针刺对缺血再灌注大鼠海马脑源性神经营养因子mRNA的影响

目的 探讨针刺对缺血再灌注大鼠海马内脑源性神经营养因子（BONF）基因表达的影响，推测针刺改善缺血再灌注的可能机制。方法 采用4-血管阴断法制备大鼠全脑缺血再灌注模型，电针刺激百会、肾俞、足三里穴后，利用RT-PCR检测BDNF mRNA。结果 正常组大鼠海马BDNF mRNA表达极低，缺血再灌注组大鼠海马BDNF mRNA表达明显增高，治疗15d的针刺1、2组大鼠海马BDNF mRNA表达较缺血再灌注组更高，及早治疗且治疗时间为20d的针刺3组大鼠海马BDNF mRNA表达较降低。结论 缺血再灌注大鼠海马BDNF水平增高有利于损伤的神经元存活、恢复；针刺促进脑内细胞分泌内源性BDNF可能是针刺有效治疗缺血再灌注的机制之一。     

大鼠心肌缺血再灌注时心肌细胞凋亡caspase-3活性变化规律及药物对其影响

目的　探讨大鼠心肌缺血再灌注 (Ischemiareperfusion ,IR)不同时相的心肌细胞凋亡、caspase 3活性变化规律及caspase 3抑制剂Ac DEVD CHO的影响。方法　Wistar大鼠 12 2只 ,设立IR组 ,IR +Ac DEVD CHO组和假手术对照组并分设缺血 3 0min后再灌注 1、3、6、12、2 4h 5个时相点 ;以缺口末端标记法 (TUNEL)标记凋亡细胞 ,用荧光分析法检测caspase 3活性 ,行TTC染色测定心肌梗死范围。结果　心肌细胞凋亡与caspase 3活性随心肌再灌注不同时相而变化 ,心肌细胞凋亡指数 (Apoptosisindex ,AI)与caspase 3活性于再灌注 12h最高 [AI :( 3 4 83± 9 3 5 ) % ;caspase 3活性 :( 1 3 4±0 2 ) ] ,其后基本维持在平台状态 ;心肌梗死范围随IR时间逐渐增加 ,至 2 4h仍未见下降趋势 ,三者间呈显著正相关 (P <0 0 5 )。IR +Ac DEVD CHO组上述指标虽也明显增高 ,但比IR组明显减小 (P <0 0 5 )。结论　Caspase 3激活及心肌细胞凋亡参与了心肌缺血再灌注损伤过程 ,Ac DEVD CHO减轻心肌缺血再灌注损伤可能部分与其抑制心肌细胞凋亡有关。     

Detailed Analysis of Mucosal Restoration of the Small Intestine After the Cavitary Two-Layer Cold Storage Method

Small bowel transplantation (SBT) is associated with a high incidence of infectious complications because of ischemia/reperfusion (I/R) mucosal injury concomitant with potent immunosuppression. In this study, we evaluated whether the cavitary two-layer method (cTLM) could reduce I/R injury and allow early mucosal restoration, particularly after prolonged preservation and transplantation. Canine heterotopic segmental SBT was performed immediately without preservation (group 1), after 24-h preservation in UW solution (group 2) or by the cTLM (group 3). The graft samples were taken 1 h after reperfusion and on days 1, 4 and 7. We assessed graft mucosa with detailed microscopic and electromicroscopic analyses. In Group 3, histological injury and cell apoptosis after transplantation were significantly alleviated and rapidly recovered to a similar level of group 1. The mucosal restoration was morphologically completed within 4 days. In contrast, in group 2, more pronounced mucosal injury and delayed recovery were noted. Crypt cell proliferation activity was well maintained in groups 1 and 3 throughout the experimental period. Our ultrastructural analysis suggested that mitochondrial integrity achieved by the cTLM was a basal mechanism under the prompt mucosal restoration. The cTLM could reduce I/R injury, facilitate mucosal regeneration and restore the nearly normal structure early after SBT.     

Pretreatment with Tongxinluo protects porcine myocardium from ischaemia/reperfusion injury through a nitric oxide related mechanism

Background The traditional Chinese medicine Tongxinluo can protect myocardium against ischaemia/reperfusion injury, but the mechanism of its action is not well documented. We examined the involvement of nitric oxide in the protective role of Tongxinluo. Methods Miniswine were randomized to four groups of seven: sham, control, Tongxinluo and Tongxinluo coadministration with a nitric oxide synthase inhibitor Nω-nitro-L-arginine (L-NNA, 10 mg/kg i.v.). Three hours after administration of Tongxinluo, the animals were anaesthetised and the left anterior descending coronary artery ligated and maintained in situ for 90 minutes followed by 3 hours of reperfusion before death. Area of no reflow and necrosis and risk region were determined pathologically by planimetry. The degree of neutrophil accumulation in myocardium was obtained by measuring myeloperoxidase activity and histological analysis. Myocardial endothelial nitric oxide synthase activity and vascular endothelial cadherin content were measured by colorimetric method and immunoblotting analysis respectively.Results Tongxinluo significantly increased the local blood flow and limited the infarct and size of no reflow. Tongxinluo also attenuated myeloperoxidase activity and neutrophil accumulation in histological sections and maintained the level of vascular endothelial cadherin and endothelial nitric oxide synthase activity in the reflow region when compared with control group. The protection of Tongxinluo was counteracted by coadministration with L-NNA. Conclusions Tongxinluo may limit myocardial ischaemia and protect the heart against reperfusion injury. Tongxinluo regulates synthesis of nitric oxide by altering activity of endothelial nitric oxide synthase.     

葛根素对家兔肢体缺血再灌注后心脏功能的保护作用

目的:观察葛根素对家兔肢体缺血再灌注所致心脏损伤的保护作用并探讨其机制.方法:家兔40只,随机分4组:Ⅰ组为假手术对照组、Ⅱ组为缺血再灌注组、Ⅲ组为葛根素低剂量治疗组、Ⅳ组为葛根素高剂量治疗组.免疫组化法检测心肌组织Bcl-2和Bax蛋白表达;原位缺口末端标记法(TUNEL)检测心肌细胞凋亡;比色法测定心肌组织超氧化物岐化酶(SOD)和髓过氧化物酶(MPO)活性,丙二醛(MDA)含量,测定血清乳酸脱氢酶(LDH)活性;通过生理记录仪观察心功能指标.结果:与Ⅱ组比较,Ⅲ、Ⅳ组左心室功能增强,且Ⅳ组的左心室收缩功能比Ⅲ组增强,同时,Ⅲ、Ⅳ组心肌组织MDA含量和血清LDH活性减少,Bax蛋白表达减少,Ⅳ组的心肌凋亡指数低于Ⅱ组,心肌Bcl-2表达高于Ⅱ组.结论:葛根素促进肢体缺血再灌注后心脏功能的恢复,表现为剂量依赖效应,其作用机制与抗氧化损伤和抗细胞凋亡有关.     

鼠脑缺血再灌注损伤炎症反应及环磷酰胺影响

目的 探讨脑缺血再灌注不同缺血区域炎症反应特点及环磷酰胺影响.方法 将大鼠随机分为假手术组、对照组、环磷酰胺预处理组,建立局灶性脑缺血再灌注模型.用免疫组化法和生化法观察额顶部皮质和基底节区P-选择素表达、髓过氧化物酶(MPO)活性变化;并进行TTC染色和HE染色.结果 (1)再灌注3h缺血侧额顶部皮质和基底节区出现P-选择素表达,12h达高峰.环磷酰胺预处理组和对照组相比较,差异无显著性(P＞o.05).(2)再灌注12h以后MPO活性明显升高.基底节区的MPO活性在再灌注48h达到高峰后下降.额顶部皮质MPO活性在再灌注24h达到高峰后至96h仍维持较高水平.和对照组相比较,环磷酰胺预处理组MP(活性升高受抑制(P＜0.05).(3)环磷酰胺预处理可显著缩小脑梗死体积(P＜0.05).结论 (1)脑缺血再灌注损伤存在主动性炎症反应,额顶部皮质比基底节区的炎症反应更持久和剧烈.(2)环磷酰胺减少缺血侧中性粒细胞浸润数量,具有神经保护作用,但不直接影响P-选择素的表达.     

SB203580对肾缺血/再灌注损伤时细胞凋亡及p38MAPK影响的实验研究

目的　探讨不同时间及不同浓度p38MAPK特异性抑制剂SB2 0 35 80对肾缺血 /再灌注损伤过程中肾功能、细胞凋亡及 p38MAPK活性、表达量、p38MAPK底物的影响。 方法　 4 9只大鼠按缺血 /再灌注及给药时间的不同 ,随机分为 7组 ,每组7只大鼠按正交拉丁方表的顺序 ,经尾静脉注射相同体积、不同剂量的SB ,使其在大鼠体内达到不同的浓度。测定BUN和Scr;用TUNEL试剂盒检测细胞凋亡情况 ;Westernblot技术用于蛋白定性及半定量分析。结果　SB可显著减轻大鼠肾缺血 /再灌注损伤造成的Scr和BUN的升高、肾小管上皮细胞的凋亡及 p38MAPK的激活 ,但存在模型、剂量及给药时机的差异 (P<0 .0 5 ) ,缺血前 3h之前给药 ,使其体内血药浓度达到 5 μmol/L左右可取得较好的效果。 结论　SB可显著减轻大鼠肾缺血 /再灌注损伤 ,在缺血前 3h之前给药 ,同时使其血药浓度达到 5 μmol/L左右可取得最佳效果。     

大鼠脑缺血再灌注后水孔蛋白-4的免疫组化表达与脑水肿关系的研究

目的　研究大鼠脑缺血再灌注后脑组织中水孔蛋白 - 4 (AQP- 4 )的表达与脑水肿的关系。方法　采用大鼠大脑中动脉栓塞 (MCAO)模型 ,经免疫组化法测定 AQP- 4表达阳性细胞数 ,干、湿重法测定脑水含量 ,脑水肿以脑水含量评价。结果　脑缺血再灌注后 12 h,脑缺血坏死周边区 AQP- 4表达阳性细胞及脑水含量增加 ,于 4 8～ 12 0 h 达到高峰 ,16 8h后仍处于较高水平 ,两者之间呈正相关 (r=0 .95 8,P<0 .0 1)。结论　脑缺血再灌注后AQP- 4参与脑水肿的发生 ,为脑缺血再灌注损伤的重要因素之一。     

一氧化氮与肺缺血再灌注损伤的研究进展

一氧化氮（nitricoxide，NO）是一种活性很强的自由基，具有广泛的生物学活性。多项研究提示NO在急性肺缺血／再灌注（ischemia／reperfusion，I／R）损伤中具有重要作用。本文重点描述有关一氧化氮在肺I／R损伤中作用的研究进展。     

P38MAPK抑制剂对缺血/再灌注大鼠肾脏功能损伤的保护作用

目的：观察P38MAPK抑制剂对缺血／再灌注大鼠肾脏功能损伤的保护作用。方法：夹闭肾动脉制遣大鼠肾脏缺血／再灌注损伤动物模型，静脉注射P38MAPK抑制剂阻断P38MAPK信号转导通路，测量其对肾功能及细胞因子含量的影响。结果：肾脏和血浆中TNF—α和IL-β含量随缺血／再灌注时间的延长而升高，肾功能损伤也随缺血／再灌注时间的延长而加重。应用P38MAPK抑制剂可显著降低TNF-α和IL-β含量，对缺血／再灌注所致的肾功能损伤具有明显改善作用。结论：P38MAPK抑制剂可通过抑制致炎因子的产生而减轻缺血/再灌注所致的大鼠肾脏功能损伤。