汉防己乙素抗肝缺血再灌注损伤

汉防己乙素(dem ethyl-tetrandrine,d-Tet)与粉防己碱均为防己科千金藤属植物粉防己块根的有效成分。有报道粉防己碱具有免疫调节、抗炎、抗纤维化、抗氧化作用,还可作为一种非特异性钙离子拮抗剂,对心、脑、肝等器官的缺血再灌注损伤具有保护作用[1~3]。但是关于肝缺血再灌注时细胞凋亡的报道较少,特别是汉防己乙素对其的影响。本研究探讨汉防己乙素对肝缺血再灌注时BCL-2和BAX蛋白表达的影响。1材料与方法SD大鼠30只,体重(230±20)g。随机分成3组:对照组(C组)、缺血再灌注组(I/R组)及汉防己乙素组(d-Tet组)。大鼠自由饮水,术前12 h…     

葛根素对肝缺血再灌注损伤的保护作用

近年来 ,有关葛根素改善心脑循环和免疫调节作用的临床研究较多。但葛根素对肝缺血再灌注损伤 (ｈｅｐａｔｉｃｉｓｃｈｅｍｉ ａ ｒｅｐｅｒｆｕｓｉｏｎｉｎｊｕｒｙ ,ＨＩＲＩ)的保护作用的研究 ,国内外未见报道。本研究测定家兔肝缺血前 ,缺血 4 5ｍｉｎ ,再灌 4 5ｍｉｎ的血清及肝组织中乳酸脱氢酶 (ＬＤＨ)活性的变化 ,并观察了葛根素对其影响 ,从而了解葛根素对ＨＩＲＩ的保护作用 ,为ＨＩＲＩ的防治提供理论依据。1　材料和方法1 1　材料 :葛根素注射液 ,陕西安康济仁制药公司产品 ,批号0 10 914 ;全自动生化分析仪 ,日本日立 70 6 …     

缺血预处理通过抑制白三烯C4生成减轻大鼠肝缺血再灌注损伤

 目的：研究缺血预处理（IP）减轻大鼠肝脏缺血再灌注（I/R）损伤是否涉及前炎症因子白三烯C4(LTC4)。方法：健康成年雄性SD大鼠随机分为3组(每组6只)。I/R组： 采用大鼠部分（70%左右）肝脏缺血60 min再灌注5 h模型,缺血前15 min开始至复灌5 h经颈外静脉输注生理盐水（3 mL·kg-1·min-1）;假手术组：只麻醉开腹,不阻断肝脏血流;IP组：在I/R前先阻断肝左、中叶血流10 min,然后开放血流10 min,余步骤同I/R模型组。应用反相高效液相色谱法（RP-HPLC）检查肝组织LTC4含量,同时生化检测血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）活性和肝组织谷胱甘肽（GSH）含量,以及HE染色法检查肝组织学损伤。结果：肝脏IP处理完全逆转了再灌注5 h所致肝组织LTC4含量增加（P<0.05）;同时增加肝组织GSH含量,明显降低血清ALT和AST活性（P<0.05）,并减轻肝脏组织结构损伤。结论：IP处理减少肝脏I/R期间LTC4堆积,同时伴随血清肝酶释放减少和肝组织结构损伤降低,以及保护肝组织氧化还原状态,表明IP的有利影响可能涉及其在肝脏I/R损伤期间抑制LTC4生成。     

大鼠肾缺血再灌注损伤对肝微细结构的影响

目的:观察大鼠肾缺血再灌注损伤对肝微细结构的影响.方法:采用光镜、电镜和免疫组织化学显色对实验性大鼠肾缺血45 min再灌注24 h后的肝进行观察.结果:肝内出现了灶状性坏死,有两种坏死细胞出现,即肿胀式坏死和固缩式坏死.多聚ADP核糖聚合酶-1(PARP-1)阳性细胞多分布在坏死灶周边.肝组织内有中性粒细胞浸润.结论:肾缺血再灌注损伤导致肝出现灶状性细胞坏死.PARP-1介导细胞损伤构成了肝细胞坏死的一个形式.中性粒细胞可能参与了肝对肾缺血再灌注损伤的反应.     

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats

OBJECTIVES:

To evaluate the effects of Urtica dioica on hepatic ischemia‐reperfusion injury.

METHODS:

Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy.

RESULTS:

Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1.In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2.

CONCLUSIONS:

Urtica dioica has a protective effect on the liver in hepatic ischemia‐reperfusion‐injured rats.     

大鼠肝脏缺血再灌注损伤后水通道蛋白4表达的变化

目的: 通过建立大鼠肝脏缺血再灌注损伤(IRI)模型,观察水通道蛋白 4(AQP4)在肝内胆管细胞的表达变化,并同时检测肝脏功能变化,探讨肝脏IRI 与AQP4表达变化的关系。方法: 建立大鼠肝脏30 min IRI模型。随机将配对动物分为对照和缺血再灌注2 h、1 d、3 d、7 d组,留取血清标本行间接胆红素(IB)、直接胆红素(DB)及丙氨酸氨基转移酶(ALT)指标检测;留取肝脏标本用于HE染色光镜下观察肝脏病理形态学变化、免疫组化染色观察AQP4表达变化, RT-PCR 方法测定 AQP4 mRNA表达变化。结果: (1)肝功能变化:缺血再灌注损伤2 h、1 d、3 d组IB、DB及ALT明显升高,与对照组间比较有显著差异(P<0.05),并于术后第1 d达到最高(P<0.05);以后逐渐降低,术后第7 d恢复正常。(2) 肝脏病理学变化:术后HE染色可见缺血再灌注可造成大鼠肝组织变性、坏死。(3) 免疫组织化学检测肝脏AQP4的变化:缺血再灌注损伤2 h、1 d、3 d组AQP4的表达量较对照组降低(P<0.05),于术后第1 d最低(P<0.05),以后逐渐增高,于术后第7 d恢复正常。(4) 肝脏AQP4 mRNA表达变化:缺血再灌注损伤组2 h、1 d、3 d组AQP4 mRNA表达水平较对照组明显降低(P<0.05),于术后第1 d最低,以后又逐渐升高,于术后第7 d恢复正常。结论: 大鼠肝脏缺血再灌注损伤后可明显引起肝内胆管上皮细胞AQP4的表达降低,术后第1 d最明显,至术后7 d逐渐恢复正常,此种损害与包括胆红素在内的肝功能损害相对应。     

高原地区缺血预处理对大鼠肝脏缺血再灌注的影响

目的研究在高原地区缺血预处理对大鼠肝脏缺血再灌注的影响。方法本组99只大鼠分为IPC1组、IPC2组及PTC组。观察并统计动物术后12、24、48、72 h存活率。术后12、24、48、72 h分别开腹,取心脏血、肝脏标本进行肝功能及病理检查。比较分析三组的病理改变、死亡率及肝功能指标变化。结果 IPC2组的ALT值及死亡率均明显高于PTC组与IPC1组,IPC1组的病理改变明显轻于IPC2组,而IPC2组与PTC组的病理改变相近。结论在高原地区反复短暂的组织器官缺血可致累加性损伤,最终导致组织坏死,器官功能衰竭。     

Dehydroepiandrosterone improves hepatic antioxidant systems after renal ischemia-reperfusion injury in rabbits

This study evaluated the effects of dehydroepiandrosterone (DHEA) on the oxidant [malondialdehyde (MDA)] and antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and glutathione (GSH)] systems in liver after renal ischemia-reperfusion (IR) injury in rabbits. Thirty rabbits were randomly assigned to 3 groups of 10: group I (sham operation), group II (renal IR group), and group III (DHEA, 25 mg/kg, s.c., 15 min pre-ischemia). Renal IR injury in group II caused a decrease of SOD (25%), GPx (36%), and CAT (26%) activities and GSH levels (32%), and increases of MDA (30%) in liver and of ALT and AST activities in serum, compared to group I. DHEA administration decreased the hepatic MDA level (19%) and serum ALT activity (30%) (p <0.01 and p <0.05, respectively), and considerably increased hepatic GSH levels and GPx activities (p <0.01 for both) in group III, compared to group II. These results suggest that DHEA treatment has beneficial effects on antioxidant defenses against hepatic injury after renal IR in rabbits, possibly by augmenting GSH levels and lowering MDA production.     

锌对肝缺血再灌注损伤的对抗作用及其机制研究

目的:观察外源性锌对缺血再灌注肝脏(HIR)的防护作用并探讨其机制,包括对粘附分子表达的影响。方法:复制大鼠HIRI模型,灌胃给锌,观察实验动物肝组织形态、血清转氨酶活性、血清丙二醛(MDA)含量及粘附分子表达的改变。结果:在肝脏缺血30min,再灌注90min时,大鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性增高,肝细胞结构受损,血清MDA含量升高,肝组织中细胞间粘附分子-1(ICAM-1)和血管细胞粘附分子-1(VCAM-1)两种粘附分子表达增强;锌+缺血再灌注组大鼠血清GPT、GOT活性及血清MDA含量均明显低于缺血再灌注组,肝组织粘附分子表达亦较弱,肝细胞的结构基本正常。结论:外源给锌可以明显减轻肝脏缺血再灌注损伤,抗脂质过氧化和抑制粘附分子表达是其作用的重要机制。     

Increasing numbers of hepatic dendritic cells promote HMGB1-mediated ischemia-reperfusion injury

Endogenous ligands released from damaged cells, so-called damage-associated molecular pattern molecules (DAMPs), activate innate signaling pathways including the TLRs. We have shown that hepatic, warm ischemia and reperfusion (I/R) injury, generating local, noninfectious DAMPs, promotes inflammation, which is largely TLR4-dependent. Here, we demonstrate that increasing dendritic cell (DC) numbers enhance inflammation and organ injury after hepatic I/R. High-mobility group box 1 (HMGB1), a NF released by necrotic cells or secreted by stimulated cells, is one of a number of ligands promoting TLR4 reactivity. Augmentation of DC numbers in the liver with GM-CSF hydrodynamic transfection significantly increased liver damage after I/R when compared with controls. TLR4 engagement on hepatic DC was required for the I/R-induced injury, as augmentation of DC numbers in TLR4 mutant (C3H/HeJ) mice did not worsen hepatic damage. It is interesting that TLR4 expression was increased in hepatic DC following HMGB1 stimulation in vitro, suggesting a mechanism for the increased liver injury following I/R. It thus appears that functional TLR4 on DC is required for I/R-induced injury. Furthermore, HMGB1 may direct the inflammatory responses mediated by DC, at least in part, by enhancing TLR4 expression and reactivity to it and other DAMPs.     

甘氨酰谷氨酰胺在大鼠离体心脏缺血/再灌注损伤中的保护作用研究

目的： 研究甘氨酰谷氨酰胺对缺血再灌注大鼠离体心脏的保护作用。方法：应用Langendorff离体心脏灌注系统建立心肌缺血再灌注模型。30只SD雄性大鼠随机分为正常对照组(control)、甘氨酰谷氨酰胺对照组(Gly-Gln)、缺血再灌注组(I/R)、缺血/再灌注+甘氨酰谷氨酰胺组(I/R+ Gly-Gln)。I/R组及I/R+ Gly-Gln组分别灌注30 min后,全心停灌20 min,再灌注40 min,I/R+ Gly-Gln组于再灌注时在灌流液中加入Gly-Gln;正常对照组连续灌流90 min,Gly-Gln对照组灌流液中加入Gly-Gln。记录各组灌注时,左室舒张末压(LVEDP)、左室发展压(LVDP)、左室压力最大变化速率(±dp/dtmax)、心率(HR)及心肌细胞单相动作电位(MAP);同时在相应的时点分别测定冠脉流出液中的乳酸脱氢酶（LDH)、肌酸激酶(CK)活性。结果：离体大鼠心脏缺血20min,再灌注40 min,导致严重的心功能抑制,表现为LVEDP升高,LVDP、±dp/dtmax降低;再灌注液中加入Gly-Gln后,LVEDP降低,LVDP、±dp/dtmax明显升高（P<0.01)。I/R+ Gly-Gln组冠脉流出液中LDH、CK活性明显低于I/R组(均P<0.01)。结论： Gly-Gln能有效减轻缺血再灌注引起的左室功能下降,减少心肌细胞LDH、CK的释出,表明Gly-Gln对缺血再灌注损伤的大鼠离体心脏具有保护作用。     

肾缺血-再灌注损伤引起的脑生化改变

目的:观察血清及脑脊液生化成分变化，初步探讨肾缺血-再灌注损伤对脑的影响。 方法: 20只健康新西兰兔随机分为对照组和肾缺血再灌注组（IR组），检测和比较血清和脑脊液中肌酐（Cr）、尿素氮(UN)、Na+ 、Ca2+、一氧化氮（NO）代谢产物含量及脑组织总一氧化氮合酶（NOS）活力。 结果: 在肾缺血再灌注后24 h，IR组血清和脑脊液中的UN、Cr和NO均显著高于对照组（P<0.05），Na+明显低于对照组；IR组血清Ca2+显著低于（P<0.05）、而脑脊液中Ca2+显著高于对照组（P<0.05）。IR组脑组织中NO2-/NO3-含量和NOS活力均明显高于对照组（P<0.05）。 结论: 肾缺血再灌注损伤不仅影响血清成分，而且还可引起脑生化的改变；NO可能参与了肾缺血-再灌注损伤对脑功能的影响。     

二苯乙烯苷对沙鼠脑缺血/再灌注引发海马损伤的保护作用

目的　研究二苯乙烯苷（tetrahydroxy stilbene glucoside, TSG）对脑缺血/再灌注（ischemia/reperfusion, I/R）沙鼠脑海马损伤的保护作用及可能机制。 方法 采用结扎沙鼠双侧颈动脉缺血30 min,再灌注5 d复制沙鼠全脑I/R模型。沙鼠随机分为6组,假手术组、模型对照组、TSG大、中、小剂量（6、3、1.5 mg/kg）组和阳性对照药依达拉奉注射组（3 mg/kg）。5 d后通过Morris水迷宫测定沙鼠学习记忆功能;Nissl染色观察沙鼠大脑海马CA1区神经元结构和数量的变化;TUNEL染色法观察沙鼠大脑海马CA1区神经元凋亡的变化;Western blot法检测脑组织active-caspase-3的表达。 结果　与假手术组相比,I/R组沙鼠学习记忆能力明显降低,海马CA1区神经元大量丢失,结构紊乱。同时,I/R组沙鼠CA1区神经元凋亡数量明显增加,脑组织中caspase-3显著活化。TSG中、高（3、6 mg/kg）剂量组和依达拉奉阳性对照组均可以显著改善I/R引发的沙鼠学习记忆能力的降低,抑制海马CA1区神经元的丢失,改善神经元结构;抑制CA1区神经元的凋亡以及caspase-3的活化。而TSG低剂量组对上述变化均没有明显的治疗作用。 结论　TSG对于I/R引发的脑损伤,尤其是海马区神经元迟发性凋亡具有明显的治疗作用,这种作用与其抑制caspase-3的活化相关。     

复方黄芪提取物抗急性肝损伤作用的研究

目的：研究复方黄芪提取物（ERAC）的抗急性肝损伤作用。方法： 分别采用D-氨基半乳糖（D-Galn）和四氯化碳（CCl4）造成急性肝损伤模型，检测血清中丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）的活性及胆红素的含量，并进行病理学检查。结果： ERAC对肝损伤引起的ALT和AST活性增加以及胆红素增高均有明显的降低作用（P<0.05）。病理组织学检查：ERAC对肝损伤引起的肝细胞变性、坏死等病变有改善作用。结论： ERAC能减轻D-Galn和CCl4所引起的肝损伤，改善肝功能。     

缺血后处理减轻兔缺血再灌注心肌细胞损伤

目的探讨缺血后处理对在体兔心肌缺血再灌注心肌细胞凋亡和线粒体结构与功能的影响以及可能机制。方法80只兔随机分为假手术组(sham组)、心肌缺血再灌注组(IR组)、缺血预处理组(IP组)、缺血后处理组(PC组)以及缺血后处理加5-羟葵酸(5-HD)干预组(PC+5-HD组)。用TUNEL法检测心肌细胞凋亡,用透射电镜观察心肌细胞的超微结构,用荧光法检测线粒体膜电位,比色法测线粒体Ca2+浓度、丙二醛(MDA)浓度、超氧化物岐化酶(SOD)活性。结果与IR组比较,PC组和IP组兔心肌细胞凋亡减少,心肌及线粒体形态结构改变明显减轻,线粒体跨膜电位、SOD活性明显升高、线粒体Ca2+浓度、MDA浓度均下降(P<0.05),5-HD部分降低上述作用。结论PC可能通过提高线粒体跨膜电位、降低线粒体氧自由基水平、减轻线粒体钙超载而减轻心肌细胞损伤,其机制可能与线粒体功能损伤有关。     

糖皮质激素受体在严重多发伤后早期继发性肝损伤中的作用研究

目的: 从组织细胞受体水平探讨糖皮质激素受体(GR)在严重多发伤后肝脏继发性损伤过程中的作用。方法: 采用严重胸部撞击伤伴单侧股骨骨折模型,对GR进行不同程度阻断后致伤,观察肝脏的大体病理及镜下改变。肝组织GR采用放射性配体结合分析法测定其最大结合容量以及用免疫印迹法测定其蛋白含量。结果: 严重多发伤后肝组织GR的最大结合容量及蛋白含量即开始下降,伤后4h即明显低于正常对照(P＜0.01),12h降至最低,分别为正常对照的12.9%(P＜0.01)及21.9%(P＜0.01),24h有所恢复(P＜0.01);但肝脏病理无明显改变;使用GR阻断剂后致伤,肝脏大体病理表现为明显淤血、肿胀,光镜下肝窦严重淤血,有较多炎性细胞浸润,阻断80%GR伴多发伤组肝损伤明显重于阻断50%GR伴多发伤组。结论: GR不足可导致严重多发伤后早期继发性肝损伤的发生;GR在严重多发伤后肝组织细胞损伤与抗损伤机制方面起着重要作用。     

Ischemic preconditioning increases the tolerance of Fatty liver to hepatic ischemia-reperfusion injury in the rat

Hepatic steatosis is a major risk factor in ischemia-reperfusion. The present study evaluates whether preconditioning, demonstrated to be effective in normal livers, could also confer protection in the presence of steatosis and investigates the potential underlying protective mechanisms. Fatty rats had increased hepatic injury and decreased survival after 60 minutes of ischemia compared with lean rats. Fatty livers showed a degree of neutrophil accumulation and microcirculatory alterations similar to that of normal livers. However, in presence of steatosis, an increased lipid peroxidation that could be reduced with glutathione-ester pretreatment was observed after hepatic reperfusion. Ischemic preconditioning reduced hepatic injury and increased animal survival. Both in normal and fatty livers, this endogenous protective mechanism was found to control lipid peroxidation, hepatic microcirculation failure, and neutrophil accumulation, reducing the subsequent hepatic injury. These beneficial effects could be mediated by nitric oxide, because the inhibition of nitric oxide synthesis and nitric oxide donor pretreatment abolished and simulated, respectively, the benefits of preconditioning. Thus, ischemic preconditioning could be an effective surgical strategy to reduce the hepatic ischemia-reperfusion injury in normal and fatty livers under normothermic conditions, including hepatic resections, and liver transplantation.     

Do H2-receptor antagonists inhibit gastric secretion induced by cholinergic agonists?

The effect of experimental design on the ability of metiamide to inhibit gastric secretion induced by histamine, bethanechol and carbachol has been investigated in the Heidenhain pouch dog. All three secretagogues can be inhibited by metiamide to an extent depending on the experimental design.     

西洛他唑对离体培养大鼠皮层细胞缺血再灌注损伤的保护作用

目的:研究磷酸二酯酶抑制剂西洛他唑对离体培养大鼠皮层细胞缺血再灌注损伤的影响及作用机制。方法:取新生Wistar大鼠皮层细胞进行原代培养,分为5组:正常对照组、西洛他唑组、依达拉奉组、溶剂对照组及缺血再灌注模型组。通过建立糖氧剥离后复糖氧的细胞损伤模型模拟细胞"缺血再灌注损伤",然后进行干预。细胞经4 h糖氧剥离24 h复糖氧培养后,测定培养上清中乳酸脱氢酶(LDH)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)、神经元型一氧化氮合酶(nNOS)、诱导型一氧化氮合酶(iNOS)及一氧化氮(NO)的含量;测定细胞内环磷酸腺苷(cAMP)水平,并通过四唑盐(MTT)比色实验测定细胞活力。结果:西洛他唑和依达拉奉均可减少"缺血再灌注"损伤细胞的LDH和MDA漏出量,提高GSH-Px释放量,降低nNOS、iNOS和NO的水平,升高细胞内cAMP水平,使细胞存活率显著提高;西洛他唑与依达拉奉组相比,LDH、MDA漏出量及GSH-Px的释放量无差别,nNOS、iNOS和NO的水平明显降低,细胞内cAMP水平显著升高,细胞存活率明显提高。结论:西洛他唑对大鼠皮层细胞缺血再灌注损伤具有保护作用,其作用机制可能通过抗氧化、降低nNOS及iNOS的水平,从而降低NO的分泌、升高细胞内cAMP水平来实现的。