KATP通道在硝酸甘油诱导的第二心肌保护窗中的作用

目的 确定硝酸甘油(NTG)对大鼠在体缺血再灌注(I／R)心肌是否具有延迟保护作用。方法 建立在体大鼠心脏缺血再灌注模型。40只大鼠随机分成5组：生理盐水 I／R组、NTG I／R组、NTG 格列苯脲 I／R组、格列苯脲 I／R组及假手术组。以心肌梗塞范围、血清肌酸激酶(CK)活性及心肌组织丙二醛(MDA)含量为观察指标。结果 与对照组相比,NTG可显著缩小24h后缺血再灌注心肌的梗塞范围(P＜0．01),而且血清CK活性、心肌MDA含量亦显著降低(P＜0．01);而在I／R前给予格列苯脲可取消NTG的保护作用,且血清CK、心肌MDA含量与对照组相比并无明显差异。结论 NTG可产生延迟心肌保护效应,而该效应可能由KATP通道介导。     

Cardioprotection from ischemia by fibroblast growth factor: role of inducible nitric oxide synthase

Growing evidence from both animal experiments and clinical observations indicates that fibroblast growth factor (FGF) plays a protective role in myocardial reperfusion injury. The molecular and cellular mechanisms that lead to this postischemic myocardial protection, however, remain largely unexplored. We studied the cardioprotective effects of human recombinant acidic fibroblast growth factor (aFGF, FGF-1) in a rat model of myocardial reperfusion injury, induced by 20 minutes of left coronary artery occlusion followed by 24 hours of reperfusion. Intravenous FGF-1 administration at the onset of heart reperfusion attenuated both the functional impairment and the histological changes of ischemia/reperfusion injury. FGF-1 increases more than twice the left ventricular contractile function (p <0.005) compared to vehicle-treated rats. As shown by histology, myocardial tissue is better preserved with FGF-1 treatment. The infarct size, normalized for the area at risk, was significantly smaller in the FGF-1 group (p <0.01) than in the vehicle group. Furthermore, FGF-1 administration resulted in expression of inducible nitric oxide synthase (iNOS) in the area at risk. Since increased expression of iNOS could potentiate cardioprotection against myocardial reperfusion injury, our findings support a new non-mitogenic role for FGF and add a clinical interest for this protein in increasing myocardial ischemic tolerance.     

缺氧预处理对乳鼠心肌细胞缺氧/复氧损伤的保护作用

目的：观察缺氧预处理（HPC）对心肌细胞的保护作用,并对其保护机制进行探讨。方法：在培养的乳鼠心肌细胞HPC模型上,设正常对照组、缺氧/复氧组、缺氧预处理组、优降糖+缺氧预处理组,检测HPC对心肌细胞的存活率、培养液中乳酸脱氢酶（LDH） ,肌酸激酶（CK）和丙二醛（MDA）含量、细胞内ATP含量和细胞黏附分子-1（ICAM-1）表达的影响。结果：HPC可提高细胞生存率,减少细胞内ATP的降解,降低细胞内LDH及CK的漏出,减少细胞脂质过氧化物（MDA）的生成,并抑制ICAM-1的表达增加。ATP敏感性钾离子通道（ATP sensitive K+ channel,KATP通道）阻断剂优降糖可完全消除HPC对心肌细胞的保护作用。结论：在HPC心肌细胞保护作用机制中,KATP通道是重要的效应子,其机制与抑制ICAM-1的表达有关。     

Ischemic preconditioning in immature hearts： mechanism and compatibility with cardioplegia

Objective To investigate (1) whether ischemic preconditioning (IPC) could protect immature rabbit hearts against ischemia-reperfusion injury and (2) the role of K(ATP) channel in the mechanism of myocardial protection. Since cardioplegia is a traditional and effective cardioprotective measure in clinic, our study is also designed to probe the compatibility between IPC and cardioplegia. Methods New Zealand rabbits aged 14-21 days weighing 220-280 g were used. The animals were anesthetized and heparinized. The chest was opened and the heart was quickly removed for connection of the aorta via Langendorff’s method within 30 s after excision. All hearts were perfused with Krebs-Henseleit buffer balanced with gas mixture (O［２］∶CO(2)=95%∶5%) at 60 cm H［2O］ (perfusion pressure). IPC consisted of 5 min global ischemia plus 10 min reperfusion. Glibenclamide was used as the K(ATP) channel blocker at a concentration of 10 μmol/L before IPC. Cardiac arrest was induced with 4℃ St. Thomas cardioplegic solution, at which point the heart was made globally ischemic by withholding perfusion for 45 min followed by 40 min reperfusion. Thirty immature rabbit hearts were randomly divided into four groups: CON (n=9) was subjected to ischemia-reperfusion only; IPC (n=9) underwent IPC and ischemia-reperfusion; Gli (n=6) was given glibenclamide and ischemia-reperfusion; and Gli+IPC (n=6) underwent glibenclamide, IPC and ischemia-reperfusion. Coronary flow (CF), HR, left ventricle developed pressure (LVDP), and ±dp/dt(max) were monitored at equilibration (baseline value) and 5, 10, 20, 30 and 40 min after reperfusion. The values resulting from reperfusion were expressed as a percentage of their baseline values. Arrhythmia quantification, myocardial enzyme in the coronary effluent and myocardial energy metabolism were also determined. Results The recovery of CF, HR, LVDP and ±dp/dt(max) in preconditioned hearts was best among the four groups. The incidence of arrhythmia was low and less CK-MB leaked out in the IPC group. Myocardial ATP content was better preserved by IPC. Pretreatment with glibenclamide completely abolished the myocardial protection provided by IPC, but did not affect ischemia-reperfusion injury. Conclusions While applying cardioplegia, IPC provides significant cardioprotective effects. Activation of K(ATP) channels is involved in the mechanism of IPC-produced cardioprotection.     

缺血预适应KATP通道的实验研究

目的探讨KATP通道在缺血预适应（ischemic preconditioning，IP）中所起的作用。方法建立在体犬鼠缺血再灌（ischemia／reperfusion，IR）模型，将60只犬鼠随机分为5组：缺血再灌（IR）组，缺血预适应（IP）组，尼可地尔（NIC）组，格列苯脲（GLI）组，5-HD组。分别测定各组的心肌梗死范围，血清CK，LDH浓度，监测各组心电图，应用透射电镜观察其超微结构的变化。结果相对与IR组，IP组明显的减少了心律失常分值和室颤发生率（P〈0．05），而5-HD组，NIC组则有加重心律失常发生的趋势；相对IR组，NIC组可部分模拟IP作用，而5-HD组则完全取消了IP的抗心肌缺血的保护作用。结论KATP通道可能是IP发生的效应器；线粒体KATP通道特异性阻滞剂能阻断KATP通道的抗心肌缺血的作用，推测至少在缺血阶段，线粒体KATP通道在IP中发挥了主要的作用。     

尼可地尔对大鼠心肌缺血再灌注损伤保护作用的实验研究

目的　确定尼可地尔 (nicorandil,NIC)对大鼠在体缺血再灌注 (IR)心肌是否具有保护作用。方法　建立在体大鼠心脏缺血再灌注模型。 64只大鼠随机分成 4组 :假手术组、IR组、NIC +IR组、GL+NIC +IR组。分别测定各组的心肌梗死范围、血清肌酸激酶 (CK)浓度和梗死部位心肌细胞ATP含量。结果　缺血后CK含量升高 ,局部ATP浓度下降 ;NIC可显著缩小心梗范围、降低CK浓度、减少梗死部位心肌细胞ATP的消耗 (P <0 .0 5 ) ;格列苯脲 (glibenclamide ,GL)可明显减弱NIC的上述作用 (P <0 .0 5 )。结论　NIC对在体缺血心肌有明显的保护作用 ,其机制可能与激活心肌细胞膜KATP通道有关。     

钾离子通道的活性状态对蛛网膜下腔注射腺苷抗伤害性作用的影响

目的探讨ATP敏感型钾离子通道的活性状态对鞘内注射腺苷类似物R-phenylisopropyladenosine(R-PIA)抗伤害性作用的影响.方法雄性SD大鼠在苯巴比妥钠麻醉下,蛛网膜下腔留置PE-10导管,测定注药后鼠尾对光热刺激的反应(抗伤害作用).结果蛛网膜下腔注射R-PIA产生剂量依赖性的甩尾时间曲线上移(P＜0.05).蛛网膜下腔注药后10min起效,镇痛时间长达60min.ATP敏感型通道开放剂nicorandil和阻滞剂glibenclamide单独蛛网膜下腔应用无镇痛作用(P＞0.05),但nicorandil明显增强R-PIA的抗伤害性作用,相反glibenclamide明显减弱R-PIA的抗伤害性作用(P＜0.05).结论蛛网膜下腔注射R-PIA可产生明显的剂量依赖性抗伤害作用,此作用受ATP敏感型钾离子通道活性调节.     

线粒体ATP敏感性钾通道与心脏缺血预适应

关于心脏缺血预适应的研究较多,其机制尚不清楚,但ATP敏感性钾通道（K     

EFFECTS OF GLIBENCLAMIDE, GLIMEPIRIDE, AND GLICLAZIDE ON ISCHEMIC PRECONDITIONING IN RAT HEART

Objective To compare the influence of different sulfonylureas on the myocardial protection effect of ischemic preconditioning (IPC) in isolated rat hearts, and ATP-sensitive potassium channel current (IKATP) of rat ventricular myocytes. Methods Isolated Langendorff perfused rat hearts were randomly assigned to five groups: (1) control group, (2) IPC group, (3) IPC glibenclamide (GLB, 10 μmol/L) group, (4) IPC glimepiride (GLM, 10 μmol/L) group, (5) IPC gliclazide (GLC, 50 μmol/L) group. IPC was defined as 3 cycles of 5-minute zero-flow global ischemia followed by 5-minute reperfusion. The haemodynamic parameters and the infarct size of each isolated heart were recorded. And the sarcolemmal IKATP of dissociated ventricular myocytes reperfused with 10 μmol/L GLB, 1 μmol/L GLM, and 1 μmol/L GLC was recorded with single-pipette whole-cell voltage clamp under simulated ischemic condition. Results The infarct sizes of rat hearts in IPC (23.7%±1.3%), IPC GLM (24.6%±1.0%), and IPC GLC (33.1%±1.3%) groups were all significantly smaller than that in control group (43.3%±1.8%; P<0.01, n=6). The infarct size of rat hearts in IPC GLB group (40.4%±1.4%) was significantly larger than that in IPC group (P<0.01, n=6). Under simulated ischemic condition, GLB (10 μmol/L) decreased IKATP from 20.65±7.80 to 9.09±0.10 pA/pF (P<0.01, n=6), GLM (1 μmol/L) did not significantly inhibit IKATP (n=6), and GLC (1 μmol/L) decreased IKATP from 16.73±0.97 to 11.18±3.56 pA/pF(P<0.05, n=6). Conclusions GLM has less effect on myocardial protection of IPC than GLB and GLC. Blockage of sarcolemmal ATP-sensitive potassium channels in myocardium might play an important role in diminishing IPC-induced protection of GLM, GLB, and GLC.     

Effect of temperature on the activation of myocardial KATP channel in guinea pig ventricular myocytes: a pilot study by whole cell patch clamp recording

Background The myocardial ATP sensitive potassium channel (K(ATP) channel) has been known for more than two decades, the properties of this channel have been intensively investigated, especially the myocardial protection effect by opening this channel. Numerous studies, including hypothermic, using K(ATP) agonists to achieve a hyperpolarizing cardioplegic arrest, have shown a better myocardial protection than potassium arrest. However, there is no evidence showing that K(ATP) channel could be opened by its agonists under profound hypothermia. We investigated the effect of temperature on activation of myocardial K(ATP) channel by nicorandil.Methods Isolated ventricular myocytes were obtained by collagenase digestion of the hearts of guinea pigs and stored in KB solution at 4&#730;C. With a steady ground current, the myocytes were perfused with 1 mmol/L nicorandil until a steady IK(ATP) occurred. Then the cells were perfused with 1 mmol/L nicorandil plus 1 &micro;mol/L glybenclamide. Currents signals were recorded on whole cells using patch clamp technique at several temperatures. The temperature of the bath solution around myocytes was monitored and was controlled at 4&#730;C, 10&#730;C, 20&#730;C, 25&#730;C and 35&#730;C respectively. About 10 cells were tested at each temperature, the cells were considered useful only when the outward current could be induced by nicorandil and blocked by glybenclamide. All data were analyzed using Graphpad PRISM 3.0 (Graphpad, San Diego, CA, USA). Nonlinear curve fitting was done in Clampfit (Axon) or Sigmaplot (SPSS). Results At 4&#730;C, 10&#730;C, 20&#730;C, 25&#730;C and 35&#730;C, the time needed to open the myocardial K(ATP) channel was (81.0±0) minutes, (50.5±11.7) minutes, (28.8±2.3) minutes, (9.4±10.2) minutes and (2.3±1.0) minutes respectively (P=0.003). The linear relationship between temperature and time needed to open the channel was y (min) = (4348.790－124.277x)/60, where y (min) is time needed to open K(ATP) channel, x is temperature, correlation coefficient r =－0.942 (P=0.00), regression coefficient b =－124.277 (P=0.00). The current densities among different temperatures were statistically different (P=0.022), the current density was greater after the activation of K(ATP) channel at higher temperatures. The lower the temperature, the fewer cells in which K(ATP) channels could be opened. At 4&#730;C, only one cell in which the K(ATP) channel could be opened, took a quite long time (81 minutes) and the I-V curve was quite untypical.Conclusions K(ATP) channel activated by nicorandil is temperature dependent and the temperature linearly related to time needed to open K(ATP) channel; the lower the temperature, the longer the time needed to open channel and the smaller the current density. At profound hypothermia, it is difficult to activate K(ATP) channels.     

Cardioprotective effects of morphine on rat heart suffering from ischemia and reperfusion

Objective To investigate the cardioprotective effects of morphine on ischemic reperfused rat heart in vitro and its mechanism.Methods The isolated rat heart was perfused in a Langendorff apparatus. Infarct myocardium was determined by TTC. Coronary flow (CF), heart rate (HR), left ventricular pressure (LVP), the first derivative of ventricular pressure (LVP/dtmax) and infarct size after ischemia and reperfusion in rat heart given 0.3 μmol/L morphine were observed. The effects of naloxone and glibenclamide on the cardioprotection of morphine were also measured.Results After ischemia and reperfusion, CF, HR, LVP and LVP/dtmax of isolated rat hearts decreased significantly (P&lt;0.01). After morphine preconditioning, HR, LVP and LVP/dtmax increased (P&lt;0.01) and infarct size was reduced significantly (P&lt;0.01), while no significant change in CF (P&gt;0.05). The cardioprotective effects of morphine were abolished by naloxone or glibenclamide completely.Conclusions Morphine can reduce ischemia-reperfusion injuries in isolated rat heart. The cardioprotective effects of morphine are mediated by a local opioid receptor-KATP channel linked mechanism in rat hearts.     

布托啡诺后处理对大鼠心肌缺血再灌注损伤的影响

目的:探讨布托啡诺后处理是否具有减轻心肌缺血再灌注损伤的作用及其可能的机制.方法:通过结扎冠状动脉前降支30 min、开放120 min的方法建立心肌缺血再灌注模型.健康SPF‘级成年雄性Wistar大鼠10只,随机分为5组(各组分别10只).A组:假手术组;B组:I/R组;C组:布托啡诺后处理组;D组:布托啡诺联合选...     

ATP敏感性钾通道开放剂对培养乳鼠窦房结细胞模拟缺血时细胞活性的影响

目的 观察ATP敏感性钾（KATP）通道开放剂对模拟缺血窦房结细胞活性的细胞,并探讨其作用机制。方法 取培养2d的窦房结细胞,以低渗（85msmol/L）台盼蓝染色四唑盐（MTT）比色观察窦房结细胞活性的变化。结果 模拟缺血4h后,窦房结细胞脆性增加、活性降低;KATP通道开放剂Pinacidil和Diazoxide能显著降低模拟缺血窦房结细胞脆性,增加细胞的活性,但两组间无明显的统计学差异;KATP通道阻断剂5-HD能逆转Pinacidil及Diazoxide的上述作用。结论 KATP通道开放剂Pinacidil和Diazoxide对缺血窦房结细胞具有显著的保护作用,但这种效果能为KATP通道阻断剂5-HD阻断。本研究提示窦房结细胞线粒体内膜可能有KATP通道存在,它的开放可能是细胞获得保护的关键。     

大鼠心肌缺血预适应对心肌缺血-再灌注损伤的保护作用及ATP敏感钾通道的作用

目的本研究旨在确定在完整大鼠模型中,心肌缺血预适应是否具有心肌保护作用,且这种保护作用是否由KATP通道介导。方法将48只大鼠随机分为4组：对照组、IPC组、优降糖十IPC组和优降糖组。所有动物均接受30min缺血／2h再灌注。预适应方案由3次5min缺血／5min再灌注组成。梗塞大小由硝基四唑氮蓝染色判定,并以坏死区占危险区的百分率表示。结果IPC几乎完全抑制了缺血/再灌注所致的室性心律失常的发生,但这种保护作用不能被KATP通道阻滞剂优降糖所阻断。IPC也能显著缩小缺血/再灌注后的心肌梗塞范围,且这种作用能被优降糖完全取消。结论IPC的心肌保护作用是由KATP介导的。     

柴胡三参胶囊对缺血性心律失常大鼠模型心肌细胞HERG K+通道蛋白的研究

目的：探讨柴胡三参胶囊对缺血性心律失常大鼠心肌中HERG K+通道蛋白表达的影响,为柴胡三参胶囊的临床应用提供实验依据,为缺血性心律失常的中医药治疗提供更多的治疗途径。方法将大鼠随机分为空白组、假手术组、模型组、柴胡三参胶囊（青蒿）组、柴胡三参胶囊（常山）组、稳心颗粒组、胺碘酮组,每组各10只,药物组在结扎左冠状动脉前降支前10 d开始预先给药,连续10 d,观察大鼠结扎左冠状动脉前降支后心电图改变及心肌中 HERG K+通道蛋白表达。结果柴胡三参胶囊能够降低缺血性心律失常的发生率(P<0.05)、显著性的降低大鼠心肌细胞HERG K+通道蛋白的失活(P<0.01)。结论柴胡三参胶囊抗缺血性心律失常的效果明显,心肌细胞HERG K+通道蛋白是其作用靶点。     

羟基红花黄色素对离体心脏功能的影响

目的研究羟基红花黄色素A（HSYA）对离体大鼠左心室收缩功能的影响。方法 42只大鼠根据实验需要随机分为正常对照组、HSYA组（1～100μmol/L）、HSYA（30μmol/L）对照组和HSYA（30μmol/L）＋K＋通道阻断剂组（分别为KATP阻断剂Gli、BKCa阻断剂Tea、KV阻断剂4-AP和KAch阻断剂Art）,每组6只。经Langendorff离体心脏恒压灌流,依次梯度给予含有HSYA的灌流液。通过左心室内的乳胶水囊经换能器连于PowerLab生物信号采集分析系统,观察给药前后以及不同浓度HSYA对左心室收缩功能的影响,并观察不同的K＋通道阻断剂对HSYA作用的影响。结果 HSYA能浓度依赖性抑制左心室收缩压、舒张末压、收缩最大速率和心率（P〈0.05或P〈0.01）;对舒张最大速率影响不大（P〉0.05）。Gli及Tea能剂量依赖性阻断HSYA的效应（P〈0.05或P〈0.01）,4-AP及Art对HSYA的效应没有影响（P〉0.05）。结论 HSYA可呈剂量依赖性抑制心脏的收缩功能和心率,其作用机制与开放KATP和BKCa通道有关。     

ATP敏感型钾通道调控剂在吗啡抗慢性神经病理性疼痛中的作用

目的:探讨ATP敏感型钾通道(K⁺_ATP)调控剂和电压依赖型钾通道（K⁺_V）调控剂对蛛网膜下腔应用吗啡抗神经病理性疼痛作用的影响。 方法:35只SD大鼠,结扎左侧L₅脊神经根建立慢性神经痛模型。3 d后蛛网膜下腔留置PE-10导管。随机每5只SD大鼠为一组于术后第7天经导管蛛网膜下腔分别注射10 μL下列药物: K⁺_ATP通道开放剂尼可的尔(Nic) 5 μg、K⁺_ATP通道抑制剂格列本脲(Gli) 2 μg、K⁺_V通道抑制剂4-氨基吡啶（4-AP）2 μg、吗啡(Mor) 5 μg、Nic 5 μg+Mor 5 μg、Gli 2 μg+Mor 5 μg、4-AP 2 μg+Mor 5 μg或等量盐水(Sal)。注药后20 min,用热平板法测量大鼠后爪的热痛敏阈值。采用最大效应百分比（%MPE）表示热痛敏阈值。 结果:术后第7天左侧L₅脊神经结扎大鼠后肢痛阈较未结扎侧对照组（右侧）大鼠后肢痛阈明显降低（P<0.01）。蛛网膜下腔单独注射K⁺_ATP通道开放剂Nic、K⁺_ATP通道抑制剂Gli、 K⁺_V通道抑制剂4-AP及Sal不影响神经病理性疼痛大鼠的痛阈,Nic(K⁺_ATP)增强Mor镇痛效果提高痛阈,Gli(K⁺_ATP) 抑制Mor镇痛效果降低痛阈,而4-AP（K⁺_V）对Mor镇痛效果无影响。 结论:在脊髓水平K⁺_ATP通道调节Mor对慢性神经病理性疼痛大鼠的镇痛作用。     

碱性成纤维细胞生长因子对急性心肌梗死时心肌细内Bcl-2、Bax表达的影响

目的 bFGF对大鼠急性心肌梗死(AMI)时心肌细胞内Bcl-2、Bax表达的影响,并探讨其发生机制.方法 实验动物随机分为假手术组,缺血 生理盐水组,缺血 bFGF组,结扎大鼠左冠状动脉复制AMI模型.术前分别注入生理盐水及bFGF,于结扎后2、4和8h处死动物,采用免疫组织化学方法 检测大鼠缺血区心肌细胞内Bcl-2、Bax蛋白的表达水平.结果 在急性心肌梗死后第2、4 h时,缺血 bFGF组心肌细胞Bcl-2蛋白的表达(141.75±26.91)‰,(125.63±24.09)‰明显高于缺血 生理盐水组(15.63±5.05)‰,(42.12±14.08)‰,P＜0.01,Bax蛋白表达(11.25±3.80)‰,(30.87±8.05)‰明显低于缺血 生理盐水组(32.62±6.61)‰,(83.638±9.84)‰,P＜0.05.结论 bFGF可促进AMI时心肌细胞内Bcl-2的表达、抑制Bax的表达,对心肌细胞具有保护作用.     

钾通道参与高铁血红素诱导的心肌保护作用

目的:研究血红素氧化酶1的诱导剂高铁血红素在对抗大鼠心肌缺血-复灌损伤中的作用及其相应机制。方法:利用离体大鼠心脏Langendorff灌流模型,观察心功能、心肌梗死面积等指标的变化。结果:腹腔注射高铁血红素后24 h,可明显改善缺血-复灌心脏(30 m in缺血/2 h复灌)的收缩功能,减少复灌期乳酸脱氢酶(LDH)和肌酸磷酸(CK)的释放,缩小心肌梗死面积。在腹腔注射高铁血红素前给予线粒体KATP通道阻断剂5-HD或肌膜KATP通道阻断剂HMR-1098均可取消高铁血红素引发的心肌保护作用。在高铁血红素预处理后24 h,缺血/复灌前10 m in给予K ca通道阻断剂pax illine,与高铁血红素组相比,心肌梗死面积扩大,心脏收缩功能下降。结论:高铁血红素预处理可对抗心肌缺血-复灌性损伤,其作用可能与激活KATP通道和K ca通道有关。     

线粒体ATP敏感性钾通道开放剂改善大鼠心脏冷保存

目的:探讨线粒体ATP敏感性钾通道开放剂二氮嗪 (DE)对离体大鼠心脏冷保存效果的影响及作用机制.方法:SD大鼠随机分成对照组、DE组、DE 5-HD组.利用Langendorff离体鼠心灌注法,各组心脏在4℃条件下分别保存3 h和8 h后,复灌60 min,观察各组大鼠血流动力学的恢复情况、冠脉流出液中心肌酶漏出量、心肌水含量的变化及心肌超微结构改变.结果:在Celsior心麻痹液中添加30 μmol/L的DE后,能明显改善冷保存3 h心脏的左心室发展压力的恢复,降低心肌酶(LDH、CK)在某些复灌时间点上的漏出,但对保存后左心室舒张末期压力的抬高和冠脉流量的恢复及心肌水肿程度无明显作用;而相同浓度的DE添加到Celsior心麻痹液中,可明显降低冷保存8 h心脏左心室舒张末期压力的抬高,改善左心室发展压力和冠脉流量的恢复,降低心肌酶(LDH、CK、GOT)的漏出,缓解心肌水肿,对心肌的超微结构也有较好的保护作用,其中30和45 μmol/L DE组对冷保存8 h心脏的保护作用优于15 μmol/L DE组,而3 0及45 μmol/L DE组之间并无显著性差异.DE的上述作用可被线粒体ATP敏感性钾通道的特异性阻断剂5-HD所取消.结论:DE可通过激活线粒体ATP敏感性钾通道显著改善离体大鼠心脏冷保存效果.