巴曲酶对沙土鼠海马CA1区的神经元保护作用的量效、时效及可能机制的探讨

目的 探讨巴曲酶对沙土鼠前脑缺血再灌注海马CA1区神经元保护作用的可能机制及量效时效关系.方法 成年雄性蒙古沙土鼠170只,随机分成巴曲酶组132只、对照组及假手术组各19只.巴曲酶组又分为A组60只包括巴曲酶1～32BU/kg各剂量组,对照组及假手术组各10只,行TUNEL染色;B组72只分别为缺血再灌注后0～72h各时间点组,每时间点组9只,对照组及假手术组各9只,其中6只分别采用TUNEL染色检测海马CA1区的凋亡细胞及SP法检测海马CA1区的Bc1-2、eNOS、VEGF及Akt蛋白的表达,3只行电镜下神经元超微结构的观察.光镜下用带刻度目镜计算沙土鼠海马CA1区的神经元阳性细胞数.结果 巴曲酶8BU/kg以上剂量组细胞凋亡率明显减少,与对照组、4BU/kg以下剂量组有显著差异(P＜0.01),8BU/kg以上剂量组之间无统计学意义(P＞0.05).不同时间点海马CA1区TUNEL阳性细胞数比较0h、1h、3h、6h、12h及24h亚组与对照组之间存在极显著性差异(P＜0.01).使用巴曲酶后,Bcl-2、eNOS、VEGF及Akt蛋白表达明显增加,神经元阳性细胞数在巴曲酶各时间点与对照组比较差异有统计学意义(P＜0.01),超微结构显示0～24h时间点较48h及72h时间点抗细胞凋亡明显.结论 巴曲酶具有明显的脑保护作用,其机制可能是通过上调Bcl-2、eNOS、VEGF及Akt蛋白表达来达到脑保护作用的.巴曲酶的脑保护作用具有量效性及时效性,其最佳剂量为8BU/kg,72h内使用巴曲酶皆具有脑保护作用,尤以24h前使用效果明显.     

巴曲酶用药次数对脑缺血再灌注沙土鼠脑保护作用的影响

目的 研究巴曲酶用药次数对脑缺血再灌注(IR)沙土鼠脑保护作用的影响.方法 沙土鼠45只,随机分为IR模型组、正常组、巴曲酶3次用药组(3次组)、5次用药组(5次组)和7次用药组(7次组).采用双侧颈总动脉夹闭5 min后再通建立沙土鼠脑IR损伤模型.3次组、5次组、7次组均在造模成功后腹腔注射巴曲酶(8 BU/kg),隔日1次,分别给药3次、5次、7次;IR模型组和正常组腹腔注射等量的生理盐水,共7次.用流式细胞仪检测各组沙土鼠海马区凋亡细胞数,电镜观察海马CA1区细胞形态.结果 巴曲酶3次组、5次组和7次组海马区凋亡细胞数显著少于IR组(均P＜0.05);5次组海马区凋亡细胞数明显少于3次组(P＜0.05),而5次组与7次组之间差异无统计学意义(P＞0.05);正常组仅有极少凋亡细胞.5次组细胞超微结构改变要轻于3次组,与7次组相比无明显差异.结论 巴曲酶3次、5次和7次用药均可减少脑IR后神经元的凋亡;但5次和7次用药的脑保护作用明显好于3次用药.     

巴曲酶对沙土鼠海马CA1区神经元保护作用及其机制的研究

目的探讨巴曲酶对沙土鼠前脑缺血再灌注神经元保护作用的可能机制及时效关系。方法实验动物随机分为10组,分别为缺血再灌注后0h、1h、3h、6h、12h、24h、48h和72h组、假手术组及对照组,各个时间点分别给予腹腔注射巴曲酶8BU／kg,采用免疫组化SP法检测海马CA1区的Bcl-2、eNOS、VEGF及Akt蛋白的表达,光镜下计算沙土鼠海马CA1区的神经元阳性细胞数。并行电镜下神经元超微结构的观察。结果使用巴曲酶后,Bcl- 2、eNOS、VEGF及Akt蛋白表达明显增加,神经元阳性细胞数在巴曲酶各时间点与对照组比较差异有显著性(P< 0．01),而巴曲酶0h-24h时间点之间比较差异无统汁学意义(P>0．05);Bcl-2、eNOS及VEGF神经元阳性细胞数在0h-24h时间点与48h-72h时间点比较差异有统计学意义(P<0．05);超微结构显示0h-24h时间点较48h及 72h时间点抗细胞凋亡明显。结论巴曲酶脑保护作用的机制可能是通过上调Bcl-2、eNOS、VEGF及Akt蛋白的表达;72h内使用巴曲酶具有神经元保护作用,但在0h-24h时间点使用较48h及72h时间点保护作用更为明显。     

巴曲酶对沙土鼠前脑缺血后组织病理学的影响

目的:研究巴曲酶对沙土鼠前脑缺血后行为学和组织病理学的影响。方法:采用沙土鼠前脑缺血模型,缺血时间10min。动物随机分为3组:假手术组、常温再灌注组、巴曲酶再灌注组,(n=7)。巴曲酶8B~U·kg~(-1)在再灌注30min经腹腔注入。动物存活第5天时行开阔法行为学检查,第7天时行海马CA1区组织病理学检查。结果:开阔法行为学检查显示,常温再灌注组沙土鼠的探索活动较假手术组活跃(P＜0.01)。巴曲酶组沙土鼠的探索活动较常温再灌注组弱(P＜0.05),但较假手术组活跃(P＜0.05)。组织病理学检查显示,巴曲酶组海马CA1区内侧、中间和外则存活神经元计数较常温再灌注组多620%、470%和200%(P均＜0.01),较假手术组少64%(P＜0.01)、43%(P＜0.05)和30%。结论:沙土鼠前脑缺血后应用巴曲酶治疗,能够减轻动物神经功能障碍,减少海马CA1神经坏死。     

牛磺酸对沙土鼠短暂性前脑缺血作用研究

目的 观察牛磺酸对沙土鼠短暂性前脑缺血的保护作用。方法 结扎沙土鼠双侧颈动脉建立前脑缺血模型,缺血5 min后进行再灌注。在缺血1 h后经静脉给予2.5 mg/kg、5 mg/kg、15 mg/kg及50 mg/kg牛磺酸。再灌注7 d时,对沙土鼠的神经功能行为缺损进行评分,并留取全脑,观察海马CA1区锥体细胞的死亡情况。结果 2.5 mg/kg牛磺酸虽然改善前脑缺血5 min再灌注7 d时沙土鼠的行为,降低海马CA1区锥体细胞的死亡,但与缺血对照组相比,无统计学意义,5 mg/kg、15 mg/kg及50 mg/kg牛磺酸可明显改善前脑缺血沙土鼠的行为缺损（P分别为0.001、0.006和0.037）,降低海马CA1区锥体细胞的死亡（P均＜0.001）,其中,5 mg/kg、15 mg/kg和50 mg/kg牛磺酸组的锥体细胞的死亡低于2.5 mg/kg牛磺酸组（P分别为0.001、0.001和0.005）。结论 牛磺酸能以剂量依赖方式降低沙土鼠前脑缺血损伤,提示牛磺酸可能是一种有效的短暂性缺血的大脑保护剂。     

巴曲酶对围产期缺氧缺血性脑损伤神经保护作用的研究

目的　制备宫内缺氧缺血性脑损伤 (HIBD)动物模型 ,应用巴曲酶研究其对 HIBD的神经保护作用。方法　宫内窒息 2 0 min为实验组 ,并设立正常对照组 ,实验组随机分为两组 ,1组于生后 3 0 min、2 4h、48h各给予腹腔注射巴曲酶 (8BU/ kg) 1次 ,共 3次 (巴曲酶干预组 ) ,另 1组 (缺氧缺血组 )及正常对照组于相同时间给予腹腔注射等量生理盐水。3组仔鼠生后 72 h、7d、14 d、2 1d断头处死 ,测量脑组织含水量及重量 ,并应用 TU NEL法观察凋亡细胞数。结果　缺氧缺血组 72 h脑含水量明显高于巴曲酶干预组及正常对照组 (P<0 .0 5) ,其余时间点 3组脑含水量无差异。缺氧缺血组 72 h脑重量高于巴曲酶干预组及正常对照组 (P<0 .0 5) ,14 d、2 1d脑重量显著低于巴曲酶干预组及正常对照组 (P<0 .0 5) ;巴曲酶干预组脑重量 14 d、2 1d低于正常对照组 ,差异显著 (P<0 .0 5)。缺氧缺血组72 h～ 14 d各时间点阳性细胞数显著高于巴曲酶干预组及正常对照组 (P<0 .0 5) ,2 1d 3组阳性细胞数无显著差异 ;巴曲酶干预组 72 h～ 7d凋亡细胞数高于正常对照组 (P<0 .0 5) ,14 d降至正常 ;正常对照组各时间点偶见阳性细胞。结论　巴曲酶可明显减轻 HIBD急性期脑水肿及恢复期脑萎缩 ,抑制 HIBD神经细胞凋亡 ,具有神经保护作用     

不同剂量巴曲酶对大鼠局灶性脑缺血再灌流后细胞凋亡的影响

目的　探讨不同剂量巴曲酶对大鼠局灶脑缺血再灌流的保护作用。方法　采用线栓法制备大脑中动脉缺血再灌流模型。利用流式细胞仪检测细胞凋亡。结果　与对照组相比，巴曲酶组DNA断裂百分率明显降低(P<0.01)，随着用药剂量增加DNA断裂百分率呈下降趋势。结论　巴曲酶对脑缺血有保护作用，其保护作用与剂量有关。     

吗啡预处理与脑缺血再灌注损伤后细胞凋亡：抑制效应的途径？

[摘要] 背景：大量研究已经证明凋亡是脑缺血再灌注损伤后神经元损伤的重要形式,且这一过程可以人为干预以改善预后。药物预处理对缺血再灌注损伤后神经元凋亡的影响是脑缺血研究的热点。吗啡是临床常用药,几项研究显示其对某种形式的脑损伤有保护作用,但吗啡预处理对脑缺血再灌注损伤后神经元凋亡的影响尚未见报道。 目的: 探讨吗啡预处理对大鼠全脑缺血再灌注损伤后神经元凋亡及相关基因表达的影响。 设计、时间及地点：2008年6月-2009年8月在青岛大学医学院脑血管病研究所完成分子生物学水平的随机对照实验。 材料：神经元凋亡及免疫组化检测试剂盒均由武汉博士德公司提供 方法: 健康雄性成年Wistar大鼠72只,随机分成4组：假手术组;脑缺血/再灌注组;吗啡预处理1mg/kg组;吗啡预处理7mg/kg组,18只/组。依再灌注时间不同,各组又分为再灌注1d、3d、7d 三个亚组,6只/亚组。以Pusinelli方法为标准建立四动脉阻断法全脑缺血模型,假手术组仅暴露第一颈椎双侧翼孔和双侧颈总动脉而不烧灼,不夹闭动脉;脑缺血组缺血前60min腹腔注射生理盐水2mg/kg;吗啡预处理1mg/kg组及吗啡预处理7mg/kg组分别在脑缺血前60min腹腔内注射吗啡1mg/kg及7mg/kg。在脑缺血8分钟后恢复血流,再灌注1d、3d、7d后断头取脑制作石蜡切片。 主要观察指标： HE染色观察海马CA1区组织病理学改变,TUNEL法检测海马CA1区神经元凋亡,免疫组化检测海马CA1区Casepase-3蛋白表达。 结果：HE染色：假手术组海马CA1区神经元结构正常;脑缺血组则出现大量的肿胀、核固缩及胞浆空泡样变异常细胞并神经元数量显著减少;吗啡预处理组细胞肿胀、核皱缩及细胞缺失的病理学改变显著轻于脑缺血再灌注组。凋亡细胞计数：与假手术组比较,缺血组和吗啡预处理组海马CA1区神经元凋亡数明显增加(P<0.01) ;与缺血再灌注组比较, 吗啡预处理组神经元的凋亡数明显减少(P<0.01);与吗啡预处理1mg/kg组比较,吗啡预处理7mg/kg组神经元凋亡数显著降低(P< 0.05 或P< 0.01)。Casepase-3蛋白表达：缺血组和吗啡预处理组Casepase-3表达明显高于假手术组(P<0.01);吗啡预处理组Casepase-3表达显著低于缺血再灌注组(P<0.01);吗啡预处理7mg/kg组Casepase-3表达明显低于吗啡预处理1mg/kg组(P< 0.05 )。应用吗啡后,在1d、3d、7d三个时点,神经元凋亡的减少趋势与Casepase-3降低的趋势一致。 结论： 吗啡预处理可减轻缺血性脑损伤,提高脑缺血耐受性,且大剂量吗啡效果优于小剂量;吗啡抗凋亡作用机制与Casepase-3密切有关。     

脑缺血再灌注后ICE、Bcl-2的表达及丹参的神经保护作用研究

目的观察凋亡相关基因白介素-lβ转化酶(ICE)、Bcl-2在脑缺血后的表达情况以及丹参(RSM)对其影响。方法健康沙土鼠63只,随机分成三组假手术组、对照组和丹参组。采用沙土鼠前脑缺血再灌注模型,在沙土鼠脑缺血再灌注后的2h、6h、12h、1d、3d、5d及7d分别处死沙土鼠,将脑组织进行免疫组织化学染色观察。结果ICE的蛋白表达主要在海马CA1区、CA4区及皮质,免疫阳性细胞呈褐色,第3天达高峰,第5天后减少;丹参组ICE的蛋白表达明显减少(P＜0.01)。Bcl～2的蛋白表达主要在大脑皮层、纹状体、丘脑及海马等广泛区域,并于6h达高峰,其后减少;丹参组Bcl-2的蛋白表达明显增加,特别是在海马CA1区及大脑皮层区(P＜0.01)。结论ICE在调节脑缺血中可能发挥重要作用;Bcl-2主要通过抑制细胞凋亡的早期环节而发挥作用;丹参能下调脑缺血后的ICE表达、上调脑缺血后的Bcl-2表达进而发挥其神经保护作用。     

巴曲酶对NJS小鼠短暂性脑缺血发作后神经细胞的保护和改善认知功能的作用

目的 观察巴曲酶对小鼠短暂性脑缺血发作（TIA）后神经细胞的保护和改善认知功能的作用。方法 选择自发性高胆固醇血症小鼠56只，分为对照组（缺血发作但未用药），缺血前2小时用药组，缺血后2小时用药组，缺血后24小时用药组。缺血后72小时测定各组小鼠的认知行为学指标和海马CA1区神经元凋亡数。结果 缺血前2小时用药组和缺血后2小时用药组神经元凋亡数较对照组少，认知功能恢复好于对照组，缺血后24小时用药组各指标与对照组相比无统计学差异。结论 巴曲酶对小鼠TIA后神经元有保护作用和促进认知功能恢复，但应早期用药。     

巴曲酶对大鼠脑缺血再灌流损伤保护作用机理的研究

为探讨巴曲酶对大鼠短暂性脑缺血再灌流损伤引起的细胞凋亡有无抑制作用，参照Ｓｍｉｔｈ等（１９８４）方法，制备大鼠前脑短暂性缺血再灌流模型，采用ＴＵＮＥＬ（脱氧核苷酸转移酶末端介导的ｄＵＴＰ－生物素切口末端标记）法，观察了海马脑区细胞凋亡的特征变化—ＤＮＡ降解片段（凋亡小体）。发现脑缺血１０ｍｉｎ再灌流２４ｈ，海马ＣＡ１区即可见凋亡小体，于再灌流４８ｈ、９６ｈ凋亡小体明显增多。给予巴曲酶（１．６ＢＵ／ｋｇ．ｉｖ）后上述变化被明显逆转。本实验提示巴曲酶对脑缺血再灌流损伤所引起的细胞凋亡有抑制作用。     

Poly(ADP-ribose) polymerase during reperfusion after transient forebrain ischemia

The activation of poly(ADP-ribose) polymerase (PARP) in the reperfused brain after ischemia has been assumed but never has been directly presented. Our studies indicate a different dynamic of PARP activity alteration in hippocampus during reperfusion after 3 and 10 min of transient forebrain ischemia in gerbils. The phasic stimulation of PARP activity was observed during reperfusion 15 min, 120 min, and 4 d after 3 min of ischemia with subsequent lowering of its activity close to control value on the seventh day of reperfusion. After 10 min of ischemic insult, PARP activity significantly increased from the third to the seventh day of reperfusion. The protein level of PARP was not significantly changed during reperfusion after 3 and 10 min of ischemia, with one exception: On the third day after 10 min of ischemia, PARP protein level was 28% lower compared to control; however, no enhancement of 85-kDa protein immunoreactivity was observed. These data indicate the lack of PARP cleavage in hippocampus of gerbils subjected to ischemia-reperfusion injury. The inhibitor of PARP, 3-aminobenzamide (3-AB) in a dose of 30 mg/kg b.w. (body weight) injected intravenously directly after 3 min of ischemia protects >60% of neuronal cells against death in the CA1 layer of hippocampus but has no effect after 10 min of ischemic episode. 3-AB decreased forebrain edema significantly after 3 and 10 min of ischemia. Our data indicate that PARP inhibitor(s) might offer a potent therapeutic strategy for short global ischemia. The combination of PARP inhibitor with potent antioxidant might enhance its ameliorating effect.     

Poly(ADP-ribose) polymerase during reperfusion after transient forebrain ischemia: its role in brain edema and cell death

The activation of poly(ADP-ribose) polymerase (PARP) in the reperfused brain after ischemia has been assumed but never has been directly presented. Our studies indicate a different dynamic of PARP activity alteration in hippocampus during reperfusion after 3 and 10 min of transient forebrain ischemia in gerbils. The phasic stimulation of PARP activity was observed during reperfusion 15 min, 120 min, and 4 d after 3 min of ischemia with subsequent lowering of its activity close to control value on the seventh day of reperfusion. After 10 min of ischemic insult, PARP activity significantly increased from the third to the seventh day of reperfusion. The protein level of PARP was not significantly changed during reperfusion after 3 and 10 min of ischemia, with one exception: On the third day after 10 min of ischemia, PARP protein level was 28% lower compared to control; however, no enhancement of 85-kDa protein immunoreactivity was observed. These data indicate the lack of PARP cleavage in hippocampus of gerbils subjected to ischemia-reperfusion injury. The inhibitor of PARP, 3-aminobenzamide (3-AB) in a dose of 30 mg/kg b.w. (body weight) injected intravenously directly after 3 min of ischemia protects >60% of neuronal cells against death in the CA1 layer of hippocampus but has no effect after 10 min of ischemic episode. 3-AB decreased forebrain edema significantly after 3 and 10 min of ischemia. Our data indicate that PARP inhibitor(s) might offer a potent therapeutic strategy for short global ischemia. The combination of PARP inhibitor with potent antioxidant might enhance its ameliorating effect.     

Delayed neuronal death in hippocampal CA1 pyramidal neurons after forebrain ischemia in hyperglycemic gerbils: amelioration by indomethacin

Hyperglycemia worsens ischemic-induced neuronal damage. Many reports argue the delayed neuronal cell death (DND) after forebrain ischemia in gerbils is due to apoptosis. We examined the effects of hyperglycemia and indomethacin on DND after forebrain ischemia in gerbils. Complete occlusion of both common carotid arteries was performed for 3.5 min followed by declamping and reperfusion. Blood glucose levels were maintained at 25-30 mmol/1 for 24 h after reperfusion in the hyperglycemic groups. We examined morphological changes consistent with DND using Nissel-stained sections and DNA fragmentation using TUNEL staining, at 12, 24, 36, 48, 60, 72, 84, 96, 108, 120 h, and 7 days after reperfusion. DND was noted 96-120 h after ischemia in normoglycemic group. Hyperglycemia enhanced the development of DND at an earlier stage (48-84 h after ischemia). TUNEL positive neurons were detected 72-108 h after reperfusion in normoglycemic group, but very few TUNEL positive neurons were detected in hyperglycemic group at 36-48 h. Indomethacin reduced the number of TUNEL-positive cells in normoglycemia and completely inhibited the appearance of TUNEL-positive cells under hyperglycemia. The number of viable neurons at 7 days after ischemia was markedly higher in indomethacin-treated groups than vehicle-treated group. Our results indicate that hyperglycemia worsens DND after forebrain ischemia in gerbils but such process is not associated with DNA fragmentation. Our results also showed that indomethacin provides a neuroprotective effect in normo- and hyperglycemic conditions.     

The N-methyl-D-aspartate antagonist, MK-801, fails to protect against neuronal damage caused by transient, severe forebrain ischemia in adult rats

The neuroprotective effects of dizocilipine maleate (MK-801), a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor/channel, were tested in the 4-vessel occlusion rat model of forebrain ischemia. Adult Wistar rats, treated intraperitoneally with MK-801 or saline using several different treatment paradigms were subjected to 5 (n = 208) or 15 (n = 62) min of severe, transient forebrain ischemia. In saline-treated animals, 15 min of ischemia (n = 13) produced extensive and consistent loss of pyramidal neurons in the CA1 zone of hippocampus. The degree and distribution of cell loss were not reduced by single dose preischemic administration of MK-801 at 1 (n = 7), 2.5 (n = 4), or 5 mg/kg (n = 8). In other animals subjected to 15 min of forebrain ischemia, multiple doses of MK-801 (5, 2.5, and 2.5 mg/kg) given immediately and at approximately 8 and 20 hr after cerebral reperfusion (n = 5) did not alter CA1 injury compared to saline-treated controls (n = 5). Five minutes of forebrain ischemia in saline-treated animals, (n = 82) resulted in significantly fewer (p less than 0.001) dead CA1 pyramidal cells and a greater variance compared to animals subjected to 15 min of ischemia. Power analysis of the preliminary saline-treated animals subjected to 5 min of ischemia (n = 22) indicated that 60 animals per group were necessary to detect a 15% difference between MK-801 and vehicle-treated groups. Multidose treatment with MK-801 (1 mg/kg) given 1 hr prior to 5 min of ischemia (n = 60) and again at approximately 8 and 16 hr after recirculation failed to attenuate hippocampal injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

妥泰对沙土鼠脑缺血再灌注损伤保护作用的实验研究

目的 研究妥泰对沙土鼠脑缺血再灌注损伤的保护作用及作用机制。方法 采用沙土鼠双侧颈总动脉结扎制成的全脑缺血模型。56只沙土鼠随机分为假手术组、缺血组、治疗组和预防组。预防组的动物分别给予大、小剂量的妥泰(100 mg/kg、50mg/kg)灌胃观察3天而行手术,术后24小时处死动物;治疗组的动物术后立即分别给于大、小剂量的妥泰(100 mg/kg、50mg/kg)灌胃观察7天处死动物。测定各组沙土鼠血、脑组织中的MDA、SOD的含量。光镜和电镜下观察脑组织CA_1区的病理及超微结构改变。结果 与缺血组相比,妥泰治疗组和妥泰预防组脑组织中的MDA含量明显降低(P<0.01),而SOD含量明显增高(P<0.01)。光镜和电镜下观察发现,妥泰治疗组和妥泰预防组的脑CA_1区缺血改变较缺血组减轻,且大剂量组缺血改变明显减轻。结论 妥泰对沙土鼠脑缺血再灌注损伤具有良好的保护作用,且保护作用与妥泰的剂量大小有关。其脑保护作用机制之一为妥泰能有效抑制氧自由基的产生及毒性。     

Pergolide protects CA1 neurons from apoptosis in a gerbil model of global cerebral ischemia

OBJECTIVE: To investigate the effects of dopamine (DA) receptor agonists and antagonists on neuronal apoptosis in hippocampal CA1 region after forebrain ischemia/reperfusion (I/R) injury in gerbils. METHODS: Gerbil forebrain ischemia was induced by occluding bilateral carotid arteries for 5 minutes. The open field test, hematoxylin-eosin staining and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) methods were used 1, 3 and 7 days after reperfusion. Western blot was used to examine the phosphorylation of c-Jun. RESULTS: Pergolide could significantly reduce the habituation impairments of ischemic gerbils, increase the number of normal neurons and reduce the number of apoptotic neurons in hippocampal CA1 region after reperfusion. SKF38393, SCH23390 and spiperone had no effects on these changes in this transient I/R injury model. Furthermore, pergolide can significantly reduce the phosphorylation of c-Jun induced by transient forebrain ischemia.     

缺血再灌注时大鼠脑细胞外液中腺苷含量的变化及巴曲酶的影响

动态观察脑缺血及再灌注时鼠脑细胞外液中腺苷及其代谢产物的变化规律以及巴曲酶对此的影响。方法在大鼠四血管结扎缺血再灌注模型上，用微透析及高效液相色谱技术测定在缺血及再灌注时各时间点脑细胞外液中腺苷及其代谢产物的含量。结果对照组的腺苷、肌苷（Ｉｎｏ）、次黄嘌呤（Ｈｙｐ）、黄嘌呤（Ｘａｎ）在缺血和再灌注后的各时间点均显著升高。腺苷出现２个高峰，分别在缺血后２０分钟及再灌注１５分钟时，到再灌注６０分钟又回落到接近基础灌流水平。Ｉｎｏ、Ｈｙｐ及Ｘａｎ只在再灌注３０分钟时出现１个高峰，到再灌注６０分钟仍滞留在较高水平。巴曲酶组腺苷、Ｉｎｏ、Ｈｙｐ及Ｘａｎ的变化规律与对照组相同，但升高的幅度低于对照组。结论脑缺血及再灌注损伤时腺苷的水平明显升高，呈现缺血及再灌注时的２个高峰。腺苷代谢产物的升高时间略滞后，仅在再灌注３０分钟时达峰值。巴曲酶可抑制腺苷及其代谢产物的升高，可能与其减轻损伤程度有关     

Effects of low molecular weight heparin-superoxide dismutase conjugate on serum levels of nitric oxide, glutathione peroxidase, and myeloperoxidase in a gerbil model of cerebral ischemia/reperfusion injury

BACKGROUND： Several studies have demonstrated that low molecular weight heparin-superoxide dismutase （LMWH-SOD） conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoagulation, decreasing blood viscosity, having anti-inflammatory activity, and scavenging oxygen free radicals. OBJECTIVE： To investigate the intervention effects of LMWH-SOD conjugate on serum levels of nitric oxide （NO）, glutathione peroxidase （GSH-Px）, and myeloperoxidase （MPO） following cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： A randomized, controlled, and neurobiochemical experiment was performed at the Institute of Biochemical Pharmacy, School of Pharmaceutical Sciences, Shandong University between April and July 2004. MATERIALS： A total of 60 Mongolian gerbils of either gender were included in this study. Total cerebral ischemia/reperfusion injury was induced in 50 gerbils by occluding bilateral common carotid arteries. The remaining 10 gerbils received a sham-operation （sham-operated group）. Kits of SOD, NO, and MPO were sourced from Nanjing Jiancheng Bioengineering Institute, China. LMWH, SOD, and LMWH-SOD conjugates were provided by Institute of Biochemistry and Biotechnique, Shandong University, China. METHODS： Fifty successful gerbil models of total cerebral ischemia/reperfusion injury were evenly randomized to five groups： physiological saline, LMWH-SOD, SOD, LMWH ＋ SOD, and LMWH. At 2 minutes prior to ischemia, 0.5 mL/65 g physiological saline, 20 000 U/kg LMWH-SOD conjugate, 20 000 U/kg SOD, a mixture of SOD （20 000 U/kg） and LMWH （LMWH dose calculated according to weight ratio, LMWH： SOD = 23.6：51）, and LMWH （dose as in the LMWH ＋ SOD group） were administered through the femoral artery in each above-mentioned group, respectively. MAIN OUTCOME MEASURES： Serum levels of NO, MPO, and GSH-Px. RESULTS： Compared with 10 sham-operated gerbils, the cerebral ischemia/reperfusion injury gerbils exhibited decreased s