帕瑞昔布钠预给药可减轻脂多糖诱导的小鼠认知功能损伤及神经炎症反应

目的:探讨帕瑞昔布钠(PA)预给药对脂多糖(LPS)诱导的小鼠疾病行为模型认知功能改变及神经炎症的影响。方法:雌性C57BL/6J小鼠80只,10～12月龄,随机分为4组(n=20):空白对照组(CON组)、PA组、LPS组和PA预处理组(P+L组)。LPS腹腔注射制备疾病行为模型,PA组和P+L组在注射LPS前1 h按10 mg/kg剂量腹腔注射PA。采用Morris水迷宫实验评价认知功能;ELISA检测血液及海马区IL-1β、IL-6、IL-18、TNF-α和PGE_2的表达;HE染色观察肺组织和海马组织的病理形态改变;免疫荧光法观察海马区小胶质细胞和星形胶质细胞的数目;Western blot法检测海马区COX-2、iNOS、NLRP3、ASC及caspase-1蛋白的表达。结果:与CON组相比,LPS组小鼠Morris水迷宫的逃避潜伏期显著延长,目标象限停留时间及穿越平台次数显著减少(P0.01),IL-1β、IL-6、IL-18、TNF-α和PGE_2的含量显著增多(P0.01),海马CA1区神经元细胞深染,坏死损伤明显,小胶质细胞和星形胶质细胞的数目显著增加(P0.05),COX-2、iNOS、NLRP3、ASC及caspase-1蛋白表达量显著增加(P0.01)。而与LPS组相比,PA明显降低小鼠的神经炎症水平,提高小鼠的记忆能力。结论:帕瑞昔布钠预给药对LPS诱发的认知功能障碍和神经炎症具有一定的预防和改善作用,其作用机制可能与特异性拮抗COX-2,抑制中枢小胶质细胞和星形胶质细胞的活化,减少NLPR3炎症小体的激活,从而降低炎症因子的水平有关。     

锌螯合剂对匹罗卡品致痫小鼠行为学及海马神经元的影响

目的:研究锌螯合剂氯碘羟喹对匹罗卡品致痫小鼠行为学及海马神经元的影响。方法:将CD1小鼠随机分成3组,对照组小鼠腹腔注射等量的生理盐水;癫痫组小鼠腹腔注射匹罗卡品300 mg/kg;氯碘羟喹治疗组(治疗组)小鼠腹腔注射匹罗卡品300 mg/kg,30 min之后腹腔注射氯碘羟喹15 mg/kg。观察各组小鼠的癫痫发作次数。Morris水迷宫实验测定逃避潜伏期和目标象限停滞时间。应用尼氏染色计数海马神经元数量;利用免疫组织化学方法、免疫印迹结合图像分析技术检测凋亡基因caspase-3在各组小鼠海马的表达变化。结果:与对照组相比,其他2组小鼠的癫痫发作次数明显增多,发作级别明显增高;其中,治疗组小鼠的发作次数和发作级别均低于癫痫组。水迷宫实验结果显示,与对照组相比,其他2组小鼠的逃避潜伏期明显延长,目标象限停滞时间明显缩短;其中,治疗组的逃避潜伏期比癫痫组短,目标象限停滞时间比癫痫组长。其他2组小鼠海马神经元数量明显少于对照组;治疗组的海马神经元数量比癫痫组多。其他2组小鼠海马caspase-3表达明显高于对照组,阳性细胞数量增多,光密度增加;治疗组海马caspase-3的表达低于癫痫组,阳性细胞数量减少,光密度降低。结论:锌螯合剂氯碘羟喹能抑制癫痫发作,保护海马神经元,提高癫痫小鼠的学习记忆能力。     

脓毒症相关性脑病小鼠模型的建立及其认知功能障碍的初步研究

目的:建立脓毒症相关性脑病(sepsis-associated encephalopathy,SAE)小鼠模型并对其认知功能障碍进行初步研究。方法:选取8～10周龄SPF级雄性C57BL/6J小鼠。第1部分实验将小鼠随机分为4组,即正常对照组,盲肠结扎穿孔术(cecal ligation and puncture,CLP)1组和CLP2组(分别用7号和12号针头行小鼠腹腔CLP)和假手术组(小鼠仅开腹分离盲肠)。第2部分实验将小鼠随机分为3组,即正常对照组,假手术组和CLP组。采用Kaplan-Meier法分析小鼠术后存活率;神经行为学评分评价小鼠的神经行为变化;Morris水迷宫实验和避暗实验检测小鼠的认知记忆功能变化;爬杆实验和悬挂实验测试小鼠的运动协调性;ELISA法检测小鼠血清前列腺素E_2(prostaglandin E_2, PGE_2)水平变化。结果:第1部分实验中,CLP术后小鼠出现明显嗜睡、竖毛、寒颤和厌食等症状,CLP1组和CLP2组小鼠48 h死亡率分别为20%和30%。两部分实验中行小鼠腹腔盲肠结扎穿孔术组小鼠神经行为学评分均显著低于对照组和假手术组(P0.01);Morris水迷宫中逃避潜伏期时间均显著延长(P0.01),目标象限停留时间和穿越平台次数减少(P0.01);悬挂实验和爬杆实验中评分均出现显著降低(P0.01);在避暗实验开始后大部分小鼠活动量显著减小甚至未曾进入暗室(P0.05)。第2部分实验中,CLP术后小鼠血清中PGE_2释放量显著增加(P0.01)。结论:通过12号针行盲肠结扎穿孔术可成功建立稳定的脓毒症相关性脑病小鼠模型,用此法建立的SAE小鼠模型存在学习记忆认知功能障碍。     

荭草苷抑制PERK/ATF4/CHOP通路改善癫痫小鼠认知功能障碍机制

目的 探索荭草苷抑制PERK/ATF4/CHOP通路改善癫痫小鼠认知功能障碍的机制。方法腹腔注射东莨菪碱与盐酸匹鲁卡品,建立癫痫小鼠模型。小鼠随机分为5组：对照组、模型组、荭草苷（50 mg/kg）组、MK-28(PERK激活剂,1 mg/kg)组、荭草苷（50 mg/kg）+MK-28(1 mg/kg)组,分组给药后,观察小鼠癫痫发作情况;Morris水迷宫检测认知功能;TUNEL染色检测海马神经元凋亡率;ELISA测量血清COX-2、IL-18及IL-6水平;免疫印迹法检测海马组织凋亡及PERK/ATF4/CHOP通路蛋白表达。结果 荭草苷组小鼠发作次数及持续时间、逃避潜伏期、海马神经元凋亡率、血清COX-2、IL-18及IL-6水平、海马组织Caspase-3、Bax、ATF4、CHOP蛋白表达及p-PERK/PERK相比模型组和荭草苷+MK-28组均降低（P<0.05）,MK-28组小鼠各指标变化趋势与荭草苷组相反。结论 荭草苷可通过抑制PERK/ATF4/CHOP通路激活阻止炎症,减轻癫痫小鼠海马神经元凋亡,改善其认知功能。     

电针对阿尔茨海默病小鼠海马神经元突触损伤及对CREB/BDNF信号通路的影响

目的探讨电针对APP/PS-1转基因小鼠海马神经元突触损伤及对CREB/BDNF信号通路的影响。方法将7月龄APP/PS-1转基因小鼠随机分为模型组、电针组及药物组,每组10只;另取10只同龄C57BL/6小鼠作为对照组。电针组针刺百合、印堂穴,并接入电针仪,20 min/次/天,共治疗15天;药物组给予盐酸多奈哌齐灌胃治疗;对照组及模型组不予以治疗。Morris水迷宫检测各组小鼠学习记忆能力;筑巢实验检测小鼠智力改变;尼式染色检测各组小鼠海马尼氏体变化;Western blot检测小鼠海马区SYN、PSD95、GAP43、CREB、pCREB及BDNF蛋白表达。结果 Morris水迷宫结果显示,与对照组相比,模型组小鼠逃避潜伏期增加,穿越平台次数减少,在目标象限停留时间减少;电针及药物组小鼠逃避潜伏期减少,穿越平台次数增加,在目标象限停留时间延长。模型组筑巢分数较对照组明显降低,电针及药物组小鼠筑巢分数明显增加。电针及药物组小鼠海马区神经元排列整齐且尼氏体数量增加,SYN、PSD95及GAP43蛋白表达增加。电针及药物组小鼠海马区pCREB及BDNF蛋白表达较模型组增加。结论电针减轻小鼠海马神经元突触损伤,改善APP/PS-1转基因小鼠的学习记忆能力,可能与调控CREB/BDNF信号通路相关蛋白表达有关。     

干扰海马spastin表达通过抑制突触传递介导小鼠认知功能障碍

目的:探讨微管切割蛋白spastin对小鼠认知功能的影响。方法:构建干扰spastin的重组腺相关病毒载体,通过立体定位注射至C57BL/6小鼠海马CA1区。利用新事物认知实验和Morris水迷宫实验分析小鼠的认知功能;利用高尔基染色法分析海马CA1区锥体细胞的形态;采用脑片膜片钳技术分析CA1区神经元的突触传递功能。结果:新事物认知实验显示干扰海马spastin的表达后,小鼠对新事物的探索时间及次数均减少(P0.05);水迷宫实验显示干扰组小鼠在目标象限的持续时间及穿越目标象限的次数均减少(P0.05);高尔基染色实验显示,干扰spastin的表达可使基树突和顶树突的树突棘密度显著降低且成熟树突棘显著减少(P0.05);膜片钳检测可见,干扰spastin的表达后,小鼠海马CA1区锥体细胞的微小兴奋性突触后电流(mEPSC)的振幅和频率以及诱发的EPSC最大幅度均显著降低且长时程增强(LTP)受损(P0.05)。结论:干扰海马CA1区spastin的表达可抑制突触传递而介导小鼠认知功能障碍。     

右美托咪定对脓毒血症大鼠血脑屏障的影响

目的探讨右美托咪定(dexmedetomidine,DEX)对内毒素血症大鼠模型血脑屏障及认知功能的影响。方法健康SD雄性大鼠24只,随机分为4组(n=6):空白对照组(C组)、脂多糖组(LPS组)、右美托咪定组(DEX组)和右美托咪定+脂多糖组(DEX+LPS组)。采用尾静脉注射LPS方法制备内毒素血症模型。各组大鼠进行Morris水迷宫实验,记录大鼠逃避潜伏期、穿越平台次数、在平台所在象限时间。处死大鼠,取海马组织,采用免疫组化法和Western blot检测各组大鼠海马组织血脑屏障(BBB)结构蛋白Occludin和ZO-1蛋白表达,采用ELISA方法检测各组大鼠海马组织炎症因子TNF-α、IL-1β和IL-6。结果 LPS组大鼠认知功能受损严重,海马组织Occludin和ZO-1蛋白的表达水平降低,炎症因子TNF-α、 IL-1β和IL-6含量显著升高;DEX+LPS组大鼠认知功能受损程度较LPS组轻,海马组织Occludin蛋白和ZO-1的蛋白表达升高,炎症因子TNF-α、IL-1β和IL-6含量显著降低。结论右美托咪定改善内毒素血症大鼠的认知功能,与上调Occludin以及ZO-1蛋白表达水平相关。     

大麻素受体激动剂花生四烯酰氯乙胺(ACEA)通过抑制炎症反应改善小鼠脓毒症相关性脑病

目的 探讨大麻素受体激动剂花生四烯酰氯乙胺(ACEA)对脓毒症相关性脑病(SAE)小鼠认知功能的影响。方法C57BL/6小鼠随机分成人工脑脊液(ACSF)组和脂多糖(LPS)组,通过采用LPS侧脑室注射构建SAE模型,小鼠脓毒症严重程度评分(MSS)和体质量变化判断小鼠的基本情况;行为学范式评估小鼠运动能力(旷场实验)、认知功能(情景前置性条件恐惧实验、 Y迷宫实验)。评估ACEA干预效果中,小鼠随机分为ACSF组、 ACEA干预的ACSF组、 LPS组和ACEA干预的LPS组,ACEA干预组给与1.5 mg/kg ACEA,实时定量PCR检测小鼠海马组织白细胞介素1β(IL-1β)、 IL-6、肿瘤坏死因子α(TNF-α)的mRNA表达水平;Western blot法检测小鼠海马组织IL-6、 TNF-α的蛋白表达水平;尼氏染色检测小鼠海马CA1区神经元损伤情况;行为学范式评估小鼠运动能力(旷场实验)、认知功能(情景前置性条件恐惧实验、 Y迷宫实验)。结果 侧脑室注射LPS 3 d后,小鼠存在显著认知功能障碍,证实SAE造模成功。与ACSF组相比,LPS组海马炎症因子IL-6、 TN...     

艾司西酞普兰对APP/PS1小鼠海马神经元突触功能及对BDNF-TrkB-CREB信号通路的影响

目的探讨艾司西酞普兰对APP/PS-1小鼠海马神经元突触功能及与BDNF-TrkB-CREB信号通路的关系。方法将7月龄APP/PS-1转基因小鼠随机分为模型组及艾司西酞普兰组,每组10只;另取10只同龄C57BL/6小鼠作为阴性对照组。给予10 mg/kg艾司西酞普兰灌胃治疗,连续8周,每天一次;对照组及模型组给予等体积生理盐水。Morris水迷宫检测各组小鼠学习记忆能力;尼式染色检测各组小鼠海马DG区尼氏体变化;酶联免疫吸附实验(ELISA)检测小鼠海马区乙酰胆碱酯酶(AChE)及胆碱乙酰转移酶(ChAT);Western blot检测小鼠海马区SYN、PSD95、GAP43、BDNF、TrkB、p-TrkB、CREB及p-CREB蛋白表达。结果艾司西酞普兰组改善APP/PS-1小鼠认知功能,小鼠逃避潜伏期减少,穿越平台次数增加,在目标象限停留时间延长,小鼠海马DG区神经元排列整齐且尼氏体数量增加,下调AChE,上调ChAT表达,且能增加SYN、PSD95及GAP43蛋白表达;此外,艾司西酞普兰还能显著增加小鼠海马区BDNF、p-TrkB及p-CREB蛋白表达,与模型组相比,差异有统计学意义(P0.05)。结论艾司西酞普兰改善小鼠海马神经元突触功能,提高APP/PS-1小鼠的学习记忆能力,可能与调控BDNF-TrkBCREB信号通路相关蛋白表达有关。     

三七总皂苷抑制星形胶质细胞活化改善脂多糖导致的小鼠抑郁样行为

目的 :观察三七总皂苷(PNS)对脂多糖(LPS)诱导的小鼠抑郁样行为以及海马星形胶质细胞(AST)活化的影响。方法 :将小鼠随机分为生理盐水(NS)组、LPS组、PNS+LPS组。利用喷糖实验、糖水偏好实验及强迫游泳实验检测小鼠抑郁样行为,免疫组织化学显色观察胶质原纤维酸性蛋白(GFAP)的表达变化,免疫印迹检测海马GFAP、乙醛脱氢酶1蛋白家族L1(ALDH1L1)的表达变化,荧光定量PCR检测海马GFAP和肿瘤坏死因子-α(TNF-α)mRNA的表达。结果 :与NS组相比,LPS组舔糖潜伏期延长、糖水偏好百分比下降、强迫游泳不动时间增加,PNS预处理可逆转上述抑郁样行为;与NS组相比,LPS组海马GFAP阳性细胞数目增加,GFAP及ALDH1L1蛋白表达上调,GFAP及TNF-αmRNA表达上调,PNS预处理均可减少GFAP、ALDH1L1及TNF-α的表达;结论 :三七总皂苷可能通过抑制星形胶质细胞活化,改善脂多糖导致的小鼠抑郁样行为。     

丰富环境对脓毒症相关性小鼠认知功能障碍的影响

目的:探讨幼年期丰富环境(EE)对脂多糖(LPS)诱导的小鼠认知功能障碍及海马区小胶质细胞活化的影响。方法:36只幼年雌性昆明小鼠随机分为对照组(Control)、脂多糖(LPS)组、丰富环境+脂多糖组(EE+LPS)。给予小鼠单次腹腔注射LPS(O.83 mg/kg)构建脓毒症小鼠模型.EE+LPS组小鼠在注射LPS前给予8周的丰富环境干预。新旧事物识别实验检测小鼠认识功能,免疫组织化学法检测小鼠海马区lba-1的表达,Western Blot检测CD68和IL-1β的表达。结果:与Control组相比,LPS组小鼠新事物辨别指数明显下降;与LPS组相比,EE+LPS组小鼠新事物辨别指数明显增加。LPS可诱导小鼠海马区小胶质细胞活化,表现为Iba-1阳性细胞数目增加,CD68和IL-1β的上调;而丰富环境干预可明显抑制小胶质细胞活化,表现为lba-1阳性细胞数目减少,CD68和IL-1β表达下调。结论:丰富环境可能通过抑制海马区小胶质细胞的激活从而改善LPS诱导的小鼠认知功能障碍。     

Acute systemic inflammation induces central mitochondrial damage and mnesic deficit in adult Swiss mice

The aim of this study was to investigate how the brain is affected during systemic inflammation. For this purpose, Swiss mice were challenged with a single intraperitoneal dose of lipopolysaccharide (LPS; 250microg/mouse) to mimic aspects of systemic infection. Spatial learning in Y-maze test demonstrated a differential learning profile during the training test between control and LPS-treated mice, with an alteration in the latter group. We show that systemic LPS-induced inflammation and oxidative injury as assessed by reactive oxygen species (ROS) and nitrites/nitrates (NOx) production associated with reduced glutathione (GSH) depletion, cyclooxygenase-2 (COX-2) expression, and lipid peroxidation. LPS also induced a loss in mitochondrial integrity as shown by a significant decrease in membrane potential and impairment in mitochondrial redox activity. Thus, peripheral inflammation by producing brain inflammation and oxidative injury causes mnesic deficits. It remains to determine whether such events can induce neuronal dysfunction/degeneration and, with time, lead to cholinergic deficiency, amyloid deposits and cognitive impairments as they occur in Alzheimer's disease.     

丰富环境通过抑制NOD样受体蛋白3炎性小体活化缓解脂多糖小鼠的认知障碍

目的探讨丰富环境(EE)对脂多糖(LPS)诱导的小鼠认知功能障碍的影响及其可能机制。方法36只3周龄昆明小鼠进行8周的EE刺激或者标准环境(SE)饲养后分为以下3组:标准环境+生理盐水(SE+NS)组、标准环境+脂多糖(SE+LPS)组及丰富环境+脂多糖(EE+LPS)组。采用旷场实验检测小鼠的活动度;新旧事物识别实验检测小鼠认知功能;免疫组织化学方法检测小胶质细胞标记物离子钙接头蛋白分子1(IBA1)表达;Western blotting方法检测海马组织小胶质细胞激活标记物CD68及NOD样受体蛋白3(NOD-like receptor protein3,NLRP3)炎性小体相关蛋白的表达。结果旷场实验中,各组小鼠穿越的总格数无明显差异。在新旧事物识别实验中,与SE+NS组相比,SE+LPS组新事物辨别指数明显下降(P<0.05);与SE+NS组相比,小胶质细胞标记物IBA1表达上调(P<0.05);SE+LPS组海马CD68及NLRP3炎性小体相关蛋白的表达明显上调(P<0.05);而丰富环境可以逆转上述改变(P<0.05)。结论丰富环境可缓解脂多糖诱导的认知功能损伤,其机制可能与抑制海马小胶质细胞激活及NLRP3炎性小体的产生有关。     

小檗碱通过非α_2肾上腺素能受体途径减轻LPS诱导的心功能障碍

目的:观察小檗碱(Ber)预防内毒素血症小鼠心功能障碍的作用机制是否与其激活α2肾上腺素能受体有关,并探讨中性粒细胞在其中的作用。方法:将雄性BALB/c小鼠随机分为对照组(control)、脂多糖组(LPS)、小檗碱+LPS组(Ber+LPS)、α2肾上腺素能受体拮抗剂育亨宾+小檗碱+LPS组(Yohimbine+Ber+LPS)、育亨宾+LPS组(Yohimbine+LPS)、小檗碱组、育亨宾+小檗碱(Yohimbine+Ber)组和育亨宾(Yohimbine)组,分别用蒸馏水,小檗碱(50 mg/kg),育亨宾+小檗碱(2 mg/kg+50 mg/kg)或育亨宾(2 mg/kg)灌胃,每天1次,连续3d,第3 d灌胃后1 h,腹腔注射生理盐水或LPS(20 mg/kg)。观察注射LPS后12 h各组小鼠心肌组织结构的改变,用VisualSonies Vevo770TM高分辨小动物超声系统测定小鼠的心功能,并用Western blotting方法测定LPS注射后0.5 h心肌髓过氧化物酶(MPO)的含量。结果:LPS注射后12 h,LPS组小鼠心肌组织出现明显水肿。小檗碱、育亨宾、小檗碱+育亨宾组小鼠心肌的病理改变明显轻于LPS组。超声心动图检测显示,LPS组小鼠心输出量(CO)和每搏量(SV)均显著低于对照组、小檗碱、育亨宾、小檗碱+育亨宾组。腹腔注射LPS后0.5 h,LPS组心肌MPO的含量显著高于对照组,小檗碱、育亨宾+小檗碱组心肌MPO的水平显著低于LPS组,而育亨宾组心肌MPO的含量与LPS组没有显著差别。结论:小檗碱预处理能够减轻内毒素血症小鼠的心功能障碍,其作用机制与其激活α2肾上腺素能受体和抑制LPS引起的心肌中性粒细胞浸润无关,体内α2肾上腺素能受体激活可能在LPS引起的心功能障碍中发挥重要作用。     

硫辛酸对LPS诱导的帕金森病小鼠黑质多巴胺能神经元损伤的影响

目的:探讨硫辛酸(LA)对脂多糖(LPS)诱导的帕金森病(PD)模型小鼠黑质多巴胺(DA)能神经元损伤的作用及机制。方法:10月龄雌性C57BL/6小鼠,随机分为生理盐水对照组、PD模型组和LA干预组。采用鼻腔滴入LPS制作PD小鼠模型,通过爬竿实验及酪氨酸羟化酶和p-NF-κB/p65的免疫组化技术观察LA对DA能神经元的保护作用。结果:LPS经鼻可以成功诱导小鼠PD模型,给予LA可明显恢复小鼠运动,减少黑质DA能神经元的丢失、抑制小胶质细胞及其NF-κB信号通路激活。结论:LA干预可缓解LPS经鼻诱导的小鼠PD行为学和病理学的改变,其作用机制可能与抑制脑内的炎症反应有关。     

Role of IL-6 in cytokine-induced sickness behavior: a study with IL-6 deficient mice

Interleukin-6 (IL-6) is synthesized and released in response to the cytokine inducer lipopolysaccharide (LPS) and IL-1, and acts as an endogenous pyrogen. Systemic administration of LPS and IL-1 to mice induces signs of sickness, including reduction of social exploration, immobility and body weight loss. To assess the role of IL-6 in the induction of sickness behavior, male IL-6-deficient mice (IL-6 -/-, Balb/cAn genetic background) were used and compared to IL-6 +/+ littermates. The depressing effects of intraperitoneal LPS (2.5 microg/mouse) and IL-1beta (1.0 microg/mouse) on behavior and change in body weight were more marked in IL-6 +/+ than in IL-6 -/- mice. The same difference was observed when mice were injected with LPS (5 ng/mouse) and IL-1beta (1 ng/mouse) into the lateral ventricle of the brain (i.c.v.). These results show that IL-6 released at the periphery and /or in the central nervous system plays a role in the behavioral response to LPS and IL-1.     

Corticostriatal synaptic function in mouse models of Huntington's disease: early effects of huntingtin repeat length and protein load

Huntington's disease (HD) is an autosomal dominant, late onset, neurodegenerative disease characterized by motor deficits and dementia that is caused by expansion of a CAG repeat in the HD gene. Clinical manifestations result from selective neuronal degeneration of predominantly GABAergic striatal medium-sized spiny neurons (MSNs). A growing number of studies demonstrate that personality, mood and cognitive disturbances are some of the earliest signs of HD and may reflect synaptic dysfunction prior to neuronal loss. Previous studies in striatal MSNs demonstrated early alterations in NMDA-type glutamate receptor currents in several HD mouse models, as well as evidence for presynaptic dysfunction prior to disease manifestations in the R6/2 HD fragment mouse model. We have compared corticostriatal synaptic function in full-length, human HD gene-carrying YAC transgenic mice expressing a non-pathogenic CAG repeat (YAC18; control) with three increasingly severe variants of pathogenic HD gene-expressing mice (YAC72 and two different lines of YAC128), at ages that precede any detectable disease phenotype. We report presynaptic dysfunction and a propensity towards synaptic depression in YAC72 and YAC128 compared to YAC18 mice, and, in the most severe model, we also observed altered AMPA receptor function. When normalized to evoked AMPAR currents, postsynaptic NMDAR currents are augmented in all three pathogenic HD YAC variants. These findings demonstrate multiple perturbations to corticostriatal synaptic function in HD mice, furthering our understanding of the early effects of the HD mutation that may contribute to cognitive dysfunction, mood disorders and later development of more serious dysfunction. Furthermore, this study provides a set of neurophysiological sequelae against which to test and compare other mouse models and potential therapies in HD.     

Production of cytotoxic factor into mouse peritoneal fluid by OK-432, a streptococcal preparation

A cytotoxic factor was induced by the injection of LPS into the peritoneal fluids of mice which had been previously primed with a streptococcal antitumor preparation, OK-432. No cytotoxic effect on L-929 cells was observed in the peritoneal fluids of mice singly treated with OK-432 or LPS. Various mouse and human tumor cell lines were effectively killed by this peritoneal cytotoxic factor, though normal cell lines were insensitive, which indicates that this factor is not species-specific. The highest level of cytotoxic activity was obtained when LPS was given to mice 5 days after the injection of OK-432. The optimal time for collection of peritoneal fluids for the cytotoxic factor was 2 h following the LPS injection. Interferon activity was found to be negative by the plaque reduction test using L-929 cells with vesicular stomatitis virus. These results suggest that this cytotoxic factor is similar to the tumor necrosis factor (TNF) in the mouse serum.     

七氟醚预处理对LPS诱导的小鼠心功能障碍的影响

目的:观察七氟醚(Sevo)预处理对脂多糖(LPS)诱导的心功能障碍的影响并初步探讨其作用机制。方法:40只雄性BALB/c小鼠随机分为4组:对照组(control)、LPS组、Sevo组和Sevo+LPS组。分别用2%Sevo(以纯氧为载气)或纯氧预处理30min,洗脱10min后,腹腔注射LPS18mg/kg或等量生理盐水。于腹腔注射后12h,通过高分辨小动物超声系统检测心功能,结束后立即采血并处死小鼠,用生化分析仪检测血清乳酸脱氢酶(LDH)和肌酸激酶同工酶(CK-MB)活性;留取小鼠心脏标本,制备石蜡切片,进行HE染色后在光学显微镜上观察各组小鼠心脏的组织结构变化,分别用硝酸还原酶法和比色法检测小鼠心肌组织中一氧化氮(NO)的含量和诱导型一氧化氮合酶(iNOS)的活性。结果:LPS腹腔注射后12h,超声检测显示LPS组小鼠左心室舒张末期容积(LVEDV)增大(P＜0.05),每搏输出量(SV)、心输出量(CO)和射血分数(EF)降低(P＜0.05);血清LDH和CK-MB水平升高(P＜0.05);病理切片见心肌明显病变。Sevo+LPS组与LPS组比较,LVEDV减小(P＜0.05),SV、CO和EF增加(P＜0.05),LDH和CK-MB水平显著降低(P＜0.05),心肌组织的病理损伤减轻。LPS引起心肌组织中NO含量和iNOS活性升高(P＜0.05),Sevo对此有抑制作用(P＜0.05)。结论:Sevo预处理减轻LPS引起的心肌损伤和心功能障碍,其机制可能与其抑制心肌iNOS活性,减少NO的生成有关。     

An antagonist of platelet-activating factor suppresses endotoxin-induced tumor necrosis factor and mortality in mice pretreated with carrageenan.

We found that carrageenan (CAR), that is, sulfated polygalactose, can enhance both lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) production and the rate of lethality in mice (M. Ogata, S. Yoshida, M. Kamochi, A. Shigematsu, and Y. Mizuguchi, Infect. Immun. 59:679-683, 1991). It has been reported that platelet-activating factor (PAF) antagonists reduce the rate of mortality from endotoxin shock. However, there are few reports regarding the effect of PAF antagonists on TNF production. The aim of the present study is to examine the effect of TCV-309, a new PAF antagonist, on LPS-induced TNF production and mortality in mice pretreated with CAR. ddY mice (6 to 7 weeks old) were injected intraperitoneally with CAR (5 mg per mouse) and were then divided into two groups: mice treated with a PAF antagonist (TCV-309; Takeda Pharmaceutical Co.) and control mice. The mice treated with PAF antagonist received indicated doses of TCV-309 subcutaneously (s.c.) at 30 min before LPS injection, while the control mice received 1 ml of saline s.c. at the same time. All mice were stimulated by intravenous injection of LPS (50 micrograms per mouse) at 24 h after pretreatment with CAR. At intervals after injection of LPS, serum samples were obtained for a TNF assay in which cytotoxicity to L929 cells was measured. TCV-309 both significantly suppressed LPS-induced TNF production and reduced mortality in a dose-dependent manner. When TCV-309 was administered at 30 min before injection of LPS, the effect of TCV-309 on the suppression of TNF activity was at its peak. Treatment with TCV-309 (990 micrograms per mouse) s.c. significantly improved the survival rate after challenge with LPS compared with the survival rate of control mice. Although the 50% lethal dose of LPS was 15 micrograms per mouse for control mice, it increased to 102 micrograms per mouse for mice that were treated s.c. with TCV-309 (990 micrograms per mouse). Even in vitro, TCV-309 also inhibited LPS-induced TNF production in thioglycolate-elicited macrophages. It was concluded that PAF plays an important role in endotoxin-induced TNF production and mortality.