吸入性麻醉药异氟醚对大鼠脑缺血/再灌注损伤的保护作用

目的 研究异氟醚预处理对大鼠脑缺血/再灌注损伤的可能保护机制.方法 采用四动脉结扎法建立大鼠脑缺血模型.分别在缺血前随机分为假手术组、直接脑缺血/再灌注组、吸入2 h 1.5 MAC异氟醚脑缺血/再灌注组和吸入纯氧2h脑缺血/再灌注对照组,全脑缺血15 min后再分别复灌3 d和5 d.复灌3 d的大鼠断头取海马进行JNK3的免疫印迹和免疫沉淀;复灌5 d的大鼠用焦油紫染色法检测海马CA1区的细胞.结果 复灌3 d后,缺血前吸入1.5 MAC异氟醚组的大鼠组其JNl.的活性明显低于直接缺血对照组和吸入纯氧对照组(P<0.05);复灌5 d后,缺血前吸入1.5 MAC异氟醚可有效降低大鼠海马CA1区锥体细胞的死亡(P<0.05).结论 1.5 MAc异氟醚对大鼠脑缺血/再灌注损伤有确切的保护作用;JNK信号通路可能介导了异氟醚对缺血性脑损伤的保护作用.     

短时长吸入一氧化氮预处理对大鼠肺缺血再灌注损伤的保护作用

目的 探讨低浓度一氧化氮(NO)预处理及其吸入时长的不同对肺缺血再灌注损伤(IRI)的影响和机制.方法 成年雄性SD大鼠77只,分为空白组(Sham组)、缺血再灌注组(I/R组)、NO预处理10 min组(NO-10 min组)、NO预处理1 min组(NO-1 min组),NO预处理60 min组(NO-60 min组),分别于不同的再灌注时间点采集标本,检测动脉血氧分压(PaO2),肺组织干/湿重比(W/D),丙二醛(MDA)浓度,髓过氧化酶(MPO)活性,肺损伤组织学评价等指标,比较前3组再灌注后2、6、24 h结果,取IRI最严重时间点,比较各组肺功能指标以及血清和左肺组织NO浓度.结果 再灌注6h肺损伤最严重;与I/R组比较,NO-10 min组各时间点指标明显改善(P＜0.05),NO吸入具有肺保护作用;NO-1 min组肺损伤无改善(P＞0.05);NO-10 min组与NO-60 min组对肺损伤保护作用相似(P＞0.05).结论 短时长吸入低浓度NO预处理可以改善IRI,但是其保护作用不与NO预处理时长成正比.     

雷米芬太尼预处理对大鼠局灶性脑缺血-再灌注损伤的保护作用

目的观察雷米芬太尼预处理对大鼠局灶性脑缺血再灌注损伤的保护作用。方法23只雄性大鼠,随机分为两组。雷米芬太尼预处理(R)组(n=13)经股静脉注入雷米芬太尼(0.6μg·kg-1·min-1),每次5min输注,连续3次,中间间隔5min;盐水对照(C)组(n=10)经股静脉注入盐水,每次5min输注,连续3次,中间间隔5min;30min后,所有动物用右侧颈内动脉尼龙线线栓法致大脑中动脉阻闭120min,然后拔出尼龙线恢复再灌注。观察再灌注后24h神经功能障碍改变并评分。再灌注24h时处死动物,取大脑行2,3,5triphenyltetrazolium(TTC)染色以计算脑梗死容积百分比。结果缺血再灌注后动物均表现一定神经功能障碍,再灌注24h内C组神经功能障碍逐渐加重,R组则呈减轻趋势;再灌注24h时神经功能障碍评分(NDS)R组明显低于C组(P<0.05);再灌注24h时脑梗死容积百分比,R组明显小于C组(P<0.01)。结论雷米芬太尼预处理对大鼠局灶性脑缺血再灌注损伤可产生保护作用。     

舒芬太尼预先给药对大鼠急性局灶性脑缺血-再灌注损伤的保护作用

目的 观察舒芬太尼预先给药对大鼠大脑中动脉栓塞(MCAO)所致局灶性脑缺血-再灌注损伤的保护作用.方法 40只雄性大鼠随机均分为四组,分别于缺血造模前腹腔注射舒芬太尼3μg/kg(S_1组)、6μg/kg(S_2组)、9μg/kg(S_3组)和等容积生理盐水为对照组(C组).给药后30 min,所有动物用右侧颈内动脉尼龙线线栓法致MCAO,120 min后恢复再灌注.再灌注24 h后记录神经功能障碍评分(NDS).随后取大脑切片行TTC染色,计算脑梗死容积百分比.结果 再灌注后24h,S_1组NDS评分明显高于其他三组(P<0.05),梗死容积百分比明显低于其他三组(P<0.05),S_2、S_3、C组间NDS评分和梗死容积百分比差异均无统计学意义.结论 舒芬太尼3μg/kg预先给药可明显减轻大鼠局灶性脑缺血-再灌注损伤.     

七氟烷后处理对不同病程糖尿病大鼠离体心肌缺血再灌注损伤的影响

目的 评价七氟烷后处理对不同病程糖尿病大鼠离体心肌缺血再灌注损伤的影响.方法 清洁级健康雄性SD大鼠72只,体重200 ～ 240 g,采用随机数字法,将其随机分成6组(n=12):非糖尿病缺血再灌注组(I/R组)、非糖尿病七氟烷后处理组(I/R+ sevo组)、2周糖尿病缺血再灌注组(2DM组)、2周糖尿病七氟烷后处理组(2DM+ sevo组)、6周糖尿病缺血再灌注组(6DM组)、6周糖尿病七氟烷后处理组(6DM+ sevo组).制备离体心脏Langendorff灌注模型,各组经主动脉灌注K-H液,平衡灌注15 min后停灌30 min,I/R组、2DM组及6DM组均采用K-H液灌注75 min; I/R+ sevo组、2DM+ sevo组及6DM+ sevo组均采用含有3％七氟烷的K-H液灌注15 min,随后用K-H液继续灌注60 min.于平衡末、再灌注15和75 min时记录左室舒张末压、左室发展压、左心室压力上升最大速率、左心室压力下降最大速率以及心率.于再灌注15 min时取心肌组织,用Western blot法测定磷酸化Akt(p-Akt)和总Akt的表达,于再灌注75 min时采用TTC法测定心肌梗死体积,计算心肌梗死体积比.结果 与2DM组比较,2DM+ sevo组心功能改善,心肌梗死体积比减小,p-Akt表达上调(P＜0.05);与I/R组比较,I/R+ sevo组再灌注期间心功能改善,心肌梗死体积比减小,p-Akt表达上调(P＜0.05);与6DM组比较,6DM+ sevo组心功能指标、心肌梗死体积比及p-Akt表达差异无统计学意义(P＞0.05).结论 随着糖尿病病程进展,七氟烷后处理减轻大鼠心肌缺血再灌注损伤的作用减弱,可能与PI3K/Akt信号通路受损有关.     

Donor treatment with mycophenolate mofetil: protection against ischemia-reperfusion injury in the rat

BACKGROUND: Mycophenolic acid, the active metabolite of mycophenolate mofetil, inhibits the glycosylation of cell membrane glycoproteins. We hypothesized that impaired glycosylation of cell adhesion molecules on endothelial cells in vivo results in decreased susceptibility to inflammation or immunogenicity after allogeneic transplantation. METHODS: The expression of mannose residues on cultured rat endothelial cells was examined after stimulation with interleukin 1 in the presence or absence of mycophenolic acid using labeled Galanthus nivalis agglutinin. The in vitro adhesion of blood leukocytes to heart tissue was examined using peripheral blood leukocytes of recipient origin and sections of donor heart tissue exposed to ischemia-reperfusion injury after pretreatment with vehicle or mycophenolic mofetil. (LEWxBN)F1 donor rats were treated with 20 or 60 mg/kg/day of mycophenolate mofetil for 1 or 2 weeks followed by transplantation of the heart into Lewis recipients after storage in heparin-containing normal saline for either 10 min at 4 degrees C or 120 min at room temperature. RESULTS: Endothelial cells stimulated in vitro with interleukin 1 showed an increase in a population of strongly mannose-positive cells, which was prevented by the addition of mycophenolic acid during the culture. The in vitro adhesion of peripheral blood leukocytes to cardiac tissue sections exposed to prolonged storage and reperfusion was significantly less if the donor had been treated with mycophenolate mofetil. Treatment of cardiac graft donors with mycophenolate mofetil protected the graft against early graft failure after prolonged storage at room temperature, because the mean graft survival was 9.4+/-0.6 days for grafts that came from donors treated with mycophenolate mofetil versus 1.2+/-0.9 days (P<0.05) for grafts that came from vehicle-treated donors. Donor pretreatment with mycophenolate mofetil did not affect the survival time of heart grafts transplanted after 15 min of standard cold storage or the survival of grafts transplanted into presensitized recipients. CONCLUSION: Donor treatment with mycophenolate mofetil protects cardiac grafts against primary nonfunction after prolonged tepid storage, which may be related to the inhibition of glycosylation of cell adhesion molecules involved in ischemia-reperfusion injury.     

Myocardial protection by anesthetic agents against ischemia-reperfusion injury: An update for anesthesiologists

PURPOSE: The aim of this review of the literature was to evaluate the effectiveness of anesthetics in protecting the heart against myocardial ischemia-reperfusion injury. SOURCE: Articles were obtained from the Medline database (1980-, search terms included heart, myocardium, coronary, ischemia, reperfusion injury, infarction, stunning, halothane, enflurane, desflurane, isoflurane, sevoflurane, opioid, morphine, fentanyl, alfentanil sufentanil, pentazocine, buprenorphine, barbiturate, thiopental, ketamine, propofol, preconditioning, neutrophil adhesion, free radical, antioxidant and calcium). PRINCIPAL FINDINGS: Protection by volatile anesthetics, morphine and propofol is relatively well investigated. It is generally agreed that these agents reduce the myocardial damage caused by ischemia and reperfusion. Other anesthetics which are often used in clinical practice, such as fentanyl, ketamine, barbiturates and benzodiazepines have been much less studied, and their potential as cardioprotectors is currently unknown. There are some proposed mechanisms for protection by anesthetic agents: ischemic preconditioning-like effect, interference in the neutrophil/platelet-endothelium interaction, blockade of Ca2+ overload to the cytosolic space and antioxidant-like effect. Different anesthetics appear to have different mechanisms by which protection is exerted. Clinical applicability of anesthetic agent-induced protection has yet to be explored. CONCLUSION: There is increasing evidence of anesthetic agent-induced protection. At present, isoflurane, sevoflurane and morphine appear to be most promising as preconditioning-inducing agents. After the onset of ischemia, propofol could be selected to reduce ischemia-reperfusion injury. Future clinical application depends on the full elucidation of the underlying mechanisms and on clinical outcome trials.     

One MAC of sevoflurane provides protection against reperfusion injury in the rat heart in vivo

Volatile anaesthetics protect the heart against reperfusioninjury. We investigated whether the cardioprotection inducedby sevoflurane against myocardial reperfusion injury was concentration-dependent.Fifty-eight     

异丙酚预处理对脑缺血再灌注损伤的保护作用

目的观察不同时间异丙酚预处理对沙土鼠脑缺血再灌注损伤的保护作用.方法沙土鼠42只,随机分为对照组、缺血损伤组、异丙酚预处理组(脑缺血前48h、24h、12h、6h、1h各组分别以异丙酚100mg@kg-1.腹腔注射)等7组,观察指标为脑组织内皮素(ET)、降钙素基因相关肽(CGRP)、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)活性的改变并制作电镜标本行透射电镜观察.结果异丙酚预处理各组ET含量、ET/CGRP含量的比值及MDA含量明显低于缺血损伤组(P＜0.05),而CGRP含量和SOD、GSH-px活性明显高于缺血损伤组(P＜0.05),其中尤以异丙酚预处理24h组的ET及ET/CGRP值降低更明显,而CGRP值明显高于其余异丙酚预处理组(P＜0.05);电镜结果也显示异丙酚预处理24h组脑组织的超微结构改变最小、损伤最轻.结论缺血前48h至缺血前1h各时点异丙酚预处理对沙土鼠缺血性脑损伤均有不同程度的保护作用,尤以缺血前24h给药对沙土鼠脑缺血再灌注损伤的保护作用优于其它各时点异丙酚预处理组.     

Opioids and protection against ischemia-reperfusion injury: from experimental data to potential clinical applications

Ischemic preconditioning, first demonstrated in animal myocardium, is an intrinsic and ubiquitous mechanism of marked protection against ischemia. Accumulating evidences have established that endogenous opioid peptides and their receptors play an important role in this adaptive phenomenon in the heart and other major organs. Of interest for therapeutic developments, opioid receptor agonists have been administered successfully to improve tolerance against experimental ischemia-reperfusion in various tissues. Recent human studies now raise the possibility to exploit this opioid-induced protection in clinical cardiac ischemia. These remarkable anti-ischemic properties of opioids and their emerging potential for organ protection in perioperative medicine will be reviewed at the light of pertinent results from basic and clinical researches.     

丝裂原活化蛋白激酶在一氧化碳抗大鼠肢体缺血再灌注所致肺损伤中的作用

目的 观察丝裂原活化蛋白激酶(MAPKs)在外源性一氧化碳(C0)抗大鼠肢体缺血再灌注(IR)所致肺损伤中的作用。方法 健康SD大鼠，随机分为4组(每组n=8)：对照组(Con-trol)、Control CO、IR和IR CO组。复制大鼠双后肢缺血及再灌注后肺损伤模型。IR CO和Control CO组在再灌注前1h或相应时间点置含CO的空气中，其余两组呼吸空气。观察大鼠肺组织学、肺组织中中性粒细胞(PMN)数目、肺组织湿重和干重之比(W／D)、丙二醛(MDA)含量以及动物生存情况变化。应用Western blotting检测肺组织中三种磷化MAPKs，即细胞外信号调节激酶(ERK)、c-Jun氨基末端激酶(JNK)和p38表达的变化。结果 与Contorl组相比。IR组动物死亡率、肺组织PMN数目、W／D、MDA含量以及磷酸化ERK、JNK和p38表达均显著增高；与IR组相比，IR CO组IR组动物死亡率、肺组织中PMN数目、W／D和MDA含量均显著降低、肺损伤减轻，p38表达显著增高，JNK表达显著降低，ERK表达无显著变化。结论 MAPKs信号通路参与了外源性CO抗大鼠肢体IR所致肺损伤作用的分子机制。     

Ischemic preconditioning provides both acute and delayed protection against renal ischemia and reperfusion injury in mice

Acute as well as delayed ischemic preconditioning (IPC) provides protection against cardiac and neuronal ischemia reperfusion (IR) injury. This study determined whether delayed preconditioning occurs in the kidney and further elucidated the mechanisms of renal IPC in mice. Mice were subjected to IPC (four cycles of 5 min of ischemia and reperfusion) and then to 30 min of renal ischemia either 15 min (acute IPC) or 24 h (delayed IPC) later. Both acute and delayed renal IPC provided powerful protection against renal IR injury. Inhibition of Akt but not extracellular signal-regulated kinase phosphorylation prevented the protection that was afforded by acute IPC. Neither extracellular signal-regulated kinase nor Akt inhibition prevented protection that was afforded by delayed renal IPC. Pretreatment with an antioxidant, N-(2-mercaptopropionyl)-glycine, to scavenge free radicals prevented the protection that was provided by acute but not delayed renal IPC. Inhibition of protein kinase C or pertussis toxin-sensitive G-proteins attenuated protection from both acute and delayed renal IPC. Delayed renal IPC increased inducible nitric oxide synthase (iNOS) as well as heat-shock protein 27 synthesis, and the renal protective effects of delayed preconditioning were attenuated by a selective inhibitor of iNOS (l-N(6)[1-iminoethyl]lysine). Moreover, delayed IPC was not observed in iNOS knockout mice. Both acute and delayed IPC were independent of A(1) adenosine receptors (AR) as a selective A(1)AR antagonist failed to block preconditioning and acute and delayed preconditioning occurred in mice that lacked A(1)AR. Therefore, this study demonstrated that acute or delayed IPC provides renal protection against IR injury in mice but involves distinct signaling pathways.     

缺血预处理对大鼠肝脏缺血再灌注损伤的保护机制

目的验证缺血预处理(IPC)对大鼠肝脏缺血再灌注损伤(I/R)的保护作用,探讨一氧化氮(NO)与蛋白激酶C(PKC)在IPC过程中的作用.方法在原位灌流的大鼠肝脏缺血再灌注模型上,观察IPC的保护作用.同时经肠系膜上静脉注射NO前体L-精氨酸和蛋白激酶C特异性激动剂1,2-二辛酸甘油(DOG)以及两者的特异性阻滞剂N-硝基-L-精氨酸甲酯(NAME)和多粘菌素B,来检测NO和PKC在IPC中的关系.结果预处理可阻止血清谷丙转氨酶(ALT)[(200.86±40.30)U/Lvs.(257.65±20.18)U/L],谷草转氨酶(AST)[(211.06±13.59)U/Lvs.(309.17±24.79)U/L],乳酸脱氢酶(LDH)[(824.73±127.11)U/Lvs.(1118.60±82.21)U/L]及脂质过氧化物(LPO)[(0.414±0.069)mmol/mgvs.(0.531±0.054)mmol/mg]水平升高(P＜0.05),而使组织超氧化歧化酶(SOD)保持在较高水平[(10.33±0.88)U/mgvs.(6.01±0.91)U/mg],(P＜0.05).NO与PKC均可模拟预处理的保护效应.结论缺血预处理对大鼠肝脏I/R有明确的保护作用,NO与PKC发挥IPC保护作用的途径不同.     

Taurine protects against ischemia-reperfusion injury in rabbit livers

Ischemia-reperfusion injury is of major clinical relevance during liver transplantation. In the present study, the therapeutic efficacy of taurine to protect against ischemia-reperfusion injury was investigated in rabbit livers. We demonstrated that intravenous injection of taurine attenuated liver dysfunction as evidenced by reductions in serum alanine aminotransferase, aspartate transaminase, and alkaline phosphatase. The recovery of morphological and ultrastructural changes in the liver was also promoted by taurine. The mechanism of the protective effect of taurine seems at least to rely on antioxidation, since the lipoperoxides contents in liver tissues were significantly reduced among taurine-treated rabbits. These results suggest that taurine is a potent useful reagent to protect the rabbit liver from ischemia-reperfusion injury.     

Protective effects of ulinastatin against ischemia-reperfusion injury

We investigated the protective effect of urinary trypsin inhibitor (ulinastatin: UTI) in vitro, in relation to the neutrophil activity in hepatic ischemia/reperfusion (I/R) injury. The rat liver was removed and preserved in cold Ringer's lactate solution for 60 min, followed by 120 min of reperfusion with oxygenated perfusate. The rats were divided into four groups (n = 8 in each group). The livers were perfused with Krebs-Henseleit (K-H) solution containing no additives in group 1, 50,000 U/kg of UTI in group 2, 3.5 x 10(6) of neutrophils in group 3, and both neutrophils and UTI in group 4. In group 3, the AST and ALT levels were always higher than those in other three groups at any point evaluated (P < 0.01) and the LDH levels were observed to be significantly higher than those in other three groups at 0, 5, 10, 60, and 90 min after reperfusion (P < 0. 01). These increase were suppressed by additional pretreatment with UTI in group 4. The bile flow during reperfusion was significantly suppressed in group 3 compared to that of group 4, at both 30 (P < 0. 01) and 60 (P < 0.05) min after reperfusion. The MPO activity after reperfusion in group 3 also significantly increased compared to other three groups (P < 0.01). These data thus suggest that UTI ameliorated the ischemia/reperfusion injury in vitro by inhibiting of neutrophil accumulation in the postischemic liver.