大鼠肝缺血再灌注时三七总皂甙的保护作用

在肝脏外科中，常需要采取肝血流阻断以控制术中的出血，但缺血再灌注会造成肝损伤。作者用大鼠按Asakawa的方法造成肝缺血再灌注模型．比较维拉帕米和三七总皂甙对大鼠肝缺血再灌注损伤的保护效果。用雄性重300～350gSD大鼠分成4组，单纯切肝组、对照组(注人生理盐水)、注入维拉帕米50mg/kg组，三七总皂甙1.25ms／kg组，在阻断肝血流前5min注入。观察大鼠肝血流阻断90min再灌注后的生存率、肝功能、肝脏的病理和丙二醛、超氧化物歧化酶(SOD)的改变。结果：三七总皂甙与维拉帕米比较在提高大鼠的生存率(120min分别为63.3％比36.0％，P<0．05)，降低ALT(2118±430比3401±592，P<0．01)，减轻肝细胞坏死(5％～25％比20％～40％)，以及提高SOD活性(149±12比125±16，P<0．05)方面均强于维拉帕米。实验表明，三七总皂甙是肝缺血再灌注损伤的有效保护药物。     

氯化钆抑制枯否细胞对大鼠肝脏缺血再灌注损伤的影响

目的探讨抑制枯否细胞对大鼠肝脏缺血再灌注损伤的影响。方法制作部分肝脏缺血再灌注大鼠模型80只,实验组注射氯化钆,对照组注射生理盐水,检测两组大鼠缺血前、再灌注后5min、1和6h血压、心率的变化,血清转氨酶(AST)、肿瘤坏死因子α(TNFα)和白细胞介素1(IL1)的水平及肝组织超微结构的改变。结果实验组再灌注6h血清TNFα和IL1为(0.475±0.069)μg/L和(0.221±0.056)μg/L,显著低于对照组的(0.831±0.167)μg/L和(0.335±0.127)μg/L(P<0.05),两组血压、心率和AST变化的差异也有统计学意义(P<0.05),实验组大鼠肝脏超微结构的损伤程度轻于对照组。结论抑制枯否细胞活化可减轻肝脏缺血再灌注损伤,枯否细胞在肝脏缺血再灌注损伤中的作用很重要。     

钙超载对低温保存肝脏细胞的损伤作用

目的探讨钙离子对肝脏的损伤作用.方法应用含胶原酶保存液灌注大鼠肝脏制成不同细胞成活率的肝细胞悬液,低温保存肝脏细胞.应用Fura-2/AM标记测细胞内钙. 结果①低温保存2小时肝细胞 实验1组(细胞成活率为5%)肝细胞内钙值为(1055.0±30.79) nmol/L; 实验2组(细胞成活率为10%)肝细胞内钙值为(853.0±20.42) nmol/L; 实验3组(细胞成活率为30%)肝细胞内钙值为(616.0±13.20) nmol/L; 实验4组(细胞成活率为50%)肝细胞内钙值为(562.0±26.06) nmol/L; 实验5组(细胞成活率为70%～80%)肝细胞内钙值为(318.0±13.01) nmol/L; 实验6组(细胞成活率为90%)肝细胞内钙值为(114.6±6.11) nmol/L.②低温保存24小时肝细胞 实验A组(细胞成活率为10%)肝细胞内钙值为(1704.0±70.11) nmol/L; 实验B组(细胞成活率为50%)肝细胞内钙值为(1125.0±23.22) nmol/L.随着细胞成活率的降低,细胞内钙值逐渐升高; 在同样细胞成活率情况下,随着保存时间延长(2小时与24小时)细胞内钙值增高1倍左右.结论在低温保存过程中,钙超载是造成肝脏细胞缺血再灌注损伤的一个主要因素.     

抑制枯否细胞对肝细胞线粒体再灌注损伤的影响

目的 :探讨抑制枯否细胞对肝细胞线粒体再灌注损伤的影响。方法 :大鼠分为对照组和实验组 ,第 1、2日经鼠尾静注氯化钆 (7mg/kg) ,对照组注射等量生理盐水 ,第 3日手术使肝缺血 2h后分别复流2h、6h和 18h ,测定肝组织和肝细胞线粒体的丙二醛 (MDA)和血清转氨酶ALT含量 ,观察肝细胞及线粒体超微结构的变化。结果 :实验组复流 2h、6h肝细胞线粒体MDA含量 (nmol/ g)分别为 1.81±0 .2 4和 1.91± 0 .5 6 ,对照组分别为 4 .89± 2 .91(P <0 0 5 )和 2 .93± 0 .5 1(P <0 0 5 ) ,实验组复流 6h肝组织MDA醛含量为 3.5 0± 2 .0 6 ,对照组为 7.6 5± 2 .4 6 (P <0 0 5 )。随着复流时间的延长 ,对照组出现核固缩 ,染色质边集 ,细胞器减少直至肝细胞破坏 ,而实验组在复流 18h后仍可见肝细胞结构基本正常 ,线粒体的损伤程度也明显减轻。结论 :抑制枯否细胞可以减轻肝细胞线粒体的再灌注损伤。     

微波预照射对家兔肝缺血再灌注损伤时氧自由基的影响

目的　探讨微波预处理对家兔肝缺血再灌注损伤的影响及其作用机理。　方法　家兔32只, 随机分为 4组: A组,对照组(假手术组); B组, 20W微波照射 20min组; C组, 微波照射+肝门阻断组(预处理组); D组, 单纯肝门阻断组。检测肝功能及肝组织中脂质过氧化物丙二醛 (malondi aldehyde, MDA)和超氧化物歧化酶 (superoxidedismutase, SOD)的浓度变化。　结果　B、C、D组手术后 2h、4h肝功能均有损害,而D组的ALT、AST、LDH均高于C组;C组肝组织MDA浓度为 (15. 3±0. 8)nmol/mg,低于D组的(21. 2±1. 2)nmol/mg,C组的SOD浓度为 (529. 5±48. 4)U/mg,高于D组的(418. 3±9. 1)U/mg(P<0. 05)。　结论　微波预处理可能通过减少氧自由基的生成而减轻家兔肝缺血再灌注损伤所致的肝脏功能损害。     

兔肝缺血/再灌注损伤肝组织氧压及线粒体形态观察

目的　观察兔肝缺血 /再灌注损伤不同时相肝组织氧压及线粒体形态变化 ,研究常温下肝脏缺血 /再灌注的损伤及其机制。方法　 4 0只兔随机分为 2组即缺血组和对照组。组织气体分析仪持续测定兔肝组织氧压 (Hepatic tissue oxygeonpressure Ptio2 ) ;电镜观察肝脏病理及线粒体形态改变 ,图像分析仪对线粒体的立体形态计量分析。结果　缺血组兔在肝脏缺血后肝 Ptio2值开始下降 ,再灌注 6 0 min时肝 Ptio2仍未恢复正常 (P<0 .0 5 )。电镜观察发现 :肝缺血 30 min,线粒体肿胀、内质网扩张 ,再灌注 6 0 m in后线粒体肿胀进一步加重 ,部分线粒体破坏 ,结构不清 ,线粒体空泡变性。兔肝缺血再灌注损伤后肝细胞线粒体与对照组相比 ,其比表面减小、平均体积增大 (P<0 .0 5 )。结论　常温下入肝血流阻断可以导致肝脏缺血 /再灌注后肝细胞功能障碍和病理损害。其作用机制与缺血期肝细胞缺氧、再灌注期肝脏微循环障碍和肝细胞线粒体的损伤有关     

人肝血流阻断对肝组织Ptio2、Ptico2、pH和T的影响

目的研究常温下入肝血流阻断对兔肝组织氧分压(Ptio2)、二氧化碳分压(Ptico2)、酸碱度(pH)和温度(T)的影响及临床意义.方法入肝血流阻断15 min后再灌注,通过组织气体分析仪持续测定兔肝组织Ptio2、Ptico2、pH和T变化.结果肝血流阻断后Ptio2下降至7.6±0.1 mmHg;Ptio2值升至163.±27 mmHg;pH值降至6.7±0.1;T下降至35.6±0.7C.再灌注15 min后,肝组织Ptio2、Ptio2、pH和T缓慢恢复.结论人肝血流阻断导致肝脏缺血/再灌注损伤,肝组织代谢异常;肝组织内Ptio2、Ptio2、pH值和T观察是监测肝缺血/再灌注损伤的一个重要方法.     

Bcl-2基因修饰的肝细胞移植对肝脏缺血再灌注损伤的影响

目的观察人Bcl-2(hBcl-2)基因修饰的肝细胞移植对肝脏缺血再灌注损伤的影响。方法将包含hBcl-2基因阅读框架(0·7kb)的核苷酸亚克隆至Psectag2A载体,脂质体转染balb/c小鼠胎肝细胞(BNL.CL2),经门静脉移植入balb/c小鼠(2×106细胞)。移植72h后左肝后叶常温下缺血45min后再灌注8h,比较测定凋亡细胞,血清ALT、AST、LDH,以及组织学的改变。结果转染hBcl-2基因的balb/c小鼠在肝脏缺血再灌注后ALT(P<0·05或0·01)、AST(P<0·05)、LDH(P<0·05)、凋亡细胞(P<0·05)均较对照组显著降低,组织学改变减轻。进行缺血再灌注的各组细胞损伤均以细胞凋亡为主(P<0·05或0·01)。结论hBcl-2基因修饰的肝细胞移植对肝脏缺血再灌注损伤具有保护作用,主要通过抑制缺血再灌注后的细胞凋亡。     

血红素氧合酶-1基因在大鼠供肝缺血再灌注损伤中的抗炎作用

目的 探讨血红素氧合酶-1(HO-1)基因在大鼠供肝缺血再灌损伤中的抗炎作用.方法 将32只雄性SD大鼠分为实验组(16只)和对照组(16只).将已转染HO-1基因的腺病毒载体和空载体分别注入实验组和对照组供体大鼠腹腔(各8只).36 h后取供肝,冷保存4 h后行大鼠原位肝移植.缺血再灌注6 h后检测血清ALT、AST、TNF-α、肝组织HO-1蛋白的表达以及阳性巨噬细胞计数.采用t检验和秩和检验行统计学分析.结果 (1)实验组血清ALT和AST分别为(439±81)U/L和(1110±73)U/L,对照组分别为(1005±120)U/L和(1583±175)U/L,两组比较,差异有统计学意义(t=11.090,7.050,P<0.05).(2)实验组和对照组血清TNF-α分别为(15±13)μg/L和(52±11)μg/L,两组比较,差异有统计学意义(t=0.009,P<0.05).(3)实验组和对照组肝组织HO-1蛋白的表达分别为0.28±0.07和0.04±0.03,两组比较,差异有统计学意义(T=42.5,P<0.05).(4)实验组中HO-1阳性细胞大量表达于血管区,其阳性巨噬细胞的计数为2±1,显著少于对照组的8±2(t=0.007,P<0.05).结论 HO-1在大鼠供肝缺血再灌注损伤中可能通过抑制肝巨噬细胞的激活,降低TNF-α的释放而发挥抗炎作用.     

依达拉奉对肝缺血再灌注损伤逆转作用的研究

目的研究依达拉奉影响肝脏缺血再灌注过程中TNF-α的表达情况,探讨依达拉奉对肝脏缺血再灌注损伤的逆转作用。方法将80只Wistar大鼠编号,根据计算机产生随机数字,前40为一组,后40为一组,分为实验组和对照组2组,建立常温下部分肝缺血再灌注损伤动物模型。在肝脏缺血再灌注损伤开始前1 h和开始时对实验组大鼠给予依达拉奉注射液10 ml,对照组则给予同等容量的生理盐水。分别于再灌注后0、1、2及4 h测定肝脏脂质过氧化物酶(LPO)和肝脏谷草转氨酶(AST)浓度;应用RT-PCR法检测肝组织TNF-αmRNA含量,并测定肝组织和血清中TNF-α水平;应用TUNEL染色法检测缺血肝组织的细胞凋亡情况。结果再灌注后1、2及4 h,实验组大鼠肝脏LPO及AST浓度均明显低于对照组(P<0.001);实验组再灌注后1 h时肝组织TNF-αmRNA表达量、肝组织和血清TNF-α含量均明显升高且达峰值,但均明显低于对照组(P<0.05);再灌注后各时相实验组肝细胞凋亡率明显升高,但均明显低于对照组(P<0.05)。结论依达拉奉能抑制氧化应激反应,从而降低肝缺血再灌注损伤;并显著减少炎性细胞因子TNF-α的产生,抑制炎性反应的发生,减少肝细胞的凋亡。     

丙泊酚与肝脏缺血/再灌注损伤

缺血/再灌注对肝脏造成损伤.众多资料显示丙泊酚对肝脏缺血/再灌注损伤有保护作用,这一保护作用与其抗氧化,阻断钙超载,减轻炎性细胞导致的损伤有关.肝脏缺血/再灌注也影响了丙泊酚的代谢.     

Protective effect of diltiazem on hepatic ischemia-reperfusion injury in rats by improving liver tissue blood flow

BACKGROUND: Cytosolic calcium ions are known to play an important role in ischemia-reperfusion (IR) injury. However, the protective effect of calcium channel blockers remains controversial in liver IR injury. Moreover, calcium channel blockers improve hepatic IR injury not due to blocking an increase in hepatic calcium concentration. Therefore, we hypothesized that calcium antagonists protected a liver from IR injury by a vasodilatory action rather than by the inhibition of an increase in Ca2+ within parenchymal cells. This study evaluated the effects of diltiazem, a calcium channel blocker, on liver energy metabolism and blood flow after IR injury. METHODS: Twenty-seven rats underwent hepatic ischemia for 30 minutes followed by 60 minutes of reperfusion. The animals were allocated into group C (without drug); group D5 (diltiazem, 5 microg/kg per min); or group D10 (diltiazem, 10 microg/kg per min). Diltiazem was infused before laparotomy and then throughout the experiment. RESULTS: After 60 minutes of reperfusion, liver tissue blood flow and ATP concentrations were significantly higher in group D10 than the other animals (both, P < .05). Changes in ATP values strongly correlated those observed in blood flow (R = 0.80, P < .001). CONCLUSION: Diltiazem improved ATP-generating capacity during reperfusion by improving liver tissue blood flow. An improvement in hepatic tissue perfusion may be a therapeutic strategy for liver IR injury.     

黄芪注射液对肝门阻断后肝功能损害的治疗作用

目的探讨黄芪注射液对肝门阻断后肝脏的治疗保护作用。方法88例肝门阻断肝脏手术的病人随机分为黄芪注射液治疗组（Ⅰ组）和非黄芪注射液治疗组（Ⅱ组）,术前和术后3d、7d分别检测直接胆红素（DBil）、碱性磷酸酶（ALP）、天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）、7谷氨酰转移酶（GGT）、白蛋白（Alb）,两组资料进行对比分析。结果与Ⅱ组比较,Ⅰ组术后3d、7dAST、ALT明显恢复,差异有统计学意义。结论黄芪注射液对肝门阻断后的肝脏缺血缺氧及再灌注损伤有一定的保护作用。     

双歧杆菌对幼鼠肝缺血再灌注损伤保护作用的实验研究

目的研究双歧杆菌对幼鼠肝缺血再灌注损伤的保护作用并探讨相关机制。方法 90只SD幼鼠随机分为3组:对照组、模型组和治疗组。采用阻断肝动脉和门静脉45 min后再灌注12 h建立幼鼠肝缺血再灌注模型。Henry速率法检测各组大鼠血清中ALT和AST的变化,HE染色观察肝组织病理学改变,ELISA法检测肝组织TNF-α以及IL-6,采用改良鲎试验测定血浆内毒素,免疫组织化学染色检测肠黏膜occludin分布。结果双歧杆菌治疗组的血清ALT及AST表达显著低于模型组。同时,组织切片显示,肝细胞坏死程度也显著减轻。与模型组相比,双歧杆菌治疗组血浆内毒素阳性率降低,TNF-α以及IL-6明显降低,occludin表达升高。结论双歧杆菌对幼鼠急性肝缺血再灌注损伤有保护作用,该作用与双歧杆菌能维持肠黏膜屏障功能,减轻炎症反应以及减少内毒素移位有关。     

Mitochondrial K(ATP) channel opener prevents ischemia-reperfusion injury in rat liver

Ischemia-reperfusion injury is responsible for the morbidity associated with liver surgery under total vascular exclusion or after liver transplantation. Recently, it has been reported that mitochondrial K(ATP) channel openers have an effect on myocardial protection via a pharmacological preconditioning action. However, it remains unclear as to whether K(ATP) channel openers can reduce ischemia-reperfusion injury in the liver. The aim of this study was to determine the effects of the mitochondrial K(ATP) channel opener, nicorandil, on ischemia-reperfusion injury in the rat liver. Male Wistar rats were subjected to 73% ischemia for 45 minutes followed by 120 minutes of reperfusion. Nicorandil (3 mg/kg) was orally administered 60 minutes before hepatic ischemia. Nicorandil significantly decreased plasma levels of alanine aminotransferase and lactate dehydrogenase by about 50% and inhibited the remarkably increased TUNEL-positive hepatocytes after reperfusion. Some mediators associated with apoptosis were analyzed by Western blotting. Cytochrome-c and caspase-3 levels in the cytosol increased after reperfusion; nicorandil inhibited the release of cytochrome-c and activation of caspase-3. The expression of Bax and Bcl-2 was significantly increased after reperfusion, being slightly inhibited by the administration of nicorandil. These results suggest that the protective effects of nicorandil against hepatic ischemia-reperfusion injury correlate with the inhibition of mitochondrial cytochrome-c release and caspase-3 activation. These findings demonstrate that nicorandil may become a therapeutic drug for ischemia reperfusion-related liver injury.     

The effect of antagonism of adenosine A1 receptor against ischemia and reperfusion injury of the liver

BACKGROUND: Adenosine is known to exert protective roles in hepatic ischemia and reperfusion injury, while all adenosine receptors do not play the cytoprotective roles. We have tested our hypothesis that blockage of adenosine binding to A(1) receptor by its antagonist, KW3902 [8-(noradamantan-3-yl)-1,3-dipropylxanthine] attenuates hepatic ischemia-reperfusion injury. METHODS: Adult female beagle dogs underwent a 2 h total hepatic vascular exclusion (THVE) with a venovenous bypass. Nontreated animals that underwent THVE with a venovenous bypass alone were used as the control (Group CT, n=6). KW3902 was given to the animals by continuous intraportal infusion for 60 min before ischemia at a dose of 1 microg/kg/min (Group KW, n=6). Two wk survival, hemodynamics, hepatic tissue blood flow (HTBF), liver function, energy metabolism, cAMP concentration, and histopathological findings were studied. RESULTS: Two wk animal survival was significantly improved in group KW compared with that in group CT (group CT: 16.7% versus group KW: 83.3%). HTBF, liver function, and hepatic adenine nucleotide concentration were remarkably better in group KW than group CT. In addition, cAMP concentration in group KW was maintained significantly higher than group CT. Histopathological examination revealed preservation of hepatic architecture and suppression of neutrophil infiltration into hepatic tissue in group KW. CONCLUSION: Administration of adenosine A(1) receptor antagonist before ischemia attenuates hepatic ischemia-reperfusion injury. To elicit the beneficial effect of adenosine against ischemia and reperfusion injury of the liver, it is important to oppose adenosine A1 receptor activation.     

潘生丁对大鼠移植肝缺血再灌注损伤保护作用的实验研究

目的探讨潘生丁对大鼠移植肝缺血再灌注损伤的保护作用及其相关机制。方法采用改良Kam ada“二袖套法”制作肝移植模型,48只雄性SD大鼠随机分成3组:假手术组(A组),同基因大鼠肝移植组(B组)和潘生丁预处理 同基因大鼠肝移植组(C组)。于供肝再灌注2 h后测定各组PAGT、ALT、AST、SOD、MDA含量,比较肝细胞凋亡和组织形态学改变。结果移植肝再灌注2 h后C组较B组肝组织损害轻,SOD、MDA、ALT、AST、PAGT变化及肝细胞凋亡差异有显著性(P<0.05)。结论潘生丁可通过改善肝脏微循环状况,改善缺血肝脏组织的能量代谢,提高肝组织抗氧化能力,抑制细胞凋亡和减少肝脏细胞的变性坏死程度而对肝脏热缺血再灌注起保护作用。     

Verapamil decreases MAC for halothane in dogs

Verapamil hydrochloride is a calcium entry blocking drug that is being prescribed with increasing frequency for cardiovascular disorders in the perioperative setting. Verapamil's calcium channel blocking effect is not selective, because it also exerts activity on the sodium channel. Because of the well-described effects of sodium channel blockers on anesthetic requirements, the authors studied the MAC for halothane in dogs before and after a therapeutic dose of verapamil 0.5 mg . kg-1. There was a 25% reduction in halothane MAC from 0.97-0.72% (P less than 0.01) when a therapeutic plasma level of verapamil (64 ng . ml-1) was present. Anesthetic requirements for halothane are reduced by dl-verapamil possibly on the basis of its local anesthetic-like sodium channel blocking properties. Adjustments in anesthetic dosage may be necessary in patients receiving verapamil.     

间断低氧预适应对大鼠肝切除缺血再灌注肝脏中EPO的影响

目的 观察术前间歇性低氧预适应对大鼠70％肝切术后肝脏中促红细胞生成素（Erythropoietin,EPO）量的影响.方法 健康清洁级SD大鼠120只,简单随机分为3组：假手术组（Sham,S组）40只;单纯大部肝切除组40只（Major hepatectomy,MH组）,即在肝门阻断下切除肝脏的左叶和中叶,肝门阻断20 min;间断低氧预适应组40只（Intermittent hypoxia preconditioning,IHP组）,术前1周将大鼠置于氧气体积分数10％的低氧环境中,每天1次,每次60 min.1周后在肝门阻断下行肝切除术（同IR组）.各组分别于术后2、6、12、24、48、72、120、168 h进行取材检测,用全自动生化分析仪检测下腔静脉血清ALT、AST含量,电镜下观察残余肝细胞中线粒体及内质网等的变化,采用ELISA测定残肝组织中促红细胞生成素的量,并运用统计学的方法比较各组中的意义.结果 MH组、S组、IHP组3组实验组中术后大鼠残肝组织中EPO水平具有显著统计学差异（P＜0.05）,间断低氧预处理组残余肝脏中EPO含量明显高于单纯肝切除组.结论 间断性低氧预适应可以促进肝切除术后残余肝组织中EPO的表达.     

硫化氢对大鼠肝缺血再灌注损伤的影响

目的 评价硫化氢对大鼠肝缺血再灌注损伤的影响.方法 健康雄性SD大鼠30只,体重220～250 g,采用随机数字表法,将其随机分为假手术组(S组)、缺血再灌注组(IR组)和不同剂量硫化氢组(H2S1～3组),每组6只.S组仅暴露肝门,不夹闭动、静脉;IR组采用夹闭左、中叶肝蒂、门静脉和肝动脉支1h恢复灌注的方法制备大鼠肝缺血再灌注模型;H2S1～3组于再灌注前5min分别腹腔注射14、28、56 μmol/kg硫化氢钠.于再灌注6h时抽取下腔静脉血样并取肝组织,采用全自动生化分析仪测定血清谷丙转氨酶(ALT)和谷草转氨酶(AST)活性,采用二硫代二硝基苯甲酸法测定肝组织谷胱甘肽(GSH)含量,光镜下观察肝组织病理学结果.结果 与S组相比,IR组血清ALT和AST活性升高,肝组织GSH含量下降(P＜0.05);与IR组相比,H2S1～3组ALT和AST活性降低,肝组织GSH含量升高(P＜0.05);H2S1～3组肝病理学损伤较IR组明显减轻.结论 H2S可减轻大鼠肝缺血再灌注损伤.