丹参及血栓通注射液对缺血再灌注大鼠肾脏的影响

丹参及血栓通注射液对缺血再灌注大鼠肾脏的影响徐幼筠，杜学海，邹万忠ＴＨＥＥＦＦＥＣＴＯＦＳＡＬＶＩＡＥＭＩＬＴＩＯＲＲＨＩＺＡＥ（ＳＭ）ＡＮＤＡＲＡＳＡＰＯＮＩＮ（ＡＲ）ＯＮＩＳＣＨＥＭＩＡ－ＲＥＰＥＲＦＵＳＩＯＮＲＡＴＫＩＤＮＥＹＸｕＹｏｕｊｕｎ；...     

参麦注射液抗肝缺血再灌注损伤的研究

目的：研究参麦注射液对肝缺血再灌注损伤的保护作用。方法：将３７只成年雄性ＳＤ大鼠随机分成假手术对照组（ＳＯＣ）、缺血再灌注组（Ｉ／Ｒ）、缺血再灌注加参麦组（Ｉ／Ｒ＋ｓｈｅｎｍａｉ）。通过阻断大鼠肝门３０ｍｉｎ后再开放建立肝缺血再灌注损伤模型,在肝脏再灌注９０ｍｉｎ时测肝组织丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）和测血ＡＬＴ、ＡＳＴ、ＬＤＨ,并取肝组织作光镜及电镜观察。结果：再灌注９０ｍｉｎ时Ｉ／Ｒ＋Ｓｈｅｎｍａｉ组的肝组织ＭＤＡ生成,ＳＯＤ消耗,血清ＡＬＴ、ＡＳＴ、ＬＤＨ升高值均少于Ｉ／Ｒ组（Ｐ＜０．０１）,且Ｉ／Ｒ＋Ｓｈｅｎｍａｉ组的肝细胞显微、超微结构损害的改变较Ｉ／Ｒ组轻。结论：参麦注射液能清除肝缺血再灌注过程中产生的氧自由基,对鼠肝缺血再灌注所致肝细胞的结构和功能损伤有保护作用     

联合应用超氧化物歧化酶,阿魏酸钠抗肝缺血再灌注损伤

目的研究联合应用外源性超氧化物歧化酶（ＳＯＤ）与阿魏酸钠（ＳＦ）对肝缺血再灌损伤的保护作用。方法将３２只成年雄性ＳＤ大鼠随机分为对照组、ＳＦ保护组、ＳＯＤ保护组和ＳＦ与ＳＯＤ联合保护组。通过阻断大鼠肝门１ｈ后再开放建立肝缺血再灌注损伤模型,在肝缺血前及肝再灌注２ｈ时测肝组织丙二醛（ＭＤＡ）,ＳＯＤ和测血谷丙转氨酶（ＡＬＴ）,谷草转氨酶（ＡＳＴ）。并取肝组织作光镜及电镜观察。结果再灌注２ｈ时ＳＦ保护组与ＳＯＤ保护组的肝组织ＭＤＡ生成,ＳＯＤ消耗,血清ＡＬＴ,ＡＳＴ升高值均高于ＳＦ与ＳＯＤ联合保护组（Ｐ＜０．０１或Ｐ＜０．０５）,且ＳＦ和ＳＯＤ联合保护组的肝细胞显微、超微结构损害的改变较ＳＯＤ或ＳＦ保护组轻。结论ＳＦ与ＳＯＤ联合保护组清除氧自由基（ＯＦＲ）的作用强于ＳＯＤ或ＳＦ保护组,对鼠肝缺血再灌注所致肝细胞的结构和功能损伤的保护作用比单独使用ＳＯＤ或ＳＦ强。     

肝硬变门脉高压休克再灌注胃粘膜损伤的实验研究

本实验应用电子自旋共振（ＥＳＲ）技术及自旋捕捉剂ＰＢＮ直接测定肝硬变门脉高压（ＰＨＴ）大鼠胃粘膜在休克再灌注前后及应用超氧化物歧化酶（ＳＯＤ）、丹参（ＲＳＭ）治疗后氧自由基（ＯＦＲ）的动态变化，同时检测胃粘膜中ＳＯＤ活性，并观察同期胃粘膜的光镜、电镜病理改变。结果：ＰＨＴ胃粘膜在休克再灌注过程中有大量ＯＦＲ产生，粘膜损伤的严重程度与ＯＦＲ含量及ＳＯＤ活性密切相关；ＰＨＴ胃粘膜更易受休克再灌注时ＯＦＲ的损伤，早期应用抗氧化剂ＳＯＤ及ＲＳＭ，可通过不同机理减轻胃粘膜再灌注损伤。     

丹参提取物F在再灌注损伤中对胃粘膜抗氧化能力影响

目的：探讨丹参提取物Ｆ的胃粘膜保护作用与氧自由基的关系。方法：复制失血性休克再灌注损伤模型,３１只大鼠随机分为单纯失血组（ＨＥ,ｎ＝９）,生理盐水对照组（ＮＳ,ｎ＝１０）及丹参提取物Ｆ组（ＤＳＥＦ,ｎ＝１２）;ＨＥ组大鼠在失血性休克２０ｍｉｎ后处死,ＮＳ及ＤＳＥＦ组则在休克２０ｍｉｎ后回输全部放出的血液,维持２０ｍｉｎ后处死。其中ＮＳ组静滴ＮＳ００３ｍｌ／ｍｉｎ,ＤＳＥＦ组静滴ＤＳＥＦ１ｇ／１００ｇｗｔ。结果：ＨＥ组损伤指数为０,ＤＳＥＦ组损伤指数明显低于ＮＳ组（Ｐ＜００１）,ＤＳＥＦ组的丙二醛（ＭＤＡ）含量明显低于ＮＳ组（Ｐ＜００１）,而超氧化物歧化酶（ＳＯＤ）活性明显高于ＮＳ组（Ｐ＜００１）。结论：ＤＳＥＦ在再灌注损伤中可减轻氧自由基对胃粘膜的损伤     

肾脏缺血再灌注损伤研究进展

肾缺血再灌注损伤不仅可发生在肾移植中,而且在复杂的肾脏手术、休克复苏过程中亦可出现。本文回顾了近年来有关肾缺血再灌注损伤机制及保护作用等方面的研究,综述如下。１损伤机制１．１氧自由基 氧自由基（ＯＦＲ）是分子氧还原为水的一系列单价途径中所产生的中间产物,包括超氧阴离子自由基（Ｏ２－）、羟基自由基（ＨＯ－）、过氧化氢（Ｈ２Ｏ２）和单线态氧（Ｏ２）,由于有超氧化物岐化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化物酶等能迅速将ＯＦＲ清除而不造成ＯＦＲ堆积［１］ 在肾脏缺血情况下,可出现下面两种后果：①ＡＴ…     

丹参防治肝缺血再灌注期肝细胞内钙超载的实验与临床研究

作者报告了应用Ｆｕｒａ－２单细胞显微荧光探测技术观察活血去瘀中药丹参注射液对肝缺血再灌注期肝细胞内游离钙浓度影响的实验及临床研究，同期观察肝组织脂质过氧化自由左ＲＯＯ，电子自旋共振信号幅值和肝细胞超微结构病理改变，结果发现丹参可明显降低肝细胞内，ＲＯＯ幅值，减轻细胞损伤的病理程度，认为丹参可作为受体操作性钙阻滞剂在肝缺血再灌注损伤中发挥良好的肝保护作用。     

腹主动脉阻断导致内脏缺血再灌注损伤的研究

目的观察腹主动脉阻断所引起的肝、肾、小肠等内脏缺血再灌注损伤的改变。方法建立小猪腹主动脉阻断１小时的模型,检测在不同再灌注时点组织及血液中丙二醛（ＭＤＡ）和超氧化物歧化酶（ＳＯＤ）的变化,同时检测肝肾功能和动脉血气分析,观察动物术后的生存情况。结果与缺血前比较,大多数再灌注时点血、组织中ＭＤＡ明显升高,而ＳＯＤ明显降低（Ｐ＜０．０５）。在再灌注２小时,血中谷丙转氨酶（ＡＬＴ）、尿素氮（ＢＵＮ）、肌酐（ＣＲＥ）较缺血前明显升高（Ｐ＜０．０１）,代谢性酸中毒也极为明显。多数动物术后能够存活,但均出现下肢截瘫。结论腹主动脉阻断１小时能引起明显的内脏缺血再灌注损伤改变,多数内脏经处理后其损伤能够得到代偿恢复,而脊髓损伤恢复困难。     

人参总皂甙对犬肾自体移植再灌注损伤中氧自由基的清除作用

为了解人参总皂甙对肾移植再灌注损伤中氧自由基（ＯＦＲ）的清除作用，采用犬肾移植模型观察再灌注后２４小时肾组织中超氧化物歧化酶（ＳＯＤ）和丙二醛（ＭＤＡ）含量的变化及移植前后不同时期内生肌酐清除值。结果发现，在肾缺血和再灌注损伤过程中肾组织ＳＯＤ活性下降，ＭＤＡ含量异常增高。给人参总皂甙后能显著减少肾组织中ＭＤＡ含量，提高ＳＯＤ活性及内生肌酐清除值。结果提示，人参总皂甙能清除肾脏再灌注损伤产生的ＯＦＲ，保护内源性ＳＯＤ活性，减轻肾脂质过氧化损伤。     

一氧化氮供体防治急性缺血性肾衰的实验研究

为了进一步证实一氧化氮（ＮＯ）在急性缺血性肾衰（ＩＡＲＦ）发生发展中的作用，采用ＮＯ供体ＳＩＮ１对大鼠ＩＡＲＦ模型进行腹主动脉持续灌注３小时。结果发现：ＮＯ供体输入体内可在肾内迅速产生高浓度ＮＯ，可明显改善肾缺血再灌注后的肾皮质缺血，减轻肾功能及组织学损害。结果表明：ＮＯ下降参与了缺血再灌注的肾功能损害，是ＩＡＲＦ发生发展的重要因素之一。ＮＯ缺乏主要导致肾血流量下降，继而ＧＲＦ下降。应用ＮＯ供体直接提供外源性ＮＯ，提高肾内ＮＯ水平可以有效增加肾缺血再灌流后肾血流，改善肾功能，是防治ＩＡＲＦ又一新途径。     

肝细胞凋亡在肝硬化大鼠肝缺血再灌注损伤中的意义

目的 研究肝硬化大鼠肝缺血再灌注（I／R）损伤和硬化肝比正常肝更容易损伤的机制是否与肝细胞凋亡有关？方法 建立原位肝I／R模型，将肝硬化大鼠随机分为2组：A组：缺血时间（I）＝20min;B组：I＝30min;C组：正常大鼠，I＝30min，比较灌注前后各组血清AST、ALT的变化和肝细胞凋亡的百分数。结果 肝硬化大鼠肝I／R后，AST、ALT明显升高，以灌注后6h为高峰，灌注24、72h后逐渐下降。灌注6h后，B组的血清转氨酶为3组中最高（P＜0．05），说明B组肝损伤最严重。肝细胞凋亡在I／R后明显增多，以灌注后6h为高峰，随后逐渐下降，变化与转氨酶一致。灌注后6h，B、A、C组肝细胞凋亡的百分数分别为20．9％、13．5％和10．7％，B组明显高于A、C两组（P＜0．01）。再灌注72h内未见明显肝细胞坏死。结论 肝细胞凋亡是肝硬化大鼠I／R损伤肝细胞死亡的主要形式，肝细胞凋亡与肝缺血时间密切相关，肝硬化肝细胞比正常肝细胞容易发生凋亡是硬化肝对缺血敏感的重要原因。     

肾缺血预处理对肾小管上皮细胞内钙超载的影响

目的：通过观察肾缺血预处理（IPC）和缺血再灌注（I/R）过程中血清超氧化物歧化酶（SOD）、丙二醛（MDA）和细胞内游离钙离子浓度（[Ca^2＋]i）含量的变化,进一步探讨肾IPC的保护机制。方法：将雄性SD大鼠88只随机分为11组,摘除右肾,分离并夹闭左肾动脉制备肾I/R和缺血预处理后缺血再灌注（IPC-I/R）动物模型。Ⅰa～Ⅴa（I/R）组为缺血再灌注0、1、24、48、72h组,Ⅰb～Ⅴb（IPC-I/R）组为缺血预处理后缺血再灌注0、1、24、48、72h组,Sham组为假手术组。比色法测定血清肌酐（Scr）、尿素氮（BUN）、SOD、MDA含量,流式细胞仪检测肾小管上皮细胞内[Ca^2＋]i水平,TUNEL原位标记法观察细胞凋亡情况。结果：除0h组外,IPC-I/R与I/R各组比较肾功能损害、细胞凋亡均明显减轻,SOD升高,MDA降低,[Ca^2＋]i水平下降;两种模型中均以再灌注24h组损伤最严重,Scr、BUN、MDA和[Ca^2＋]i水平最高,SOD水平最低,细胞凋亡最多;再灌注24h前损伤呈加重趋势,24h后逐渐减轻;组间比较,[Ca^2＋]i与血清SOD水平呈负相关,与MDA呈正相关。结论：肾IPC可以减轻I/R过程中膜脂质过氧化损伤和细胞内钙超载,从而减轻肾脏形态及功能损伤;膜脂质过氧化和细胞内钙超载相互作用,共同发挥对肾I/R损伤的保护作用。     

缺血预处理和Caspase抑制剂对缺血再灌注损伤保护作用的比较

目的　比较缺血预处理和Caspase抑制剂治疗对大鼠肝缺血再灌注的保护作用及其机制。方法　SD大鼠随机分为 6组 :( 1)缺血再灌注1 (IR1 )组 ;( 2 )IR2 组 ;( 3 )缺血预处理1 (IP1 )组 ;( 4 )IP2 组 ;( 5 )Caspase抑制剂治疗1 (T1 )组 ;( 6)T2 组。比较各组大鼠 70 %肝脏 60min或 12 0min缺血 ,在再灌注 3h时的肝组织Caspase 3活性 ,肝细胞凋亡率和血清AST和ALT水平 ,及实验动物 7d存活率。结果　在 60min缺血及 3h再灌注时间 ,IP1 组和T1 组的保护作用相同 ,在 12 0min缺血及 3h再灌注时 ,T2 组对Caspase活性和肝细胞凋亡的抑制优于IP2 组 (P <0 .0 1) ,但两者的AST和ALT水平及动物 7d存活率均无显著性差异。结论　缺血预处理和Caspase抑制剂治疗对鼠肝缺血再灌注损伤都有保护作用 ,两者的保护效果无显著性差异。缺血预处理对缺血再灌注损伤的保护更简便、经济、安全 ,临床应用前景十分广阔。     

Endothelial cell and hepatocyte deaths occur by apoptosis after ischemia-reperfusion injury in the rat liver

BACKGROUND: Ischemic injury of the liver is generally considered to result in necrosis, but it has recently been recognized that mediators of apoptosis are activated during ischemia/reperfusion. This study was designed to characterize the extent and the type of cells within the liver that undergo apoptosis at different periods of ischemia and reperfusion. METHODS: Male Wistar rats were subjected to 30 or 60 min of normothermic ischemia. Liver sections were evaluated at the end of ischemia and at 1, 6, 24, and 72 hr after reperfusion. Apoptosis was determined by DNA fragmentation as evaluated by laddering on gel electrophoresis, in situ staining for apoptotic cells using TdT-mediated dUTP-digoxigenin nick-end labeling (TUNEL), and morphology on electron microscopy. RESULTS: In situ staining of liver biopsy specimens using TUNEL showed significant apoptosis after reperfusion. Sinusoidal endothelial cells (SEC) showed evidence of apoptosis earlier than hepatocytes. For example, at 1 hr of reperfusion after 60 min of ischemia, 22+/-4% of the SEC stained TUNEL positive compared with 2+/-1% of the hepatocytes (P<0.001). With a longer duration of ischemia, a greater number of SEC and hepatocytes became TUNEL positive. An increase in TUNEL-positive cells was also noted with an increasing duration of reperfusion. The presence of apoptotic SEC and hepatocytes was supported by DNA laddering on gel electrophoresis and cell morphology on electron microscopy. Several Kupffer cells were seen containing apoptotic bodies but did not show evidence of apoptosis. Only rare hepatocytes showed features of necrosis after 60 min of ischemia and 6 hr of reperfusion. CONCLUSION: These results suggest that apoptosis of endothelial cells followed by hepatocytes is an important mechanism of cell death after ischemia/reperfusion injury in the liver.     

大鼠肝脏冷/热缺血再灌注损伤钠钾ATP酶、钙ATP酶及镁ATP酶与肝细胞死亡方式的研究

目的:研究肝脏冷/热血再灌注损伤条件下,钠钾ATP酶、钙ATPATP酶及镁ATP酶活性与细胞凋亡和胀亡的关系,并探讨减少此类损伤的途径.方法:建立大鼠肝门部分阻断热缺血1h再灌注模型及大鼠原位肝移植冷缺血1h再灌注模型,分别于再灌注0h、1h、12h和72h处死取材,测定肝细胞钠钾ATP酶、钙ATP酶及镁ATP酶活性.用形态学及Annexin V、PI双染法流式细胞仪定量测定早期细胞凋亡和胀亡百分数. 结果:与对照组相比,冷/热缺血1h(再灌注0h)后钠钾ATP酶、钙ATP酶及镁ATP酶活性均持续显著下降,再灌注1h达低谷.但热缺血再灌注后72h钠钾ATP酶活性恢复,钙ATP酶及镁ATP酶活性仍未恢复.冷缺血再灌注后12h钙ATP酶先恢复活性,72h钠钾ATP酶、镁ATP酶活性才恢复.细胞死亡方式:①冷缺血再灌注损伤,细胞死亡以凋亡为主,并于再灌注后12h后到顶峰.②热缺血1h胀亡细胞显著增多,再灌注1h后减少,细胞死亡方式转为以凋亡为主.结论:肝脏冷/热缺血再灌注损伤均能导致3种ATP酶活性下降,细胞内离子浓度失衡,热缺血期ATP酶活性严重下降,细胞死亡,以胀亡为主.冷缺血期ATP酶轻度下降,细胞死亡以凋亡为主.术前或术中给予能量物质,对提高钠钾ATP酶、钙ATP酶及镁ATP酶活性,减轻炎症反应,延长肝门阻断时间有利.     

Protective role of dehydroascorbate in rat liver ischemia-reperfusion injury

BACKGROUND: Oxidative stress plays an important role in liver ischemia/reperfusion (I/R) injury. Thus, enhancing the liver antioxidant capacity could be a promising therapeutic strategy. Ascorbate (AA) is considered the perfect antioxidant, but its therapeutic efficacy is greatly limited by its slow achievement of high intracellular levels. This might be circumvented by administering dehydroascorbate (DHA), which presents a several-fold greater uptake than AA, and undergoes rapid intracellular reduction to AA. Thus, our aim was to assess the protective role of DHA in liver I/R injury. MATERIALS AND METHODS: Wistar rats (200-300 g bw) were pretreated iv with different doses of AA or DHA 20 min before liver ischemia, followed by 6 h reperfusion. Liver damage was assessed by biochemical and morphological indices. RESULTS: DHA pretreatment induced a rapid increase in liver ascorbate levels, significantly higher than findings for AA, without any significant reduction in glutathione levels. Liver damage during I/R in controls showed significant increases in serum transaminases and hepatic thiobarbituric acid reactive substances with alterations of liver morphology. DHA administration induced a clear, significant protection against I/R injury, whereas liver damage was only moderately prevented by AA. CONCLUSIONS: DHA might represent a simple, effective therapeutic option to prevent liver damage associated with ischemia/reperfusion.     

Glutathione protects the rat liver against reperfusion injury after prolonged warm ischemia

OBJECTIVE: To evaluate the potential of postischemic intravenous infusion of the endogenous antioxidant glutathione (GSH) to protect the liver from reperfusion injury following prolonged warm ischemia. BACKGROUND DATA: The release of reactive oxygen species (ROS) by activated Kupffer cells (KC) and leukocytes causes reperfusion injury of the liver after warm ischemia. Therefore, safe and cost-effective antioxidant strategies would appear a promising approach to prevent hepatic reperfusion injury during liver resection, but need to be developed. METHODS: Livers of male Lewis rats were subjected to 60, 90, or 120 minutes of normothermic ischemia. During a 120 minutes reperfusion period either GSH (50, 100 or 200 micromol/h/kg; n= 6-8) or saline (n= 8) was continuously administered via the jugular vein. RESULTS: Postischemic GSH treatment significantly prevented necrotic injury to hepatocytes as indicated by a 50-60% reduction of serum ALT and AST. After 1 hour of ischemia and 2 hours of reperfusion apoptotic hepatocytes were rare (0.50 +/- 0.10%; mean +/- SD) and not different in GSH-treated animals (0.65 +/- 0.20%). GSH (200 micromol GSH/h/kg) improved survival following 2 hours of ischemia (6 of 9 versus 3 of 9 rats; P < 0.05). Intravital fluorescence microscopy revealed a nearly complete restoration of sinusoidal blood flow. This was paralleled by a reduction of leukocyte adherence to sinusoids and postsinusoidal venules. Intravenous GSH administration resulted in a 10- to 40-fold increase of plasma GSH levels, whereas intracellular GSH contents were unaffected. Plasma concentrations of oxidized glutathione (GSSG) increased up to 5-fold in GSH-treated animals suggesting counteraction of the vascular oxidant stress produced by activated KC. CONCLUSIONS: Intravenous GSH administration during reperfusion of ischemic livers prevents reperfusion injury in rats. Because GSH is well tolerable also in man, this novel approach could be introduced to human liver surgery.     

Intracellular sodium hydrogen exchange inhibition and clinical myocardial protection

Although the mechanisms underlying ischemia/reperfusion injury remain elusive, evidence supports the etiologic role of intracellular calcium overload and oxidative stress induced by reactive oxygen species. Activation of the sodium hydrogen exchanger (NHE) is associated with intracellular calcium accumulation. Inhibition of the NHE-1 isoform may attenuate the consequences of this injury. Although there is strong preclinical and early clinical evidence that NHE inhibitors may be cardioprotective, definitive proof of this concept in humans awaits the results of ongoing clinical trials.     

The effect of FK506 on Warm Ischemia and reperfusion Injury in the Rat Liver

The protective effect of FK506 on hepatocytes against ischemia and reperfusion injury was examined by evaluating the following: the high energy phosphorus metabolism obtained using 31P magnetic resonance spectroscopy (³¹P-MRS) and the tissue blood flow of the liver in ischemia and the reperfusion process, mitochondrial glutamic oxaloacetic transaminase (m-GOT) and glutamic pyruvic transaminase (GPT), the survival rates of the animals, a histological study and immunohistological staining for intercellular adhesion molecule-1 (ICAM-1) in the liver after ischemia. The rats were treated with FK506 1 mg/kg/day i.m. for 4 days before testing. Ischemia was induced by clamping the hepatoduodenal ligament for 30 min. In³¹P-MRS, the recovery of the hepatic energy status after ischemia, evaluated by -ATP/inorganic phosphate (Pi), was significantly better in the FK506 group. It also coincided with the recovery of tissue blood flow monitored with a laser Doppler flowmeter. In the histological examination, the congestion observed in the periportal region of the control group was mild, while there was less induction of ICAM-1 in the endothelial cells of the portal veins and hepatic veins in the FK506 group. From these findings, we concluded that FK506 had a protective effect on hepatocytes against warm ischemia and reperfusion injury, and the mechanism for this could partially be attributed to improved tissue blood flow after ischemia by the modulation of immunological events.     

热休克蛋白70对肝缺血再灌注损伤的作用及机制探讨

目的 探讨热休克蛋白70（Heat shock protein 70,HSP70）对大鼠肝缺血再灌注损伤的作用及机制。方法 实验大鼠分为持续阻断组、间断阻断组和假处理组。用免疫金银法观察再灌注1h后肝组织HSP70蛋白的表达,并检测其肝细胞及线粒体功能、肝组织内钙和脂质过氧化物（Lipid peroxide,LPO）含量,以及超氧化物歧化酶（Superoxide dismuase,SOD）活性。结果 HSP70蛋白在持续性缺血再灌注后无表达,肝细胞功能、线粒体功能和SOD活性均显著下降,而肝组织内钙和LPO值均显著升高。间断性血流阻断组则有HSP70蛋白的合成表达,该组与假处理组的上述各项指标的差异均无显著意义。结论HSP70蛋白在肝缺血再灌注后的诱导产生有利于保护肝细胞及线粒体的功能,该效应与细胞内钙稳定和SOD活性增高有关。