阿司匹林预处理对大鼠局灶性脑缺血再灌注后神经细胞凋亡和Bcl-2、Bax蛋白表达的影响

目的观察预先使用阿司匹林(ASA)进行药物处理对大鼠局灶性脑缺血/再灌注(CI/RP)损伤后神经细胞凋亡及其调节基因(Bcl-2、Bax)表达的影响。方法48只SD雄性大鼠被随机分为对照组(n=12)和实验组(n=36),实验组又分为:小剂量组(ASA10 mg/kg)(n=12)、中剂量组(ASA50mg/kg)(n=12)、大剂量组(ASA150mg/kg)(n=12)。实验组于术前5d连续给予相应剂量的ASA灌胃。然后建立大鼠局部脑缺血2h、再灌24h的动物模型。第6天处死各组大鼠,TTC染色法测定脑梗死体积,TUNEL技术原位标记凋亡细胞,免疫组化法检测凋亡调节基因相关蛋白Bcl-2和Bax的表达。结果ASA干预后,小、中、大剂量ASA组梗死病灶体积与对照组相比均减小,缺血周边区凋亡细胞阳性率均显著降低。小、中剂量ASA组的作用优于大剂量ASA组,小,中剂量两个实验组缺血区域Bcl-2蛋白的表达增加,Bax蛋白的表达降低,3个实验组间进行比较,小、中剂量ASA组的作用优于大剂量ASA组。结论ASA预处理可以缩小大鼠脑缺血再灌注损伤后的梗死体积,可以减少大鼠缺血再灌注损伤脑组织的细胞凋亡,这一过程可能与上调Bcl-2蛋白的表达和减少Bax蛋白的表达有关,抑制CI/RP后细胞凋亡的表达可能是ASA的神经保护作用之所在。     

rHuEPO对大鼠脑出血病理变化及神经细胞凋亡的影响

目的 观察重组人促红细胞生成素(rHuEPO)对大鼠脑出血不同时期病理变化及神经细胞凋亡的影响,探讨rHuEPO对出血性脑损伤的脑保护作用及其作用机制.方法 Wistar雄性大鼠随机分为正常组(N)、假手术组(S)、模型组(M)、低剂量rHuEPO治疗组(LR)、高剂量rHuEPO治疗组(Ha).Ⅶ型胶原酶注射法制备脑出血模型,观察治疗前后脑组织含水量及脑出血量变化,采用免疫组织化学方法检测脑组织Bcl-2、Bax表达,TUNEL法检测凋亡细胞.结果与M组比较,LR组及HR组脑组织含水量降低,出血量及凋亡细胞数减少,Bcl-2蛋白表达升高,Bax蛋白表达下降,尤以HR组为著.结论 rHuEPO可通过介导Bcl-2表达上调及Bax表达下调抑制细胞凋亡,同时可减轻脑水肿,促进血肿吸收,其上述作用与剂量呈正相关.     

精原干细胞冷冻保存后再移植的生精功能

背景：精原干细胞的冷冻保存在男性不育治疗方面具有潜在的临床应用价值,但冷冻保存过的精原干细胞移植后,其精子发生过程及生精能力目前尚不完全清楚。 目的：观测精原干细胞冷冻保存后移植的生精功能。 方法：采用复合酶消化、差速贴壁结合非连续性Percoll 密度梯度离心的方法获取雄性SD 大鼠及雄性C57BL/6 小鼠精原干细胞;以雄性BALB/c 裸小鼠为受体,出生后6 周予腹腔注射白消安破坏其内源性生精功能。将供体精原干细胞分为冷冻保存组与非冷冻保存组,分别以曲细精管微注射的方法异种移植精原干细胞,采用形态学方法观察生精过程;采集附睾精液,观察精子形态并进行体外受精实验。移植后1,2,3个月取受体睾丸组织,采用免疫组化SABC 法检测α6-Integrin 蛋白表达情况;移植后1周、1个月、3个月取受体睾丸组织,应用扫描电镜观察生精过程。 结果与结论：冷冻保存前的精原干细胞活性率高于冷冻保存后的细胞活性率(P < 0.01)。冷冻保存组与未冷冻保存组受体睾丸组织精原细胞膜和细胞质中均有α6-Integrin 的阳性表达,随时间增加而增加,两组间α6-Integrin 蛋白的表达无统计学差异;SD 大鼠精原干细胞移植后能在BALB/c 裸小鼠生精上皮中克隆增殖,并能分化形成大鼠形态特征的精子,在小鼠精子发生巢内既有大鼠来源的精子发生,又有小鼠内源性精子发生,其供体来源的精子数量较小鼠自身来源的精子数量多。通过体外受精实验提示移植后的精原干细胞在受体内增殖分化形成的精子功能正常,具有受精的能力。结果说明采用常规方法冷冻保存的精原干细胞,移植后能在受体生精上皮中克隆增殖,并能分化形成成熟的精子。 关键词：冷冻保存;精原干细胞;精子发生;移植;组织细胞移植     

白芍总苷对EAE大鼠中枢神经系统炎症浸润细胞凋亡及Bcl-2、Bax表达的影响

目的 探讨白芍总苷（TGP）对实验性自身免疫性脑脊髓炎（EAE）大鼠中枢神经系统（CNS）炎症浸润细胞凋亡及Bcl-2、Bax表达的影响.方法 建立大鼠EAE模型,将大鼠随机分为正常对照组、模型组、TGP组、泼尼松组,TGP组免疫后第1天起每天经口灌服白芍总苷悬浊液0.2 g/kg,泼尼松组给予泼尼松,正常对照组、模型组给予同体积生理盐水溶液,第17天处死,病理切片观察CNS炎症细胞浸润情况,TUNEL法检测浸润细胞凋亡情况,免疫组化检测浸润细胞Bcl-2、Bax蛋白的表达.结果 泼尼松组、TGP组与模型组相比,中枢神经系统炎症浸润细胞的数目减少,凋亡率增高.TGP组与模型组相比,Bcl-2表达下降,Bax的表达上调,Bcl-2/Bax的比值下降.泼尼松组与模型组相比,Bcl-2/Bax的比值下降.结论 TGP能减轻EAE的病情,其机制可能是下调Bcl-2的表达,上调Bax蛋白的表达,降低Bcl-2/Bax比值,促进EAE大鼠CNS炎症浸润细胞的凋亡,减少CNS炎症细胞的浸润.     

自由基清除剂预处理对大鼠脑缺血再灌注损伤后脑组织细胞凋亡及其相关蛋白表达的影响

目的探讨自由基清除剂依达拉奉预处理对大鼠脑缺血再灌注损伤后神经细胞凋亡及其相关蛋白Bcl-2、Bax、热休克蛋白70(HSP70)表达的影响。方法将45只雄性SD大鼠随机分为假手术组、对照组、依达拉奉预处理组,每组15只。采用线栓法制作大鼠缺血2h再灌注24h模型。预处理组大鼠建模前12h腹腔注射依达拉奉(3mg/kg),对照组给予等容量生理盐水。再灌注24h后断头取脑,应用免疫组织化学法检测Bcl-2、Bax、HSP70蛋白表达,末端脱氧核糖核酸转移酶介导的原位缺口末端标记法检测凋亡细胞。结果依达拉奉预处理组和对照组大鼠缺血周围脑组织中凋亡细胞和Bcl-2、Bax及HSP70阳性细胞数比假手术组均明显增加(P<0.01);与对照组比较,其凋亡细胞和Bax阳性细胞数均明显减少(P<0.01),而Bcl-2和HSP70阳性细胞数明显增加(P<0.01)。结论细胞凋亡在缺血再灌注损伤中起着重要作用;依达拉奉可能通过上调Bcl-2、HSP70蛋白表达、下调Bax蛋白表达减轻大鼠脑缺血再灌注后的细胞凋亡,增加脑缺血再灌注损伤耐受性,从而起到神经保护作用。     

人尿激肽原酶对急性局灶性脑缺血再灌注损伤大鼠细胞凋亡的影响

目的 研究人尿激肽原酶(HUK)对大鼠急性局灶性脑缺血再灌注(FCIR)损伤后细胞凋亡数量及B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2联合X蛋白(Bax)蛋白表达的影响.方法 84只雄性SD大鼠分为假手术组(12只)、脑缺血再灌注(IR)组(36只)、HUK处理组(36只),IR组和HUK处理组剩余大鼠又按照再灌注时间6 h、12 h、24 h、72 h、168 h分为5个亚组(均为6只).建立大鼠大脑中动脉FCIR模型.假手术组、IR组及HUK处理组中各取6只SD大鼠用于测定梗死体积,其余大鼠用于观察神经功能缺陷评分、TIJNEL法及免疫组化检测凋亡细胞数量及凋亡蛋白Bcl-2、Bax的表达.结果 HUK处理组神经功能缺陷评分、梗死灶体积、除168 h亚组外的各时 间点的凋亡细胞数及Bax蛋白表达均显著少于IR组(P＜0.05),除168 h亚组外的各时间点的Bcl-2蛋白表达均显著高于IR组(P＜0.05).结论 HUK对FCIR后的脑组织起保护作用,其机制可能为损伤后3 d内通过上调Bcl-2、下调Bax蛋白表达来抑制细胞凋亡.     

川芎嗪对大鼠重型颅脑损伤后神经细胞凋亡及Bcl-2、Bax表达的影响

目的探讨川芎嗪对大鼠重型颅脑损伤后神经细胞凋亡及相关基因Bcl-2、Bax表达的影响和对脑神经的保护作用。方法120只SD健康大鼠随机分为假手术组、模型组、治疗组,其中模型组和治疗组采用Feeney自由落体撞击装置制作大鼠重型颅脑损伤模型,治疗组给予盐酸川芎嗪,用TUNEL及免疫组化法检测三组间细胞凋亡及Bcl-2、Bax蛋白的表达情况。结果大鼠脑组织中细胞凋亡率及Bcl-2、Bax表达水平在治疗组和模型明屁高于假手术组（P〈0．05）。在伤后72h、168h,治疗组的细胞凋亡率及Bax表达水平明显低于模型组,而Bcl-2的表达水平则明显高于模型组（P〈0．05）。结论川芎嗪可能通过抑制Bax的表达,上调Bcl-2的表达,减少神经细胞凋亡,减轻重型颅脑损伤后继发脑损害,从而发挥脑神经保护作用。     

大鼠脑缺血再灌注后Caspase-3、Bcl-2和Bax的表达

目的探讨大鼠脑缺血再灌注后caspase-3、Bcl-2和Bax在脑皮质神经元中的表达。方法将动物随机分为假手术组及缺血组,参照zea longa线栓法建立大鼠左侧大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)局灶性脑缺血再灌注模型,各组大鼠分别在左侧MCAO2h再灌注不同时间点断头取脑,脑皮质神经元中caspase-3、Bcl-2和Bax的表达通过免疫组化法来测定。结果缺血组大鼠脑皮质caspase-3的表达较假手术组显著增强(P<0.01),缺血组大鼠脑皮质Bcl-2的表达较假手术组显著增强(P<0.01),缺血组大鼠脑皮质Bax的表达较假手术组显著增强(P<0.01)。结论短暂性脑缺血再灌注上调脑皮质神经元中caspase-3和Bax的表达促细胞凋亡,上调脑皮质神经元中Bcl-2的表达抗细胞凋亡。     

局灶性脑缺血再灌注大鼠海马CA1区神经元凋亡研究

目的 观察大鼠局灶性脑缺血再灌注(ischemia reperfusion,I/R)损伤后海马CA1区神经元凋亡、TUNEL阳性细胞变化,以及凋亡相关蛋白Bcl-2与Bax蛋白的表达情况.方法 将健康雄性SD (Sprague-Dawley)大鼠随机分为假手术组和I/R组,每组再分为缺血再灌注后3、6、12、24、48、72 h亚组.应用免疫组化方法检测再灌注后不同时间点大鼠海马CA1区神经元凋亡基因Bcl-2和Bax蛋白的表达及Bcl-2/Bax比值变化,采用原位细胞凋亡检测(TUNEL)技术检测凋亡阳性细胞数.结果 各组非缺血侧相应区域神经元胞质中Bcl-2均有微弱表达.I/R组缺血侧海马CA1区于再灌注3 h开始出现Bcl-2和Bax蛋白微弱表达,随再灌注时间延长神经元内Bcl-2表达逐渐增强,再灌注24 h后Bcl-2表达达高峰,假手术组与I/R组比较差异有统计学意义(P<0.05).结论 I/R损伤后海马CA1区神经元不仅存在变性坏死,还存在明显的细胞凋亡且细胞凋亡在大鼠I/R损伤中发挥重要作用;I/R可诱导海马CA1区细胞凋亡基因Bcl-2和Bax蛋白表达,且其表达呈一定规律.     

高剂量灵芝孢子粉干预戊四氮致痫模型大鼠海马及皮质区神经细胞Bcl-2、Bax的表达

采用中药灵芝孢子粉低、中、高剂量（150, 300, 450 mg/kg）干预戊四氮致癫痫模型28 d，并设空白对照组。经免疫组织化学染色和TUNEL检测后发现，与模型相比，灵芝孢子粉高剂量组大鼠海马和皮质区神经细胞TUNEL阳性细胞数及Bax阳性细胞数均减少，而Bcl-2阳性表达细胞数增加。Morris水迷宫实验检测结果显示，灵芝孢子粉高剂量组大鼠逃避潜伏期缩短，跨过原平台次数增加。说明高剂量灵芝孢子粉上调癫痫模型大鼠海马和皮质区神经细胞Bcl-2蛋白的表达，抑制Bax免疫反应及癫痫所致的神经细胞凋亡，明显改善其学习记忆功能。     

低氧增强骨髓间充质干细胞对缺氧诱导心肌细胞凋亡的可能性

背景：骨髓间充质干细胞移植入缺血心肌后存活率低,而低氧有可能增强骨髓间充质干细胞的增殖,促进其存活。 目的：体外模拟心肌细胞缺血微环境,探索低氧预处理后,骨髓间充质干细胞对持续缺氧诱导的心肌细胞凋亡的保护作用。 方法：取第4代SD大鼠骨髓间充质干细胞用于制备条件培养液。取胚胎大鼠心肌细胞株,随机分成4组：对照组：心肌细胞正常培养组;模型组：心肌细胞单纯缺氧;骨髓间充质干细胞组：心肌细胞与骨髓间充质干细胞条件培养液共缺氧;低氧组：心肌细胞与骨髓间充质干细胞低氧条件培养液共缺氧。MTT检测各组细胞活力变化,Annexin V-FITC双染标记心肌细胞凋亡,免疫组化检测各组Bax和Bcl-2蛋白的表达。 结果与结论：免疫组化显示,低氧组的Bcl-2表达较其他各组增强,而Bax的表达比模型组和骨髓间充质干细胞组减弱,Bcl-2/Bax比值最大。与对照组和骨髓间充质干细胞组相比,低氧组的细胞活力高(P < 0.05),凋亡率降低(P < 0.05)。提示低氧可能是通过增强旁分泌机制,从而对Bax和Bcl-2进行调节,对心肌细胞凋亡有保护效应。     

醒脑静联合丁苯肽对脑缺血再灌注损伤后细胞凋亡的影响

目的 观察醒脑静、丁苯酞及二者联合分别对大鼠脑缺血再灌注损伤后神经细胞凋亡及Bcl-2和Bax表达的影响。方法 60只雄性wistar大鼠(250±20)g采用改良线栓法制作脑缺血再灌注损伤模型(Middle cerebral artery occlusion,MCAO),随机分为4组,即模型组、醒脑静组、丁苯酞组、醒脑静联合丁苯酞(联合用药)组,每组又分为6、24、72 h三个亚组; 通过原位末端转移酶标记技术(TUNEL)检测神经细胞凋亡情况,采用免疫组化法观察大鼠脑缺血再灌注各个时间点Bcl-2、Bax的表达水平。结果(1)模型组手术对侧大脑半球偶见凋亡细胞,病灶区可见大量神经细胞凋亡。丁苯酞用药组、醒脑静用药组凋亡细胞数明显减少,醒脑静联合丁苯酞组凋亡细胞数最少(P<0.05);(2)丁苯酞组及联合用药组Bcl-2阳性表达水平较模型组均有提高,联合用药组Bcl-2阳性表达水平在各时间点均最高(P<0.05); 丁苯酞组及联合用药组Bax阳性表达水平较模型组均有降低,联合用药组Bax阳性表达水平最低(P<0.05)。结论(1)醒脑静、丁苯酞及二者联合均可能通过抑制脑缺血再灌注损伤后神经细胞凋亡来实现神经细胞保护作用,其中二者联合效果最佳;(2)丁苯酞可能通过增加脑缺血再灌注损伤大鼠Bcl-2表达,减少Bax表达的方式来减少神经细胞凋亡,从而减轻脑缺血再灌注损伤;(3)醒脑静本身不能对Bcl-2、Bax的表达水平产生影响,但其可能通过增强丁苯酞作用的方式影响Bcl-2、Bax的表达,从而减轻脑缺血再灌注损伤。     

香港远志提取物对局灶性脑缺血大鼠脑保护作用与作用机制

目的探讨香港远志提取物对局灶性脑缺血大鼠脑保护作用与机制。方法线栓法制备SD大鼠大脑中动脉闭塞(MCAO)模型,随机分4组:假手术组、模型组及治疗A、B组。治疗组按设定方式给药,假手术组、模型组给1%吐温溶液。观察术后24h神经功能缺损评分(NBDS)、脑梗死体积(IV)、血清神经元烯醇化酶(NSE)及神经元凋亡、Bcl-2、Bax表达。结果与假手术组比较,模型组和治疗组NBDS、IV、NSE、神经元凋亡及Bcl-2、Bax显著增高、Bcl-2/Bax显著降低(P<0.05)。与模型组比较,治疗组NBDS、IV、NSE及神经元凋亡、Bax显著降低、Bcl-2、Bcl-2/Bax显著增高(P<0.05),治疗组间数据亦有显著差异(P<0.05)。结论香港远志提取物预处理,对局灶性脑缺血大鼠脑神经有保护作用,机制可能是促进Bcl-2、抑制Bax表达,上调Bcl-2/Bax比值,阻止神经元凋亡。     

Ginkgo biloba leaf extract effects on inducible nitric oxide synthase, Bcl-2, and Bax expression in rat models of spinal cord injury★

BACKGROUND:Ginkgo biloba leaf extract exhibits neuroprotective effects in spinal cord injury. However, the mechanisms of action remain unclear. OBJECTIVE: To investigate inducible nitric oxide synthase (iNOS) and Bcl-2/Bax expression in the injured spinal cord, and to explore the neuroprotective mechanisms of ginkgo biloba leaf extract in rats with spinal cord injury. DESIGN, TIME AND SETTING: The randomized, controlled, cell molecular biology experiment was performed at Soochow University, China from March...     

曲札茋苷对二氯化钴诱导PC12细胞氧化应激的保护作用

目的 探讨曲札茋苷注射液对二氯化钴诱导PC12细胞氧化应激的保护作用及其机制。方法 取对数生长期PC12细胞随机分为5组:对照组、模型组、曲札茋苷低水平组、曲札茋苷高水平组、依达拉奉组; 甲基三氯硅烷(Methyltrichlorosilane,MTS)法检测细胞活力:分光光度法检测超氧化物歧化酶(Superoxide dismutase,SOD)活性、乳酸脱氢酶(Lactate dehydrogenase,LDH)水平; 荧光探针法检测活性氧(Reactive oxygen species,ROS)荧光强度; Western Blot法检测细胞中半胱氨酸天冬氨酸蛋白酶-3(Cysteinyl aspartate specific proteinase-3,Caspase-3)、B淋巴细胞瘤-2基因(B-cell lymphoma-2,Bcl-2)、Bcl-2-相关X(Bcl-2-Associated X,Bax)蛋白的表达水平。结果 与对照组比较,模型组细胞活力下降,SOD活性降低,LDH释放增加,活性氧水平增高,Caspase-3,Bax蛋白的表达水平上升,Bcl-2蛋白表达水平下降(P<0.05); 与模型组比较,曲札茋苷组、依达拉奉组细胞活力上升,SOD活性升高,LDH释放较少,活性氧水平降低,Caspase-3,Bax蛋白的表达水平下降,Bcl-2蛋白表达水平上升(P<0.05)。结论 曲札茋苷可明显升高氧糖剥夺/复糖复氧PC12细胞的存活率,其机制可能是通过调控相关凋亡蛋白的表达,从而抑制细胞的凋亡。     

依达拉奉对大鼠脑外伤后细胞凋亡率及Bcl-2／Bax表达的影响

目的研究依达拉奉对大鼠脑外伤（TBI）后细胞凋亡率及Bcl-2／Bax表达的影响,探讨其对脑外伤后脑组织损害的保护作用。方法成年SD大鼠36只随机分为假手术组、脑外伤组、依达拉奉组。Allen＇s改良法制作脑外伤的模型;流式细胞仪检测伤侧海马细胞凋亡率的变化,免疫组化法检测海马细胞Bcl-2和Bax蛋白的表达,图象分析仪进行灰度定量分析。结果假手术组没检测到明显的细胞凋亡;脑外伤组检测到较高的细胞凋亡率;依达拉奉组细胞凋亡率较外伤组明显下降。外伤组脑细胞Bcl-2、Bax蛋白表达水平均明显高于假手术组;与外伤组相比,依达拉奉组Bcl-2蛋白表达水平显著增高,Bax蛋白表达水平明显下降。结论依达拉奉可有效抑制大鼠外伤后神经细胞凋亡,此作用可能与其有效清除氧自由基、上调Bcl-2和下调Bax蛋白表达水平有关。     

Ginkgo biloba leaf extract effects on inducible nitric oxide synthase, Bcl-2, and Bax expression in rat models of spinal cord injury★

BACKGROUND: Ginkgo biloba leaf extract exhibits neuroprotective effects in spinal cord injury. However, the mechanisms of action remain unclear. OBJECTIVE: To investigate inducible nitric oxide synthase (iNOS) and Bcl-2/Bax expression in the injured spinal cord, and to explore the neuroprotective mechanisms of ginkgo biloba leaf extract in rats with spinal cord injury. DESIGN, TIME AND SETTING: The randomized, controlled, cell molecular biology experiment was performed at Soochow University, China from March 2007 to March 2008. MATERIALS: A total of 120 healthy, adult Sprague Dawley rats were selected for this study. Rat models of moderate acute thoracic (T9) spinal cord injury were established using the modified Allen method. Shuxuening injection was obtained from Zhenbaodao Pharmaceutical Co., Ltd., China. Methylprednisolone was purchased from North China Pharmaceutical Co., Ltd. METHODS: All rats were equally and randomly divided into four groups. Only the spinal cord was exposed in the sham operation group rats. In the trauma group, rats were not treated with drugs following spinal cord injury. Rats in the hormone group were intraperitoneally injected with 30 mg/kg methylprednisolone following spinal cord injury. Rats in the ginkgo biloba leaf extract group were intraperitoneally infused with a 1.0 mL/kg Shuxuening injection per day. MAIN OUTCOME MEASURES: At 1 hour, as well as 1, 3, 5, 7, and 14 days after spinal cord injury, iNOS- and Bcl-2/Bax-positive cells were quantified with immunohistochemistry. Pathological changes were detected using hematoxylin-eosin staining under an optical microscope. RESULTS: Spinal cord injury in the ginkgo biloba leaf extract and hormone groups was milder compared with the trauma group. Demyelination was significantly ameliorated and the necrotic cavity was obviously reduced in the injured spinal cord of rats in the ginkgo biloba leaf extract and hormone groups at each time point. iNOS expression was increased in the injured spinal cord, and reached a peak at 5 days. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract and hormone groups compared with the trauma group (P < 0.05-0.01). The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury (P < 0.05). Bcl-2 expression reached a peak at 3 days, and Bax expression reached a peak at 5 days following rat spinal cord injury. Bcl-2 expression was increased, but Bax expression was decreased in the ginkgo biloba leaf extract and hormone groups compared with the trauma group (P < 0.05-0.01). Bcl-2 expression was greater, but Bax expression was reduced in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury (P < 0.05). CONCLUSION: Ginkgo biloba leaf extract exhibits neuroprotective effects by upregulating Bcl-2 expression, downregulating Bax expression, and significantly inhibiting high expressions of iNOS in the injured spinal cord. The neuroprotective effects of ginkgo biloba leaf extract are greater compared with methylprednisolone at 1 week after spinal cord injury. Key Words: apoptosis; Bcl-2/Bax; ginkgo biloba leaf extract; inducible nitric oxide synthase; methylprednisolone; neuroprotection; spinal cord injury     

Neuroprotective effects of subthalamic nucleus high-frequency stimulation on substantia nigra neurons in a Parkinson''s disease rat model

BACKGROUND: Deep-brain stimulation has proven to be beneficial in the treatment of Parkinson's disease (PD) patients. OBJECTIVE: To investigate the effects of high-frequency stimulation (HFS) to the subthalamic nucleus (STN) on neuronal apoptosis and apoptosis-related gene expression in the substantia nigra pars compacta, and to analyze the neuroprotective effect of HFS-STN. DESIGN, TIME AND SETTING: Neuronal morphology experiments were performed in the Beijing Nearosurgical Institute from May to December in 2005. MATERIALS: Forty healthy, adult, Sprague Dawley rats were used to establish a PD model with a unilateral microinjection of 6-hydroxydopamine into two target areas of the right medial forebrain bundle. 6-hydroxydopamine was purchased from Sigma (USA); high-frequency electrical stimulator was produced by World Precision Instruments (USA); Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) kit was a product of Nanjing Jiancheng Technology Co., Ltd. (China); and Bcl-2 and Bax protein assay kit were purchased from Wuhan Boster Bioengineering Co., Ltd. (China). METHODS: Forty rats were randomly divided into three groups. The stimulation group (n = 15) received HFS-STN on the day of PD modeling. The PD model group (n = 15) was used to establish the PD model. The control group (n = 1 0) was injected with normal saline containing 0.2 g/L ascorbic acid into two areas of the right medial forebrain bundle. MAIN OUTCOME MEASURES: Survival of dopaminergic neurons in the substantia nigra pars compacta was determined using Nissl staining. Apoptosis of dopaminergic neurons was detected using TUNEL techniques. Expression of anti-apoptotic protein, Bcl-2, and pro-apoptotic protein, Bax, were assayed by immunohistochemistry. RESULTS: Following 6-hydroxydopamine injection, the number of substantia nigra pars compacta neurons was reduced in the stimulation and PD model groups, compared to the control group. At 2 and 4 weeks post-surgery, the grey value of Nissl stained images was significantly less in the PD model and stimulation groups (P < 0.05), and the stimulation group exhibited greater grey values compared to the model group (P < 0.05). At 2 and 4 weeks post-surgery, the number of apoptotic neurons was significantly less in the stimulation group compared to the model group (P < 0.05). In addition, Bcl-2 and Bax expression, as well as the Bcl-2/Bax ratio, was much higher in the stimulation group compared to the model group (P < 0.05). CONCLUSION: HFS-STN has a neuroprotective effect on dopaminergic neurons in the substantia nigra pars eompacta of PD rats by promoting Bcl-2 expression, inhibiting Bax expression, and reducing the number of apoptotic dopaminergic neurons.     

Effects of Rubus parvifolius L. on neuronal apoptosis and expression of apoptosis-related proteins in a rat model of focal cerebral ischemic-reperfusion injury*★

BACKGROUND： Studies have shown that the Rubus parvifolius L. （RP） plant extract exhibits protective effects on cerebral ischemia. This effect is reflected in altered ischemic neuronal apoptosis and associated protein expression.
OBJECTIVE： To explore the neuroprotective mechanism of RP after cerebral ischemia injury.
DESIGN, TIME AND SETTING： Randomized control experiment of cellular, molecular, and protein levels. The experiment was completed at Chongqing Medical University at the School of Pharmacy Laboratories and Basic Medical Institute from October 2005 to January 2006.
MATERIALS： Twenty-four adult, male, Wistar rats, weighing （28 ± 20） g. RP extract, which was a product of ethanol extraction, was provided by the Laboratory of Pharmaceutical Analysis, Chongqing Medical University. RP was dissolved in distilled water to a concentration of 10 mg/mL. All rats were randomly assigned into four groups： 5 g/kg RP, 10 g/kg RP, model, and sham-surgery, with 6 rats in each group.
METHODS： In the 5 and 10 g/kg RP groups, as well as the model group, the middle cerebral artery was occluded （MCAO） for 60 minutes, resulting in focal cerebral ischemia, followed by reperfusion for 24 hours. Rats in the 5 and 10 g/kg RP groups received 5 and 10 g/kg RP, respectively. The RP treatment group received RP intragastrically （once a day） for 3 days. One hour after the last dose, rats were subjected to MCAO. The same surgical procedure was performed in the sham-surgery group, except the suture was introduced into the external carotid artery, but not advanced. Rats in the model group were subjected to MCAO. The sham-surgery and model groups received intragastrically administered normal saline once per day for 3 days. One hour after the last dose, the rats were subjected to surgery.
MAIN OUTCOME MEASURES： TUNEL labeling and immunohistochemical methods were used to investigate changes in neuronal apoptosis and expression of the apoptosis-related proteins, Bax and Bcl-2, on the ischemic hemisphere