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。     

三种鼠尾草注射液对大鼠心肌缺血再灌注损伤的保护作用

本文研究了云南产鼠尾草属药物滇丹参、甘西鼠尾、褐毛甘西鼠尾对急性心肌缺血再灌注损伤的保护作用 ,并与丹参进行对比其疗效的相似性。结扎大鼠冠脉左前降支 ,30分钟后剪断结扎线造成心肌缺血再灌注模型 ,经股静脉给药。测定再灌注 6 0分钟后血清中CK、LDH、SOD、GSH -Px和MDA含量。结果滇丹参、甘西鼠尾、褐毛甘西鼠尾可以显著降低心肌缺血再灌注后血清CK、LDH和MDA含量 ,升高血清SOD和GSH -Px活力 (P <0 0 1,P <0 0 5 ) ,与丹参有相似的抗心肌缺血再灌注损伤作用。     

Cardioprotective effects of resveratrol following myocardial ischemia and reperfusion

Resveratrol (RSV), a plant origin polyphenol, has shown beneficial cardiovascular effects. In this study, isolated hearts from male Wistar rats were studied using the Langendorff technique. Following 30 min stabilization, the hearts underwent 30 min global ischemia and 120 min reperfusion. The perfusion solution in the test group contained RSV (10 μM). Hemodynamics of the hearts, the markers of myocardial damage including creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and troponin I were studied during the study. Furthermore, the infarct size and the markers of oxidative stress including catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPX) were assayed in the homogenates of the hearts. The release of nitrite from the hearts and the occurrence of ventricular arrhythmias were also monitored throughout the experiment. Resveratrol caused a significant improvement in the restoration of the mechanical performance of the hearts following myocardial ischemia and reperfusion (MIR). Besides, the infarct size, CK-MB, LDH, and troponin I declined in the test group. Besides, the cardiac release of nitrite increased, and the redox status of the heart was improved as indicated by the levels of CAT, SOD, GPX, and MDA. Finally, the treatment caused significant decreases in the occurrences of single and salvo arrhythmias, ventricular tachycardia, and ventricular fibrillation. The current study suggests strong cardioprotective and antiarrhythmic effects for RSV following MIR.

     

Chinese medicinal formula Guan-Xin-Er-Hao protects the heart against oxidative stress induced by acute ischemic myocardial injury in rats

Guan-Xin-Er-Hao (GXEH) is a Chinese medicine formula for treating ischemic heart diseases (IHD) and has a favorable effect. Our aim was to examine whether or not acute oral GXEH could protect the heart against myocardial infarction and apoptosis in acute myocardial ischemic rats. If so, we would explain the antioxidative mechanism involved. The left anterior descending coronary artery was occluded to induce myocardial ischemia in hearts of Sprague-Dawley rats. At the end of the 3 h ischemic period (or 24 h for infarct size), we measured the myocardial infarct size, myocardial apoptosis and the activities of antioxidative enzymes. GXEH reduced infarct size, myocardial apoptosis and the serum level of malondialdehyde (MDA), increased the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and GSH-peroxidase (GPX) activities and the serum level of glutathione (GSH). GXEH exerts significant cardioprotective effects against acute ischemic myocardial injury in rats, likely through its antioxidation and antilipid peroxidative properties, and thus may be used as a promising agent for both prophylaxis and treatment of IHD.     

B型钠尿肽对急性心肌缺血损伤发挥保护作用的机制

本研究旨在研究B型钠尿肽(brain natriuretic peptide, BNP)对异丙肾上腺素(isoproterenol, ISO)诱导的急性心肌缺血(acute myocardial ischemia, AMI)相关损伤的保护作用。将大鼠随机分作5组:对照组、ISO处理组、ISO+普萘洛尔(5 mg/kg)处理组、ISO+BNP (5 mg/kg)和ISO+BNP (10 mg/kg)处理组。再将4个给药组中的大鼠连续2 d皮下注射ISO。通过心电图(ECG)记录ST段数据;ELISA检测血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6 (IL-6)和IL-1β的表达水平;接着使用Western blotting对Bax-2、Bcl-2、PI3K、Akt、GSK-3β、MDA5和SOD1蛋白表达水平进行检测,并测定PI3K、Akt和GSK-3β的磷酸化。实验结果显示,BNP (5 mg/kg, 10 mg/kg)可降低血清中MDA和CK的表达水平以及SOD和LDH的蛋白活性;经BNP预处理显著降低了促炎因子IL-1β、IL-6和TNF-α的表达水平;同时BNP也降低了ST段抬高。此外,BNP改善了ISO诱导的大鼠中SOD1、MDA5、Bax-2、Bcl-2、p-PI3K、p-Akt和p-GSK-3β的表达。综上所述,通过调节PI3K/Akt/GSK-3β信号传导途径,BNP保护大鼠免受AMI损伤。     

NOTCH1信号通路介导白藜芦醇抗肝缺血/再灌注所致大鼠心脏损伤保护作用的机制研究

目的：观察Notch1信号通路在肝缺血/再灌注损伤时对心脏损伤的保护作用并探讨其相关的机制。方法：36只健康雄性SD大鼠随机分为3组,假手术组（SC组）、肝缺血/再灌注组（HIR组）、白藜芦醇预处理组（Res处理组）,每组12只。各组均与肝脏缺血40 min再灌注2 h（SC组旷置相等时间）后,记录左室血流动力学变化,测定血清肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、肿瘤坏死因子（TNF-α）和白细胞介素-6（IL-6）浓度,取心肌组织测定SOD活力及MDA含量,Western blot检测心肌组织反应Notch通路活化标志的NICD表达,以RT-PCR法从转录水平检测Notch1和TNF-α的表达水平。结果：与SC比较,HIR组左室收缩及舒张功能均显著降低（P<0.01）,血清CK、LDH活力,TNF-α和IL-6浓度明显升高（P<0.01）,心肌MDA含量明显升高而SOD活力明显降低（P<0.01）,且Notch1表达下降,TNF-α表达增加;与I/R组相比,Res处理组左室舒缩功能明显升高,血清CK、LDH活力及TNF-α、IL-6浓度明显降低,同时心肌SOD活力明显升高而MDA含量明显降低,Notch1表达上升TNF-α表达降低。结论：白藜芦醇对肝缺血/再灌注大鼠心脏具有保护作用,其机制可能与Notch1信号通路的激活进而调节炎症反应及氧化应激有关。     

蒙药绍沙-7味丸防治大鼠心肌缺血/再灌注损伤的作用

目的: 探讨蒙药绍沙-7味丸对心肌缺血/再灌注损伤大鼠的防治作用及机制。方法: 60只大鼠随机分成6组:假手术组、模型组、蒙药绍沙-7味丸低、中、高剂量组以及阳性药对照组,每组10只;蒙药绍沙-7味丸低、中、高剂量组分别灌胃0.4 g/kg、0.8 g/kg、1.6 g/kg蒙药绍沙-7味丸,阳性药对照组灌胃0.3 g/kg复方丹参片,假手术组和模型组灌胃2 ml/100 g蒸馏水,均连续灌胃15 d,1次/日;15 d后,模型组及治疗组大鼠开胸结扎冠状动脉30 min后,解开结扎线行再灌注120 min后关闭胸腔处理;6组大鼠术后行心电图检查后处死大鼠取心脏行HE染色、TTC染色,观察梗死面积及病理变化。ELISA法检测血清中cTnI、CK-MB、 LDH、MDA、SOD、GSH-PX及TNF-α、IL-18、IL-6、IL-1β的水平,免疫组化法检测心肌组织NF-кB水平。结果: 与假手术组相比,心肌缺血/再灌注损伤大鼠心肌梗死面积增大,同时血清中cTnI、CK-MB、 LDH、MDA、GSH-PX及TNF-α、IL-18、IL-6、IL-1β的含量明显增加(P＜0.01),SOD的含量则明显降低(P＜0.01),心脏组织中的NF-кB水平增加;与心肌缺血/再灌注损伤大鼠相较,蒙药绍沙-7味丸改善大鼠心律失常现象及病理变化,减少梗死面积;血清中cTnI、CK-MB、 LDH、MDA、GSH-PX及TNF-α、IL-18、IL-6、IL-1β的含量明显降低(P＜0.01),SOD的含量明显增加(P＜0.01),心脏组织中的NF-кB水平降低。结论: 蒙药绍沙-7味丸可有效缓解大鼠心肌缺血/再灌注损伤,其作用与氧化应激和凋亡相关。     

Post-infarct treatment with [Pyr1]-apelin-13 reduces myocardial damage through reduction of oxidative injury and nitric oxide enhancement in the rat model of myocardial infarction

Apelin is a newly discovered peptide that has been recently shown to have cardioprotective effects in the animal model of myocardial infarction (MI) and ischemia/reperfusion (I/R) injuries. The aim of the present study was to investigate the long term cardioprotective effect of [Pyr1]-apelin-13 in the rat model of MI. Male Wistar rats (n = 22) were randomly divided into three groups: (1) sham operated group (2) control MI group and (3) MI treated with apelin (MI-AP group). MI animals were subjected to 30 min of left anterior descending coronary artery (LAD) ligation and 14 days of reperfusion. 24 h after LAD ligation, apelin (10 nmol/kg/day) was administered i.p. for 5 days. Blood sampling was performed at days 1, 3, 5 and 7 after MI for determination of serum changes of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), malondialdehyde (MDA) and nitric oxide (NO). Myocardial infarct size (IS) and hemodynamic function were also measured at the end of the study at day 14. We found out that post infarct treatment with apelin decreases infarct size, serum levels of LDH, CK-MB and MDA and increases heart rate and serum level of NO in the consecutive days, but there were no significant differences in blood pressure in the MI-AP group in comparison with MI. In conclusion, apelin has long term cardioprotective effects against myocardial infarction through attenuation of cardiac tissue injury and lipid peroxidation and enhancement of NO production.     

褐毛甘西鼠尾注射液对大鼠在体心肌缺血再灌注损伤的保护作用

本实验与丹参进行对比研究云南产鼠尾草属药物褐毛甘西鼠尾对急性心肌缺血再灌注损伤的保护作用。采用结扎大鼠冠脉左前降支方法造成心肌缺血再灌注模型,测定再灌注60 min后血清中CK、LDH、SOD、GSH-Px和MDA含量。实验结果显示:该药可以显著降低心肌缺血再灌注后血清CK、LDH和MDA含量,升高血清SOD和GSH-Px活力(P<0.01,P<0.05)。表明褐毛甘西鼠尾对在体缺血/再灌注心肌有保护作用。     

对肾上腺素性心肌缺血模型大鼠相关指标的探讨

目的进一步探讨客观评价大鼠心肌缺血模型的指标。方法观察皮下注射10mg kg异丙肾上腺素(ISO)造成SD大鼠心肌缺血性损伤模型后心电图的变化、检测血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)、游离脂肪酸(FFA)以及心肌组织的坏死面积、超氧化物歧化酶(SOD)、丙二醛(MDA)含量的变化。结果腹腔注射ISO后30s,大鼠心电图的J点开始降低,2min后缓慢回升,但20min后仍未回复到原来的水平,而且20min内各时间点与给药前比较,模型对照组大鼠的J点与生理盐水对照组比较,差异有显著性(P<0.05);T波则在注射异丙肾上腺素30s后开始下降,10min内两组的T波一直保持显著差异(P<0.05),而且注射异丙肾上腺素后30s(P<0.01)以及5min(P<0.05)与给药前比较,T波均有显著差异;模型对照组大鼠血清中CK、LDH、FFA以及心肌组织中MDA浓度均显著高于生理盐水对照组,心肌坏死面积与这些指标呈正相关关系,心肌组织中SOD浓度显著低于生理盐水对照组。结论J点可以作为评价此种动物模型的主要指标,T波可以作为辅助指标,应重点观察20min内心电图的变化;可以选择CK、LDH、FFA、SOD、MDA等生化指标以及心肌坏死面积等来探讨抗心肌缺血药物的作用机理。