缺血后处理对大鼠肾脏缺血再灌注损伤的影响

目的 探讨缺血后处理对大鼠肾缺血再灌注(I/R)损伤的影响及其机制.方法 采用摘除右肾夹闭左侧肾蒂45 min再灌注6 h制备肾脏缺血再灌注损伤模型.2 w前已行右肾切除术的30只雄性SD大鼠随机分为3组(n=10):假手术组(S组)、缺血再灌注组(I/R组)和缺血后处理组(IPO组).IPO组在夹闭左侧肾蒂45 min后,再灌注10 s,缺血10 s,重复6次后,完全恢复肾血流.再灌注6 h处死大鼠抽取颈动脉血和切取左肾.测定血清肌酐(Cr)、尿素氮(BUN)浓度,肾组织中丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性;光镜下观察肾组织病理学改变 ,采用流式细胞仪检测细胞凋亡率.结果 与S组比较,I/R组和IPO组Cr和BUN浓度升高,肾组织SOD活性降低,MDA含量升高,肾细胞凋亡率升高,病理损伤明显.与I/R组比较,IPO组Cr和BUN浓度降低,肾组织SOD活性升高,MDA含量降低,肾细胞凋亡率降低,病理损伤减轻.结论 缺血后处理能减轻大鼠肾缺血再灌注损伤,其机制与增强肾脏抗氧化能力和制肾组织细胞凋亡有关.     

再灌注时亚低温对大鼠肾缺血再灌注损伤的保护作用

移植肾缺血再灌注损伤的防治是肾移植工作中的一个研究热点。近１０余年来大量实验研究和临床结果都表明，亚低温（体温降至３０～３５℃）对脑缺血和脑外伤具有肯定的保护作用，且具有安全、无并发症、操作简便、易于临床推广应用等优点［１］。而对肾移植受者实施亚低温治疗，是否也能减轻移植肾缺血再灌注损伤，是一个令人感兴趣的课题。本实验在大鼠肾缺血６０ｍｉｎ再灌注的模型上初步从功能和结构两方面研究了再灌注时亚低温的保护作用，为临床应用提供实验依据。１　材料和方法１．１　动物及分组　雌性ＳＤ大鼠，由本校实验动物中心…     

缺血后处理及川芎嗪对大鼠肾缺血再灌注氧自由基的影响

目的:探讨缺血后处理及川芎嗪对大鼠肾缺血再灌注氧自由基的影响.方法:成年雌性SD大鼠32只,随机分为4组,每组8只,分别为:假手术对照组(S组)、缺血再灌注组(I/R组)、川芎嗪治疗组(I/R T组)和缺血后处理组(IPO组).各组动物于再灌注24 h时取血,检测血尿素氮(BUN)和肌酐(Cr),同时留取肾组织进行匀浆,测定匀浆中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性、丙二醛(MDA)含量和总抗氧化能力(TAC).结果:与I/R组大鼠相比,I/R T组和IPO组大鼠的BUN和Cr均下降(P<0.01),SOD升高(P<0.01),MDA下降(P<0.01),CAT升高(P<0.05),TAC升高(P<0.01);与I/R T组大鼠相比,IPO组大鼠的BUN,Cr,SOD,MDA,CAT和TAC均无统计学差异(P>0.05).结论:缺血后处理能够抑制肾脏缺血再灌注损伤后氧自由基的过度生成,对缺血再灌注损伤有一定的保护作用,其保护效应与川芎嗪治疗无明显差异.     

缺血后处理对大鼠肾脏缺血再灌注损伤及NF-κB表达的影响

[目的]探讨缺血后处理对大鼠肾缺血再灌注损伤影响。[方法]夹闭左侧肾动脉60 min后再灌注6 h法制备肾脏缺血再灌注损伤模型。雄性SD大鼠18只随机分为3组：缺血再灌注组（IR组,n=6）,缺血后处理组（IPO组,n=6）,假手术组（Sham组,n=6）。测定血肌酐（Cr）浓度、尿素氮（Bun）,检测肾脏组织中超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量和髓过氧化物酶（MPO）活性;取左肾组织行HE染色,光镜下观察肾组织病理学改变,免疫组化法检测肾组织中NF-κB表达。[结果]与Sham组比较,IR组血Cr浓度和血Bun浓度上升,达到（93.02±13.44）μmol/L和（15.58±0.56）mmol/L（P〈0.01）,SOD活性下降为（185.87±17.68）U/mgprot（P〈0.01）,MDA含量和MPO活性增加分别达到（4.09±0.34）nmol/mgprot、（0.90±0.07）U/g（P〈0.01）。与Sham组比较IPO组血Cr、Bun浓度、MPO活性差异有统计学意义（P〈0.05）,SOD活性和MDA含量差异无统计学意义;病理损伤明显,肾脏组织中NF-κB表达增强。与IR组比较,IPO组血Cr和血Bun浓度降低分别为（58.98±8.02）μmol/L（P〈0.01）、（9.45±1.03）mmol/L（P〈0.01）,SOD活性升高为（230.90±9.19）U/mgprot（P〈0.01）,MDA含量降低为（3.67±0.20）nmol/mgprot（P〈0.01）,MPO活力降低为（0.78±0.06）U/g（P〈0.01）,病理损伤减轻,肾脏组织NF-κB表达减弱。[结论]缺血后处理对肾脏有保护作用,其机制与增强肾脏抗氧化能力,减轻肾脏组织炎性细胞浸润和抑制肾组织NF-κB表达有关。     

心脑肾康对大鼠肾缺血再灌注损伤的保护作用

目的：探讨心脑肾康对大鼠肾缺血再灌注损伤的保护作用。方法：通过结扎双肾动脉60min后再灌注,建立大鼠肾缺血再灌注损伤的模型。化学法观察大鼠血清肌酐(Scr)、尿素氮(SUN)、丙二醛(MDA)含量,肾组织内MDA和超氧化物歧化酶(SOD)的变化。结果：与模型对照组比较,0.8g／kg的心脑肾康高剂量可抑制由肾缺血再灌注引起的血清SUN、Scr、MDA含量和组织内MDA含量的变化,增强SOD的活性。结论：心脑肾康有保护大鼠肾缺血再灌注损伤的作用,其作用机制可能与抗自由基损伤有关。     

小檗胺对大鼠肾缺血再灌注损伤保护作用的研究

采用大鼠肾动脉夹闭方法制备肾缺血再灌注损伤模型,缺血６０ｍｉｎ后再灌注３０ｍｉｎ,肾皮质丙二醛含量及钙含量较缺血组增高,过氧化氢酶活性低于缺血组。盐酸小檗胺可明显改善再灌注后的组织学损伤,降低ＭＤＡ及钙含量,提高ＣＡＴ活性。结果表明,小檗胺可以减轻氧自由基的损害作用,减轻细胞内钙超载,对缺血肾组织有一定保护作用。     

开心散对肾缺血再灌注大鼠肾脏保护作用研究

目的：研究中药开心散对肾缺血再灌注损伤的保护作用。方法：复制大鼠肾缺血再灌注损伤模型,用开心散治疗,观察肾组织病理变化,并对肾组织ＬＤＨ用显微镜－计算机真彩色图像分析系统分析;测定血清和肾组织ＳＯＤ、ＭＤＡ、ＮＯ含量。结果：肾缺血１ｈ灌注１５ｍｉｎ后,肾组织出现明显病理改变,肾小管ＬＤＨ活性增加;血清和肾组织ＳＯＤ、ＮＯ活性下降,ＭＤＡ含量升高。结论：开心散具有减轻脂质量过氧化反应、清除自由基、保护血管内皮细胞等作用,这可能是开心散减轻肾缺血再灌注损伤作用机制之一。     

川芎嗪和SOD对大鼠肾缺血再灌注损伤的保护作用

目的 探讨川芎嗪对肾缺血再灌注损伤的保护作用。方法 选用大鼠一侧发除，对侧肾缺血６０分钟动物模型，观察再灌注前，再灌注后２４小时肾组织中丙二醛（ＭＤＡ）含量及Ｎａ＾＋、Ｋ＾＋－ＡＴＰａｓｅ活力的改变以及使用超氧化物歧化酶（ＳＯＤ）和川嗪 治它们的影响。结果 ６０分钟肾缺血和再灌注导致肾皮质ＭＤＡ含量显著增高，而Ｎａ＾＋、Ｋ＾＋－ＡＴＰａｓｅ活力明显降低，用ＳＯＤ和川芎嗪治疗后，肾皮质ＭＤＡ含量明显     

茶多酚对肾缺血再灌注损伤大鼠一氧化氮的影响

肾脏缺血再灌注损伤（ischemiareperfusioninjury,IRI）屑急性肾损伤范畴,在临床上十分常见,如心脏停跳、失血性休克、肾移植术、需暂时阻断肾血流的手术等均可导致急性肾脏IRI。但目前这一病理损伤过程尚无有效的防治方法。已有研究证明：一氧化氮参与体内许多病理及生理过程,具有强烈的舒血管作用。茶多酚（teapolyphenols,TP）是茶叶中的一种主要活性成分,有着独特的抗氧化效果,目前关于TP在肾IRI方面的研究较少。本实验建立大鼠肾IRI模型,研究TP对肾IRI的防治作用。     

急性肾损伤患者尿液与血液中肾脏损伤分子-1的表达及其对肾衰竭的早期诊断价值

目的:探讨急性肾损伤患者尿液与血液中肾脏损伤分子-1的表达及其对肾衰竭的早期诊断价值.方法:回顾性分析在本院肾内科接受诊治的84例急性肾损伤患者的临床资料.根据其是否发生肾衰竭分为RF组和非RF组,ELISA检测两组入院时尿液与血液中肾损伤分子-1(Kim-1)的水平,并绘制受试者工作特征曲线(ROC曲线),评价Kim-1的表达及其对急性肾损伤患者肾衰竭的早期诊断价值.结果:RF组尿液与血液中Kim-1水平均明显高于非RF组,差异具有统计学意义(P＜0.05);尿液Kim-1 ROC曲线下面积为0.855(P=0.000),血液中Kim-1 ROC曲线下面积为0.640(P=0.028).结论:尿液与血液中肾脏损伤分子-1的水平对急性肾损伤患者肾衰竭的发生具有预测性,可作为急性肾损伤患者肾衰竭早期诊断标志物.     

不同浓度七氟烷后处理对大鼠肾脏缺血/再灌注损伤的影响

目的 探讨不同浓度七氟烷后处理对大鼠肾脏缺血/再灌注损伤的影响,评价七氟烷后处理对大鼠肾脏缺血/再灌注损伤后肾内皮型一氧化氮合成酶(eNOS)、诱导型一氧化氮合成酶(iNOS)的影响.方法 SD雄性大鼠60只,随机分为5组(每组12例):假手术组、缺血/再灌注组[建立肾脏缺血/再灌注(I/R)模型]、不同浓度七氟烷后处理组[(1.2%七氟烷为S1.2组,1.8%七氟烷为S1.8组和2.2%七氟烷为S2.2组):先建立I/R模型,在缺血后再灌注的同时用不同浓度的七氟烷处理2 h.测定再灌注24 h时血清肌酐(Cr)、尿素氮(BUN)浓度;大体标本观察再灌注肾横切面坏死情况;光镜下观察肾皮质肾小管坏死百分率].为探讨七氟烷后处理作用机制,采用免疫组化法测假手术组,缺血/再灌注组,S1.8组肾组织eNOS、iNOS的表达.结果 再灌注24 h时,与假手术组相比,其余4组血清Cr、BUN、肾小管坏死率明显升高(P<0.05);与缺血/再灌注组相比,S1.2组、S1.8组、S2.2组血清Cr、BUN、肾小管坏死率明显下降(P<0.05);S1.2组、S1.8组、S2.2组之间上述各指标差异无统计学意义(P>0.05).与假手术组相比,缺血/再灌注组肾eNOS、iNOS的表达明显增强(P<0.05);与缺血/再灌注组相比,S1.8>组肾eNOS、iNOS的表达明显下降(P<0.05).结论 七氟烷后处理可以减轻大鼠肾缺血/再灌注损伤;七氟烷3种不同浓度(1.2%,1.8%,2.2%)后处理对减轻大鼠缺血/再灌注损伤无明显差别;七氟烷后处理可抑制肾eNOS、iNOS的表达.     

联合应用缺血后处理、远隔缺血后处理和纳洛酮后处理对大鼠脑缺血-再灌注损伤的影响

目的 评价联合应用缺血后处理、远隔缺血后处理和纳洛酮后处理对大鼠局灶性脑缺血-再灌注损伤的影响.方法 将110只大鼠随机分为5组(n=22),通过阻塞右侧大脑中动脉90 min和再灌注24 h实施局灶性脑缺血.再灌注.Ⅰ组为对照组;Ⅱ组为缺血后处理组,再灌注开始时实施3次30 s的缺血和再灌注;Ⅲ组为远隔缺血后处理组,再灌注开始前实施5 min的右侧股动脉缺血;Ⅳ组为纳洛酮后处理组,再灌注开始时腹腔注射纳洛酮10 mg/kg;Ⅴ组为联合应用组.再灌注2 h和24 h时测定大鼠的神经功能障碍评分(NDS);再灌注24 h时,测定脑梗死区面积(n=10)、脑组织微管相关蛋白2(MAP2)表达(n=6)和脑组织血浆容量、血管直径和节段长度(n=6).结果 观察期所有时间点的心率和平均动脉压(MAP)组间比较差异均无统计学意义(均P＞0.05).再灌注24 h后,Ⅰ～Ⅴ组的缺血侧脑梗死面积与同侧大脑半球面积的比值(即脑梗死严重程度)分别是43%±6%、31%±4%、32%±5%、28%±6%和21%±7%.与Ⅰ组比较,Ⅱ～Ⅴ组的NDS和脑梗死严重程度均低(均P＜0.05),MAP2表达、血浆容量、血管直径和节段长度均高,但上述指标在Ⅱ组、Ⅲ组和Ⅵ组之间比较差异均无统计学意义(均P＞0.05).与Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组比较,Ⅴ组的NDS评分和脑梗死程度均低(均P＜0.05),MAP2表达和血浆容量显著高(均P＜0.05),但是缺血侧脑组织的血管直径和节段长度在Ⅱ组、Ⅲ组Ⅵ组和Ⅴ组之问差异均无统计学意义(均P＞0.05).结论 在局灶性脑缺血-再灌注损伤大鼠,缺血后处理、远隔缺血后处理和纳洛酮后处理均具有明显的神经保护作用,表现为脑梗死严重程度降低和神经功能障碍改善.联合应用3种后处理措施可获得增强的神经保护效应.

Abstract：

Objective To assess the effects of ischemic postconditioning, remote ischemic postconditioning and naloxone postconditioning on focal cerebral ischemia-reperfusion injury in rats.Methods A total of 110 adult SD rats were randomly divided into 5 groups (n =22 each). The focal cerebral ischemia-reperfusion injury was induced by a 90-minute occlusion of right middle cerebral artery (MCA) and a 24-hour reperfusion sequentially. Group 1 was of ischemia-reperfusion control; Group 2 ischemic postconditioning induced by three 30-second cycles of MCA occlusion followed by a 30-second reperfusion; Group 3 remote ischemic postconditioning performed via a transient occlusion of right femoralartery at 5 min before the initiatlon of reperfusion:Group 4 naloxone posteonditioning with naloxone 10 mg/kg intraperitoneaUy injected at the initiation of reperfusion;Group 5 combined ischemic,remote ischernic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2,3 & 4.The neumlogie deftcit scores(NDS)were obtained at 2 h & 24 h post-reperfusion.At 24 h post-reperfusion.the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to asseSS the size ofcerebral infaret(n=10),detect the cerebral expression of microtubule-associated protein2(MAP2)(n=6),measure the plasma volume of cerebral tissues and quantify the diameter and segment artery at 5 min before the initiation of reperfusion; Group 4 naloxone postconditioning with naloxone 10 mg/kg intraperitoneally injected at the initiation of reperfusion; Group 5 combined ischemic, remote ischemic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2, 3 & 4. The neurologic deficit scores ( NDS) were obtained at 2 h & 24 h post-reperfusion. At 24 h post-reperfusion, the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to assess the size of cerebral infarct (n = 10), detect the cerebral expression of microtubule-associated protein2 ( MAP2) (n =6) , measure the plasma volume of cerebral tissues and quantify the diameter and segment length of cerebral microvessel (n = 6 ). Results There were no significant differences in the heart rate (HR) and mean arterial pressure (MAP) among the above five groups at all observed time points (P ＞ 0. 05). At 24 h post-reperfusion, the percentage of ischemic cerebral infarct size was 43% ±6% , 31% ±4% , 32% ±5% , 28% ±6% & 21% ±7% in ipsilateral hemisphere area (i. e. , cerebral infarct severity)in Groups 1-5 respectively. Compared with Group 1, the levels of NDS and cerebral infarct severity significantly decreased at ischemic side in Groups 2-5 ( P ＜ 0. 05 ). And the cerebral expression of MAP2,plasma volume of cerebral tissues, diameter and segment length of cerebral microvessel significantly increased at the ischemic side (all P＜0. 05). However, there were no significant differences in the abovementioned parameters at ischemic side among Groups 2, 3 and 4 (all P ＞0. 05). The parameters of NDS,cerebral infarct severity, cerebral expression of MAP2 and plasma volume of cerebral tissues in the ischemic side significantly increased in Group 5 compared with Groups 1,2,3 and 4 (all P ＜ 0. 05). The diameter and segment length of cerebral microvessel at ischemic side were not different among Groups 2,3,4 and 5 (all P＞0. 05). Conclusion In focal cerebral ischemia-reperfusion rats, ischemic, remote ischemic and naloxone postconditioning may produce significant neuroprotective effects of reduced cerebral infarct severity and improved neurologic dysfunctions. A combination of three postconditioning approaches enhances the above neuroprotective effects.     

丙泊酚对大鼠心肌缺血后处理的作用

目的 探讨不同剂量丙泊酚缺血后处理对大鼠心肌缺血/再灌注损伤的作用.方法 制备大鼠心肌缺血/再灌注损伤模型,结扎冠状动脉左前降支60 min,再灌注120 min.随机分为假手术组(S组)、生理盐水对照组(C组)、丙泊酚1 mg/kg组(P1组)、丙泊酚2 mg/kg组(P2组)、丙泊酚5 mg/kg组(P3组),除S组其余各组所用药物均以生理盐水稀释至2.5 ml,于再灌注前3 min经股静脉匀速输注至再灌注后5 min,测定心肌危险区面积和梗死区面积;采用免疫组化方法 检测心肌组织Caspase-3的表达;应用流式细胞仪检测心肌细胞凋亡率;运用Western印迹方法 测定Akt磷酸化水平.结果 与C组[危险区面积(41.5±1.0)%,梗死区面积(45.5±1.0)%,Caspase-3表达5.87±0.29,心肌细胞凋亡率(26.8±1.3)%,Akt磷酸化(10.8±1.9)%]相比,P1组和P2组大鼠危险区面积和梗死区面积明显减小[危险区面积(38.3±1.0)%和(37.3±1.2)%;梗死区面积(33.8±1.2)%和(30.2±1.7)%,均P<0.05];Caspase-3表达降低(1.50±0.36和1.48±0.30,均P<0.05);心肌细胞凋亡率下降[(16.3±1.2)%和(16.5±1.0)%,均P<0.05];而Akt磷酸化水平明显升高[(68.7±4.0)%和(58.3±2.8)%,均P<0.05].结论 丙泊酚1 mg/kg和2 mg/kg通过促进Akt磷酸化发挥I-postC保护作用.     

缺血后处理对大鼠后肢肌肉缺血再灌注损伤作用的实验研究

目的探讨不同方式缺血后处理对大鼠后肢肌肉缺血再灌注损伤的保护作用。方法取Wistar雄性大鼠54只,建立后肢肌肉缺血再灌注模型,实验分为3组,每组18只,每个时间点6只,A组为缺血再灌注组,B组为缺血再灌注前给予1 min灌注1 min缺血重复3次后继续再灌注组,C组为缺血再灌注前给予10 min灌注10 min缺血重复3次后继续再灌注组,分别检测各组在再灌注1 h、3 h、9 h血清中的乳酸脱氢酶(LDH)、细胞间黏附分子-1(ICAM-1)及肌肉组织中丙二醛(MDA)含量,比较上述指标的变化。结果 3组各项指标均升高,不同时点比较差异均有统计学意义(P<0.01)。B组除1h ICAM-1外,各时间点上述指标均明显低于A组(P<0.01),C组各时点各指标与A组比较差异无统计学意义(P>0.05)。结论短时间多次重复停灌复灌后处理可减轻实验大鼠后肢肌肉缺血再灌注损伤     

大鼠缺血再灌注损伤肾脏组织中褪黑素受体表达情况研究

目的 研究褪黑素受体(MR)在缺血再灌注损伤(I/R)大鼠肾脏组织中的表达情况及意义.方法 24只健康雄性SD大鼠随机分为正常组、假手术组和肾脏I/R组,每组8只.采用双侧肾蒂夹闭60 min后再灌注建立I/R肾脏损伤动物模型.术后24h常规生化法检测血肌酐、尿素氮的水平,HE染色观察肾脏组织学改变.荧光定量PCR(RT-PCR)检测肾脏组织中褪黑素受体MT含量.结果 以U6为内参基因,荧光定量PCR显示正常情况下大鼠肾脏组织中MR1和MR2 mRNA表达强度分别为(0.75±0.16)和(0.64±0.10),I/R处理24h后肾脏组织中MR1和MR2的表达强度分别为(0.37±0.08)和(0.28±0.05),较正常组和假手术组显著下降(P＜0.01).结论 MR在I/R损伤大鼠肾脏组织中的表达明显下降,提示MR表达与肾脏应激损伤相关,可能作为判断肾脏I/R损伤程度的指标或治疗的靶点.     

粘附分子在缺d再灌注肾损伤中的作用及阻断意义

目的探讨粘附分子P-选择素和细胞间粘附分子-1(ICAM-1)在肾缺d再灌注损伤中的作用,以及P-选择素单克隆抗体的阻断意义。方法建立肾缺d再灌注损伤大鼠模型,观察P-选择素单抗处理前后的大鼠肾组织中P-选择素及ICAM-1表达,及其丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和细胞凋亡等变化。结果缺d再灌注后,大鼠肾组织中P-选择素和ICAM-1先后明显表达,且MDA含量增加和SOD活性下降,出现明显的细胞凋亡及组织学病理改变。经给予P-选择素单抗处理,肾组织中P-选择素和ICAM-1表达受到抑制,MDA含量降低和SOD活性增高,细胞凋亡减少及组织学病理改变减轻。结论粘附分子P-选择素和ICAM-1参与了肾缺d再灌注损伤机制,以单抗抑制P-选择素可明显减少肾内炎症细胞浸润,脂质过氧化反应,细胞凋亡及组织损伤。     

联合应用缺血后处理、远隔缺血后处理和纳洛酮后处理对大鼠脑缺血-再灌注损伤的影响

Objective To assess the effects of ischemic postconditioning, remote ischemic postconditioning and naloxone postconditioning on focal cerebral ischemia-reperfusion injury in rats.Methods A total of 110 adult SD rats were randomly divided into 5 groups (n =22 each). The focal cerebral ischemia-reperfusion injury was induced by a 90-minute occlusion of right middle cerebral artery (MCA) and a 24-hour reperfusion sequentially. Group 1 was of ischemia-reperfusion control; Group 2 ischemic postconditioning induced by three 30-second cycles of MCA occlusion followed by a 30-second reperfusion; Group 3 remote ischemic postconditioning performed via a transient occlusion of right femoralartery at 5 min before the initiatlon of reperfusion:Group 4 naloxone posteonditioning with naloxone 10 mg/kg intraperitoneaUy injected at the initiation of reperfusion;Group 5 combined ischemic,remote ischernic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2,3 & 4.The neumlogie deftcit scores(NDS)were obtained at 2 h & 24 h post-reperfusion.At 24 h post-reperfusion.the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to asseSS the size ofcerebral infaret(n=10),detect the cerebral expression of microtubule-associated protein2(MAP2)(n=6),measure the plasma volume of cerebral tissues and quantify the diameter and segment artery at 5 min before the initiation of reperfusion; Group 4 naloxone postconditioning with naloxone 10 mg/kg intraperitoneally injected at the initiation of reperfusion; Group 5 combined ischemic, remote ischemic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2, 3 & 4. The neurologic deficit scores ( NDS) were obtained at 2 h & 24 h post-reperfusion. At 24 h post-reperfusion, the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to assess the size of cerebral infarct (n = 10), detect the cerebral expression of microtubule-associated protein2 ( MAP2) (n =6) , measure the plasma volume of cerebral tissues and quantify the diameter and segment length of cerebral microvessel (n = 6 ). Results There were no significant differences in the heart rate (HR) and mean arterial pressure (MAP) among the above five groups at all observed time points (P ＞ 0. 05). At 24 h post-reperfusion, the percentage of ischemic cerebral infarct size was 43% ±6% , 31% ±4% , 32% ±5% , 28% ±6% & 21% ±7% in ipsilateral hemisphere area (i. e. , cerebral infarct severity)in Groups 1-5 respectively. Compared with Group 1, the levels of NDS and cerebral infarct severity significantly decreased at ischemic side in Groups 2-5 ( P ＜ 0. 05 ). And the cerebral expression of MAP2,plasma volume of cerebral tissues, diameter and segment length of cerebral microvessel significantly increased at the ischemic side (all P＜0. 05). However, there were no significant differences in the abovementioned parameters at ischemic side among Groups 2, 3 and 4 (all P ＞0. 05). The parameters of NDS,cerebral infarct severity, cerebral expression of MAP2 and plasma volume of cerebral tissues in the ischemic side significantly increased in Group 5 compared with Groups 1,2,3 and 4 (all P ＜ 0. 05). The diameter and segment length of cerebral microvessel at ischemic side were not different among Groups 2,3,4 and 5 (all P＞0. 05). Conclusion In focal cerebral ischemia-reperfusion rats, ischemic, remote ischemic and naloxone postconditioning may produce significant neuroprotective effects of reduced cerebral infarct severity and improved neurologic dysfunctions. A combination of three postconditioning approaches enhances the above neuroprotective effects.     

联合应用缺血后处理、远隔缺血后处理和纳洛酮后处理对大鼠脑缺血-再灌注损伤的影响

Objective To assess the effects of ischemic postconditioning, remote ischemic postconditioning and naloxone postconditioning on focal cerebral ischemia-reperfusion injury in rats.Methods A total of 110 adult SD rats were randomly divided into 5 groups (n =22 each). The focal cerebral ischemia-reperfusion injury was induced by a 90-minute occlusion of right middle cerebral artery (MCA) and a 24-hour reperfusion sequentially. Group 1 was of ischemia-reperfusion control; Group 2 ischemic postconditioning induced by three 30-second cycles of MCA occlusion followed by a 30-second reperfusion; Group 3 remote ischemic postconditioning performed via a transient occlusion of right femoralartery at 5 min before the initiatlon of reperfusion:Group 4 naloxone posteonditioning with naloxone 10 mg/kg intraperitoneaUy injected at the initiation of reperfusion;Group 5 combined ischemic,remote ischernic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2,3 & 4.The neumlogie deftcit scores(NDS)were obtained at 2 h & 24 h post-reperfusion.At 24 h post-reperfusion.the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to asseSS the size ofcerebral infaret(n=10),detect the cerebral expression of microtubule-associated protein2(MAP2)(n=6),measure the plasma volume of cerebral tissues and quantify the diameter and segment artery at 5 min before the initiation of reperfusion; Group 4 naloxone postconditioning with naloxone 10 mg/kg intraperitoneally injected at the initiation of reperfusion; Group 5 combined ischemic, remote ischemic & naloxone postconditioning performed simultaneously in accordance with the methods used in Groups 2, 3 & 4. The neurologic deficit scores ( NDS) were obtained at 2 h & 24 h post-reperfusion. At 24 h post-reperfusion, the anesthetized rat was sacrificed by decapitation and the brain rapidly extracted to assess the size of cerebral infarct (n = 10), detect the cerebral expression of microtubule-associated protein2 ( MAP2) (n =6) , measure the plasma volume of cerebral tissues and quantify the diameter and segment length of cerebral microvessel (n = 6 ). Results There were no significant differences in the heart rate (HR) and mean arterial pressure (MAP) among the above five groups at all observed time points (P ＞ 0. 05). At 24 h post-reperfusion, the percentage of ischemic cerebral infarct size was 43% ±6% , 31% ±4% , 32% ±5% , 28% ±6% & 21% ±7% in ipsilateral hemisphere area (i. e. , cerebral infarct severity)in Groups 1-5 respectively. Compared with Group 1, the levels of NDS and cerebral infarct severity significantly decreased at ischemic side in Groups 2-5 ( P ＜ 0. 05 ). And the cerebral expression of MAP2,plasma volume of cerebral tissues, diameter and segment length of cerebral microvessel significantly increased at the ischemic side (all P＜0. 05). However, there were no significant differences in the abovementioned parameters at ischemic side among Groups 2, 3 and 4 (all P ＞0. 05). The parameters of NDS,cerebral infarct severity, cerebral expression of MAP2 and plasma volume of cerebral tissues in the ischemic side significantly increased in Group 5 compared with Groups 1,2,3 and 4 (all P ＜ 0. 05). The diameter and segment length of cerebral microvessel at ischemic side were not different among Groups 2,3,4 and 5 (all P＞0. 05). Conclusion In focal cerebral ischemia-reperfusion rats, ischemic, remote ischemic and naloxone postconditioning may produce significant neuroprotective effects of reduced cerebral infarct severity and improved neurologic dysfunctions. A combination of three postconditioning approaches enhances the above neuroprotective effects.     

丹参对大鼠肝缺血后再灌注损伤的保护作用

目的 通过检测丹参对大鼠肝缺血再灌注损伤后核因子-Kappa B(NF-κB)、细胞间黏附因子-1(ICAM-1)表达的影响,观察丹参对大鼠肝缺血后再灌注损伤的保护作用.方法 按Nauta等方法制备大鼠肝脏缺血再灌注模型,随机分为3组:假手术组(S组)、缺血再灌注组(I/R组)、丹参预处理组(P组),分别于肝缺血再灌后2、8、24 h取材,用免疫组化方法检测肝组织NF-κB、ICAM-1的表达,测肝组织中髓过氧化酶(MPO)浓度评价肝组织中中性粒细胞浸润情况,检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)水平及做光镜、电镜检查反映肝组织细胞损伤程度.结果 I/R组NF-κB A值于再灌注2h(0.418 4±0.039)明显升高,8h(0.308 4±0.028)、24h(0.240 ±0.032)逐渐下降.ICAM-1 A值也于再灌注2h(0.367±0.034)升高,8h(0.451±0.031)达高峰,24h(0.293±0.025)下降.MPO、ALT、AST变化与ICAM-1类似.在P组上述各指标在各时间点均较I/R组低(P<0.05),但较S组高(P<0.05).ALT、MPO、NF-κB和ICAM-1之间的变化均具有正相关(P<0.01);光镜、电镜观察各组之间也具有明显区别.结论 大鼠肝缺血再灌注时刺激NF-κB、ICAM-1的表达参与肝脏缺血再灌注损伤的发生过程,丹参能显著降低缺血再灌注时肝组织中NF-κB、ICAM-1的表达,并有效改善肝缺血再灌注损伤.