青霉胺对缺血后再灌注心肌损伤的保护作用

为了解青霉胺对缺血后再灌注心肌损伤的影响,我们采用Ｌａｎｇｅｎｄｒｏｆ离体大鼠心脏灌注模型,先灌注１５ｍｉｎ后停止灌注,模拟缺血６０ｍｉｎ,然后再灌注６０ｍｉｎ。动物分为对照组及青霉胺处理组（３０ｍＭ）。分别测定缺血前及再灌注后心肌组织内三磷酸腺苷（ＡＴＰ）、谷胱甘肽（ＧＳＨ）及谷胱甘肽氧化酶（ＧＳＨ－Ｐｘ）的含量变化,再灌注过程中冠状动脉血流阻力及冠脉流出液中磷酸肌酸激酶（ＣＰＫ）的释放量。结果显示,青霉胺处理组再灌注后心肌组织的ＡＴＰ、ＧＳＨ、ＧＳＨ－Ｐｘ含量均明显高于对照心肌组织中的含量,而青霉胺处理组在再灌注过程中ＣＰＫ的总释放量及平均冠状血流动脉阻力明显低于对照组ＣＰＫ总释放量及平均冠状动脉血流阻力。提示青霉胺可以减轻缺血后再灌注的心肌的损伤,起到保护作用     

高氧预适应对大鼠心肌缺血损伤时抗氧化酶的影响

抗氧化酶具有减轻心肌缺血再灌注损伤的作用,在抗氧化酶中,比较重要的是超氧化物歧化酶（ＳＯＤ）,谷胱甘肽过氧化物酶（ＧｌｕｔａｔｈｉｏｎｅＰｅｒｏｘｉｄａｓｅ,ＧＳＨｐｘ）和过氧化氢酶（ＣＡＴ）。为了解高氧预适应（ＨｙｐｅｒｏｘｉｃＰｒｅｃｏｎｄｉｔｉｏｎｉｎｇ,ＨＯＰ）对大鼠心肌缺血损伤时抗氧化酶的影响,本实验将实验组大鼠放入高压氧舱内,每日吸８０－８５％氧气（１ａｔｍ,１５－２０％为氮气）６ｈ,连续７ｄ。利用Ｌａｎｇｅｎｄｏｒｆ装置做成心肌缺血再灌注模型。实验动物随机分为二个部分。第一部分可逆性心肌缺血（ＨＯＰＡ组与对照Ａ组）：缺血１０ｍｉｎ,再灌注６０ｍｉｎ。观察冠脉回流液中ＳＯＤ活力,检测心肌内抗氧化酶活力（ＳＯＤ,ＧＳＨｐｘ,ＣＡＴ）。第二部分不可逆性心肌缺血（ＨＯＰＢ组与对照Ｂ组）：缺血６０ｍｉｎ,再灌注６０ｍｉｎ。测定冠脉回流液中肌酸磷酸激酶（ＣＰＫ）含量,ＳＯＤ及心肌内抗氧化酶活力。结果表明：对于可逆性心肌缺血：ＳＯＤ,ＧＳＨｐｘ活力升高;对于不可逆性心肌缺血损伤：ＨＯＰ能减少ＣＰＫ释放,ＳＯＤ活力升高。     

宫粉郁金的组织培养和快速繁殖

１植物名称宫粉郁金（Ｃｕｒｃｕｍａ　ｋｗａｎｇｓｉｅｎｓｉｓ）。２材料类别　块茎萌动芽。３培养条件　萌动芽生长培养基：（１）ＭＳ＋６－ＢＡ１ｍｇ·Ｌ－１（单位下同）＋ＮＡＡ０．２。不定芽增殖与愈伤组织诱导培养基：（２）ＭＳ＋６－ＢＡ１０＋ＫＴ５;（３）ＭＳ＋６．ＢＡ１０;（４）ＭＳ＋６－ＢＡ５＋ＫＴ２．５;（５）ＭＳ＋６－ＢＡ５;（６）ＭＳ＋６－ＢＡ２＋ＫＴ１。生根培养基：（７）ＭＳ＋ＮＡＡ０．５;（８）ＭＳ＋６－ＢＡ０．５＋ＮＡＡ０．５;（９）ＭＳ。以上培养基均加０．７％琼脂,３％蔗糖,ｐＨ５…     

人参二酵组皂甙对缺血-再灌注脑组织超微结构及NOS的影响

目的：研究人参二醇组皂甙（ＰＤＳ）对大鼠脑缺血－再灌注海马超微结构、皮层和海马一氧化氮合酶（ＮＯＳ）活性的影响。方法：双侧颈总动脉阻断和再灌注建立脑缺血－再灌流模型,电镜技术和ＮＡＤＰＨ－ｄ组织化学技术。结果：电镜观察可见,缺血３０ｍｉｎ再灌注２ｈ大鼠海马超微结构发生缺血性病理改变,ＰＤＳ对缺血脑组织病理变化有显著保护作用。ＮＡＤＰＨ－ｄ组织化学实验表明,脑缺血１５ｍｉｎ和再灌注２４ｈ后,皮层及海马ＮＯＳ阳性细胞数目显著增多,ＰＤＳ可显著抑制此增多。结论：ＰＤＳ可通过降低脑内ＮＯＳ的活性,减少脑缺血－再灌注过程中ＮＯ的产生,对缺血脑组织产生保护作用     

人参二酶组皂甙对缺血—再灌注脑组织超微结构及NOS的影响

目的：研究人参二醇组皂甙（ＰＤＳ）对大鼠脑缺血－再灌注海马超微结构、皮层和海马一氧化氮合酶（ＤＮＯ）活性的影响。方法：双侧颈总动脉阻断和再灌注建立脑缺血－再灌流模型,电镜技术和ＮＡＤＰＨ－ｄ组织化学技术。结果：电镜观察可见,缺血３０ｍｉｎ再灌注２ｈ大鼠海马超微结构发生缺血性病理改变,ＰＤＳ对缺血脑组织病变化有显著保护作用。ＮＡＤＰＨ－ｄ组织化学实验表明,脑缺血１５ｍｉｎ和再灌注２４ｈ后,皮层海马Ｎ     

缺血预处理减轻在体家兔心肌细胞凋亡

对麻醉家兔心肌缺血－再灌注（ｉｓｃｈｅｍｉａ－ｒｅｐｅｒｆｕｓｉｏｎ,ＩＲ）模型上,观察ＩＲ和缺血预处理（ｉｓｃｈｅｍｉｃ ｐｒｅｃｏｎｄｉｔｉｏｎｉｇｎ,ＩＰ）对血流动力学、心外膜电图、心肌梗塞范围、心肌细胞调亡和调亡相关调控基因蛋白（Ｆａｓ、Ｂｃｌ－２、Ｂａｘ等）的影响。所得结果如下：⑴在ＩＲ过程中,动脉血压、心率和心肌耗氧量进行性降低;心外膜电图ＳＴ段在缺血期明显抬高（Ｐ＜０．００１）,再灌     

高氧预适应对大鼠心肌缺血─再灌注时自由基的影响

为了解决高氧预适应（ＨｙｐｅｒｏｘｉｃｐｒｅｃｏｎｄｉｔｉｏｎｉｎｇＨＯＰ）对大鼠心肌缺血再灌注时自由基的影响,本实验将实验组大鼠放入高压氧舱内,每日吸８０－８５％氧气（１ａｔｍ）６ｈ,连续７ｄ。利用Ｌａｎｇｅｎｄｏｒｆ装置做成心肌缺血再灌注模型,采用电子自旋共振技术测定自由基含量。实验动物随机分为二组,第一组为对照组：缺血１０ｍｉｎ,再灌注６０ｍｉｎ。第二组为ＨＯＰ组：缺血１０ｍｉｎ,再灌注６０ｍｉｎ。实验观察冠脉回流液中自由基ＰＢＮ加合物含量。结果表明：在再灌注过程中,１、５、１０ｍｉｎ３个时间点,ＨＯＰ组ＰＢＮ加合物含量较对照组明显减少。提示：ＨＯＰ能减少缺血再灌注时自由基的产生。     

大鼠心脏预处理后产生的内源性保护物质的研究

以外源性腺苷前质硫酸腺嘌呤大鼠心脏预处理和经典缺血预处理建立模型,监测心脏内源性保护物质的变化。方法：采用２５０～３００ｇＳＤ大鼠３２只分成４组,即假手术组（ＳＯ组）、缺血再灌组（Ｉ／Ｒ组）、经典缺血预处理组（ＩＰＣ组）及硫酸腺嘌呤预处理组（ＡＳＰＣ组）。比较各组心肌内源性保护物质的变化。结果：ＩＰＣ组、ＡＳＰＣ组均显示缩小心梗面积、改善心功能的ＩＰＣ效应,同时,肌酸激酶（ＣＫ）、过氧化氢酶（ＣＡＴ）、５”核苷酸酶（５’ＮＴ）、超氧化物歧化酶（ＳＯＤ）活性增强以及一氧化氮（ＮＯ）含量增高,热休克蛋白７０（ＨＳＰ７０）ｍＲＮＡ表达增强。结论：ＣＫ、ＣＡＴ、５’ＮＴ、ＳＯＤ、ＮＯ及ＨＳＰ７０是大鼠腺苷性和缺血性心脏预处理后产生的重要的内源性保护物质。     

酸枣仁总皂甙对缺氧—再给氧心肌细胞的保护作用

按Ｌａａｒｓｅ’ｓ方法建立培养心肌细胞缺氧－再给氧（Ａ－Ｒ）模型,缺糖缺氧６０ｍｉｎ,再给氧３０ｍｉｎ。结果发现,缺氧组心肌细胞ＭＤＡ含量增加,ＳＯＤ活性降低,细胞膜脂质流动性下降,再给氧组上述改变加剧。酸枣仁总皂甙（ＺＳ）能剂量依赖性地显著降低心肌细胞ＭＤＡ含量,提高ＳＯＤ活性,增加细胞膜脂质流动性。证明ＺＳ有明显抗心肌细胞缺氧－再给氧损伤作用。     

电剌激及心肌缺血所致豚鼠心脏神经肽Y释放变化的研究

电剌激豚鼠心脏左星状交感神经节,可引起钙依赖性的神经肽Ｙ（ＮＰＹ）胞外释放,缺血１０ｍｉｎ后行电刺激（Ｓ２）,与对照期（Ｓ１）比较,ＮＰＹ释放无明显变化,缺血２０ｍｉｎ后行电剌激,ＮＰＹ释放受到一定程度的抑制,（Ｓ２／Ｓ１：０．７２,Ｐ＜０．０５）,而再灌注５ｍｉｎ后行电剌激ＮＰＹ释放抑制作用逐步消失,与Ｓ１比较,已无明显减少（Ｓ２／Ｓ１;１．０１,Ｐ＞０．０５）。仅缺血无电剌激几乎不引起ＮＰＹ释放。这些结果提示,电剌激交感神经节可致ＮＰＹ呈现一种钙依赖性出胞释放,缺血早期ＮＰＹ释放受到某些代谢产物抑制,恢复再灌注后,代谢产物逐步冲洗出,抑制作用也随之消失。     

心肌缺血／再灌注损伤后血清和心肌组织Leptin水平的变能

目的：观察大鼠心肌缺血／再灌注损伤对血清和心肌组织瘦素（Leptin）表达的影响,探讨Leptin在心肌缺血／再灌注损伤中的作用。方法：建立大鼠心肌缺血／再灌注模型,检测血清乳酸脱氢酶（LDH）和Leptin浓度,并用HE染色和免疫组织化学观察心肌组织病理学及Lepfin表达水平。结果：缺血组、再灌注组血清LDH水平显著升高（P〈0．05）,表明该模型制作成功,造成心肌局部一定程度的损伤。缺血组血清Leptin含量（6．34±2．49）ng／ml显著低于对照组（7．50±2．93ng／ml,P〈0．05）;再灌注后Leptin水平缓慢恢复,于再灌注2h时Leptin达到（8．32±1．74）ng／ml,恢复到损伤前水平（8．38±2．56）ng／ml,且随再灌注时间延长有升高趋势。免疫纽化显示与假手术纽心肌Leptin蛋白表达水平相比,其他四组均有显著降低（P〈0．01）,按缺血45min后再灌注1h组、缺血45min后再灌注3h组、单纯缺血45min组、缺血45min后再灌注2h组依次递减。结论：Leptin在心肌缺血／再灌注损伤后早期45min血中有明显减少,心肌组织中也明显表达下降。心肌组织病理损伤与Leptin的改变可能有一定的关系。     

Reduction of asymmetric dimethylarginine involved in the cardioprotective effect of losartan in spontaneously hypertensive rats

Previous studies have indicated that nitric oxide synthase (NOS) inhibitors can induce an increase of blood pressure and exacerbate myocardial injury induced by ischemia and reperfusion, whereas angiotensin II receptor antagonists protect the myocardium against injury induced by ischemia and reperfusion. Isolated hearts from male spontaneously hypertensive rats (SHR) or male Wistar-Kyoto rats (WKY) were subjected to 20 min global ischemia and 30 min reperfusion. Heart rate, coronary flow, left ventricular pressure, and its first derivatives (+/-dP/dt(max)) were recorded, and serum concentrations of asymmetric dimethylarginine (ADMA) and NO and the release of creatine kinase in coronary effluent were measured. The level of ADMA was significantly increased and the concentration of NO was decreased in SHR. Ischemia and reperfusion significantly inhibited the recovery of cardiac function and increased the release of creatine kinase, and ischemia and reperfusion-induced myocardial injury in SHR was aggravated compared with WKY. Vasodilation responses to acetylcholine of aortic rings were decreased in SHR. Treatment with losartan (30 mg/kg) for 14 days significantly lowered blood pressure, elevated the plasma level of NO, and decreased the plasma concentration of ADMA in SHR. Treatment with losartan significantly improved endothelium-dependent relaxation and cardiac function during ischemia and reperfusion in SHR. Exogenous ADMA also aggravated myocardial injury induced by ischemia and reperfusion in isolated perfused heart of WKY, as shown by increasing creatine kinase release and decreasing cardiac function. The present results suggest that the protective effect of losartan on myocardial injury induced by ischemia and reperfusion is related to the reduction of ADMA levels.     

Improved myocardial performance induced by clofibrate during reperfusion after acute myocardial infarction

The increase of cellular fatty acids appears to be one of the causes of the myocardial injury during ischemia and reperfusion. This study was designed to examine whether a hypolipidemic drug such as clofibrate can reduce the myocardial injury during ischemia and reperfusion. Clofibrate was fed to experimental pigs for 9 days. Isolated in situ hearts from both experimental and control pigs were subjected to 60 min of regional ischemia induced by occluding the left anterior descending coronary artery, followed by 60 min of global ischemia by hypothermic cardioplegic arrest and 60 min of reperfusion. The clofibrate feeding resulted in the better cardiac performance as judged by increased coronary blood flow, improved left ventricular function, and reduced myocardial injury as judged by creatine kinase release. Although the clofibrate-fed animals contained higher levels of thiobarbituric reactive materials, the free fatty acid levels of plasma and myocardium were much lower compared with control animals. The clofibrate feeding was also associated with increased peroxisomal catalase and beta-oxidation of fatty acids. These results suggest that decreased levels of free fatty acids in the plasma and the myocardium and increased catalase activity induced by antilipolytic therapy appear to provide beneficial effects to the myocardium during ischemia and reperfusion.     

白鲜皮水提物对大鼠心肌缺血再灌注损伤的保护作用

目的研究白鲜皮水提物对大鼠心肌缺血再灌注损伤的保护作用。方法 Wistar大鼠随机分为假手术组,模型组,阳性药组(地奥心血康)及白鲜皮低、中、高剂量组(白鲜皮水提物0.128、0.64、1.28 g/kg),每组6只。结扎冠状动脉左前降支制备大鼠心肌缺血再灌注损伤模型,观察给药后大鼠心电图ST段的改变,测量心肌梗死面积,观察大鼠心肌组织病理形态,检测大鼠血清CK,SOD活性、MDA含量。结果白鲜皮中、高剂量组给药后能明显减少心肌梗死面积,明显降低缺血30 min和再灌注120 min时ST段的抬高,并能降低大鼠血清中MDA含量,升高SOD活性,减少因缺血导致的心肌组织病理损害。结论白鲜皮水提物对大鼠心肌缺血再灌注损伤具有保护作用,其作用机制可能与保护心肌细胞功能、提高心肌抗氧化能力、清除氧自由基有关。     

Matrix metalloproteinases and collagen ultrastructure in moderate myocardial ischemia and reperfusion in vivo

Severe ischemic injury or infarction of myocardium may cause activation of matrix metalloproteinases (MMPs) and damage the interstitial matrix. However, it is unknown whether MMP activation and matrix damage occur after moderate ischemia and reperfusion that result in myocardial stunning without infarction, and if so whether such changes contribute to postischemic myocardial expansion and contractile dysfunction. To address these questions, open-chest anesthetized pigs underwent 90 min of regional ischemia (subendocardial blood flow 0.4 +/- 0.1 ml. g(-1). min(-1)) and 90 min of reperfusion. After ischemia plus reperfusion, histological and ultrastructural examination revealed no myocardial infarction or inflammatory cell infiltration. Myocardial MMP-9 content increased threefold with a fourfold increase in the active form (P < 0.001). Myocardial collagenase content doubled (P < 0.01) but remained in latent form. MMP-2 and tissue inhibitors of metalloproteinases were unaffected. Despite increases in MMPs, collagen ultrastructure (assessed by cell maceration scanning electron microscopy) was unaltered. Intracoronary administration of the MMP inhibitor GM-2487 did not prevent or attenuate myocardial expansion (assessed by regional diastolic dimensions at near-zero left ventricular pressure) or contractile dysfunction. We conclude that although moderate ischemia and reperfusion alter myocardial MMP content and activity, these effects do not result in damage to interstitial collagen, nor do they contribute to myocardial expansion or contractile dysfunction.     

芹菜素对缺血再灌注大鼠心肌核转录因子-κB和ICAM-1表达的影响

目的研究芹菜素对缺血再灌注大鼠心肌核转录因子-κB(NF-κB)和粘附分子ICAM-1表达的影响,探讨其抗心肌缺血再灌注损伤的可能机制。方法将Wistar大鼠随机分为6组:假手术组、缺血再灌注组(IR组)、溶剂对照组、维拉帕米阳性对照组、芹菜素低、高剂量用药组。采用结扎左冠状动脉前降支制作缺血再灌注模型,心肌缺血30 min,再灌注2 h。免疫组化染色检测心肌组织的NF-κB和ICAM-1的表达.结果芹菜素组可降低心肌组织NF-κB和ICAM-1的表达,与IR组比较有显著差异(P0.05)。结论芹菜素对缺血再灌注心肌的保护作用可能与其减少心肌缺血再灌注后NF-κB和ICAM-的激活有关。     

楤木皂苷对大鼠心肌缺血/再灌注损伤的保护作用

目的:观察楤木皂苷(total saponins extracted from Aralia taibaiensis,s AT)对大鼠心肌缺血/再灌注(myocardia1 ischemia/reperfusion,MI/R)损伤的影响。方法:可逆性冠脉左前降支结扎缺血30 min再灌注3 h复制MI/R模型,将SD大鼠随机分为假手术组、模型组、s AT低、中、高剂量组,每组10只。采用伊文思蓝(EB)、2,3,5-氯化三苯基四氮唑蓝(TTC)双染法测定心肌梗死面积,苏木精-伊红(HE)染色法观察心肌病理学形态变化,并检测血清中乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)、超氧化物歧化酶(SOD)、丙二醛(MDA)、过氧化氢酶(CAT)及谷胱甘肽过氧化物酶(GSH-Px)水平。结果:与模型组比较,s AT中、高剂量组可明显缩小心肌梗死面积(P0.05),并显著降低血清中LDH、CK-MB及MDA的含量,同时使得血清中SOD、CAT和GSH-Px的活性增加。且所有给药组心肌组织的病理损伤也小于模型组。结论:s AT对大鼠MI/R损伤具有保护作用,其机制可能与抗氧化作用相关。     

Ischemia increases detectable endothelial nitric oxide synthase in rat and human myocardium.

The aims of the present study were to establish if myocardial ischemia/reperfusion is associated with altered eNOS activity and if myocardial eNOS detection depends on its activity. We determined detectable eNOS in (1) myocardium of isolated perfused rat hearts subjected to either global or regional ischemia and (2) in left ventricular biopsies from patients undergoing two different methods of myocardial protection (i.e., intermittent cold blood cardioplegia and continuous coronary perfusion with warm, beta-blocker-enriched blood) during coronary artery surgery. NOS detection was performed by NADPH-d staining and three eNOS-antibodies against different eNOS epitopes. In addition, activity dependent alteration of detectable eNOS was proofed by bradykinin treatment for 2 to 10 min. Ischemic and receptor mediated eNOS activation increased NADPH-d reactivity and eNOS immunoreaction as measured by antibodies against either amino acids of a central bovine eNOS domain or the human eNOS N-terminal end. In contrast, the antibody against the human eNOS C-terminal end exhibited no alteration of eNOS immunoreaction. The transient eNOS activation was associated with increased cGMP content. In human myocardium subjected to ischemia during cardiac surgery we found that early reperfusion increases eNOS activity. These data demonstrate a strong association between myocardial ischemia/reperfusion and increased eNOS activity as measured by immunocytochemical staining against specific eNOS epitopes. It appears that eNOS activation and subsequent NO release may act as a regulatory system to counter balance the potentially deleterious effects of myocardial ischemia/reperfusion.     

Acupuncture pretreatment protects heart from injury in rats with myocardial ischemia and reperfusion via inhibition of the beta(1)-adrenoceptor signaling pathway

Our previous study showed that a cardioprotective effect was produced by pretreatment with acupuncture at bilateral Neiguan acupoints (PC6) and the effect of EA was diminished by propranolol, a nonspecific antagonist of beta-adrenoceptors (beta-ARs) which are the most powerful cardiac receptors, indicating an involvement of beta-ARs. The present study explored further the signaling mechanism underlying the cardioprotective effect of acupuncture pretreatment in rats subjected to myocardial ischemia and reperfusion (MIR). Myocardial ischemia was achieved by ligating the left anterior descending coronary artery and reperfusion by releasing the ligation. Adult rats were divided into three groups, namely, a normal control (NC) group, a group subjected to ischemia and reperfusion (IR) only, and a group given electro-acupuncture (EA) before IR. For EA, bilateral Neiguan points (PC6) of the rats were stimulated for 30 min once a day for 3 consecutive days. The ST segment of ECG, the ratio of infarct size over risk zone, and the contents of beta(1)-adrenoceptor (beta(1)-AR), Gsalpha protein and cAMP in ischemic myocardium were compared among the three groups. IR increased the elevation of ECG ST segment, myocardial infarct size, contents of beta(1)-AR, Gsalpha protein and cAMP. These effects were attenuated by EA pretreatment at bilateral Neiguan acupoints. In conclusion, the present results indicate that EA produces cardioprotective effect against IR which may be mediated via the beta(1)-AR-Gs-protein-cAMP pathway.     

后处理对心肌缺血再灌注致脑损伤中炎症因子及GFAP的影响

目的:探讨缺血后处理对心肌缺血再灌注致脑损伤中炎症因子及胶质纤维酸性蛋白的影响。方法:24只雄性SD大鼠随机分为3组(n=8),假手术组(Sham)、心肌缺血/再灌注组(IR)、后处理组(IPost)。结扎大鼠冠状动脉左前降支30 min,复流120 min建立大鼠心肌缺血/再灌注模型。后处理组于再灌注前进行缺血后处理,再灌注10 s,缺血10 s,共3次。断头处死大鼠取脑组织,光镜下观察病理学结果,Western blot检测炎性因子IL-6、IL-8、IL-10,免疫组化法检测GFAP。结果:与Sham组相比较,IR组脑组织炎症因子IL-6,IL-8表达增加,IL-10下降(P0.01),而后处理可以降低脑组织中IL-6,IL-8的表达,增加IL-10的表达(P0.01);与Sham组相比较,IR组脑组织GFAP表达增多(P0.05),而后处理可以显著增加脑组织中GFAP的表达(P0.01)。结论:心肌缺血后处理可以减少脑组织中炎症因子的表达,增加GFAP的表达,从而起到脑保护作用。