Protective Effects of Sodium Magnesium Fructose Diphosphate on Brain Damage of Rats Subjected to Focal Cerebral Ischemia and Reperfusion

Objective: To study the effects of sodium magnesiusm fructose diphosphate(FDPM) on brain damage of rats after ischemia-reperfusion. Methods: Rats were subjected to cerebral ischemia-reperfusion induced by inserting a nylon thread into internal carotid artery to block the origin of middle cerebral artery and removing the thread later. FDPM (400 mg·kg -1), fructose-1,6-diphosphate (FDP, 400 mg·kg -1)and magnesium sulfate (MgSO 4, 30 mg·kg -1) were administrated 10 min after the onset of ischemia. Neurological scale, brain infarct area, Malondialdehyde(MDA) content and histopathological changes of brain tissue were studied. Results: FDPM decreased neurological scale, diminished brain infarct area, reduced MDA content and relieved histopathological change of rat brain tissue subjected to ischemia-reperfusion. These effects were more powerful than that of FDP or MgSO 4. Conclusions: It is suggested that FDPM markedly prevented rats against brain damage after cerebral ischemia-reperfusion, and its effect was better than that of FDP or MgSO 4.

Effect of Magnesium on Nitric Oxide Synthase of Neurons in Cortex during Early Period of Cerebral Ischemia

Summary: To investigate the effect of magnesium on nitric oxide synthase (NOS) of neurons in cortex during early cerebral ischemic period, a rat model of middle cerebral artery occlusion (MCAO) was established. The results showed that the NOS activity of neurons in cortex was in- creased significantly at 15 min after MCAO, reached its peak at 30 min after MCAO and returned to normal levels at 60 min after MCAO. The NOS activity of neurons in the magnesium-treated group was decreased significantly as compared with that in the ischemic group at 15 min and 30 ruin after MCAO respectively. The results suggested that magnesium could inhibit the elevated NOS activity of neurons in cortex induced by cerebral ischemia.

Protective effects of combined Astragalus membranaceus and magnesium ions on global brain ischemia

The traditional Chinese herb Astragalus membranaceus is a well-known treatment for neurological diseases and is considered to exhibit anti-dementia properties.This study investigated the synergistic effects of magnesium ions and Astragalus membranaceus on global brain ischemia in rats.4＇-6-diamidino-2-phenylindole staining demonstrated that the number of living neurons was significantly greater in the rat hippocampus after administration of a combination of Astragalus membranaceus and magnesium,compared with a vehicle group,an Astragalus membranaceus alone group,and a magnesium alone group.Western blot assay revealed that cleaved Caspase-3 protein expression was significantly reduced in the rat hippocampus in the combined Astragalus membranaceus and magnesium group compared with the Astragalus membranaceus alone group and the magnesium alone group.The results suggested that the combination of Astragalus membranaceus and magnesium exhibits a stronger neuroprotective effect on global brain ischemia in rats compared with Astragalus membranaceus or magnesium alone.This effect was associated with decreased Caspase-3 expression.

Effect of protective myocardium by allitridum from decreasing apoptosis in rats with ischemia/reperfusion injury

Objective: Previous studies have shown t hat allitridum can protect myocardium from ischemia/reperfusion (I/R) injury, bu t whether allitridum had the effect of anti-apoptosis is unclear. The aim of th is study was to investigate whether allitridum had the effects of pharmacologica l preconditioning and decreasing myocardium apoptosis after ischemic insult. Methods: Pentobarbital sodium-anesthetized Sprague-Dawley (SD) rats underwent 30 min of left anterior descending (LAD) coronary occlusion foll owed by 120 min of reperfusion. Thirty-six rats were divided into three groups randomly: Control group, I/R group and allitridum (G) group. The control and I/R groups with saline, G group with allitridum were administrated 24 h before oper ation. Control group underwent only sham operation; the other two groups underwe nt I/R operation. Infarcted size (IS/AAR %) was measured in I/R and G groups. Ma londialdehyde (MDA), Creatine kinase isoenzyme-MB (CK-MB ), Superoxide dismuta se (SOD)and the apoptosis index (AI) by TUNEL staining were measured in each gro up. In addition, DNA fragmentation by agarose gel electrophoresis was conducted on DNA isolated from these groups. Results: Allitridum p retreatm ent decreased the infarcted size compared with I/R group in IS/ AAR%[(21.85±1. 49)% vs. ( 44.65±4.65)%, P<0.01], CK-MB [(986.40±94.01) vs. (2044.2 5±1 07.28) U/L, P<0.01] and MDA [(3.26±0.35) vs. (4.96±0.46) nmol/mg pro, P<0.01], and SOD level in G group was higher than that of I/R group [(140 .20±12.89)vs. (73.16±11.22) U/mg pro, P<0.01]. AI of I/R group was highe r than that of G group [(13.99±3.05)% vs. (6.97±1.23)%, P<0.01], which was consistent with that in DNA fragmentation by agarose gel electrophoresis. Conclusion: This study indicated that allitridum had the effect of protecting myocardium against I/R injury and decreasing infarcted zone. The e ffect was probably through decreasing myocardium apoptosis in I/R injury.

Effects of Potassium Aspartate and Magnesium on Ventricular Arrhythmia in Ischemia-reperfusion Rabbit Heart

The aim of this study was to determine if the potassium aspartate and magnesium （PAM） prevent reperfusion-induced ventricular arrhythmias （RIVA） in ischemia-reperfusion （IR） rabbit heart. Thirty rabbits were randomly divided into control, ischemia and PAM groups. Arterially-perfused rabbit left ventricular preparations were made, and transmural ECG as well as action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments. In control group rabbit ventricular wedge preparations were continuously perfused with Tyrode＇s solution, and in ischemia group and PAM groups the perfusion of Tyrode＇s solution was stopped for 30 min. Then the ischemia group was reperfused with Tyrode＇s solution and the PAM group with Tyrode＇s solution containing 2.42 mg/L PAM, respectively. ECG, QT interval, transmural repolarization dispersion （TDR） and action potentials from epicardium and endocardium were simultaneously recorded, and the RIVA of the wedge preparation was observed. Compared with control group, TDR and incidence of RIVA were significantly increased in ischemia group （P〈0.05）. The incidence of RIVA in control, ischemia and PAM group was 0/10, 9/10 and 1/10, respectively. Compared with ischemia group, TDR and incidence of RIVA were significantly reduced in PAM group （P〈0.05）. Potassium aspartate and magnesium significantly reduce TDR and prevent ventricular arrhythmia in ischemic rabbit heart.

THE EXPERIMENTAL RESEARCH ON CARDIOPLEGIC SOLU-TION CONTAINING SELENIUM AND MAGNESIUM AGAINST MYOCARDIAL ISCHEMIA REPERFUSION DAMAGE

The model of this test was set up according to Langendoff isolated heart reperfusion mechanics. The experimental research was designed to observe the protective effects on ischemic andreperfuslon myocardial tissue by using ST. Thomas cardioplegic solution containing selenium andmagnesium. We conclude that using cold crystallold cardioplegic solution containing Se'+, Mg' 4 canobviously reduce ischemic and reperfusion myocardlal injury and bas an advantage of recovering myocardial runctlon after operation by observing the content or lactic dehydrogenase (LDH); creatineI,kasphoklnase CK in the coronary vessel's sinus reflux solutlonl glutatblone peroxldase (GPX); suI,eroxlde dismutase (SOD); maloydladehyde (MDA ) I Se4+ .Mg'+ .Ca'+ and cia-nging or myocardialultrastructure.

Endoxin antagonist lessens myocardial ischemia reperfusion injury

Objective To elucidate whether endoxin is one of important factors involved in myocardial ischemia reperfusion (MIR) injury, the change of myocardial endoxin level was determined in rats with MIR injury model and the effects of anti-digoxin antiserum (ADA), an endoxin specific antagonist, on MIR injury were studied. Methods MIR injury model was obtained by ligating left anterior descending coronary artery 30 min followed by 45 min reperfusion. Sprauge Dawley rats were randomly divided into six groups of 10 rats, each. Sham group, MIR group, normal saline group, ADA 9, 18 and 36 mg/kg. ECG was continuously recorded. After reperfusion left ventricular myocardium samples of ischemic area were processed immediately. Myocardial endoxin level, Na++/K++-ATPase, Ca+{2+}-ATPase, Mg+{2+}-ATPase activities, and intramitochondrial Ca+{2+} content were measured. Results Myocardial endoxin level was significantly increased; Na++/K++-ATPase, Ca+{2+}- ATPase , and Mg+{2+}-ATPase activities were remarkably decreased; intramitochondrial Ca+{2+} content was remarkably raised; ST segments of ECG were significantly elevated and occurrence and scores of ventricular arrhythmias were significantly increased in early stage of reperfusion in rats with MIR. In all groups with ADA, myocardial endoxin level was remarkably decreased; Na++/K++-ATPase, Ca+{2+}-ATPase and Mg+{2+}-ATPase activities were drastically increased; intramitochondrial Ca+{2+} content was declined; ST segments and ventricular arrhythmias were improved. Conclusion Myocardial endoxin level was increased in MIR, which implies that the elevated endoxin may be one of major factors inducing MIR injury. This postulate is supported by the observation that ADA has protective and therapeutic effects against MIR injury probably by antagonizing the action of endoxin. The underlying mechanism may be ascribed to restoration of energy metabolism, and attenuation of intracellular Ca+{2+} overload.

Dynamics of Interstitial Calcium in Rat Myocardial Ischemia Reperfusion Injury In Vivo

Intracellular calcium overload is a key factor for myocardial ischemia reperfusion injury（IR）. However, there was no report for interstitial calcium concentration dynamics. We investigated the interstitial calcium dynamics in rat myocardial IR model in vivo. A microdialysis system was involved, and the time delay of the system and recovery time was introduced and tested with a fluids switching method. Twelve SD rats were divided into IR or control group. Myocardial IR was induced by ligating（20 min） then releasing（60 min） the suture underlying left anterior descending branch. Mycrodialyisis probe was implanted into the left ventricular myocardium perfusion area for occlusion. Dialysate samples were collected every 10 min. Dialysate calcium concentration was detected with an atomic absorption spectrophotometer. Recovery time for the microdialysis system was 20 min, and recovery rate was 16%. Dialysate calcium concentration showed no changes during ischemia, descended immediately after reperfusion, reached the lowest level（67% of baseline value） 20 min after reperfusion, then escalated slowly. Recovery time was an important parameter for mycrodialysis technique, and it should not be neglected and needed to be tested. Our data suggest that interstitial calcium concentration in rats with myocardial IR in vivo kept steady in ischemia, descended rapidly at the initial reperfusion, then rebounded slowly. In conclusion, we introduced the concept of recovery time for microdialysis and provided a simple testing method.

The effect of stunned myocardium on heart function and the protection of fructose－1，6－diphosphate on it

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Influences of ischemic postconditioning at different positions on oxidative stress of myocardial ischemia-reperfusion injury in rats

Objective:To analyze the influences of locial ischemic postconditioning and remote limb ischemic postconditioning on oxidative stress response with myocardial ischemia reperfusion in rats.Methods:Thirty-two SD rats were randomly divided into Sham group,ischemia/reperfusion(I/R)group,local ischemic postconditioning(LIPC)group,and remote limb ischemic postconditioning(RIPC)group,after 3 hourse reperfusion,the contents of serum creatinine kinase,MB isoenzyme(CK-MB),xanthine oxidase(XOD),superoxide dismutase(SOD),myeloperoxidase(MPO),tumor necrosis factor-α(TNF-α)were measured.The 2,3,5-triphenyltetrazolium chloride(TTC)staining was carried out to evaluate the area of myocardial infarction,cardiac function was evaluated by echocardiography,and HE staining was performed to observe the morphology of myocardial cells.Results:Compared with the Sham group,the SOD contents of the I/R group,LIPC group,RIPC group reduced significantly(P<0.05),the XOD,MPO,TNF-αcontents increased significantly(P<0.05);Compared with the I/R group,the TNF-αcontents of the LIPC group reduced significantly(P<0.05),other oxidative stress indicators of the LIPC group had no significant differences;Compared with the I/R group,the MPO and TNF-αcontents reduced(P<0.05),the SOD and XOD contents of the RIPC group had no significant differences;Compared with the LIPC group,the MPO contents reduced(P<0.05)in the RIPC group,other oxidative stress indicators had no significant differences.Compared with the Sham group,myocardial infarction area,CK-MB contents,LVIDs increased with the reduction of EF in I/R group,LIPC group,RIPC group(P<0.05),HE staining had differences;Compared with the I/R group,myocardial infarction area,CK-MB contents,LVIDd,LVIDs,EF and HE staining results had no significant differences in the LIPC group and the RIPC group;Compared with the RIPC group,the LIPC group had no significant differences.Conclusion:Remote limb ischemic postconditioning and local ischemic postconditioning can partially reduce the oxidative stress response,but does not significantly reduce myocardial infarction area,improve cardiac function.

Angiogenesis effects of adenovirus-mediated gene transfer of VEGF-B on chronic ischemic myocardium

Objective: To study the angiogenesis effects of adenovirus-mediated gene transfer of VEGF-B on chronic ischemic myocardium. Methods: Domestic pigs underwent thoracotomy and placement of an ameroid constrictor on the circumflex coronary artery. Four weeks later, Ad. VEGF-B, Ad. LacZ or PBS were administrated directly into the myocardium at 10 sites in the circumflex distribution (109 PFU or 100 μl) according to groups. Echocardiography and ex vivo coronary angiography were performed. The injection sites around myocardium were harvested and subjected to histological analysis and immunochemical staining. Results: E-chocardiography assessment 4 weeks after vector administration demonstrated significant improvement of regional wall systolic function. Collateral vessel development assessed by angiography was also significantly greater in Ad. VEGF-B animals than that in control animals. Vascular density analysis revealed a mean of 43±5 neovessels per high-power field in Ad. VEGF-B group versus 19±4 and 17±6 in Ad. LacZ and PBS group. Conclusion: Direct intramyocardial administration of Ad. VEGF-B can induce focal angiogenesis and result in improvement in regional myocardial function, which may be useful in patients with ischemic heart disease who are not eligible for conventional therapies.

miR-155-5p通过调控心肌细胞焦亡对大鼠心肌缺血-再灌注损伤的影响及机制研究

目的探讨微小RNA(miR)-155-5p对心肌缺血-再灌注损伤(IRI)大鼠心肌细胞焦亡的影响及机制。方法60只SD大鼠随机分为假手术(sham)组、IRI组、agomir-NC组、miR-155-5p agomir组、antagomir-NC组和miR-155-5p antagomir组,每组10只。采用超声心动图仪测定大鼠左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)和左心室短轴缩短率(LVFS)。酶联免疫吸附试验检测大鼠血清肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)和心肌肌钙蛋白T(cTnT)水平,心肌组织白细胞介素(IL)-1β、IL-6、IL-18和肿瘤坏死因子(TNF)-α水平;苏木素-伊红染色观察大鼠心肌组织病理学变化;实时荧光定量聚合酶链反应检测大鼠心肌组织miR-155-5p和沉默信息调节因子1(SIRT1)信使RNA(mRNA)表达水平;双荧光素酶报告基因实验验证miR-155-5p与SIRT1的靶向关系;蛋白质印迹法检测大鼠心肌组织SIRT1、NOD样受体蛋白3(NLRP3)、剪切型半胱氨酸天冬氨酸蛋白水解酶-1(Cleaved Caspase-1)和GSDMD蛋白表达水平。结果与sham组比较,IRI组大鼠LVEDD和LVESD升高,LVEF和LVFS降低,血清CK-MB、LDH和cTnT水平升高,心肌组织IL-1β、IL-6、IL-18、TNF-α水平升高,心肌组织结构破坏严重,心肌纤维排列紊乱,NLRP3、Cleaved Caspase-1和GSDMD蛋白相对表达量升高,SIRT1蛋白相对表达量降低(均为P<0.05/5)。与IRI组比较,miR-155-5p agomir组大鼠LVEDD和LVESD升高,LVEF和LVFS降低,血清CK-MB、LDH和cTnT水平升高,心肌组织中IL-1β、IL-6、IL-18、TNF-α水平升高,心肌组织病变程度加重,NLRP3、Cleaved Caspase-1和GSDMD蛋白相对表达量升高,SIRT1蛋白相对表达量降低;miR-155-5pantagomir组大鼠LVEDD和LVESD降低,LVEF和LVFS升高,血清CK-MB、LDH和cTnT水平降低,心肌组织中IL-1β、IL-6、IL-18、TNF-α水平降低,心肌组织病变程度减轻,NLRP3、Cleaved Caspase-1和GSDMD蛋白相对表达量下降,SIRT1蛋白相对表达量升高(均为P<0.05/5)。miR-155-5p与SIRT1在大鼠心肌组织中的表达水平呈负相关,且SIRT1是miR-155-5p的靶基因。结论miR-155-5p可能通过靶向下调SIRT1促进NLRP3介导的心肌细胞焦亡参与调节大鼠心肌IRI。

NLRP3炎性小体在治疗性浅低温后处理大鼠心肌缺血-再灌注中的作用

目的 分析NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎性小体在治疗性浅低温(34℃)后处理的大鼠离体心肌缺血-再灌注模型中的作用并探讨其机制。方法 选择清洁级成年雄性SD大鼠60只,7~10周龄,体重250~300 g。采用随机数字表法将大鼠分为五组:空白对照组(S组)、心肌缺血-再灌注组(IR组)、34℃浅低温后处理心肌缺血-再灌注组(MH组)、34℃浅低温后处理心肌缺血-再灌注+3-TYP组(HT组)和34℃浅低温后处理心肌缺血-再灌注+3-TYP+MCC950组(HTM组),每组12只。S组在37℃灌流液平衡灌流大鼠心脏180 min;IR组在37℃灌流液平衡灌流大鼠心脏30 min后,缺血30 min, 37℃灌注液再灌注120 min;MH组在37℃灌流液平衡灌流大鼠心脏30 min后,缺血30 min, 34℃灌注液再灌注120 min;HT组在37℃灌流液平衡灌流大鼠心脏30 min后,缺血30 min,在灌注液中加入沉默信息调节因子2同源蛋白3(sirt3)抑制剂3-TYP后行34℃灌注液再灌注120 min;HTM组在37℃灌流液平衡灌流大鼠心脏30 min后,缺血30 min,在灌注液中加入sirt3抑制剂3-TYP和NLRP3抑制剂MCC950后行34℃灌注液再灌注120 min。再灌注120 min后取离体心脏,采用ELISA法测定灌注后心脏漏液中IL-1β、IL-6浓度,Western blot法检测心肌组织中NLRP3和sirt3蛋白相对含量,1%氯化三苯基四氮唑染色计算心肌梗死面积,HE染色观察心肌病理变化。结果 与S组比较,IR组、MH组、HT组和HTM组再灌注30、60、90、120 min时HR明显减慢,LVSP、dp/dt_(max)明显降低,LVEDP明显升高;心脏漏液中IL-6和IL-1β浓度、心肌梗死面积百分比明显升高(P<0.05);IR组、HT组和HTM组心肌组织中sirt3蛋白含量明显降低,NLRP3蛋白含量明显升高(P<0.05);MH组心肌组织中sirt3和NLRP3蛋白含量明显升高(P<0.05)。与IR组比较,MH组和HTM组再灌注30、60、90、120 min时HR明显增快,LVSP、±dp/dt_(max)明显升高,LVEDP明显降低;心脏漏液中IL-6和IL-1β浓度、心肌梗死面积百分比明显降低(P<0.05);MH组心肌组织中sirt3蛋白含量明显升高,NLRP3蛋白含量明显降低(P<0.05);HTM组心肌组织中NLRP3蛋白含量明显降低(P<0.05)。与MH组比较,HT组再灌注30、60、90、120 min时HR明显减慢,LVSP、±dp/dt_(max)明显降低,LVEDP明显升高;心脏漏液中IL-6和IL-1β浓度、心肌梗死面积百分比、心肌组织中NLRP3蛋白含量明显升高(P<0.05);HT组和HTM组心肌组织中sirt3蛋白含量明显降低(P<0.05)。与HT组比较,HTM组再灌注30、60、90、120 min时HR明显增快,LVSP、±dp/dt_(max)明显升高,LVEDP明显降低;心脏漏液中IL-6和IL-1β浓度、心肌梗死面积百分比、心肌组织中NLRP3蛋白含量明显降低(P<0.05)。结论 治疗性浅低温(34℃)可通过改善离体心脏血流动力学参数、降低IL-6、IL-1β浓度、心肌组织中NLRP3蛋白含量、心肌梗死面积百分比、改善心肌病理学改变,减轻大鼠心肌缺血-再灌注损伤,其机制可能与线粒体介导sirt3通路抑制炎性小体NLRP3的高表达有关。

基于生物信息学对心肌缺血再灌注损伤关键基因的筛选及实验验证

目的:运用生物信息学分析方法挖掘参与心肌缺血再灌注损伤(MIRI)的关键基因。方法:首先,从数据库中下载大鼠MIRI相关数据集GSE122020、E-MEXP-2098和E-GEOD-4105。其次,一方面利用微阵列数据线性模型(limma)包筛选各数据集中的差异表达基因(DEGs),再用稳健排序整合(RRA)方法筛选稳健DEGs;另一方面,利用替代变量分析(SVA)包将各数据集合并为1个数据集,再利用limma包筛选合并DEGs;将2种渠道的DEGs取交集获取共同DEGs。接着,构建共同DEGs的蛋白相互作用(PPI)网络,利用最大邻域组件密度(DMNC)算法筛选关键基因,并绘制关键基因的受试者工作特征(ROC)曲线,以评价其诊断效能。然后,构建MIRI大鼠模型,检测关键基因的mRNA和蛋白表达情况;并对关键基因参与MIRI的研究开展文献回顾分析。最后,对关键基因开展基因集富集分析(GSEA),进一步揭示其介导MIRI可能的机制。结果:共鉴定出143个稳健DEGs,48个合并DEGs,两者取交集后,获得48个共同DEGs。在共同DEGs的PPI网络中,共筛选出了5个关键基因,即MYC原癌基因bHLH转录因子(MYC)、前列腺素内过氧化物合酶2(PTGS2)、血红素加氧酶1(HMOX1)、胱天蛋白酶3(CASP3)和尿激酶型纤溶酶原激活物受体(PLAUR)。这些关键基因的ROC曲线下面积均大于0.8。在MIRI大鼠心肌组织中MYC、PTGS2、CASP3和PLAUR的mRNA和蛋白高表达,而HMOX1的mRNA和蛋白表达无显著差异。回顾文献,5个关键基因中仅PLAUR未被报道参与MIRI。PLAUR的GSEA结果显示,PLAUR的功能富集主要集中在NOD样受体信号通路、P53信号通路、Toll样受体信号通路、细胞凋亡和脂肪酸代谢等途径。结论:MYC、PTGS2、CASP3、HMOX1和PLAUR参与了MIRI的病理过程。PLAUR为潜在的关键基因,其可能通过调控NOD样受体信号通路、P53信号通路、Toll样受体信号通路、细胞凋亡和脂肪酸代谢等途径介导MIRI,结果可为进一步探讨MIRI的分子机制和治疗靶点提供参考。

几种常见镇静镇痛药对缺血性心脏病患者心血管保护作用机制的研究进展

目前人们的生活水平不断提高,但经济发展的同时也带来了生活习惯上的变化,不良饮食使心血管疾病的发生率逐年增加,我国每年缺血性心脏病患者人数居高不下,其起病急骤、病情变化快、病死率高的特点对很多家庭造成极大打击。现代医学的发展使缺血性心脏病患者手术风险大大降低,但想要在保证患者安全的前提下顺利完成手术,仍需要掌握和理解镇静镇痛药物对心血管的影响作用。丙泊酚、七氟烷、舒芬太尼、瑞芬太尼和右美托咪定是较为常用的镇静镇痛药,本文就以上药物对心血管保护作用的机制进行综述。

TRPV1激动剂通过MAPK信号通路调节缺血/再灌注大鼠心肌自噬的作用研究

目的探讨瞬时受体电位香草素1型(TRPV1)介导的丝裂原活化蛋白激酶(MAPK)信号通路对缺血/再灌注(I/R)大鼠心肌自噬的调控及其在损伤修复中的作用。方法将24只成年雄性大鼠随机分为假手术组、I/R组(模型)、I/R+Capsaicin(CS)组,每组8只。除假手术组外,其他组建立I/R模型。建模前5 min,I/R+CS组大鼠腹腔注射CS(TRPV1激动剂,剂量为20 mg/kg)。通过超声心动图评估心脏功能。使用伊文思蓝(EB)/2,3,5-三苯基四氮唑染色(TTC)估计梗塞面积。定量免疫印迹分析自噬体和自噬体相关蛋白。将H9c2细胞分为对照(Con)组、缺氧/复氧(H/R)组、H/R+Capsaicin(CS)组、H/R+CS+Anisomycin(p38激动剂)组,通过用mCherry-GFP-LC3腺病毒评估各组细胞的自噬通量。结果与假手术组相比,I/R组的射血分数和缩短分数均显著降低,并出现大面积心肌梗死(P<0.05),而I/R+CS组的射血分数和缩短分数均较I/R组显著升高,心肌梗死面积较I/R组显著降低(P<0.05)。与假手术组相比,I/R组心肌组织中IC3-II、LC3-I、Becl-1和P62、p-p38/p38、p-JNK/JNK表达显著上调(均P<0.05),而TRPN、Atg5和Rab 7表达显著降低(均P<0.05);与I/R组相比,I/R+CS组的TRPV1、LC3-II/LC3-I、Atg5、Beclin-1、Rab 7蛋白表达显著上调(均P<0.05),P62、p-p38/p38、p-JNK/JNK的表达显著降低(均P<0.05)。与Con组相比,H/R组自噬体和自噬溶酶体均显著增加(P<0.05)。与H/R组相比,H/R+CS组自噬体显著增加(P<0.05)。此外,H/R+CS+Anisomycin组自噬体较H/R+CS组显著减少(P<0.05)。结论Capsaicin可以通过MAPK信号通路增强自噬通量以减轻心肌I/R损伤,这为TRPV1的心脏保护作用提供了新的见解。

镁对缺血心肌的保护作用

本工作在大鼠离体等容收缩心脏模型上首次观察单纯在缺血期灌注高镁溶液对低血流缺血及缺血后再灌注心肌的作用。结果表明，高镁溶液能减轻缺血期左心室舒张末期压力（ＬＶＥＤＰ）升高的幅度，减少缺血后再灌注心肌乳酸脱氢酶（ＬＤＨ）的漏出，维持谷胱甘肽过氧化物酶（ＧＳＨ—Ｐｘ）的活性，脂质过氧化反应终末产物丙二醛（ＭＤＡ）生成减少，心功能得到较好的恢复，综合评价各项指标，１５ｍｍｏｌＭｇ￣（２＋）可能为最佳浓度。

四逆汤抗犬急性心肌缺血的实验研究

目的：观察四逆汤对急性心肌缺血犬心内膜心电图及心肌酶学脂质过氧化损伤等指标的影响。方法：应用结扎犬冠状动脉的方法造成急性心肌缺血模型，描记心电图，检测磷酸肌酸激酶（ＣＰＫ） 、磷酸肌酸激酶同功酶（ＣＰＫ－ＭＢ） 、谷丙转氨酶（ ＡＬＴ） 、乳酸脱氢酶（ＬＤＨ） 、超氧化物歧化酶（ＳＯＤ） 、丙二醛（ ＭＤＡ） 等指标。结果：四逆汤能显著降低急性心肌缺血犬心电图缺血范围和缺血程度，降低血ＣＰＫ、ＣＰＫ－ ＭＢ、ＡＬＴ、ＬＤＨ 等酶的活性，提高ＳＯＤ 活性，降低ＭＤＡ 含量。

川芎嗪的药理性预适应对麻醉大鼠心肌缺血再灌注损伤的保护作用

用心肌缺血预适应的实验模型，观察了川芎嗪的药理性预适应对麻醉大鼠心肌缺血再灌注损伤的保护作用。实验结果表明：川芎嗪２０ｍｇ／ｋｇ 和４０ｍｇ／ｋｇ 于冠状动脉结扎前连续静脉给药５ 分钟，能降低大鼠缺血再灌注时室颤（ ＶＦ） 和室速（ＶＴ） 的发生率、心肌梗塞面积和血浆乳酸脱氢酶（ＬＤＨ） 增高的程度；推迟心律失常发生的开始时间，缩短其持续时间。这种保护作用与预适应产生的结果一致。

菟丝子提取物对大鼠心肌缺血/再灌注损伤的保护作用

目的观察菟丝子提取物(CCLE)对大鼠心肌缺血/再灌注损伤(MI/RI)的保护作用。方法 30只SD大鼠随机分为3组(n=10):假手术组、生理盐水对照组、菟丝子提取物组。结扎左冠状动脉前降支,建立大鼠心肌缺血/再灌注损伤模型,记录各组心电图,HE染色观察心肌组织细胞形态,测定血清肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、谷草转氨酶(AST)的含量变化。结果与对照组相比,CCLE可使MI/RI大鼠:①心率(HR)减慢(再灌注期各时间点P<0.05或P<0.01);②再灌注60、90、120 min时ST段明显降低(P<0.05或P<0.01);③心肌梗死程度明显减轻;④心肌酶CK、CK-MB、LDH、AST的含量(U.L-1)比对照组分别降低3 360(P<0.01)、5 478(P<0.01)、922(P<0.05)、235(P<0.01)。结论 CCLE对再灌注损伤心肌有明显的保护作用。