H_2S Protecting against Lung Injury following Limb Ischemia-reperfusion by Alleviating Inflammation and Water Transport Abnormality in Rats

Objective To investigate the effect of H2S on lower limb ischemia-reperfusion （LIR） induced lung injury and explore the underlying mechanism. Methods Wistar rats were randomly divided into control group, IR group, IR＋ Sodium Hydrosulphide （NariS） group and IR＋ DL-propargylglycine （PPG） group. IR group as lung injury model induced by LIR were given 4 h reperfusion following 4 h ischemia of bilateral hindlimbs with rubber bands. NariS （0.78 mg/kg） as exogenous H2S donor and PPG （60 mg/kg） which can suppress endogenous H2S production were administrated before LIR, respectively. The lungs were removed for histologic analysis, the determination of wet-to-dry weight ratios and the measurement of mRNA and protein levels of aquaporin-1 （AQP1）, aquaporin-5 （AQP5） as indexes of water transport abnormality, and mRNA and protein levels of Toll-like receptor 4 （TLR4）, myeloid differentiation primary-response gene 88 （MyD88） and p-NF-KB as indexes of inflammation. Results LIR induced lung injury was accompanied with upregulation of TLR4-Myd88-NF-κB pathway and downregulation of AQP1/AQP5. NariS pre-treatment reduced lung injury with increasing AQP1/AQP5 expression and inhibition of TLR4-Myd88-NF-KB pathway, but PPG adjusted AO.PJAO.Ps and TLR4 pathway to the opposite side and exacerbated lung injury. Conclusion Endogenous H2S, TLR4-Myd88-NF-κB pathway and AQP1/AQP5 were involved in LIR induced lung injury. Increased H2S would alleviate lung injury and the effect is at least partially depend on the adjustment of TLR4-Myd88-NF-κB pathway and AQP1/AQP5 expression to reduce inflammatory reaction and lessen pulmonary edema.

microRNA-455-5p alleviates neuroinflammation in cerebral ischemia/reperfusion injury

Neuroinflammation is a major pathophysiological factor that results in the development of brain injury after cerebral ischemia/reperfusion.Downregulation of microRNA(miR)-455-5p after ischemic stroke has been considered a potential biomarker and therapeutic target for neuronal injury after ischemia.However,the role of miR-455-5p in the post-ischemia/reperfusion inflammatory response and the underlying mechanism have not been evaluated.In this study,mouse models of cerebral ischemia/reperfusion injury were established by transient occlusion of the middle cerebral artery for 1 hour followed by reperfusion.Agomir-455-5p,antagomir-455-5p,and their negative controls were injected intracerebroventricularly 2 hours before or 0 and 1 hour after middle cerebral artery occlusion(MCAO).The results showed that cerebral ischemia/reperfusion decreased miR-455-5p expression in the brain tissue and the peripheral blood.Agomir-455-5p pretreatment increased miR-455-5p expression in the brain tissue,reduced the cerebral infarct volume,and improved neurological function.Furthermore,primary cultured microglia were exposed to oxygen-glucose deprivation for 3 hours followed by 21 hours of reoxygenation to mimic cerebral ischemia/reperfusion.miR-455-5p reduced C-C chemokine receptor type 5 mRNA and protein levels,inhibited microglia activation,and reduced the production of the inflammatory factors tumor necrosis factor-αand interleukin-1β.These results suggest that miR-455-5p is a potential biomarker and therapeutic target for the treatment of cerebral ischemia/reperfusion injury and that it alleviates cerebral ischemia/reperfusion injury by inhibiting C-C chemokine receptor type 5 expression and reducing the neuroinflammatory response.

2-(2-Benzofuranyl)-2-imidazoline treatment within 5 hours after cerebral ischemia/reperfusion protects the brain

We previously demonstrated that administering 2-（2-benzofuranyl）-2-imidazolin（2-BFI）, an imidazoline I2 receptor agonist, immediately after ischemia onset can protect the brain from ischemic insult. However, immediate administration after stroke is difficult to realize in the clinic. Thus, the therapeutic time window of 2-BFI should be determined. Sprague-Dawley rats provided by Wenzhou Medical University in China received right middle cerebral artery occlusion for 120 minutes, and were treated with 2-BFI（3 mg/kg） through the caudal vein at 0, 1, 3, 5, 7, and 9 hours after reperfusion. Neurological function was assessed using the Longa＇s method. Infarct volume was measured by 2,3,5-triphenyltetrazolium chloride assay. Morphological changes in the cortical penumbra were observed by hematoxylin-eosin staining under transmission electron microscopy. The apoptosis levels in the ipsilateral cortex were examined with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling（TUNEL） assay. The protein expression of Bcl-2 and BAX was detected using immunohistochemistry. We found the following： Treatment with 2-BFI within 5 hours after reperfusion obviously improved neurological function. Administering 2-BFI within 9 hours after ischemia/reperfusion decreased infarct volume and alleviated apoptosis. 2-BFI administration at different time points after reperfusion alleviated the pathological damage of the ischemic penumbra and reduced the number of apoptotic neurons, but the protective effect was more obvious when administered within 5 hours. Administration of 2-BFI within 5 hours after reperfusion remarkably increased Bcl-2 expression and decreased BAX expression. To conclude, 2-BFI shows potent neuroprotective effects when administered within 5 hours after reperfusion, seemingly by up-regulating Bcl-2 and down-regulating BAX expression. The time window provided clinical potential for ischemic stroke by 2-BFI.

Puerarin inactivates NLRP3-mediated pyroptotic cell death to alleviate cerebral ischemia/reperfusion(I/R)injury through modulating the LncRNA DUXAP8/miR-223-3p axis

NLRP3 inflammasome-mediated cell pyroptosis aggravates the development of cerebral ischemia/reperfusion(I/R)injury,and the aim of this study is to investigate the potential utilization of the Chinese medicine,Puerarin,in treating this disease.Through conducting in vitro and in vivo experiments,the present study illustrated that Puerarin regulated LncRNA double homeobox A pseudogene 8(DUXAP8)/miR-223-3p axis to inactivate NLRP3-mediated pyroptotic cell death,resulting in the attenuation of I/R injury.Specifically,the cerebral I/R injury in rat models and hypoxia/reoxygenation(H/R)in primary hippocampus neuron(PHN)cells were inducted,which were subsequently exposed to Puerarin treatment.As expected,we validated that Puerarin suppressed cell pyroptosis and rescued cell viability in I/R rat hippocampus tissues and H/R PHN cells.Next,through bioinformatics analysis,we noticed that miR-223-3p targeted both LncRNA DUXAP8 and NLRP3 mRNA,and both LncRNA DUXAP8 ablation and miR-223-3p overexpression inactivate NLRP3-mediated cell pyroptosis to rescue cell viability in H/R PHN cells.Interestingly,we evidenced that Puerarin restrained LncRNA DUXAP8 expressions,but upregulated miR-223-3p in I/R rat tissues and H/R PHN cells,and the protective effects of Puerarin on H/R PHN cells were abrogated by overexpressing LncRNA DUXAP8 and silencing miR-223-3p.Collectively,we concluded that Puerarin regulated LncRNA DUXAP8/miR-223-3p/NLRP3 signaling cascade to attenuate I/R injury.

3-硝基-N-甲基水杨酰胺对肢体缺血再灌注损伤大鼠骨骼肌的保护作用及机制

背景:线粒体活性氧爆发已被证明在骨骼肌缺血再灌注中起着关键作用。3-硝基-N-甲基水杨酰胺(3-nitro-N-methyl salicylamide,3-NNMS)可以有效降低电子传递速度,对肢体缺血再灌注损伤具有潜在的保护作用,但目前尚无明确的研究和临床应用。目的:探讨3-NNMS对肢体缺血再灌注损伤大鼠骨骼肌的保护作用及机制。方法:40只健康8周龄SD大鼠随机分为对照组及3-NNMS的0μg/mL组、25μg/mL组、125μg/mL组,每组10只。除对照组外,其余各组制备肢体缺血再灌注损伤大鼠模型,于再灌注前30 min,向损伤部位注射相应浓度的3-NNMS。再灌注2 h后,心尖取血,取大鼠右下肢股直肌组织进行检测。苏木精-伊红染色观察大鼠股直肌组织病理形态;ELISA检测血清骨骼肌损伤因子肌酸激酶(Creatine Kinase found in the skeletal muscle,CK-MM)、乳酸脱氢酶、髓过氧化物酶水平,并检测股直肌核因子κB、肿瘤坏死因子α、白细胞介素1β、环氧合酶2、丙二醛、活性氧、超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶水平,以及股直肌ATP水平、ATPase活性、线粒体呼吸控制率(RCR)水平。结果与结论:①与对照组相比,缺血再灌注模型大鼠血清CK-MM、乳酸脱氢酶、髓过氧化物酶水平升高,股直肌核因子κB、肿瘤坏死因子α、白细胞介素1β、环氧合酶2、丙二醛及活性氧水平升高,过氧化氢酶、谷胱甘肽过氧化物酶水平下降,ATPase活性、线粒体呼吸控制率水平降低;细胞形态不规则,炎性细胞浸润明显,细胞出现肿胀。②与0μg/mL组相比,25μg/mL组大鼠血清CK-MM、乳酸脱氢酶水平降低,股直肌核因子κB、环氧合酶2水平降低,活性氧减少,超氧化物歧化酶活性升高;细胞形态较规则,炎性细胞浸润较轻,细胞肿胀现象缓解。③与0μg/mL组相比,125μg/mL组大鼠血清CK-MM、乳酸脱氢酶、髓过氧化物酶水平降低,股直肌核因子κB、肿瘤坏死因子α、环氧合酶2量减少,丙二醛、活性氧水平降低,超氧化物歧化酶、谷胱甘肽过氧化物酶活性升高,线粒体呼吸控制率水平升高;细胞排列较整齐,轮廓较清晰完整,炎性细胞浸润较轻。④结果说明:3-NNMS可以减轻肢体缺血再灌注引起的骨骼肌功能损伤,其作用机制可能是通过改善线粒体功能、减少活性氧产生、降低氧化应激和炎症反应,进而减轻组织损伤,修复骨骼肌功能。

Oxidative stress and hypoxia-induced factor 1α expression in gastric ischemia

AIM:To investigate the relation of reactive oxygen species (ROS) to hypoxia induced factor 1α (HIF-1α) in gastric ischemia. METHODS:The animal model of gastric ischemia reperfusion was established by placing an elastic rubber band on the proximal part of the bilateral lower limb for ligature for 3 h and reperfusion for 0,1,3,6,12 or 24 h. Ischemic post-conditioning,three cycles of 30-s reperfusion and 30-s femoral aortic reocclusion were conducted before reperfusion. Histological and immunohistochemical methods were used to assess the gastric oxidative damage and the expression of HIF1-α in gastric ischemia. The malondialdehyde (MDA) content and superoxide dismutase (SOD),xanthine oxidase (XOD) and myeloperoxidase (MPO) activities were determined by colorimetric assays. RESULTS:Ischemic post-conditioning can reduce post-ischemic oxidative stress and the expression of HIF-1α of gastric tissue resulting from limb ischemia reperfusion injury. MDA,SOD,XOD and MPO were regarded as indexes for mucosal injuries from ROS,and ROS was found to affect the expression of HIF-1α under gastric ischemic conditions. CONCLUSION:ROS affects HIF-1α expression under gastric ischemic conditions induced by limb ischemia reperfusion injury. Therefore,ROS can regulate HIF-1α expression in gastric ischemia.

桃红四物汤通过LncRNA H19对肢体缺血-再灌注损伤中细胞凋亡的影响研究

目的:研究桃红四物汤通过LncRNA H19对肢体缺血-再灌注损伤中细胞凋亡的影响,探讨治疗肢体缺血再灌注损伤的新思路。方法:将78只2月龄雄性SD大鼠随机分为对照组、模型组、H19阻断剂组、桃红四物汤组;对照组正常饲养,剩余各组均造成肢体缺血-再灌注损伤模型;在造模前,H19阻断剂组予以H19阻断剂,通过尾静脉注射进行干预;在造模前,桃红四物汤组予以桃红四物汤进行灌胃处理,余下各组使用相同体积的蒸馏水灌胃处理;所有动物在再灌注损伤后的0、2、4、8 h 4个不同时间点,取大鼠骨骼肌肌肉组织,RT-PCR法检测骨骼肌中H19的mRNA的表达,HE染色法和电镜技术观察骨骼肌形态及病理性改变,DAPI法观察骨骼肌细胞凋亡情况。结果:在相同的时间点与对照组相比,模型组、H19阻断剂组、桃红四物汤组的H19 mRNA水平均升高,差异有统计学意义(P<0.05);在相同的时间与模型组相比,H19阻断剂组、桃红四物汤组的H19 mRNA水平均降低,差异有统计学意义(P<0.05);与对照组相比,模型组、H19阻断剂组和桃红四物汤组骨骼肌细胞凋亡率明显高于对照组,差异有统计学意义(P<0.05);与模型组相比,H19阻断剂组和桃红四物汤组骨骼肌细胞凋亡率明显低于模型组,差异有统计学意义(P<0.05)。结论:LncRNA H19是肢体缺血再灌注损伤中的重要分子,抑制LncRNA H19的表达可以降低骨骼肌细胞的凋亡率,从而治疗肢体缺血再灌注损伤。

基于“毒、瘀”病机对桃红四物汤防治肢体缺血-再灌注损伤理论探讨

以“毒、瘀”病机为角度,探讨“毒、瘀”病机与肢体缺血-再灌注损伤复杂的发病机制的关联性及桃红四物汤对肢体缺血-再灌注损伤的重要防护作用,认为“毒、瘀”是引起肢体缺血-再灌注损伤的重要发病因素;桃红四物汤通过化瘀生新,活血减毒在防治肢体缺血-再灌注损伤中发挥保护作用;为肢体缺血-再灌注损伤的中医辨证论治提供新思路。

Cardioprotective Effect of Angiotensin n Receptor Antagonist on Perfused Ischemic Reperfusion Injury of Whole Isolated Rat Hearts

Objectives Investigated the cardioprotective and mechanisms of losartan on whole isolated ischemic reperfused rat heart. Methods Langendorff perfused systems was used to investigate losartan effect on whole isolated rat hearts in CPK, LDH, MDA, SOD, ang II and arrhythmia. Results Losartan decreased incidence of arrhythmia, improved atrial ventricular block recovery in reperfu-sion period, during ischemic period, CPK and LDH in I/R group increased significantly compared with control group, 51. 33±27. 02 vs 22. 42 ± 13. 33, 31. 80 ±4.56 vs 22. 28 ± 15. 96, respectively, but greatly decreased in losartan group compared with I/R group, 23. 90±21.74 vs 51. 33 ±27. 02 and 11. 50 ±13. 20 vs 31. 80 ±4. 56, respectively. During reperfusion period CPK, LDH increased significantly in I/R group compared with control group, 49. 11 ± 20. 63 vs 12. 14 ±5.92 and 28. 70±4. 69 vs 23. 10±21. 38, respectively, but decreased greatly in losartan group compared with I/R group, 39. 40 ± 9. 60 vs 49. 11 ± 20.63 and 14. 50 ±13. 75 vs 28. 70±4. 69. The content of MDA, ang II in I/R group myocytes is higher than control group's , 26. ± 9. 25 vs 17. 2 ± 3. 37 and 8. 43 ± 3. 81 vs 4. 80 ± 0. 20. However the content of SOD in two groups has no significantly change, 148. 20 ± 8. 72 vs 145. 08±6. 82. the content of MDA in losartan group myocardial tissue is much lower than control group, 15.92±4.05 vs 26. 80 ± 9. 25 and the content of ang II in losartan group myocardial tissue is much higher than I/R group, 12. 44 ± 6. 09 vs 8. 43 ± 3. 21. The department of cardiology of second hospital of Tianjin medical u-niversity Tianjin 300211 However, SOD has no significant change in two groups, 143. 47±7. 91 vs 145. 08 ± 6. 82. Conclusions Losartan against is-chemic - reperfusion injury of whole isolated rat hearts, those beneficial effects are mediate primarily by the inhibited of angiotensin II binding with its receptor and inhibited oxygen free radical scavenging potential.

Ischemic preconditioning produces more powerful anti- inflammatory and cardioprotective effects than limb remote ischemic postconditioning in rats with myocardial ischemia-reperfusion injury

Background Both ischemic preconditioning （IPC） and limb remote ischemic postconditioning （LRIPOC） have been shown to possess significantly different cardioprotective effects against the myocardial ischemia reperfusion injury （IRI）, but no study has compared the anti-inflammatory effects of IPC and LRIPOC during myocardial IRI process. We hypothesized that IPC and LRIPOC would produce different anti-inflammatory effects in an in vivo rat model with myocardial IRI.

Mechanism of the protective effects of noninvasive limbs preconditioning on myocardial ischemia-reperfusion injury

Background This study aimed at assessing the effect of noninvasive limb preconditioning on myocardial infarct size, and determining whether nitric oxide and neurogenic pathway play an important role in the mechanism of acute remote ischemic preconditioning （IPC）.Methods Forty Wistar rats were randomly divided into four experimental groups. In Group I , the rats underwent 30-minute occlusion of the left anterior descending coronary artery, and 120-minute reperfusion. In Group PL, the rats underwent four cycles of 5-minute occlusion and reperfusion of both hind limbs using a tourniquet before the experiment was continued as in Group I. In Group PL-N and Group PL-,, we administered L-nitro-arginine methyl ester （L-NAME） 10 mg/kg or hexamethonium chloride 20 mg,/kg intravenously, 10 minutes before IPC. Infarct size as a percentage of the area at risk was determined by triphenyhetrazolium chloride staining.Results There were no statistically significant differences in mean arterial pressure and heart rate among these groups at any time point during the experiment （ P〉0. 05 ）. The myocardial infarct size （IS） was decreased significantly in Group PL and Group PL-U compared with Group I , and the IS/AAR was 34. 5%± 7.6%, 35.9%±8.6% and58.5%±8.5%, respectively （P〈0.05）. The IS/AAR was 49.1%±6.5% in Group PEN, and there was no significant difference compared with Group I （P〉0. 05 ）.Conclusions Noninvasive limb IPC is effective in protecting the myocardium from ischemia reperfusion injury. Nitric oxide plays an important role in the mechanism of acute remote IPC, in which the neurogenic pathway is not involved.

β-七叶皂甙钠对肢体缺血再灌注损伤的保护作用

目的 :观察 β 七叶皂甙钠对肢体缺血再灌注损伤的保护作用。方法 :用兔造成肢体缺血再灌注损伤动物模型。实验分对照组、缺血再灌注组和 β 七叶皂甙钠组。取血浆测定丙二醛、肌酸磷酸激酶、谷草转氨酶和乳酸脱氢酶含量。取骨骼肌标本测定丙二醛、髓过氧化酶活性、肌细胞线粒体钙含量和组织湿 /干重比值。结果 :缺血再灌注组与对照组比较 ,血浆和骨骼肌的各项生化指标显著增高 (P <0 .0 1) ;使用 β 七叶皂甙钠后 ,血浆及骨骼肌各项测定指标较缺血再灌注组相比明显降低 (P <0 .0 5 ,P <0 .0 1)。结论 :β 七叶皂甙钠可减轻肢体缺血再灌注损伤 。

大鼠肢体预缺血减小心肌缺血-再灌注后的梗塞范围

在氨基甲酸乙酯麻醉大鼠上观察肢体预缺血(limb ischemic preconditioning,LIP)对缺血-再灌注(ischemia—reperfusion,IR)心肌的影响,旨在探讨LIP对IR心肌有无保护效应,并明确腺苷和神经通路是否参与此效应。所得结果如下:(1)在心脏缺血30 min和再灌注120 min过程中,梗塞心肌占缺血心肌的51.48±0.82％。(2)LIP时心肌梗塞范围为35.14±0.88％,较单纯心肌缺血-再灌注时显著减小(P<0.01),表明LIP对心肌有保护作用。(3)事先切断股神经可取消LIP的保护效应。(4)股动脉内局部给予腺苷(10nmol/kg),可模拟LIP对心肌的保护作用;心肌梗塞范围是37.28±1.68％,而股静脉内注射同等剂量腺苷则无保护作用。(5)股动脉内预先应用腺苷A.受体拈抗剂8-环戊-1,3-二丙基嘌呤(DPCPX)(32 nmol/kg)可部分阻断LIP诱发的心肌保护效应。以上结果表明,肢体短暂预缺血可减小心肌缺血-再灌注后的梗塞范围,而局部释放的腺苷和由此所激活的相关的神经通路在LIP的心肌保护中起重要作用。

肢体远隔缺血预处理对肝脏手术中血清 TNF-α和 HMGB1水平的影响

目的：探讨肢体远隔缺血预处理对肝脏手术中血清 TNF-α和 HMGB1水平的影响。方法60例择期行肝部分切除手术的患者,ASA Ⅰ或Ⅱ级,随机分成两组：RIPC 组（R 组）接受右上肢缺血预处理,对照组（C 组）不进行预处理。分别于肝脏缺血前10 min（T0）、再灌注后1 h（T1）、6 h （T2）、24 h（T3）、48 h（T4）经中心静脉导管采集血样测定 TNF-α、高迁移率族蛋白 B1（HMGB1）及谷草转氨酶（AST）、谷丙转氨酶（ALT）水平。结果与 T0比较,T1~T4时两组血清 TNF-α、HMGB1及 AST、ALT 水平均明显升高（P 〈0.05）。与 C 组比较,T1~T4时 R 组 TNF-α、HMGB1及 AST、ALT 水平均明显降低（P 〈0.05）。结论肢体远隔缺血预处理用于肝脏部分切除术中,能够减轻肝脏缺血-再灌注损伤程度,可能与缓解肝脏缺血-再灌注时血清 TNF-α、HMGB1的释放,减轻全身炎症反应有关。

JAK2-STAT3通路介导肢体缺血后处理脑缺血再灌注损伤保护作用的研究

目的探讨肢体缺血后处理对大鼠脑缺血再灌注损伤后脑保护的作用机制。方法健康雄性SD大鼠48只,随机分为4组即假手术组(sham)、缺血再灌注组(I/R组)、肢体缺血后处理组(Lpost组)、肢体缺血后处理+AG490组(AG组)。I/R组、Lpost组、AG组均做缺血2 h再灌注24 h,Lpost组:再灌注前实施肢体缺血后处理(缺血15 min,灌注15 min)3个循环,AG组:再灌注前5 min时腹腔注射AG490(l mg/kg),其他处理与Lpost组相同。各组大鼠神经功能评分后,采用TTC染色测脑梗死体积,TUNEL法测定脑细胞凋亡。结果 1与sham组相比,I/R组大鼠神经功能缺损加重(P<0.05);与I/R组相比,Lpost组大鼠神经功能缺损减轻(P<0.05);与Lpost组相比,AG组大鼠神经功能缺损加重(P<0.05);2 sham组大鼠无梗死灶,与I/R组相比,Lpost组大鼠梗死体积减小(P<0.05);与Lpost组相比,AG组梗死体积增大(P<0.05);3与I/R组相比,Lpost组大鼠脑细胞凋亡率明显降低(P<0.05);与Lpost组相比,AG组脑细胞凋亡率明显增高(P<0.05)。结论肢体缺血后处理具有显著的脑保护作用,这一作用是由JAK2-STAT3通路介导的。

缺血后处理对双后肢缺血-再灌注大鼠小肠的影响

目的观察缺血后处理对肢体缺血-再灌注大鼠小肠损伤的保护作用。方法雄性Wistar大鼠108只随机均分为双后肢缺血一再灌注组（LIR组）、缺血后处理组（IPo组）和假手术组（S组）。检测再灌注即刻（T1）、1h（T2）、3h（T3）、6h（T4）、12h（T5）和24h（R）小肠组织中超氧化物歧化酶（SOD）活性、髓过氧化物酶（MPO）活性、丙二醛（MDA）含量和小肠组织的湿／干重比值（W／D），光镜下对小肠黏膜行Chiu’S病理分级。结果与s组比较，LIR组和IPo组各时点小肠黏膜Chiu’S病理分级、MDA含量、MPO活性和W／D升高，SOD活性降低（P〈O．05），并随再灌注时间的变化而变化；与LIR组比较，T3～T6时IPo组Chiu’S病理分级降低，，T2～T6时MDA含量、MPO活性和w／D显著下降，而SOD活性升高（P〈O．05）。结论缺血后处理对大鼠双后肢缺血再灌注小肠具有保护作用，其保护机制可能与抑制氧自由基及中性粒细胞活化有关。

大鼠肢体缺血/再灌注后肝脏HO-1表达的变化及其意义

目的探讨肢体缺血/再灌注(I/R)致肝脏损伤时肝组织诱导型血红素氧合酶(HO1)表达的变化及其意义。方法夹闭大鼠双侧股动脉根部4h、开放2～24h,制备肢体I/R模型。RTPCR检测肝组织HO1mRNA表达的变化,免疫组化染色法观察HO1蛋白在肝内的生成与分布。对肢体I/R大鼠应用锌原卟啉抑制其体内HO1活性后,光镜观察其肝组织的病理变化。结果肢体I/R后肝组织HO1mRNA的表达水平显著高于各对照组,再灌12h表达至峰值,至再灌24h仍显著高于各对照组(P<0.01)。肢体I/R组肝组织内出现大量弥散分布的HO1阳性肝细胞,抑制HO1活性,使肢体I/R组肝组织损伤明显加重。结论肢体I/R损伤可诱导肝细胞HO1基因表达上调,所诱生的HO1对肝细胞具有保护效应。

断肢再植肌组织缺血再灌注损伤的细胞凋亡及Bax、Bcl-2表达

目的研究断肢再植过程中缺血性损伤和缺血-再灌注损伤的发生情况和病理改变,探讨细胞凋亡及相关基因Bax、Bcl-2表达规律。方法建立大鼠后肢断肢实验模型,以光镜观察缺血和缺血再灌注早期的骨骼肌组织病理变化,检测缺血和缺血再灌注过程中细胞凋亡(apoptosis)现象的发生及相关基因表达。结果缺血5h的大鼠断肢再植全部存活,而缺血9h者未获存活。大鼠断肢再植过程中,缺血性和缺血-再灌注性损伤引起骨骼肌细胞水肿,坏死和细胞凋亡,并于再灌注过程观察到微循环障碍和中性粒细胞趋化浸润现象。缺血7h凋亡率最高,相关基因Bax表达与缺血时间成正比。Bcl-2表达与缺血时间成反比。结论骨骼肌存在缺血性和缺血-再灌注性损伤,细胞凋亡是缺血和缺血-再灌注损伤的重要病理改变。骨骼肌缺血再灌注过程存在微循环障碍和中性粒细胞趋化浸润,它们是缺血-再灌注损伤的重要原因之一。相关基因表达与凋亡的发生关系密切。

大鼠肢体缺血-再灌注所致胃粘膜损伤及其机制

目的 :观察肢体缺血再灌注 (LIR)对胃粘膜的损伤作用 ,探讨其可能的作用机制。方法 :按Rosenthal方法复制大鼠LIR模型 ,观察并测定肢体缺血4h再灌注4h后胃粘膜的损伤性变化 ,测定各组胃粘膜损伤指数 ,检测胃粘膜中髓过氧化物酶 (MPO)、超氧化物歧化酶(SOD)、丙二醛(MDA)及黄嘌呤氧化酶 (XOD)含量的变化 ,以及血浆中MDA、XOD、SOD含量的变化。结果 :大鼠LIR后胃粘膜损伤严重 ,胃粘膜损伤指数增加 ;胃粘膜中MPO、MDA、XOD的值均较对照组增加 ,血浆中MDA、XOD的值亦较对照组显著增加 ,血浆及胃粘膜中SOD的酶活力下降。结论 :肢体缺血再灌注作为应激原可引起胃粘膜损伤,导致应激性溃疡的发生 ;

桃红四物汤对肢体缺血-再灌注损伤大鼠骨骼肌三磷酸肌醇受体表达的影响

目的观察桃红四物汤对肢体缺血-再灌注损伤大鼠骨骼肌三磷酸肌醇受体(IP3R)表达的影响,从Wnt/Ca2+信号通路角度探讨其作用机制。方法取2月龄雄性SD大鼠80只,随机分为正常组、模型组、桃红四物汤组和阻滞剂组,每组20只,除正常组外,其余各组均阻断血流制备大鼠右后肢缺血-再灌注损伤模型,桃红四物汤组、阻滞剂组造模前分别给予桃红四物汤灌胃、阻滞剂腹腔注射预处理,HE染色和DAPI荧光染色观察再灌后8 h腓肠肌细胞凋亡,免疫组化检测再灌后8 h腓肠肌IP3R蛋白的表达,RT-PCR检测再灌后0、2、4、8 h腓肠肌IP3R mRNA的表达。结果HE染色和DAPI荧光染色结果显示,与正常组比较,模型组大鼠腓肠肌细胞凋亡率明显升高(P<0.05);与模型组比较,桃红四物汤组和阻滞剂组大鼠腓肠肌细胞凋亡率明显降低(P<0.05),桃红四物汤组低于阻滞剂组(P<0.05)。免疫组化及RT-PCR检测结果显示,与正常组比较,模型组大鼠腓肠肌IP3R蛋白和m RNA表达明显上调(P<0.05);与模型组比较,桃红四物汤组、阻滞剂组大鼠腓肠肌IP3R蛋白和m RNA表达明显下调(P<0.05)。结论桃红四物汤通过下调Wnt5a/Ca2+信号通路IP3R的表达减轻肢体缺血-再灌注损伤。