乙酰半胱氨酸对小鼠缺血再灌注损伤肝肺组织的保护作用及机制

目的:研究抗氧化剂N-乙酰半胱氨酸(NAC)对小鼠肝脏缺血再灌注损伤模型中肝肺组织的保护作用及机制.方法:制备BALB/c小鼠肝部分缺血再灌注损伤模型, 将小鼠随机分为3组: 假手术组(SH组), 缺血再灌注组(I/R组)和NAC组(I/R-NAC组).分别于再灌注后1 h、 3 h取静脉血测定血清TNF-α浓度和ALT水平;取肺组织标本测湿干质量比及病理.同时取肝、肺组织行RT-PCR以观测Toll样受体2/4(TLR2/4)表达.结果:肺组织病理结果显示I/R组肺组织毛细血管充血, 肺泡结构破坏, 肺泡间质中性粒细胞浸润, 肺泡腔内不同程度渗出及少量红细胞.肺湿干质量比显示肺水肿.缺血再灌注后静脉血清TNF-α浓度和ALT水平较假手术组显著升高.受损肝叶和肺组织内均出现TLR2/4 mRNA高表达, NAC干预后, 肺水肿明显减轻;TLR2/4 mRNA表达受到抑制;血清TNF-α浓度和ALT水平较I/R组明显下降.结论:N-乙酰半胱氨酸抑制再灌注后TLR2/4的活化, 降低TNF-α的分泌, 从而减轻缺血再灌注肝、肺组织的损伤.     

乙酰半胱氨酸对糖尿病大鼠心肌缺血再灌注损伤的保护作用及其机制

目的: 观察乙酰半胱氨酸对糖尿病大鼠心肌缺血/再灌注后导致的细胞凋亡的影响,探讨其机制.方法: 链尿佐菌素诱导糖尿病大鼠模型,随机分为假手术组、缺血/再灌注组和缺血/再灌注+乙酰半胱氨酸治疗组.组织匀浆检测心肌组织还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)含量和半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)的活性;脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)和琼脂糖凝胶电泳检测DNA片段化两种方法检测心肌细胞凋亡并计算凋亡指数.结果: 缺血/再灌注后,糖尿病和非糖尿病组均出现明显的心肌细胞凋亡,同时伴有GSH含量降低,GSSG含量和Caspase-3的活性升高,上述变化糖尿病组比非糖尿病组更明显(P<0.05);乙酰半胱氨酸干预的糖尿病和非糖尿病大鼠的心肌细胞凋亡均减轻,同时伴有GSH含量上升,GSSG含量和Caspase-3的活性下降,上述变化非糖尿病组比糖尿病组更明显(P<0.05).结论: 乙酰半胱氨酸干预可以通过提高心肌GSH含量、降低Caspase-3的活性减轻糖尿病和非糖尿病大鼠缺血/再灌注引起的心肌细胞凋亡,对缺血/再灌注心肌有保护作用,但糖尿病组的疗效低于非糖尿病组.     

N-乙酰半胱氨酸对肾缺血再灌注致肺损伤氧化应激及炎症反应的影响

目的探讨N-乙酰半胱氨酸(NAC)对肾缺血再灌注致肺损伤氧化应激及炎症反应的影响。方法Wistar大鼠30只,体重250~300g,随机分为3组(n=10):假手术组(S组,仅切除右肾,游离左肾动脉)、肾缺血再灌注组(I/R组)和NAC处理组(N+I/R组)。NAC组和I/R组切除右肾,夹闭左肾动脉45min再灌注以制备肾缺血再灌注模型,分别于夹闭动脉前30min给予NAC150mg/kg和等量生理盐水。三组均于再灌注4h处死大鼠,取肺组织,光镜下观察病理学结果;比色法检测肺组织谷胱甘肽(GSH)及其过氧化物酶(GSH-Px)、ELISA试剂盒检测丙二醛(MDA)和超氧化物歧化酶(SOD)活性及血清及肺泡灌洗液(BALF)中TNF-α、IL-6、IL-10浓度。结果NAC可减轻缺血再灌注致肺损伤,使肾缺血再灌注后肺组织GSH、GSH-Px、SOD含量升高,MDA降低,使血清及BALF中TNF-α、IL-6含量降低,IL-10升高(P0.05)。结论N-乙酰半胱氨酸对肾缺血再灌注肺损伤有保护作用,其机制与抗氧化及抑制炎症反应有关。     

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 …     

量子氧合血对肝缺血再灌注损伤的保护作用

作者建立了兔肝脏缺血再灌注模型,于阻断入肝血流前输注量子氧合血(QOB),与对照组比较,观察肝脏缺血前后肝静脉、下腔静脉血气变化及组织SOD、MDA含量变化.结果表明,对照肝脏缺血25min时肝静脉血表现为极严重的酸中毒,肝脏几乎处于无氧状态,而QOB组仅表现为轻度酸中毒,肝组织内仍维持足够的氧供.另外,QOB组肝组织内SOD总活力明显提高,肝组织内MDA的生成也明显得到抑制,与对照组比较差异极显著(P<0.01).本研究认为,肝切除前或手术中应用QOB,具有较强的抗肝脏缺血再灌注损伤的防治效应.     

视网膜缺血再灌注损伤机制的研究进展

视网膜缺血再灌注损伤(RIR)是造成视神经损害和致盲的常见眼科临床疾病病理过程。大量学者通过建立不同的实验模型研究视网膜缺血再灌注损伤的机制,研究发现视网膜缺血再灌注损伤的机制与兴奋性氨基酸、氧自由基、一氧化氮、基因调控、钙超载、炎症因子等因素密切相关。对视网膜缺血再灌注损伤机制的深入研究对临床治疗视网膜缺血再灌注损伤造成的眼科疾病具有非常重要的意义。     

缺血—再灌注损伤机制的研究进展

随着临床新技术开展。缺血器官恢复灌流成为现实。然而恢复灌流器官往往不仅功能未恢复,反而使结构损伤和功能障碍更加重了,故称为缺血再灌注损伤(IRI)。IRI的机制至今未能完全阐明,但从近来的大量研究看,IRI与自由基、钙代谢紊乱、血管内皮损伤及白细胞浸润等现象密切相关。 一、自由基的作用机制 自由基的产生:正常情况下,ATP代谢产物次黄嘌呤能迅速被黄嘌呤氧化酶(XOD)转变为黄嘌呤,进而     

大鼠小肠缺血预适应对缺血-再灌注损伤保护作用及机制

目的:探讨小肠缺血预适应(ischemic preconditioning,IP)对缺血再灌注(ischemia／reperfusion,I／R)肠黏膜损伤的保护作用及可能机制。方法:以大鼠肠系膜前动脉制造I／R和IP模型;用分光光度法测血和肠组织二胺氧化酶(diamine oxidase,DAO)活性;用H-E和PAS特染显示肠黏膜的病理改变并进行Chiu CJ评分;用免疫组化方法显示肠绒毛CGRP、NPY肽能神经并用测微尺测定阳性神经纤维密度。结果:与对照组相比,I／R组及IP I／R组血DAO水平升高而肠黏膜DAO水平降低,肠黏膜损伤Chiu CJ评分数升高;肠绒毛CGRP阳性神经纤维密度降低而NPY阳性神经纤维密度升高;但IP轻于I／R的变化。结论:小肠IP能减轻I／R引起的肠黏膜机械屏障的组织病理损伤,其机制是通过肠黏膜局部CGRP、NPY肽能神经参与调节其微血管舒缩平衡而实现的。     

乙酮可可碱对大鼠肝脏缺血／再灌注损伤影响的实验研究

目的探讨乙酮可可碱保护大鼠肝缺血／再灌注损伤的机制。方法采取大鼠第一肝门阻断的缺血再灌注模型,将健康雄性SD大鼠64只随机分为四组：对照组及乙酮可可碱给药组,观察每组动物的病理切片,分别检测血浆谷丙转氨酶（ALT）、乳酸脱氢酶（LDH）、肿瘤坏死因子-α（TNF-α）以及肝组织匀浆中内皮素-1（ET-1）的含量,免疫组化测定P-选择素的表达。结果肝脏缺血／再灌注后,病理有明显的损伤改变。PTX保护组再灌注2、4h血清ALT、LDH、TNF-α和肝组织匀浆中ET-1含量与对照组相比显著降低（P〈0．01）,PTX保护组P-选择素蛋白表达显著低于对照组（P〈0．01）。结论肝脏微循环障碍是肝脏缺血／再灌注损伤的病理基础,给予PTX预处理可降低TNF-α、ET-1产生和减少P-选择素表达,从而减轻肝脏损伤。     

参附注射液对缺血再灌注肢体保护作用

目的： 探讨参附注射液（SF）对缺血再灌注肢体保护作用及机制。方法: 30只月龄相当的健康大鼠随机分为A、B、C、D、E 5组，A组为单纯缺血再灌注组（IR）， B组、C组分别于阻断血流前 30 min 股动脉注射参附注射液 10 mL/kg、20 mL/kg; D组和E组分别于再灌注后立即股动脉注射参附注射液 10 mL/kg、20 mL/kg。5组动物均在股动静脉阻断前后 1 h 及再灌注后 1 h、2 h 分别从股静脉采集血样，测定血浆中肌酸磷酸激酶（CPK）、谷草转氨酶（GOT）的含量以及测定血浆超氧化物歧化酶（SOD）、丙二醛（MDA）的含量。结果: 各治疗组中SOD活性明显高于IR组,MDA、CPK、 GOT水平则明显低于IR组。但B组和C组之间有明显差异。而B、C组与D、E组之间有明显差异。结论: 参附注射液对缺血再灌注肢体具有保护作用，但术前给药、剂量 20 mL/kg 效果更佳。     

Apelin-13对离体缺血/再灌注大鼠心脏损伤的影响

目的观察apelin-13对离体大鼠缺血/再灌注心脏损伤的影响,并初步探讨其对apelin受体APJ(putative re-ceptor protein related to the angiotensin receptorAT1)及细胞信号Akt1/2的影响。方法Langendorff装置恒流灌注大鼠离体心脏,采用停灌/复灌方式复制缺血/再灌注模型;观察缺血/再灌注期间心脏收缩期左心室内压上升的最大变化速率( LVdp/dtmax)及舒张期左心室内压下降的最大变化速率(-LVdp/dtmax);RT-PCR和Western blot测定组织中APJ受体mRNA和Akt1/2蛋白的表达情况。结果Apelin-13可以增加缺血/再灌注损伤心脏的±dp/dtmax(P<0·01);可以明显增强心肌组织中Akt1/2的表达;缺血/再灌注可以引起心肌组织中APJ受体表达上调。结论Apelin-13拮抗缺血/再灌注引起的心脏收缩及舒张功能障碍;可能与组织中APJ受体表达上调引起Akt1/2表达增强有关。     

天麻素预处理对大鼠离体心脏缺血/再灌注损伤的保护作用

目的探讨天麻素对大鼠离体心脏缺血/再灌注(I/R)损伤的保护作用。方法 60只SD雄性大鼠随机分为正常对照组、缺血/再灌注组、天麻素预处理(10、50、100、200μmol/L)组,应用Langendorff离体心脏灌注系统建立心脏I/R损伤模型。除正常对照组外,各组分别进行平衡灌注、全心停灌/再灌处理,从心功能各项指标、心肌酶学、心肌梗死面积(TTC染色)及组织病理学(HE染色)变化4个层面评估天麻素预处理对大鼠离体心脏(I/R)损伤的影响,评价不同浓度天麻素预处理对心脏(I/R)损伤心肌的保护作用。结果与缺血/再灌注组相比,不同浓度天麻素预处理组均可改善缺血/再灌注损伤心功能的各项指标,包括左心室发展压(LVDP)、左室内压上升/下降最大速率(±dp/dtmax)和心率(HR);并降低冠脉流出液中肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)和肌钙蛋白(Trop-I)的活性,有效减少心肌梗死面积,其中以100μmol/L浓度的天麻素效果最显著(P0.05)。结论天麻素预处理对大鼠离体心脏缺血/再灌注引起的心肌损伤有保护作用,其中以100μmol/L的保护作用最为显著。     

褪黑素对大鼠心肌缺血再灌注损伤的保护作用和新机制

目的 观察褪黑素对大鼠心肌缺血再灌注损伤(IRI)的作用,并从细胞坏死方面探讨其可能机制.方法 将48只SD大鼠随机分为4组:假手术组、模型组、褪黑素低剂量(1 mg/kg)组、褪黑素高剂量(5 mg/kg)组,采用冠状动脉左前降支阻断法建立大鼠心肌梗死模型,缺血30 min后再灌注90 min,建立心肌IRI模型.用氯化三苯四唑(TTC)染色法检测心肌梗死面积,并测定左心室舒张末压(LVEDP)和左心室发展压(LVDP)以反映心脏功能.用Western blot检测受体相互作用蛋白激酶3(RIPK3)及磷酸化MLKL的表达水平.结果 心肌IRI后,心梗面积较假手术组显著增加,LVEDP值升高,而LVDP值降低,损伤区RIPK3及磷酸化MLKL蛋白表达水平显著增加(P＜0.01).与IRI组相比,褪黑素可剂量依赖性地减小梗死面积,降低LVEDP值,回升LVDP值,改善心功能,并抑制RIPK3及磷酸化MLKL蛋白的表达水平.结论 褪黑素对大鼠心肌IRI的保护作用与抑制程序性细胞坏死关键蛋白的表达相关.     

人参皂苷Rb3对心肌缺血再灌注损伤模型大鼠的保护

BACKGROUND: Ginsenoside Rb3 has a variety of physiological activities, which mainly reflected in the cardiovascular treatment. OBJECTIVE:To study the protective effects of ginsenoside Rb3 on the ischemia/reperfusion injury of rats. METHODS: 120 Sprague-Dawley rats were randomly assigned to six groups, with 20 in each group. Rats in the model and sham operation groups were intragastrically given physiological saline 2 mL/kg•d for 2 consecutive days. Rats in the positive drug group were intragastrically given diltiazem 2 mL/kg•d for 2 consecutive days. Rats in the low-dose drug group, moderate-dose drug group and high-dose drug group were intragastrically given ginsenoside Rb3 10, 20, 30 mg/kg•d, for 2 consecutive days. At 2 days after administration, the chest of rats in the sham operation was opened, but these rats did not receive any other treatment. In other five groups, anterior descending branch of left coronary artery was ligated to establish models of ischemia/reperfusion injury. 48 hours later, we observed pathological sections of rat cardiac muscle, calculated percentage of organ coefficient and myocardial infarction area, measured the levels of serum isozyme, malondialdehyde, lactate dehydrogenase, endothelial relaxing factor, superoxide dismutase and glutathione peroxidase. RESULTS AND CONCLUSION: (1) Pathological sections: ginsenoside Rb3 significantly improved the ischemia/reperfusion injury. (2) Percentages of organ coefficient and myocardial infarction area: compared with the model group, the percentages were significantly lower in the moderate-dose and high-dose drug groups (P < 0.05, P < 0.01). (3) Serum indexes: compared with the model group, ginsenoside Rb3 decreased isozyme, malondialdehyde, lactate dehydrogenase and endothelial relaxing factor levels in a dose-dependent manner, but increased superoxide dismutase and glutathione peroxidase levels in a dose-dependent manner. (4) Results suggested that ginsenoside Rb3 has protective effects on ischemia/reperfusion injury. Its mechanism of action may be associated with anti-lipid peroxide activities in cells, the anti-free radical effects, anti-inflammatory functions and the influence of cardiac enzymes on energy metabolism. 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程     

Lymphocyte function during hepatic ischemia/reperfusion injury

The liver is the primary organ affected by ischemia/reperfusion (I/R) injury after shock, surgical resection, or transplantation. The actions of myeloid leukocytes have been well studied and are thought to be the primary cells responsible for propagating the injury response. However, there is an emerging view that T lymphocytes can also regulate liver I/R-induced inflammation. Resident lymphocytes found within the liver include conventional alphabeta TCR cells as well as unconventional NK and gammadelta T cells. These lymphocytes can alter inflammation through the secretion of soluble mediators such as cytokines and chemokines or through cognate interactions in an antigen-dependent manner. Expression of these mediators will then result in the recruitment of more lymphocytes and neutrophils. There is evidence to suggest that T cell activation in the liver during I/R can be driven by antigenic or nonantigenic mechanisms. Finally, immune cells are exposed to different oxygen tensions, including hypoxia, as they migrate and function within tissues. The hypoxic environment during liver ischemia likely modulates T cell function, at least in part through the actions of hypoxia-inducible factor-1alpha. Further, this hypoxic environment leads to the increased concentration of extracellular adenosine, which is generally known to suppress T cell proinflammatory function. Altogether, the elucidation of T lymphocyte actions during liver I/R will likely allow for novel targets for therapeutic intervention.     

The effects of hepatic ischemia/reperfusion injury on postoperative cognitive function in aged rats

IntroductionHepatic ischemia/reperfusion injury (I/R) is a significant source of morbidity and mortality after liver surgery. The aim of this study was to investigate the effect of hepatic I/R injury on the hippocampus in rats with postoperative cognitive dysfunction (POCD).Material and methodsAdult male Sprague-Dawley rats (n = 160, age: 20–25 months, weight: 300–350 g) received I/R surgery with ischemia for 20 min, 30 min, and 40 min in different groups. Behavior tests of the Morris water maze (MWM) test and the passive avoidance test were applied. Population spike (PS) of pyramidal cells, nuclear factor κB (NF-κB) and protein kinase γ (PKCγ) in the hippocampus were observed.ResultsWithin 10 days after surgery, in aged rats with varying impaired cognitive function, spike size and spike latency period were reduced, level of PKCγ was decreased and an increased level of NF-κB was observed in the I/R group, especially in the I/R group with ischemia for 40 min. The parameters showed no significant difference in rats in the I/R group compared with the sham group at the 18^th day after surgery.ConclusionsHepatic I/R injury has a negative impact on the postoperative cognitive function in aged rats, leading to hippocampus changes with PS abnormity and level changes of NF-κB, PKCγ. However, this cognitive deficit improved over time.     

依那普利拉对大鼠缺血再灌心肌的作用

在体大鼠心肌缺血／再灌模型上观察心肌超微结构，明素－血管紧张素系统和脂质过氧化物三者之间的关系以及依那普利拉的影响，以探讨再灌心肌损害的发病机理。结果；再灌后三者异常改变呈一致性，用依那普利拉后三者改变亦呈一一致性，超微结构明显改善，ＲＡＳ活性降低而以血ＲＡＳ为主，ＬＰＯ代谢紊乱得到改善。