Montelukast reduces ischaemia/reperfusion-induced bladder dysfunction and oxidant damage in the rat

The present study aimed to investigate the possible beneficial effects of the cysteinyl leukotriene-1 receptor antagonist montelukast on contractility and oxidant damage after ischaemia/reperfusion (I/R) of rat urinary bladder. The abdominal aorta of Sprague-Dawley rats was occluded to induce I/R. Montelukast (10 mg kg(-1)) or saline was administered intraperitoneally before I/R. In the sham-operated group, the abdominal aorta was left intact and the animals were treated with montelukast or saline. After decapitation, the bladder was removed and the tissue was either used for functional studies or stored for biochemical assays. In the I/R group, the isometric contractile responses of the bladder strips to carbachol (10(-8)-10(-4) M) were lower than those of the control group and were reversed by treatment with montelukast. Lipid peroxidation and myeloperoxidase activity of the bladder tissues in the I/R group were greater than in the sham-operated group. Montelukast treatment in the I/R group decreased these parameters compared with I/R alone. Similarly, the significant decrease in tissue glutathione level in the I/R group compared with controls was also prevented by montelukast. Treatment with montelukast almost completely reversed the low contractile responses of rat urinary bladder to carbachol and prevented oxidative tissue damage following I/R.     

The protective effect of qiancao naomaitong mixture on neuronal damage and cerebral ischemia/reperfusion injury

Context Qiancao Naomaitong Mixture (QNM) is mainly used to treat ischemic stroke patients in the clinic.

Objective This study evaluates the protective effect of QNM on neuronal damage in vitro, and clarifies the underlying mechanism against cerebral ischemia-reperfusion (I/R) injury in vivo.

Materials and methods Activity assay of caspase 3 (C-3) and caspase 8 (C-8) were measured with microplate reader and cell apoptosis was investigated. Cerebral I/R injury was induced by MCAO model. QNM groups were given at 0.27, 0.54 and 1.08?mL/100?g body weight. The weight ratio of cerebral infarction tissue was obtained. The cytokine levels in serum and brain tissue were measured using ELISA.

Results Compared with the OGD group (C-3: 29.69?±?5.63, C-8: 74.05?±?6.86), 100?mg/mL QNM (C-3: 19.80?±?2.62, C-8: 48.94?±?6.41) and 200?mg/mL QNM (C-3: 16.28?±?4.55, C-8: 41.08?±?4.05) treatments decreased C-3 and C-8 activities significantly, and inhibited apoptosis of SH-SY5Y cells. The weight ratios of cerebral tissues in low, medium and high dose groups were 17.33?±?5.1%, 17.78?±?5.4% and 14.25?±?4.2%, respectively, significantly lower than in control group. QNM also improved the cytokine levels in serum and brain tissue. In addition, histological examination indicated that dense neuropil and largely surviving neurons were seen in treated rats.

Conclusion QNM exerted protective effect by inhibiting the cell apoptosis in vitro. The protective mechanisms of QNM were associated with its properties of anti-apoptosis and antioxidation as well as improved neuronal nutrition in I/R rats.     

Neuroprotective effects of scutellarin on rat neuronal damage induced by cerebral ischemia/reperfusion

AIM: To investigate the neuroprotective effect and mechanisms of scutellarin, a flavonoid extracted from Erigeron breviscapus Hand Mazz, against neuronal damage following cerebral ischemia/reperfusion. METHODS: Rats were pretreated ig with scutellarin for 7 d and then subjected to cerebral ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion (MCAO). The infarct volume and neurological deficit were determined by TTC staining and Longa's score. The permeability of the blood-brain barrier was evaluated by measurement of the Evans blue (EB) content in the brain with a spectrophotometer. The total NOx content was determined. Nitric oxide synthase (NOS) isoforms (iNOS, eNOS, nNOS) and the key angiogenic molecules, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), were detected by Western blotting. RESULTS: Scutellarin significantly reduced infarct volume (P<0.05 or P<0.01), ameliorated the neurological deficit and reduced the permeability of the blood-brain barrier (BBB) (P<0.05). When rats were pretreated with scutellarin (50 or 75 mg/kg), upregulation of eNOS expression and downregulation of VEGF, bFGF, and iNOS expression was observed, whereas scutellarin had no effect on nNOS expression. CONCLUSION: Scutellarin has protective effects for cerebral injury through regulating the expression of NOS isoforms and angiogenic molecules.     

黄连素对大鼠心肌缺血再灌注所致心肌损伤的保护作用

目的探讨黄连素对缺血再灌注所致心肌损伤的保护作用。方法 60只雄性健康SD大鼠随机分为5组,即对照组、模型组、阳性对照组及黄连素低[75 mg/(kg·d)]、高[150 mg/(kg·d)]剂量组。黄连素连续灌胃给药14 d后,除对照组外,其余各组结扎冠状动脉左前降支建立大鼠心肌缺血再灌注模型,监测心电图,记录心律失常评分;检测血浆中心钠肽(ANP)、脑钠肽(BNP)、心肌肌钙蛋白-I(c Tn-I)浓度;HE染色与Masson染色方法检测心肌机构损伤情况。结果黄连素预防给药可缩短缺血再灌注所致心律失常恢复正常的时间,同时显著抑制血浆中ANP、BNP和c Tn-I水平的上升,改善心肌结构。结论黄连素对缺血再灌注所致的心肌损伤具有保护作用。     

Protective effect of ginsenoside-Re against cerebral ischemia/reperfusion damage in rats

To investigate the protective effect of ginsenoside Re (Re) against cerebral ischemia-reperfusion injury, adult male Wistar rats weighing 250-300 g were subjected to either sham surgery or middle cerebral artery occlusion (MCAO) for 2 h of brain ischemia and 2 h reperfusion. A fluorescence polarization assay was carried out for membrane fluidity of brain mitochondria. Lipid peroxidation [malondiadehyde (MDA) formation], superoxide dismutase (SOD) and glutathion peroxidase (GSH-Px) of rat brain were estimated by fluorometric methods. It was observed that Re (5, 10, 20 mg kg-1 p.o. pretreatment for 7 d, once a day) significantly improved the fluidity of mitochondrial membranes as demonstrated by a reduction of average microviscosity, ameliorated lipid peroxidation by raising the activities of SOD and GSH-Px, and reduced the content of MDA in rat brain. This study demonstrated a direct protective effect of Re against cerebral ischemia-reperfusion injury.     

白藜芦醇抗心律失常和抗心肌缺血作用研究

白藜芦醇（Resveratrol，RVL）为多酚类物质，是广泛存在于水果、中药和葡萄酒中的一种植物抗毒素。随着对RVL研究的深入，人们发现它具有多种药理学活性，其中RVL的心血管保护作用逐渐成为研究热点，但其有关抗心律失常及抗心肌缺血作用鲜见报道。本文就RVL对实验性心律失常和急性心肌缺血的保护作用进行研究。     

羟乙葛根素对大鼠局灶性脑缺血再灌注氧化损伤的保护作用

目的探讨羟乙葛根素对大鼠局灶性脑缺血再灌注氧化损伤的保护作用。方法制备大脑中动脉阻塞再灌注损伤模型,测定脑缺血再灌注损伤大鼠神经病学评分、脑组织超氧阴离子和羟自由基水平和脑梗死面积。结果羟乙葛根素能明显降低局灶性脑缺血再灌注损伤大鼠神经病学评分、缩小脑梗死面积,降低脑组织超氧阴离子和羟自由基水平。结论羟乙葛根素的脑保护作用可能与清除体内超氧阴离子和羟自由基有关。     

N-乙酰半胱氨酸和氯胺酮联用对脑缺血再灌注损伤的影响

目的:研究巯基供体物质N 乙酰半胱氨酸(NAC)和非竞争性NMDA受体拮抗剂氯胺酮(KT)联用对小鼠脑缺血再灌注损伤的影响。方法:雄性ICR小鼠,随机分为假手术组、生理盐水组(0 .0 1L·g- 1)、氯胺酮组(15mg·kg- 1)、N 乙酰半胱氨酸组(75mg·kg- 1)和联合组(KT 15mg·kg- 1 NAC75mg·kg- 1)。参照蒋晓帆等建立的方法,制备局灶性短暂性脑缺血再灌注模型(tMCAO) ,再灌注后6、2 4h测定神经行为缺陷评分,处死TTC染色测定脑梗死面积百分比;制备不完全性脑缺血再灌注模型(2 VO) ,在再灌注0 .5、2和6h时取全脑制成10 %匀浆,比色法测定MDA含量、SOD和GSH Px活力。结果:(1)短暂性局灶性脑缺血再灌注后6、2 4h ,各组小鼠脑组织均有不同程度梗死灶、神经行为缺陷明显,与生理盐水组比较,药物联合组可显著改善缺血再灌注小鼠的神经行为缺陷(均为P <0 .0 1) ,减少脑梗死面积百分比(均为P <0 .0 1) ,药物单用对以上指标有轻度的改善作用(P >0 .0 5 )。(2 )联合用药可明显改善脑细胞损伤。(3)与假手术组比较,不完全性全脑缺血再灌注损伤0 .5、2和6h后,生理盐水组小鼠MDA含量显著升高(均为P <0 .0 1) ,SOD活性(均为P <0 .0 1)和GSH Px活性均显著降低(均为P <0 .0 1)。与生理盐水组比较,联合组可显著地降低缺血再灌注小鼠脑组织     

巯基供体化合物NAC和S-8744对局灶性脑缺血/再灌损伤保护作用的比较

目的与方法　本文用插线法制作局灶性脑缺血 /再灌损伤模型 ,利用激光共聚焦扫描显微镜和fluo 3或DCF DA与PI荧光探剂双标技术检测了活体脑片细胞内脂质过氧化物、Ca2 + 含量及细胞的坏死程度。同时观察巯基供体NAC、S 8744对脑缺血 /再灌损伤的保护作用。结果　①缺血 /再灌时脑片细胞内脂质过氧化物、Ca2 + 含量增加 ,同时脑片细胞发生坏死 ;②巯基供体NAC、S 8744均可降低缺血 /再灌损伤引起的脑片细胞内脂质过氧化物、Ca2 + 的含量 ,减轻细胞坏死程度。结论　巯基供体NAC、S 8744可拮抗局灶性脑缺血 /再灌损伤     

白藜芦醇对心肌缺血再灌注过程中线粒体的保护

目的:探讨白藜芦醇对心肌缺血再灌注损伤过程中Ca²⁺-ATPase及HSP70表达的影响。方法:健康雄性SD大鼠40只,采用随机数字量表法分为4组(假手术组、缺血再灌注组、缺血预适应组、白藜芦醇组),采用结扎冠状动脉前降支制备心肌缺血再灌注损伤模型,于结扎前15 min及再灌注前1 min经舌下静脉注射白藜芦醇10 mg·kg^-1。提取心肌线粒体,紫外可见光分光光度计测定线粒体中SDH、Na⁺-K⁺-ATPase、Ca²⁺-ATPase活性;荧光分光光度计测定线粒体中游离钙、mPTP开放度及跨膜电位;RT-PCR及Western blot检测心肌组织HSP70、Ca²⁺-ATPase mRNA及蛋白质的表达。结果:白藜芦醇与缺血再灌注组及缺血预适应组相比,线粒体中SDH、Na⁺-K⁺-ATPase、Ca²⁺-ATPase的活性明显提高(P<0.05或P<0.01);线粒体内钙离子浓度明显下降(P<0.05或P<0.01)、mPTP开放程度减小(P<0.01)、线粒体膜电位增高(P<0.01);Ca²⁺-ATPase、HSP70在 mRNA或蛋白水平上的表达均有所增加(P<0.05或P<0.01)。结论:白藜芦醇可能通过增加心肌组织中Ca²⁺-ATPase、HSP70 mRNA和蛋白的表达,提高线粒体Ca²⁺-ATPase的活性,产生对大鼠心肌缺血再灌注损伤时线粒体的保护作用。     

白藜芦醇对大鼠脑缺血/再灌注损伤后星形胶质细胞活化的影响

目的研究白藜芦醇对大鼠脑缺血/再灌注损伤后星形胶质细胞活化的影响。方法 45只SD♂大鼠随机分成假手术组(Sham)、对照组(Con)和白藜芦醇组(30 mg·kg-1,Res),每组15只。于缺血/再灌注后3 h使用白藜芦醇或溶剂治疗,连用7 d。脑缺血24 h时,TTC法检测脑梗死体积,HE染色检测病理变化,Longa评分行神经功能评分,免疫组织化学检测缺血半暗带皮质半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)的表达。脑缺血14 d时,免疫组织化学及免疫荧光法检测胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和神经元NeuN蛋白表达。结果白藜芦醇治疗较对照组能明显改善神经功能、减小梗死体积、减少神经元脱失及凋亡,抑制星形胶质细胞的活化与增殖(P<0.01)。结论白藜芦醇治疗可抑制星形胶质细胞的异常活化,保护缺血半暗带神经元,改善神经功能。     

白藜芦醇对脑缺血/再灌注氧化应激损伤保护机制的研究进展

白藜芦醇是一种广泛存在于植物中的多酚类化合物,具有广泛的生物学活性。该文主要从白藜芦醇的性质以及在脑缺血/再灌注氧化应激损伤中的保护作用及其机制作一综述。     

异丙酚对宫内窘迫胎鼠的神经保护作用

目的观察异丙酚对宫内窘迫胎鼠的神经保护作用。方法 SD大鼠♀18只,交配后获得孕鼠。将孕鼠随机分为6组(n=3):假手术组(S组)、缺血/再灌注组(IR组)、异丙酚低、中、高剂量组(P1~P3组)和荷包牡丹碱组(B组)。S组和IR组孕鼠经尾静脉注射生理盐水1 m L。P_1~P_3组孕鼠经尾静脉分别注射异丙酚10、30、50 mg·kg~(-1)。B组在注射异丙酚50 mg·kg~(-1)的同时,腹腔注射荷包牡丹碱5 mg·kg~(-1)。夹闭子宫卵巢动脉11 min。再灌注3 d后取材,每只孕鼠各取2只胎鼠,每组6只。制作切片,计算海马CA1区神经元损伤指数(LI)。硫代巴比妥酸反应法检测胎鼠脑组织丙二醛(MDA)含量。结果 S组LI为7.2±0.9,MDA为(3.86±0.20)μmol·g~(-1),与之相比,IR组的LI为71.9±2.8,MDA为(9.10±0.45)μmol·g~(-1)(P<0.01)。与IR相比,异丙酚各组的LI分别为40.8±2.6,21.4±1.4,20.1±1.3,MDA分别为(7.32±0.41),(5.65±0.27),(5.44±0.28)μmol·g~(-1)(P<0.05)。B组的LI,MDA分别为(51.2±2.3),(7.54±0.31)μmol·g~(-1),翻转了异丙酚的保护作用。结论异丙酚对宫内窘迫胎鼠具有神经保护作用。     

中性粘多糖对沙土鼠缺血再灌流脑组织的影响

应用沙土鼠制成脑缺血再灌流的模型，研究中性粘多糖（ＮＭ）对其脑组织的影响。提示ＮＭ可通过某些途径抑制或消除氧自由基，阻止脂质过氧化反应，具有保护内源性ＳＯＤ和抗氧化作用。     

Effect of astaxanthin on hepatocellular injury following ischemia/reperfusion

This study investigated the effect of astaxanthin (ASX; 3,3-dihydroxybeta, beta-carotene-4,4-dione), a water-dispersible synthetic carotenoid, on liver ischemia–reperfusion (IR) injury. Astaxanthin (5 mg/kg/day) or olive oil was administered to rats via intragastric intubation for 14 consecutive days before the induction of hepatic IR. On the 15th day, blood vessels supplying the median and left lateral hepatic lobes were occluded with an arterial clamp for 60 min, followed by 60 min reperfusion. At the end of the experimental period, blood samples were obtained from the right ventricule to determine plasma alanine aminotransferase (ALT) and xanthine oxidase (XO) activities and animals were sacrificed to obtain samples of nonischemic and postischemic liver tissue. The effects of ASX on IR injury were evaluated by assessing hepatic ultrastructure via transmission electron microscopy and by histopathological scoring. Hepatic conversion of xanthine dehygrogenase (XDH) to XO, total GSH and protein carbonyl levels were also measured as markers of oxidative stress. Expression of NOS2 was determined by immunohistochemistry and Western blot analysis while nitrate/nitrite levels were measured via spectral analysis. Total histopathological scoring of cellular damage was significantly decreased in hepatic IR injury following ASX treatment. Electron microscopy of postischemic tissue demonstrated parenchymal cell damage, swelling of mitochondria, disarrangement of rough endoplasmatic reticulum which was also partially reduced by ASX treatment. Astaxanthine treatment significantly decreased hepatic conversion of XDH to XO and tissue protein carbonyl levels following IR injury. The current results suggest that the mechanisms of action by which ASX reduces IR damage may include antioxidant protection against oxidative injury.     

白藜芦醇预处理对局灶性脑缺血/再灌注大鼠海马CA1区神经元凋亡的保护作用和机制

目的探讨白藜芦醇(resveratrol,Res)预处理对局灶性脑缺血/再灌注大鼠海马CA1区神经元凋亡的保护作用及其机制。方法♂SD大鼠60只,随机分为假手术组(Sham)、缺血/再灌注组(I/R)、白藜芦醇预处理组(Res+I/R),每组20只。采用线栓法阻断大脑中动脉血供90 min,拔出栓线造成局部脑区缺血/再灌注损伤。Res+I/R组缺血前1 h腹腔注射白藜芦醇(30 mg·kg-1)。缺血/再灌注后第5天,TUNEL法原位标记海马CA1区凋亡的神经元细胞,免疫组化法检测海马CA1区PI3K、p-Akt及Caspase-3的表达。结果 TUNEL染色结果显示,与I/R组相比较,白藜芦醇预处理明显减少脑缺血/再灌注损伤所引起的大鼠海马CA1区神经元凋亡(P<0.05);免疫组织化学结果显示,与I/R组相比,白藜芦醇预处理使海马CA1区PI3K、p-Akt表达明显增多(P<0.05),Caspase-3表达明显减少(P<0.05)。结论缺血前1 h白藜芦醇预处理对局灶性脑缺血大鼠海马CA1区神经元凋亡具有保护作用,其主要作用机制可能是通过激活PI3K-Akt信号通路进而抑制凋亡相关蛋白Caspase-3的表达有关。     

Attenuation of ischemia/reperfusion injury in rats by the anti-inflammatory action of resveratrol

Resveratrol (trans-3,4',5-trihydroxystilbene, CAS 501-36-0), a natural antioxidant and polyphenol found in grapes and wine, has been found to pharmacologically precondition the heart in nitric oxide (NO)-dependent manner. In the vascular system, NO functions as an endogenous inhibitor of leukocyte chemotaxis, adherence, and activation. The present study was designed to determine if resveratrol, through NO, can block the proadhesive molecules generated in the ischemic reperfused myocardium. Isolated hearts were prepared from properly anesthetized rats, and mounted on a Langendorff apparatus. The hearts were randomly assigned to one of the three groups: (i) control, (ii) resveratrol, and (iii) resveratrol + NG-nitro-L-arginine ethyl ester (L-NAME). The hearts were perfused in the absence (n = 6) or presence of 10 micromol/L resveratrol (n=6) or resveratrol + L-NAME (n = 6) for 15 min. All the hearts were then subjected to 30 min ischemia followed by 2 h of reperfusion. Ventricular function was monitored, infarct size and apoptotic cell death measured, and the proadhesive molecules and malonaldehyde formation determined in the perfusate. Resveratrol significantly improved postischemic ventricular function and reduced myocardial infarct size compared to the non-treated control group. The amount of proadhesive molecules including soluble intracellular adhesion molecule-1 (sICAM-1), endothelial leukocyte adhesion molecule-1 (sE-Selectin) and vascular cell adhesion molecule-1 (sVCAM-1) were each significantly decreased during reperfusion in the resveratrol group. L-NAME, a NO blocker, completely abolished such beneficial effects of resveratrol. The results support an anti-inflammatory action of resveratrol through a NO-dependent mechanism.     

Protective effect of novel pyridoindole derivatives on ischemia/reperfusion injury of the isolated rat heart

Generation of reactive oxygen species is a major, well-known cause of heart injury induced by ischemia-reperfusion. This injury is manifested through myocardial stunning, reperfusion and lethal reperfusion injury of cardiocytes. The pyridoindole stobadine has been shown to exhibit significant antioxidant, free-radical scavenging and hypoxic-tissue-protecting properties. The present study examined the effects of stobadine and two novel derivatives, SMe1 and SMe1EC2, which exhibit improved pharmacodynamic and toxicity profiles, on the functional properties and reperfusion dysrhythmias of the isolated rat heart in ischemia-reperfusion conditions. All experiments were performed on isolated Langendorff-perfused hearts isolated from 3-month-old male Wistar rats. After 15 min of stabilization, the hearts were subjected to a 30-minute period of global no-flow ischemia, followed by a 30-minute reperfusion period. Stobadine, SMe1 and SMe1EC2 were applied at a concentration of 1 x 10(-5) 10 min before the onset of ischemia, and during reperfusion through the perfusion medium. As compared to the untreated group, addition of SMe1EC2 during reperfusion significantly increased left ventricular developed pressure, decreased pathologically elevated left ventricular end-diastolic pressure and enhanced recovery of the stunned myocardium after ischemia. Both SMe1 and stobadine failed to influence these parameters; however, all derivatives tested inhibited serious life-threatening reperfusion dysrhythmias such as ventricular tachycardia and ventricular fibrillation. Our findings suggest that SMe1EC2 promotes an improved recovery of the left ventricular function following ischemia compared to either stobadine or SMe1. However, both SMe1EC2 and SMe1 manifested a significant anti-dysrhythmic effect comparable with that of stobadine and partially reduced myocardial ischemia-reperfusion-induced injury.     

Detrimental or beneficial: the role of TRPM2 in ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is the main cause of tissue damage and dysfunction. I/R injury is characterized by Ca²⁺ overload and production of reactive oxygen species (ROS), which play critical roles in the process of I/R injury to the brain, heart and kidney, but the underlying mechanisms are largely elusive. Recent evidence demonstrates that TRPM2, a Ca²⁺-permeable cationic channel and ROS sensor, is involved in I/R injury, but whether TRPM2 plays a protective or detrimental role in this process remains controversial. In this review, we discuss the recent progress in understanding the role of TRPM2 in reperfusion process after brain, heart and kidney ischemia and the potential of targeting TRPM2 for the development of therapeutic drugs to treat I/R injury.     

KB-R7943对大鼠离体心脏缺血/再灌注的后适应保护作用

目的研究钠钙交换抑制剂KB-R7943对大鼠离体心脏缺血/再灌注损伤的后适应保护作用,探索给药的最佳时机。方法大鼠麻醉后,取心脏,置Langendorff灌流装置上以台氏液灌流,结扎冠状动脉左前降支制备大鼠离体心脏缺血(30min)/再灌注(120min)模型,监测心功能,测定心肌梗死面积。结果KB-R79431μmol·L-1于再灌注开始前1min至再灌注14min给药可改善心功能各项指标,心肌梗死面积较对照组缩小约77%(P<0·01),与钠氢交换抑制剂cariporide 1μmol·L-1及其与KB-R7943联合于再灌注早期给药产生的心肌保护作用差异无显著性。同浓度KB-R7943于再灌注全程灌流也具有一定的心肌保护作用,再灌注后期给药则对心肌缺血/再灌注损伤无保护作用。结论KB-R7943对大鼠离体心脏缺血/再灌注损伤具有药理性后适应保护作用,最佳给药时机为再灌注早期用药。