西洛他唑对小鼠慢性缺血性脑损伤的保护作用及机制

目的：观察西洛他唑对小鼠慢性缺血性脑损伤的保护作用,探讨其与促血管生成的关系。方法：以大脑中动脉栓塞方法诱导小鼠局灶性脑缺血,缺血后1、4、7h和术后1～14d腹腔注射西洛他唑（10mg／kg）,每天一次,观察缺血后35d西洛他唑对神经症状评分、斜板角度、脑梗死体积、神经元密度和缺血侧血管内皮生长因子（VEGF）、血管内皮生长因子受体2（Flk-1）表达的作用。结果：西洛他唑能降低缺血后神经症状评分,提高斜板角度,减少脑梗死体积,增加存活神经元密度和VEGF、Flk-1表达的数目。结论：西洛他唑对小鼠慢性局灶性脑缺血具有保护作用,其作用机制可能与诱导缺血侧VEGF、Flk-1表达,促进血管生成有关。     

西洛他唑对小鼠局灶性持续脑缺血的保护作用

目的:观察磷酸二酯酶3抑制剂西洛他唑对小鼠持续性局灶性脑缺血的保护作用,探讨其有效剂量和治疗时间窗。方法:以大脑中动脉阻塞诱导小鼠持续性局灶性脑缺血。缺血前30 min腹腔注射不同剂量的西洛他唑(0．3～30 mg·kg~(-1)),以普鲁司特(0．1 mg·kg~(-1))作为阳性对照;观察药物对缺血后神经功能缺损症状、脑梗死体积、两侧大脑半球比值、IgG渗出的影响。在另一批小鼠,分别在缺血后1,2和3 h腹腔注射西洛他唑10 mg·kg~(-1),观察药物对上述指标(除IgG渗出)的影响。结果:缺血前30 min注射西洛他唑3,10 mg·kg~(-1)及普鲁司特,均能减轻缺血后24 h的神经症状、减小脑梗死体积、减轻脑水肿和IgG的渗出;缺血1和2 h内给予西洛他唑10 mg·kg~(-1),对上述指标有显著抑制作用。结论:西洛他唑对急性脑缺血损伤有保护作用,其有效剂量为3～10 mg·kg~(-1),治疗时间窗为缺血后2 h。     

前胡甲素对小鼠局灶性脑缺血的保护作用

目的观察前胡甲素(Pd-Ia)对小鼠局灶性脑缺血损伤的保护作用及特点。方法线栓法制备小鼠大脑中动脉栓塞脑缺血损伤模型。Pd-Ia(1,5,10mg/kg)在缺血前0.5h腹腔给药1次;或在缺血前1,0.5h、缺血同时、再灌注同时、再灌后0.5h及再灌后1h各腹腔给予Pd-Ia5mg/kg。脑缺血1.5h,再灌注24h后,测定小鼠神经功能缺失评分、脑梗死体积、脑水肿等评定脑缺血损伤的指标;测定血清中丙二醛(MDA)和超氧化物岐化酶(SOD)的活性。结果Pd-Ia(5,10mg/kg)缺血前0.5h给药及Pd-Ia5mg/kg缺血前0.5h、缺血同时、再灌注同时及再灌后0.5h给药可明显改善小鼠神经功能损伤,减小脑梗死体积和减轻脑水肿程度,且以再灌注同时单次给药效果最为显著;Pd-Ia(5,10mg/kg)能够明显提高脑缺血损伤小鼠血清中SOD活性,降低MDA含量。结论Pd-Ia保护小鼠局灶性脑缺血急性损伤,最佳剂量为5mg/kg,最佳治疗时间点为再灌注同时;其保护脑缺血损伤的机制可能与抑制脂质过氧化、提高氧化酶的活性有关。     

归芪饮对小鼠急性脑缺血的保护作用

目的探讨临床有效中药方剂归芪饮对小鼠急性脑缺血损伤的保护作用.方法用线栓法阻塞小鼠大脑中动脉诱导持续性局灶性脑缺血.术前分别给小鼠口服不同剂量的归芪饮7d,观察药物对脑缺血引起的神经功能缺损症状、脑梗死发生率、脑梗死体积、脑水肿面积、神经元密度及白蛋白渗出的影响.此外,小鼠口服不同剂量的归芪饮7d后,观察对离体脑片缺氧缺糖造成损伤的保护作用.结果归芪饮5～60g/kg及尼莫地平2mg/kg可不同程度减轻神经功能缺失症、减少梗死发生率、减小梗死体积、减小水肿面积、减少神经元损伤、降低血管通透性.其中15g/kg归芪饮的作用更为显著.口服5,15g/kg归芪饮对小鼠离体脑片缺氧缺糖损伤有显著的保护作用.结论归芪饮对小鼠急性脑缺血损伤有确定的保护作用.     

小鼠局灶性脑缺血梗死灶的定量分析

目的:用小鼠持续性局灶性脑缺血模型,证明新建的透光法测定局灶性脑缺血梗死灶的实用性。方法:采用大脑中动脉阻塞法(MCAO)造成小鼠持续性局灶性脑缺血,于缺血后2 4h进行Bederson’s症状评分和爬板、悬挂试验,并以计算机图像分析技术测定和分析脑缺血梗死体积、脑半球面积、皮层及皮层下神经元密度;在大脑中动脉线栓手术前3d和术前1h分别腹腔注射Pranlukast 0 .1mg·kg-1或尼莫地平0 .4mg·kg-1,观察药物的神经保护作用。结果:透光测定的梗死体积与TTC染色测定的梗死体积、神经元密度密切相关,与神经症状综合评分具有等级相关。Pranlukast和尼莫地平能减少脑梗死体积和脑半球的缺血侧 非缺血侧比值,减轻神经症状和神经元死亡。结论:透光法结合神经症状综合评分法可用于小鼠局灶性脑缺血的定量分析和药物的神经保护作用评价。     

归芪饮对小鼠急性脑缺血的保护作用

目的　探讨临床有效中药方剂归芪饮对小鼠急性脑缺血损伤的保护作用。方法　用线栓法阻塞小鼠大脑中动脉诱导持续性局灶性脑缺血。术前分别给小鼠口服不同剂量的归芪饮7d ,观察药物对脑缺血引起的神经功能缺损症状、脑梗死发生率、脑梗死体积、脑水肿面积、神经元密度及白蛋白渗出的影响。此外,小鼠口服不同剂量的归芪饮7d后,观察对离体脑片缺氧缺糖造成损伤的保护作用。结果　归芪饮5～60g/kg及尼莫地平2mg/kg可不同程度减轻神经功能缺失症、减少梗死发生率、减小梗死体积、减小水肿面积、减少神经元损伤、降低血管通透性。其中15g/kg归芪饮的作用更为显著。口服5 ,15g/kg归芪饮对小鼠离体脑片缺氧缺糖损伤有显著的保护作用。结论　归芪饮对小鼠急性脑缺血损伤有确定的保护作用。     

黄连解毒汤对小鼠脑缺血慢性神经损伤的保护作用

目的：观察黄连解毒汤对小鼠脑缺血慢性神经损伤的保护作用。方法：以大脑中动脉阻塞（MCAO）15min诱导小鼠短暂性局灶性脑缺血。从术前7d开始，用药组灌服黄连解毒汤2g/kg和4g/kg，实验对照组和假手术组灌服生理盐水，均连续给药21d，1次／d。缺血后35d（5周）内进行神经症状评分、斜板试验，并计录小鼠的逐日生存率。实验结束后，测定脑损伤体积和神经元数量。     

氨基胍对大鼠局灶性缺血—再灌流后脑内MPO活性的影响

目的：探讨大鼠局灶性脑缺血后脑组织MPO活性变化规律、与脑缺血－再灌流损伤的关系以及氨基胍（AG）对其影响。方法：用线栓法制备大鼠脑中动脉缺血－再灌流模型，检测缺血3小时后再灌流不同时点脑组织中MPO活性、脑梗死体积及光镜病理学变化。结果：缺血组脑组织有MPO活性升高、中性粒细胞浸润，以再充后48、72小时最为明显，脑梗死体积、神经元变性程度随再灌流时间延长而加重，AG可以明显减轻缺血再灌流12小时后的脑组织中MPO活性、神经元变化，降低脑梗死体积，减轻脑损伤。结论：局灶性缺血脑组织中MPO活性与缺血－再灌流损伤间具有一定的关系，炎症反应是加重脑组织损伤的重要因素，AG可以减轻缺血区炎症反应，具有脑保护作用。     

半胱氨酰白三烯受体拮抗剂pranlukast对小鼠局灶性脑缺血的治疗作用

目的　观察半胱氨酰白三烯受体拮抗剂pranlukast(ONO 10 78)在小鼠局灶性脑缺血后的治疗作用。方法　采用大脑中动脉阻塞造成小鼠持续性局灶性脑缺血 ,缺血后1、6、2 4h分别给小鼠腹腔注射 pranlukast或依达拉奉 ,观察药物对缺血 2 4、4 8h后的神经功能缺损症状 ,4 8h后的脑梗死体积、两侧大脑半球比值、神经元密度的影响。结果　Pranlukast 0 1、0 2mg·kg-1及依达拉奉 3、10mg·kg-1均能减轻神经症状、减小脑梗死体积、降低缺血侧 /非缺血侧大脑半球比值、减轻海马CA1区、皮层和纹状体的神经元密度降低。结论　Pranlukast脑缺血后给药对脑损伤有治疗作用 ,提示有治疗缺血性脑卒中的临床前景。     

阿托伐他汀对局灶性脑缺血大鼠脑组织超氧化物歧化酶的影响

目的：探讨阿托伐他汀对局灶性脑缺血大鼠脑组织超氧化物歧化酶（SOD）活性的影响。方法选用健康Sprague-Dawley（SD）大鼠,随机分为阿托伐他汀预处理组、单纯缺血组和假手术组。阿托伐他汀预处理组于术前15 d灌胃阿托伐他汀,6 mg/（kg·d）,然后制备大鼠局灶性脑缺血模型,缺血后24 h行神经行为学评分、化学比色法测定脑组织匀浆中SOD活性。结果与假手术组比较,局灶性脑缺血24 h,脑组织SOD活性明显下降（P〈0.05）。与单纯缺血组比较,阿托伐他汀预处理组明显降低神经行为学评分（P〈0.05）,提高脑组织匀浆SOD活性（P〈0.05）。结论阿托伐他汀可以改善局灶性脑缺血大鼠神经行为学评分,提高脑组织SOD活性,增强氧自由基清除作用,具有神经保护作用。     

Pranlukast, a cysteinyl leukotriene receptor 1 antagonist, protects mice against brain cold injury

We have reported the neuroprotective effect of cysteinyl leukotriene receptor 1 (CysLT1) antagonists on cerebral ischemia. Here, we further determined the protective effect of pranlukast, a CysLT1 receptor antagonist, on brain cold injury in mice. Brains were injured by placing a cooled metal probe on the skull surface for 30 s. We found that pranlukast significantly reduced cold-induced lesion volume (0.3 mg/kg) and the percentage increase in lesioned hemisphere volume (0.03-0.3 mg/kg) 24 h after injury, but did not show any effect 72 h after injury. Pranlukast also significantly inhibited neuron loss 24 h (0.1 mg/kg) and 72 h (0.1-0.3 mg/kg) after injury, and decreased the density of degenerated neurons 24 h (0.01-0.3 mg/kg) and 72 h (0.03-0.3 mg/kg) after injury. In addition, pranlukast (0.1-0.3 mg/kg) significantly reduced endogenous IgG exudation both 24 h and 72 h after injury. Thus, this study indicates the protective effect of pranlukast on brain cold injury.     

Pranlukast reduces neutrophil but not macrophage/microglial accumulation in brain after focal cerebral ischemia in mice

AIM: To determine whether pranlukast, a cysteinyl leukotriene receptor-1 antagonist, exerts an anti-inflammatory effect on focal cerebral ischemia in mice. METHODS: Focal cerebral ischemia in mice was induced by permanent middle cerebral artery occlusion (MCAO). In addition to neurological deficits, infarct volume, degenerated neurons and endogenous IgG exudation, we detected accumulation of neutrophils and macrophage/microglia in the ischemic brain tissue 72 h after MCAO. Pranlukast was ip injected 30 min before and after MCAO. RESULTS: Pranlukast significantly attenuated neurological deficits, infarct volume, neuron degeneration and IgG exudation. Importantly, pranlukast (0.01 and 0.1 mg/kg) inhibited myeloperoxidase-positive neutrophil, but not CD11b-positive macrophage/microglial accumulation in the ischemic cortical tissue. CONCLUSION: Pranlukast exerts an anti-inflammatory effect on focal cerebral ischemia in the subacute phase that is limited to neutrophil recruitment through the disrupted blood-brain barrier.     

白三烯受体拮抗剂ONO—1078对大鼠局灶性脑缺血的神经保护作用

AIM: To determine whether ONO-1078 (pranlukast), a potent leukotriene receptor antagonist, has neuroprotective effect on focal cerebral ischemia in the rat. METHODS: Focal cerebral ischemia was induced by 30 min of middle cerebral artery (MCA) occlusion and followed by 24 h reperfusion. ONO-1078 (0.003-1.0 mg/kg) or vehicle (saline 1 mL/kg) was ip injected 30 min before MCA occlusion and 2 h after reperfusion. The neurological score, infarct volume, neuron density (in cortex, hippocampus, and striatum), brain edema, and albumin exudation around the vessels were determined 24 h after reperfusion. RESULTS: ONO-1078 slightly improved the neurological deficiency, and dramatically decreased infarct volume and neuron loss which showed a bell shaped dose response effect with highest effect at doses of 0.01-0.3 mg/kg. Enlargement of the ischemic hemisphere and albumin exudation were inhibited at doses of 0.01-1.0 mg/kg. CONCLUSION: ONO-1078 has the protective effect on focal cerebral ischemia in rats, which is partially attributed to the inhibition of brain edema. This may represent a novel approach to the treatment of acute cerebral ischemia with cysteinyl leukotriene receptor antagonists.     

Montelukast, a cysteinyl leukotriene receptor-1 antagonist, dose- and time-dependently protects against focal cerebral ischemia in mice

Our previous studies showed that cysteinyl leukotriene receptor-1 (CysLT1) antagonist pranlukast has a neuroprotective effect on cerebral ischemia in rats and mice. However, whether the neuroprotective effect of pranlukast is its special action or a common action of CysLT1 receptor antagonists remains to be clarified. This study was performed to determine whether montelukast, another CysLT1 receptor antagonist, has the neuroprotective effect on focal cerebral ischemia in mice, and to observe its dose- and time-dependent properties. Permanent focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO). Montelukast was injected intraperitoneally either as multiple doses (once a day for 3 days and 30 min before MCAO) or as a single dose (at 30 min before, 30 min after, or 1 h after MCAO), respectively, and pranlukast and edaravone were used as controls. The neurological deficits, infarct volumes, brain edema, neuron density, and Evans blue extravasation in the brain were determined 24 h after MCAO. Pretreatments with multiple doses or a single dose of montelukast (0.1 and 1.0 mg/kg) before MCAO significantly attenuated all the ischemic insults. Post-treatment with a single dose of montelukast (0.1 and 1.0 mg/kg) at 30 min after MCAO also significantly decreased brain edema and infarct volume, but not neurological deficits. However, post-treatment with a single dose of montelukast at 1 h after MCAO had no significant effect. Pranlukast showed the same effects as montelukast, but edaravone attenuated the ischemic insults only with multiple doses before MCAO. Thus, montelukast has a dose- and time-dependent neuroprotective effect on permanent focal cerebral ischemia in mice, with an effective dose range of 0.1-1.0 mg/kg and a therapeutic window of 30 min. These findings further support the therapeutic potential of CysLT1 receptor antagonists in the treatment of cerebral ischemia at earlier phases.     

Pranlukast dose-and time-dependently protects against ischemic neuronal damage in the rat hippocampus

Objective Our previous studies showed that the neuroprotective effect of pranlukast,a cysteinyl leukotriene receptor-1(CysLT1)antagonist,on global cerebral ischemia in rats.This study was performed to evaluate dose-and time-dependent properties of pranlukast on CA1 neuron loss following transient global ischemia in rats.Methods Brain injury was induced by an improved four-vessel occlusion(4-VO)in rats.pranlukast(0.03-0.30 mg·kg-1)was injected intraperitoneally either as multiple doses(before or after ischemia)or as a single dose(30 min before ischemia),respectively.Physiological variables were monitored and neuron count was measured by computer-assisted imaging.Results The 4-VO model produced continuing postischemic neuronal death in CA1 region.Administration of pranlukast(0.1 and 0.3 mg·kg-1,30 min before ischemia and 1,24,48 and 72 h after ischemia)markedly reduced CA1 death.Treatment with a single dose of pranlukast(0.1 mg·kg-1,30 min before ischemia)also resulted in a significant increase in the number of healthy CA1 neurons at 3 days.Of interest is the finding that pranlukast(0.1 mg·kg-1)rescued CA1 neurons from ischemic death even when treatment was delayed until 30 min or 1 h after ischemia.Conclusions The present study confirms pranlukast has a dose-and time-dependent cerebroprotective effects on CA1 neuron loss following transient global ischemia in rats,with an effective dose range of 0.1-0.3 mg·kg-1 and a therapeutic window of 1 h.These findings further support the therapeutic potential of CysLT1 receptor antagonists in the treatment of global cerebral ischemia.     

Cilostazol, a phosphodiesterase 3 inhibitor, protects mice against acute and late ischemic brain injuries

Cilostazol, a selective inhibitor of phosphodiesterase 3, exerts neuroprotective effects on acute brain injury after cerebral ischemia in rats. However, it is unknown whether cilostazol affects the subacute or chronic ischemic injury. In the present study, we evaluated the dose- and time-dependent effects of cilostazol on acute ischemic brain injury and the long-lasting effect on the late (subacute/chronic) injury in mice with focal cerebral ischemia induced by transient middle cerebral artery occlusion. We found that pre-treatment of cilostazol (injected i.p. at 30 min before ischemia) significantly ameliorated the acute injury 24 h after ischemia, and the effective doses were 3-10 mg/kg. The post-treatment of cilostazol (10 mg/kg) was effective on the acute injury when it was injected 1 and 2 h after ischemia. In addition, for the late injury, post-treatment of cilostazol (10 mg/kg, i.p., for 7 consecutive days after ischemia) attenuated neurological dysfunctions, brain atrophy and infarct volume. It also inhibited astrocyte proliferation/glial scar formation and accelerated the angiogenesis in the ischemic boundary zone 7 and 28 days after ischemia. Thus, we conclude that cilostazol protects against not only the acute injury, but also the late injury in mice with focal cerebral ischemia; especially it can modify brain remodeling, astrogliosis and angiogenesis.     

Montelukast, a cysteinyl leukotriene receptor-1 antagonist, attenuates chronic brain injury after focal cerebral ischaemia in mice and rats

Objectives Previously we demonstrated the neuroprotective effect of montelukast, a cysteinyl leukotriene receptor‐1 (CysLT₁) antagonist, on acute brain injury after focal cerebral ischaemia in mice. In this study, we have determined its effect on chronic brain injury after focal cerebral ischaemia in mice and rats. Methods After transient focal cerebral ischaemia was induced by middle cerebral artery occlusion, montelukast was intraperitoneally injected in mice or orally administered to rats for five days. Behavioural dysfunction, brain infarct volume, brain atrophy and neuron loss were determined to evaluate brain lesions. Key findings Montelukast (0.1 mg/kg) attenuated behavioural dysfunction, brain infarct volume, brain atrophy and neuron loss in mice, which was similar to pranlukast, another CysLT₁ receptor antagonist. Oral montelukast (0.5 mg/kg) was effective in rats and was more effective than edaravone, a free radical scavenger. Conclusion Montelukast protected mice and rats against chronic brain injury after focal cerebral ischaemia, supporting the therapeutic potential of CysLT₁ receptor antagonists.     

Enalapril and moexipril protect from free radical-induced neuronal damage in vitro and reduce ischemic brain injury in mice and rats.

Angiotensin-converting enzyme inhibitors have been demonstrated to protect spontaneously hypertensive rats from cerebral ischemia. The present study investigated the protective effect of enalapril and moexipril in models of permanent focal cerebral ischemia in normotensive mice and rats. To elucidate the mechanism of neuroprotection the influence of these angiotensin-converting enzyme inhibitors on glutamate-, staurosporine- or Fe2+/3+-induced generation of reactive oxygen species and neuronal cell death in primary cultures from chick embryo telencephalons was studied. Treatment with moexipril or enalapril dose-dependently reduced the percentage of damaged neurons, as well as mitochondrial reactive oxygen species generation induced by glutamate, staurosporine or Fe2+/3+. Furthermore, moexipril and enalapril attenuated staurosporine-induced neuronal apoptosis as determined by nuclear staining with Hoechst 33258. In mice, 1 h pretreatment with enalapril (0.03 mg/kg) or moexipril (0.3 mg/kg) significantly reduced brain damage after focal ischemia as compared to control animals. Additionally, moexipril (0.01 mg/kg) was able to reduce the infarct volume in the rat model after focal cerebral ischemia. The results of the present study indicate that the angiotensin-converting enzyme inhibitors enalapril and moexipril promote neuronal survival due to radical scavenging properties.     

白三烯拮抗剂ONO-1078对小鼠局灶性脑缺血的保护作用

AIM　To determine whether ONO-1078 {pranlukast, 4-oxo-8-［p-(4-phenylbutyloxy) benzoyl-amino]-2-(tetrazol-5-yl)-4H-1-benzopyran hemihydrate}, a potent leukotriene antagonist, has protective effect on focal cerebral ischemia in mice. METHODS　Focal cerebral ischemia was induced by permanent middle cerebral artery (MCA) occlusion in mice. ONO-1078 (0.01, 0.05, 0.10 mg·kg^-1), dexamethasone (0.5 mg·kg^-1), nimodipine (0.2 mg·kg^-1) or saline (control) were injected ip once daily for 3 days, and 30 min before MCA occlusion. Twenty-four hours after cerebral ischemia, the neurological scores were evaluated, infarct volumes and areas of the right and left cerebral hemispheres were measured by computer imaging analysis. RESULTS　ONO-1078, dexamethasone and nimodipine reduced the neurological scores. ONO-1078 and dexamethasone reduced the ratio of right/left hemisphere area, indicating inhibition of brain edema, while nimodipine showed no effect. ONO-1078 dose-dependently reduced infarct size, and dexamethasone and nimodipine showed the same effect. CONCLUSION　ONO-1078 showed protective effect on focal cerebral ischemia. This may represent a novel approach to the treatment of acute cerebral ischemia.