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1.
目的:探讨maFGF对大鼠缺氧再灌注心脏的保护作用及其机制。 方法: 在Langendorff离体心脏灌流装置上建立缺氧再灌注模型,用BL-410生物机能实验系统记录左室发展压(LVDP)、左室内压上升/下降的最大速率(dp/dtmax、dp/dtmin),比较经maFGF和aFGF预处理,心肌缺氧再灌前后LVDP、dp/dtmax、dp/dtmin的变化,测定冠脉流出液中的LDH、MDA、SOD水平。 结果: maFGF和aFGF预处理均明显促进心肌缺氧再灌后心功能恢复,减少缺氧再灌注导致的LDH漏出、SOD降低和MDA升高。 结论: maFGF对缺氧再灌注心脏具有一定的保护作用,其作用机制可能与提高自由基清除酶活性及抑制脂质过氧化反应有关。  相似文献   

2.
目的: 研究缺血后处理(postconditioning)对抗大鼠离体心脏缺血再灌注损伤及其作用机制。方法:采用SD大鼠心肌缺血/再灌注模型,并于再灌注一开始即给予3次全心停灌30 s,再灌30 s处理作为缺血后预处理。记录心肌收缩功能指标,以Even’s blue-TTC法监测心肌梗死范围,并对心律失常严重程度进行定量分析。结果:缺血后处理组左室峰压(LVSP)、最大左室收缩速率(+dp/dtmax)以及心率明显高于缺血对照组。缺血后处理可明显缩小心肌梗死范围(22.97%±3.96% vs 缺血对照组 44.30%±13.61%,P<0.01)。观察复灌10 min时心律失常评分发现,缺血后处理组明显低于缺血对照组。缺血后处理组和缺血预处理组具有类似的心肌保护作用。5-HD组LVSP和+dp/dtmax低于缺血后处理组,心律失常评分增高,心肌梗死范围扩大。结论: 缺血后处理对大鼠缺血再灌注损伤具有心脏保护作用,其作用机制可能是部分通过激活线粒体ATP依赖性钾离子(mitoKATP)通道起作用。  相似文献   

3.
尾加压素预处理对大鼠心脏缺血再灌注损伤的影响   总被引:3,自引:1,他引:3       下载免费PDF全文
目的:探讨尾加压素(UII)预处理对于离体灌流大鼠心脏缺血再灌注(I/R)损伤的影响。方法:在离体灌流的SD大鼠心脏I/R模型上,以UII预灌注心脏,采用MFLLab200心功能软件监测心功能,以试剂盒测定心肌细胞ATP、总钙、丙二醛含量和乳酸脱氢酶(LDH)漏出,并观察其对于冠脉流出量(CPF)的影响。结果:UII预处理组与单纯I/R组比较,冠脉流出液中LDH低28%[(78.3±18.1)U/Lvs(10.93±23.9)U/L,P<0.05],心肌组织MDA和钙含量分别低24%和27%(P<0.05);ATP含量高73%(P<0.05)。与I/R组比较,UII预处理组CPF高42%[(5.4±0.7)mL/minvs(3.8±0.8)mL/min,P<0.05],LVEDP低20%(P<0.05),±dp/dtmax分别高25%和45%(P<0.05);冠脉流出液中NO2-/NO3-含量高63%(P<0.05)。结论:UII预处理可以减轻离体灌注大鼠心脏I/R所造成的损伤,其机制与NO介导的冠脉扩张效应有关。  相似文献   

4.
 目的: 运用蛋白质组学研究方法探讨吡那地尔后处理对缺血再灌注损伤大鼠心肌的保护作用。方法: 建立Langendorff大鼠离体心脏缺血再灌注损伤模型,随机分为吡那地尔后处理组(Pina组)和缺血再灌注损伤组(I/R组),每组9只。提取心肌线粒体蛋白质行双向凝胶电泳,应用质谱鉴定差异大于2倍的蛋白质点。结果: Pina组与I/R组比较,共发现7个差异蛋白质:Pina组NADH脱氢酶1α亚复合体10亚基(NDUFA10)﹑NADH脱氢酶铁硫蛋白2(NDUFS2)和NADH脱氢酶黄素蛋白2(NDUFV2)表达低于I/R组;Pina组异柠檬酸脱氢酶α亚基(IDHA)和Δ3,52,4-二烯酰辅酶A异构酶(ECH1)表达高于I/R组;另有2个蛋白质点均被鉴定为ATP合酶δ亚基,一个蛋白质点表达升高,而另一个表达降低。结论:吡那地尔后处理可能抑制了复合体Ⅰ的亚基(NDUFA10﹑NDUFS2和NDUFV2)代偿性增加,但促进了IDHA和ECH1表达并引发了ATP合酶δ亚基发生磷酸化,这些改变可能均与吡那地尔后处理保护心肌的作用有关。  相似文献   

5.
目的:观察钙调素拮抗剂三氟拉嗪(TFP)及钙通道阻滞剂异博定(VP)对缺钙-复钙损伤心肌的保护作用。方法:应用TFP与VP对离体大鼠心脏进行灌流。检测心肌钙含量、灌流液中乳酸脱氢酶(LDH)及心肌蛋白漏出量等指标。结果:TFP显著减少损伤心肌的钙含量、LDH及蛋白漏出量,与对照组相比差异显著(P<0.01)。VP灌注组与对照组相比各项指标差异无显著(P>0.05)。TFP与VP联合应用各项检测指标值明显低于单独应用TFP(P<0.01)。结论:TFP有效减轻钙反常心肌损伤的程度;VP对钙反常心肌无保护作用。联合应用TFP与VP的心肌保护效果更佳。钙反常时Ca2+大量内流主要通过钙调素介导,但慢钙通道在钙超载形成过程中也可能起一定作用。  相似文献   

6.
Myocardial functional recovery and creatine kinase (CK) release following various periods of ischaemia were investigated in isolated mouse hearts. The hearts were perfused in the Langendorff mode with pyruvate-containing Krebs-Hensleit (KH) buffer under a constant perfusion pressure of 80 mmHg, and were subjected to either continuous perfusion or to 5, 15, 20, 25, 30, 45 or 60 min of global ischaemia followed by 45 min of reperfusion. In hearts subjected to ischaemic periods of 5, 15 or 20 min, there was a transient reduction in the left ventricular (LV) dP/dt max during the early phase of reperfusion, while the recovery at the end of reperfusion reached a level similar to that in hearts subjected to continuous perfusion. In hearts subjected to longer ischaemic periods, i.e. 25, 30, 45 or 60 min, the decrease in the cardiac performance was more pronounced and persistent, with significantly lower recovery in LV dP/dt max and higher LV end diastolic pressure (LVEDP) at the end of reperfusion than in the non-ischaemic hearts. There were no significant differences in the recoveries in coronary flow or in heart rate (HR) between groups. Similarly to the functional recovery, the release of CK showed a clear ischaemic length-related increase. In conclusion, the Langendorff-perfused isolated mouse heart could be a valuable model for studies of myocardial ischaemia/reperfusion injury. Future studies using gene-targeted mice would add valuable knowledge to the understanding of myocardial ischaemia/reperfusion injury.  相似文献   

7.
目的探讨缺血后处理对大鼠离体心脏缺血再灌注损伤的作用及相关机制。方法 36只Wistar大鼠(257-326g),随机分为3组,对照组(Con组),缺血再灌注组(IR组),缺血后处理组(IPo C组)。采用Langendorff灌流装置建立缺血再灌注损伤模型,TTC染色评价梗死面积,Western blot检测凋亡蛋白及内质网应激相关通路蛋白表达。结果 IR组较Con组梗死面积增加,而Bcl-2表达显著降低,GRP78、CHOP、cleaved caspase12、cleaved caspase3、Bax及p-PERK表达水平显著增加。缺血后处理显著缩小梗死面积,并部分逆转相关蛋白表达的变化。结论缺血后处理减轻大鼠离体心脏缺血再灌注损伤,可能与抑制PERK通路介导的ERS相关凋亡相关。  相似文献   

8.
Amiloride对低血流缺氧再灌注心肌的保护作用   总被引:2,自引:0,他引:2  
本文采用离体大鼠等容收缩心脏模型,探讨Na/H交换机制在心脏低血流缺氧后再灌注损伤中的意义。心脏富氧灌流30min后,随机分为三组:(1)富氧组:富氧灌流75 min;(2)对照组:低血流缺氧45 min后再恢复富氧灌流30 min;(3)Amiloride组:低血流缺氧期间,溶0.5(mmol/L)Amiloride(Na/H交换抑制剂)于K-H液中,余同组(2)。实验发现Amiloride组心脏各血液动力学指标优于对照组,冠脉流出液中LDH活性及心肌组织MDA含量均少于组(2),线粒体及胞浆液中GSH-Px活力得以保护,心肌组织Na~ 、Ca~(2 )超负荷减轻,K~ 丢失减少。结果表明:抑制Na~ /H~ 交换能明显减轻低血流缺氧心肌再灌注损伤。  相似文献   

9.
目的观察不同浓度镁离子对豚鼠离体心脏缺血再灌注损伤的影响。方法建立离体心脏缺血再灌注模型,应用含不同浓度镁离子的Krebs-henseleit(KH)液,观察心率(heart rate, HR)、冠脉流量(coronary flow, CF)以及灌流液中乳酸脱氢酶(lactate dehydrogenase, LDH)等指标的变化。结果缺血再灌注模型组与正常对照组(Control)相比较,HR、CF和CF/HR均有明显降低,而灌流液中LDH含量明显增加。与模型组相比较,低浓度镁离子再灌注诱发缺血再灌注损伤心脏的HR异常增加,对CF、CF/HR、LDH含量没有影响。高浓度镁离子再灌注对HR没有影响,却增加了CF和CF/HR,同时降低灌注液中LDH含量。结论低镁增加缺血再灌注中的心率,可能带来增加耗氧量,增大心律失常的危险性。而高镁可能通过改善心肌收缩力(CF/HR)降低缺血再灌注损伤。  相似文献   

10.
目的:观察非创伤性肢体缺血预处理对大鼠离体再灌注心肌是否有保护作用。方法:实验采用体重(250±30)gSD雄性大鼠25只随机分成3组,在Langendorff装置上对大鼠离体心脏进行灌流。对照组(C,n=8):在灌注全程均用富氧K-H液(充以95%O2+5%CO2),在恒压(8.33kPa)、恒温(37℃)条件下灌注;缺氧/复氧组(A,n=8):预灌15min后,灌注心脏先全心缺血缺氧15min,随后15min复氧再灌注(37℃);非创伤性肢体缺血预处理组(N-WIP,n=9):先将大鼠双后肢捆绑5min,松开5min,反复4次后,随后的方法同R组。在相应时点分别测定冠脉流出液和心肌匀浆中超氧化物歧化酶(SOD)活性,Ca2+-Mg2+-ATP酶活性和丙二醛(MDA)含量,同时记录心肌细胞的单相动作电位(MAP)和心肌收缩张力曲线。结果:非创伤性肢体缺血预处理能使再灌注心律失常发生率显著低于A组;心肌组织中MDA含量显著低于A组,心肌组织中SOD活性显著高于A组,心肌细胞的膜电位、Ca2+-Mg2+-ATP酶活性及肌张力较稳定。结论:非创伤性肢体缺血预处理对大鼠离体再灌注心肌有明显的保护作用,可能是通过增强心肌的抗氧化能力、稳定心肌Ca2+-Mg2+-ATP酶活性和膜相结构等途径,提高心肌细胞对再灌注损伤的抵抗力。  相似文献   

11.
Myocardial functional recovery and creatine kinase (CK) release following various periods of ischaemia were investigated in isolated mouse hearts. The hearts were perfused in the Langendorff mode with pyruvate‐containing Krebs–Hensleit (KH) buffer under a constant perfusion pressure of 80 mmHg, and were subjected to either continuous perfusion or to 5, 15, 20, 25, 30, 45 or 60 min of global ischaemia followed by 45 min of reperfusion. In hearts subjected to ischaemic periods of 5, 15 or 20 min, there was a transient reduction in the left ventricular (LV) dP/dt max during the early phase of reperfusion, while the recovery at the end of reperfusion reached a level similar to that in hearts subjected to continuous perfusion. In hearts subjected to longer ischaemic periods, i.e. 25, 30, 45 or 60 min, the decrease in the cardiac performance was more pronounced and persistent, with significantly lower recovery in LV dP/dt max and higher LV end diastolic pressure (LVEDP) at the end of reperfusion than in the non‐ischaemic hearts. There were no significant differences in the recoveries in coronary flow or in heart rate (HR) between groups. Similarly to the functional recovery, the release of CK showed a clear ischaemic length‐related increase. In conclusion, the Langendorff‐perfused isolated mouse heart could be a valuable model for studies of myocardial ischaemia/reperfusion injury. Future studies using gene‐targeted mice would add valuable knowledge to the understanding of myocardial ischaemia/reperfusion injury.  相似文献   

12.
 目的:观察银杏达莫注射液预处理对大鼠离体心脏缺血/再灌注损伤的影响,并探讨其可能的作用机制。方法:SD雄性大鼠40只随机分成5组(n=8):正常对照(NC)组、缺血/再灌注(I/R)组、缺血预处理(IPC+I/R)组、银杏达莫注射液预处理(GD+I/R)组和银杏达莫+氯化镧预处理(GD+LaCl3+I/R)组。观察各组相同时点(预灌30 min稳定点,缺血30 min,再灌5 min、30 min、60 min)的心功能指标,包括心率(HR)、左室收缩压(LVSP)和室内压变化速率(±dp/dtmax),同时收集各时点冠脉流出液,检测其中乳酸脱氢酶(LDH)和肌酸激酶(CK)活性。实验结束后检测心肌线粒体Ca2+浓度和α-酮戊二酸脱氢酶(α-OGDH)含量。结果:与I/R组比较,IPC+I/R组和GD+I/R组在心脏再灌注期各项心功能指标均得到改善(P<0.05);心肌LDH和CK的释放量降低(P<0.01);线粒体内Ca2+超载降低(P<0.01),且线粒体内α-OGDH含量升高(P<0.05);而GD+I/R组中银杏达莫对心肌的保护作用被LaCl3抑制(P<0.05)。结论:银杏达莫可能通过抑制钙超载、增强线粒体酶活性以稳定线粒体能量代谢,从而缓解缺血/再灌注诱导的心肌细胞损伤。  相似文献   

13.
BACKGROUND: We evaluated the contribution of endogenous and exogenous nitric oxide (NO) in ischaemia reperfusion (IR) injury and histamine release in the isolated guinea pig heart. METHODS: Ischaemia reperfusion was performed in isolated Langendorff perfused guinea pig heart throughout the ligature of the left anterior descending coronary (LAD) artery for 20 min, and following the release of the ligature for a further 20 min. RESULTS: IR promoted a linear release of lactate dehydrogenase (LDH) and a preferential release of histamine in the reperfusion phase. The amount of nitrite (NO2-, one of the breakdown products of NO) released during IR was significantly lower than in the control hearts. These effects were accompanied by an increase in calcium levels and malonyl-dialdehyde (MDA) production in the left ventricle and by a decrease in cardiac mast cell metachromasia. Perfusion of the hearts with two inhibitors of the nitric oxide synthase pathway, namely N(G)-monomethyl-L-arginine (L-NMMA, 10(-4) M) or nitroarginine methylester (L-NAME, 10(-5) M) significantly enhanced histamine and LDH release; these effects were attenuated by co-infusion with L-arginine (10(-4) M) but not D-arginine (10(-4) M), while L-arginine (10(-4) M) alone had no effect. Perfusion of the heart with sodium nitroprusside (SNP), 3-morpholinosydnonimine (SIN-1), glyceryl trinitrate (GTN), all at 10(-5) M, reduced histamine release, LDH release, calcium overload and MDA production induced by IR. These effects were amplified by concomitant perfusion with superoxide dismutase (SOD, 50 IU/ml). CONCLUSION: The endogenous production of NO provides significant myocardial protection from IR injury and histamine release. These effects were mimicked by various NO donors.  相似文献   

14.
川芎嗪对缺血再灌注所致大鼠离体心脏损伤的保护作用   总被引:7,自引:0,他引:7  
陈义斌 《医学信息》2006,19(5):826-829
目的:观察川芎嗪对缺血再灌注所致大鼠离体心脏损伤的保护作用。方法:心脏缺血再灌注模型:大鼠离心脏Langen-dorff灌流,全心停灌20分钟后复灌40分钟造成缺血--再灌注损伤。将充水乳胶球囊通过左心房插入左心室,Medlab-u/81生物信号采集处理系统记录分析心功能指标LVP,±dp/dtmax,HR和CF,收集再灌5分钟时,冠脉流出液。用分光光度法测定肌酸激酶(CK)活性。结果:缺血再灌注能降低冠脉流量,LVP,±dp/dtmax值,减慢心率、增加CK释放量,两个浓度的川芎嗪(40与80mg·L-1)对离体大鼠心脏缺血再灌注损伤有保护作用,表现为改善心功能,增加冠脉流量,减少心肌细胞内酶CK的释放,川芎嗪与维拉帕米有相似的心肌保护作用。结论:川芎嗪对心脏缺血再灌注心功能损伤具有保护作用。  相似文献   

15.
The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE) pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S) postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g) were divided into 6 groups (N = 14 per group): time-matched perfusion (Sham) group, ischemia/reperfusion (I/R) group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM) group, and dimethyl sulfoxide (DMSO; <0.2%) group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), and the maximum rate of increase or decrease of left ventricular pressure (± dp/dtmax) were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC) staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05) and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05). However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.  相似文献   

16.
Free radicals have been implicated in myocardial reperfusion injury. Hydrogen peroxide (H2O2) is a precursor of highly reactive oxygen intermediates. In this study, we investigated myocardial injury caused by endogenous H2O2 during the early reperfusion period following brief ischemia with electron microscopy and the cerium method. This method involves formation of an electrondense precipitate when H2O2 reacts with cerium chloride (CeCl3). We used isolated, functioning hearts prepared according to the working heart model, which were reperfused with a solution containing 0.5mM CeCl3 for 5 min after 10 min of ischemia. Some hearts were treated with 3-amino-1,2,4-triazole (ATZ) to inhibit catalase; others were treated with ATZ and superoxide dismutase (SOD), which dismutates the superoxide anion to hydrogen peroxide. In the control group (no drugs given) and the ATZ-treated group, the CeCl3–H2O2-dependent reaction products during the reperfusion period appeared in 12% and 28%, respectively, of the microvascular spaces. Treatment with SOD did not produce a decrease in electron-dense precipitates or a decrease in myocardial injury during ischemia-reperfusion. Moreover, in the ATZ group, moderately injured myocytes were seen (swelling of mitocondria, intermyofibrillar edema). Our results indicate that in myocytes, catalase plays an important role in the defense against H2O2 and that the increase in H2O2 is a cause of reperfusion injury. However, SOD does not protect against H2O2 in the absence of catalase.This study was presented in part at the 27th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Kurashiki, September 29, 1995  相似文献   

17.
Myocardial ischemia-reperfusion injury increases both tissue levels and release of histamine. To study the possible effects of ischemia-reperfusion on histamine metabolism tissue activities of histidine decarboxylase (HDC), histamine N-methyl transferase (HNMT) and diamine oxidase (DAO) were investigated in isolated rat hearts subjected to either 20 min global ischemia and 40 min reperfusion (n=10) or control perfusion (n=8). Histamine in the coronary effluent increased from 21±4 nmol/min (mean ± SEM) before ischemia to 55±5 and 50±7 nmol/min after 4 and 10 min reperfusion (p<0.004 and p<0.004). Tissue HDC activity did not change during observation in any group. HNMT activity was unchanged in controls, but increased from 0.37±0.04 to 0.84±0.18 and 0.96±0.22 pmol methlylhistamine/mg protein hour after 4 and 10 min reperfusion (p<0.008 and p<0.01). DAO decreased similarily in controls and ischemic-reperfused hearts during observation. In conclusion, the previously observed increase of tissue histamine during reperfusion cannot be explained by increased histamine synthesis or decreased histamine catabolism.accepted by W. Lorenz  相似文献   

18.
目的:探讨Bcl-2、PCNA等蛋白表达在成肌细胞氧化应激损伤中的意义。方法:将对数生长期成肌细胞进行分组,结合碱性成纤维细胞生长因子(bFGF)预处理2 h及过氧化氢处理,分为正常对照(control)组、单纯bFGF组、氧化应激组(H_2O_2组)和干预组(bFGF+H_2O_2组)。免疫组化检测Bcl-2和Bax阳性沉积颗粒;免疫荧光观察成肌细胞形态及Bcl-2和Bax荧光表达;Western blot检测Bcl-2、PCNA等蛋白表达情况。结果:免疫荧光及免疫组化结果显示,与氧化应激组比较,干预组Bcl-2表达增加,Bax表达减少;Western blot显示,干预组Bcl-2和PCNA水平增加,Bax水平降低。结论:氧化应激诱导的大鼠成肌细胞损伤参与肌细胞病理进程。Bcl-2和PCNA表达上调可减轻成肌细胞损伤程度。  相似文献   

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脂联素对氧应激所致心肌损伤的影响   总被引:4,自引:3,他引:1       下载免费PDF全文
目的: 通过原代培养SD大鼠的乳鼠心肌细胞建立过氧化氢(H2O2)心肌细胞氧应激损伤模型,观察脂联素 (adiponectin)对氧应激所致心肌细胞损伤的影响。方法: 采用酶消化法原代培养乳鼠心肌细胞,α-肌动蛋白免疫荧光法进行细胞鉴定。选用培养至3-4 d的细胞,用H2O2建立细胞损伤模型,细胞损伤前用脂联素和阿糖胞苷(Ara-A)进行预处理。观察心肌细胞形态的变化,测定乳酸脱氢酶(LDH)的释放、丙二醛(MDA)的含量和超氧化物歧化酶(SOD)的活性,通过琼脂糖凝胶电泳和流式细胞术来检测心肌细胞的凋亡。结果: 脂联素预处理可以明显降低H2O2损伤后心肌细胞LDH的释放(P<0.05)和MDA的含量(P<0.05),DNA ladder条带减弱,心肌细胞凋亡率也下降(P<0.05),而心肌细胞SOD活性较H2O2损伤组增高(P<0.05)。Ara-A(终浓度为1 mmol/L)能够部分阻断脂联素预处理后对心肌细胞损伤的影响。结论: H2O2可以诱导心肌细胞的损伤及凋亡,脂联素可以通过单磷酸腺甘(AMP)激活蛋白激酶(AMPK)通道发挥保护作用。  相似文献   

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