银杏总黄酮通过调节自噬减轻大鼠心肌缺血再灌注损伤

摘要 目的:探讨银杏总黄酮是否可以通过调节自噬减轻心肌缺血再灌注（I/R）损伤以及可能的机制。方法：采用大鼠心肌I/R模型（缺血30min,再灌注4h）,雄性SD大鼠30只随机分为三组：假手术组(SO组,n=10)、缺血再灌注组（I/R组,n=10）和银杏总黄酮治疗组（YLTF I/R组,n=10,Yinxing leaf total flavonoid: 100mg/kg,造模前灌胃7天）。检测心肌损伤标记物肌酸激酶（CK）、乳酸脱氢酶（LDH）和肌钙蛋白I（cTnI）;检测氧化应激水平（丙二醛（MDA）和超氧化物歧化酶（SOD）水平）;检测自噬蛋白beclin-1和LC3水平。结果：与SO组比较,I/R可诱导心肌损伤标记物（CK、LDH和cTnI）表达升高,氧化应激水平的增加（MDA表达增加,SOD表达降低）和自噬的过度激活（LC-3-II/I比值增加,beclin-1表达增加）;与I/R比较,银杏总黄酮可显著的降低心肌损伤标记物（CK、LDH和cTnI）的表达、氧化应激水平（MDA表达降低,SOD表达增加）和自噬的过度激活（LC-3-II/I比值降低,beclin-1表达减低）。结论：1）银杏总黄酮可以通过抑制过度自噬减轻心肌I/R损伤,这可能与其抑制氧化应激作用有关。     

依托咪酯对缺血再灌注大鼠心肌损伤的保护作用

目的 本文探讨依托咪酯(Etomidate)对缺血再灌注大鼠心肌损伤的保护作用及其机制。方法 将大鼠随机分为5组：假手术组(Ctrl组)、模型组(I/R组)、I/R+ Etomidate (5 mg)组、I/R+ Etomidate (10 mg)组和I/R+ Etomidate (20 mg)组,采用冠状动脉结扎法建立缺血再灌注(Ischemia Reperfusion, I/R)模型。治疗组腹腔注射对应剂量的依托咪酯,假手术组和模型组给予等量生理盐水,每天给药1次,连续14天。对大鼠心肌组织进行HE染色,观察心肌损伤情况;Elisa检测血清样本中心损标记物肌钙蛋白(Cardiac troponin I, cTnI)、肌酸激酶同工酶(Creatine kinase-MB, CK-MB)和肌红蛋白(Myoglobin, Mb)表达水平,以及氧化应激指标丙二醛(malondialdehyde, MDA)、超氧化物歧化酶(superoxide dismutase, SOD)和乳酸脱氢酶(Lactate dehydrogenase, LDH)的含量;TUNEL染色检测心肌凋亡情况;蛋白印迹法检测心肌组织凋亡蛋白Bcl-2和Bax的表达情况,P65磷酸化及下游靶基因IL-1β和TNF-α的蛋白表达水平。结果 依托咪酯能改善缺血再灌注大鼠心肌损伤程度,并剂量依赖性的降低cTnI、CK-MB和Mb表达(P＜0.05),增加SOD活性(P＜0.05)、降低LDH和MDA含量(P＜0.05),下调Bax(P＜0.05)、增加Bcl-2蛋白表达(P＜0.05),降低心肌凋亡水平(P＜0.05),抑制NF-κB p65的磷酸化(P＜0.05)及下游靶基因IL-1β、TNF-α的蛋白表达水平(P＜0.05)。结论 依托咪酯对缺血再灌注大鼠的心肌损伤起到保护作用,其机制与缓解氧化应激及抑制NF-κB p65的磷酸化相关。     

芳香新塔花总黄酮对大鼠离体心脏缺血再灌注损伤的保护作用

目的研究芳香新塔花总黄酮(Ziziphora clinopodioides flavonoids,ZCF)对大鼠离体心脏缺血再灌注(I/R)损伤的保护作用。方法 SD大鼠40只,随机分为5组:空白组,I/R组,ZCF低剂量组(12.5mg·L-1),ZCF中剂量组(25mg·L-1),ZCF高剂量组(50mg·L-1),采用Langendorff法建立离体大鼠心脏I/R模型。观察I/R期间室内压最大上升速率(+dp/dtmax)、室内压最大下降速率(-dp/dtmax)、左心室舒张压(LVEDP)、冠脉流量(CF)和心率(HR)。测定心肌组织中肌酸激酶(CK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量。结果 ZCF高剂量组和中剂量组均可显著改善I/R所致的心功能损伤,减少CK、LDH的释放和心肌组织MDA的产生,增加SOD的活性(与模型组相比,P<0.001,P<0.01或P<0.05)。结论ZCF对大鼠离体心脏I/R损伤具有保护作用,其作用可能与清除氧自由基、减少脂质过氧化反应、提高心肌抗氧化能力、维持细胞膜的完整性有关。     

恩施板党提取液对心肌缺血再灌注损伤酶活性的影响

目的观察恩施板党提取液对家兔心肌缺血再灌注（I/R）损伤后酶活性的影响,探讨其对I/R损伤心肌的可能保护机制。方法选取健康家兔30只,随机分为提取液组、模型组及对照组,每组10只,造模前提取液组于耳缘静脉注射板党根提取液,对照组与模型组行生理盐水腹腔注射。建立家兔在体I/R损伤模型,以缺血（I）40min、再灌注（R）50min为观察点,采用硫代巴比妥酸显色法检测MDA含量,黄嘌呤氧化酶法测定超氧化物歧化酶（SOD）,二硫代二硝基苯甲酸法测定谷胱甘肽过氧化物酶（GSH-PX）,乳酸脱氢酶（LDH）、肌酸激酶（CK）采用国际临床化学联合会（IFCC）推荐的方法检测。对比3组GSH-PX、SOD、MDA、LDH、CK、Ca2＋-ATPase及Na＋-K＋-ATPase水平。结果模型组血清、心肌组织中MDA水平高于对照组,GSH-PX、SOD水平均低于对照组,差异均有统计学意义（P〈0.01）;提取液组血清、心肌组织的GSH-PX、SOD、MDA水平均优于模型组,差异均有统计学意义（P〈0.05或P〈0.01）。模型组LDH、CK活性高于对照组（P〈0.01）,Ca2＋-ATPase和Na＋-K＋-ATPase水平明显低于对照组（P〈0.01）;提取液组LDH、CK及ATP酶活力水平均优于模型组,差异均有统计学意义（P〈0.01）。结论恩施板党提取液可通过影响心肌I/R损伤后酶活性水平而保护I/R损伤后的心肌组织。     

淡竹叶黄酮对大鼠心肌缺血/再灌注损伤的保护作用

目的研究淡竹叶总黄酮(TFLG)对大鼠心肌缺血/再灌注损伤的作用及其机制。方法采用结扎大鼠左冠状动脉前降支法,建立心肌缺血/再灌注损伤模型。测定血清乳酸脱氢酶(LDH)、肌酸激酶(CK)、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)、一氧化氮(NO)含量。结果 TFLG 50、100 mg.kg-1可抑制大鼠心肌中LDH及CK的漏出,降低血清和心肌组织中LDH与CK活性,降低MDA含量,提高SOD、GSH-PX和NO浓度。TFLG 100 mg.kg-1可抑制NF-κB和TNF-α蛋白的表达,下调caspase-3蛋白表达。结论 TFLG对心肌缺血/再灌注损伤有一定的保护作用,其作用机制可能与抗自由基、抑制炎症反应和减少细胞凋亡有关。     

自噬促进大鼠肠缺血再灌注损伤的细胞铁死亡

目的:探讨自噬对肠缺血再灌注损伤中细胞铁死亡的影响。方法:采用随机数字表法将24只SPF级Wistar大鼠(体质量200～220 g)分为4组(n=6):伪手术组(sham组)、缺血组(I组)、缺血再灌注组(I/R组)、缺血再灌注+自噬抑制剂组(I/R+3-MA组)。夹闭肠系膜上动脉1 h构建缺血模型，再灌注2 h建立大鼠肠缺血再灌注损伤模型；采用HE染色光镜下观察肠黏膜病理改变并行Chiu评分；比色法检测Fe²⁺含量；ELISA法检测乳酸脱氢酶(LDH)、过氧化脂质(LPO)含量；Western Blot检测铁蛋白重肽(ferritin heavy polypeptide, FTH)1、核受体共激活子(nuclear receptor coactivator, NCOA)4、LC3-II/I表达，透射电镜检测线粒体形态。结果:与sham组比较，其余3组小肠组织Chiu评分均增高(P<0.01),LC3II/I表达上调，FTH1、NCOA4表达下调(P<0.01),I组、I/R组LDH、Fe²⁺含量升高(P<0.01),I/...     

新化合物TG6对心肌缺血/再灌注损伤的影响及机制研究

目的研究TG6对心肌缺血/再灌注损伤的保护作用及机制。方法采用整体大鼠心肌缺血/再灌注（I/R）实验,离体大鼠心脏低灌复灌实验和乳鼠心肌细胞缺氧/复氧损伤（H/R）实验等模型,以血清CK、LDH、T-SOD、MDA等为指标,研究TG6对心肌缺血再灌注损伤的保护作用。结果在整体大鼠心肌缺血再灌注损伤实验中,TG6显著减少I/R损伤后心肌梗死面积,减少血清中CK活力和MDA含量,减少LDH活力,增加T-SOD活力;在离体大鼠心脏低灌复灌实验中,TG6显著增加低灌复灌后心肌冠脉流量,减少心肌组织中MDA含量和CK、LDH外漏,提高心肌组织中T-SOD活力;在乳鼠心肌细胞H/R损伤实验中,TG6对正常生长条件下的细胞没有明显影响,提高Na2S2O4制备的心肌细胞H/R模型下细胞的存活率、降低细胞CK的释放率及细胞[Ca^2＋]i的含量。结论 TG6对心肌I/R损伤有一定的保护作用。     

巴曲酶对抗狗心脏缺血/再灌损伤(英文)

目的:研究巴曲酶(Bat)对狗心脏缺血/再灌损伤的影响。方法:狗冠脉左前降枝结扎30 min后恢复血液灌注,于缺血前(Bat-Ⅰ组)或缺血后再灌前15min(Bat-Ⅱ组)静脉注射Bat(1 Bu·kg~(-1))。测定dp/dt_(max)和LVEDP及血浆CK和LDH及心肌MDA含量,观察心肌病理形态学改变。结果:I/R组动物缺血或再灌后死亡率高达65.0％,心肌损伤明显。Bat-Ⅰ和Bat-Ⅱ组动物的死亡率分别为30.0％和28.6％,P<0.05,心肌损伤减轻;血浆CK、LDH含量,LVEDP及心肌MDA含量降低; dp/dt_(max)和-dp/dt_(max)增加。结论:Bat可明显拮抗狗心脏缺血/再灌注损伤,改善心功能。     

辛伐他汀后处理对离体大鼠心肌缺血再灌注损伤的影响及机制

目的观察辛伐他汀对离体大鼠心肌缺血再灌注损伤(I/R)细胞凋亡的影响,初步探讨其机制。方法采用Langendorff离体心脏灌流模型,32只SD大鼠随机等分为4组:对照组、I/R组、辛伐他汀后处理组、辛伐他汀+L-硝基精氨酸甲酯(L-NAME)组。进行再灌注心律失常分析;冠脉流出液中肌酸激酶(CK)、乳酸脱氢酶(LDH)及NO含量测定;Western印迹法检测心肌组织p-Akt信号蛋白的表达;Annexin-V-FITC/PI法检测细胞凋亡指数(AI)。结果与I/R组比较,辛伐他汀后处理组心律失常发生率下降、CK和LDH含量降低、p-Akt蛋白表达及NO含量增加、细胞AI降低(P<0.01)。辛伐他汀+L-NAME组较辛伐他汀后处理组心律失常发生率升高、CK和LDH含量增加、p-Akt蛋白表达及NO含量降低、细胞AI增高(P<0.01);与I/R组比较,无显著差异(P>0.05)。结论辛伐他汀后处理能减轻大鼠心肌I/R损伤,减少心肌细胞凋亡,其作用机制可能与PI3K-Akt通路活化有关。     

褪黑素对在体大鼠心肌缺血再灌注损伤的作用

目的　探讨外源性褪黑素(MLT)对在体大鼠心肌急性缺血再灌注损伤的保护作用。方法　36只大鼠随机分为对照组、缺血再灌注(I/R)组及缺血再灌注+褪黑素(I/R+MLT)组,I/R组及I/R+MLT组在体大鼠心脏左冠状动脉前降支完全阻断10min,再灌15min,术中监测记录心电及血流动力学的变化,随后测定局部受损心肌中MDA(丙二醛)的含量和SOD(超氧化物歧化酶)的活性并用电镜检查心肌结构。结果心脏血流动力学指标I/R+MLT组好于I/R组(P<0 .01);I/R组MDA的含量明显高于对照组及I/R+MLT组(P<0.01 ),SOD活性明显低于对照组及I/R+MLT组(P<0 .01),I/R+MLT组MDA含量及SOD活性与对照组无明显差异(P>0 .05);电镜下I/R组心肌细胞结构损伤明显,而I/RMLT组心肌细胞结构基本正常。结论　褪黑素对在体大鼠心肌急性缺血再灌注损伤具有保护作用,其作用与抗氧化损伤有关。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.