脏SOD活性增加,改善肝组织微循环,减轻肝脏水肿有关.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号