腺苷A1受体敲除小鼠戊四氮点燃后脑组织病理形态学变化

目的:通过观察腺苷A1受体敲除小鼠戊四氮点燃后脑组织病理形态学变化,探讨腺苷A1受体的神经保护作用。方法:腺苷A1受体基因敲除纯合型(-/-)小鼠20只纳入敲除鼠组,腺苷A1受体基因敲除野生型小鼠20只纳入野生型组,C57BL/6小鼠10只纳入对照组。敲除鼠组和野生型组小鼠制作戊四氮点燃癫痫模型,于点燃成功后24 h、30 d采用尼氏染色观察各组小鼠海马及皮质神经元的形态结构变化。结果:野生型组小鼠点燃后皮质和海马神经元损伤较敲除鼠组出现晚、范围小,损伤程度轻。结论:腺苷A1受体对癫痫发作小鼠具有神经保护作用。     

ERK信号转导通路在癫痫大鼠脑部作用的研究

目的:研究ERK信号转导通路在癫痫发病机制中的作用。方法:将54只雄性Wistar大鼠分为正常组6只,假模型组和癫痫组各24只,后2组按大鼠存活时间各分为30 min组1、.5 h组5、h组和8 h组各6只。癫痫组腹腔注射戊四氮制作癫痫大鼠模型,假模型组以生理盐水代替戊四氮腹腔注射。应用免疫组化染色、组织病理学染色及Western blot检测,分别检测各组大鼠大脑皮质ERK1、ERK2和p-ERK1/2的表达及神经元的损伤情况。结果:免疫组化染色结果显示正常组和假模型组大鼠脑内有少量的ERK1和ERK2阳性神经元,无p-ERK1/2阳性神经元;癫痫组致痫30 min后脑内p-ERK1/2阳性细胞开始出现,同时ERK1和ERK2阳性细胞较正常水平也有增多,1.5 h后3种阳性细胞均明显增多(P<0.05),5 h后3者开始减少,8 h后仅见少量阳性神经元。组织病理学染色示癫痫组皮质出现散在异常神经元。Western blot检测显示痫性发作各时点大鼠皮质内ERK1、ERK2和p-ERK1/2蛋白表达较正常水平显著增多(P<0.05),1.5 h时点组的蛋白表达水平高于其他各时点组(P<0.05)。结论:皮质ERK信号途径在戊四氮致痫模型中被激活,参与癫痫发作的病理生理过程。     

白细胞介素1 β、白细胞介素1受体拮抗剂对癫痫大鼠行为、海马超微结构及NMDAR活性的影响

目的探讨白细胞介素1β(IL-1β)及白细胞介素1受体拮抗剂(IL-1ra)对癫痫的影响,揭示癫痫发作的免疫学机制.方法实验于2003-10/2004-06在哈尔滨医科大学第二临床医学院实验中心完成,侧脑室注射生理盐水,L-1β及IL-1ra 30 min后戊四氮致痫观察大鼠行为,分别于致痫后2,,24 h处死大鼠,通过放射配基结合实验测定NMDA受体(NMDAR)活性,取海马CA3区电镜下观察超微结构的变化.结果外源性IL-1β能够缩短癫痫发作的潜伏期,与生理盐水对照组相比差异有显著性意义(t=3.85,＜0.05),对癫痫发作强度的影响与对照组相比差异无显著性意义,观察到明显的神经元变性坏死,大鼠脑内NMDAR活性在致痫后个时间点均显著增强;IL-Ira对发作潜伏期的影响及发作强度的影响与对照组相比差异无显著性意义,但可明显减轻戊四氮致痫所导致的神经元损害,致痫大鼠脑内NMDAR活性各时间与对照组相比明显减低.结论IL-1 β通过提高NMDAR活性促进癫痫发生及发展,加重癫痫所导致的神经元损伤的程度,L-1ra可以通过抑制IL-1β的活性,减轻其上述作用.     

腺苷受体激动剂对致痫大鼠海马神经细胞bcl-2, Bax基因表达的影响

背景癫痫发作后大脑海马神经元有明显受损,而癫痫后神经细胞损害有坏死和凋亡两种形式,在癫痫神经损害中起着重要作用.腺苷作为内源性神经保护递质,可以抑制兴奋性氨基酸的释放、氧自由基的产生以及一氧化氮的作用,同时还有改善脑血流以及抗惊厥作用.但有关腺苷与癫痫后细胞凋亡之间的关系尚不完全清楚.目的观察腺苷受体激动剂2-CAdo对癫痫大鼠海马神经细胞bcl-2,Bax基因表达的影响,进一步探讨腺苷抗惊厥及脑保护的作用机制.设计以实验动物为研究对象,完全随机对照实验研究.单位一所油田总医院的儿科和普外科,一所大学医院儿内科.材料实验于2002-10/2003-03在哈尔滨医科大学实验动物学部及病理教研室完成.体质量200～250 g健康成年Wistar大鼠104只,雌雄各半.动物随机分为正常组8只,致痫组32只,致痫+2-CAdo组32只,致痫+生理盐水组32只.干预按1.5 mg/kg腹腔注射马桑内酯(由哈尔滨医科大学药理学部提供)建立动物癫痫模型,全部大鼠于注射后5 min出现抽搐,持续时间一两分钟.致痫+2-CAdo组于马桑内酯注射前1 h及抽搐后1 h经尾静脉注射2-CAdo(由ICN公司提供)剂量为0.6 mg/kg,致痫+生理盐水组于马桑内酯注射前1 h及抽搐后1 h经尾静脉注射等量的生理盐水.主要观察指标海马CA1区bcl-2,Bax基因表达阳性细胞数.结果癫痫发作后24 h海马CA1区神经细胞bcl-2表达量增多,48 h明显下降,72 h仅有少量表达,7 d时其表达量再度升高.而Bax表达则在癫痫发作24 h开始增多,48 h显著增多,72 h表达达高峰,7 d表达量最少.致痫+2-CAdo组各相应时间点bcl-2表达量较致痫组、致痫+生理盐水组明显增高(P＜0 05),Bax表达量较致痫组、致痫+生理盐水组明显减少(P＜0.05),有统计学意义.结论2-CAdo能够减少癫痫发作后海马神经细胞的凋亡,对神经细胞有一定的保护作用.     

腺苷受体激动剂对致痫大鼠海马神经细胞bcl-2,Box基因表达的影响

背景：癫痫发作后大脑海马神经元有明显受损，而癫痫后神经细胞损害有坏死和凋亡两种形式，在癫痫神经损害中起着重要作用。腺苷作为内源性神经保护递质，可以抑制兴奋性氨基酸的释放、氧自由基的产生以及一氧化氮的作用，同时还有改善脑血流以及抗惊厥作用。但有关腺苷与癫痫后细胞凋亡之间的关系尚不完全清楚。目的：观察腺苷受体激动剂2-CAdo对癫痫大鼠海马神经细胞bcl-2，Box基因表达的影响，进一步探讨腺苷抗惊厥及脑保护的作用机制。设计：以实验动物为研究对象，完全随机对照实验研究。单位：一所油田总医院的儿科和普外科，一所大学医院儿内科。材料：实验于2002—10／2003—03在哈尔滨医科大学实验动物学部及病理教研室完成。体质量200—250g健康成年Wistar大鼠104只，雌雄各半。动物随机分为正常组8只，致痫组32只，致痫+2-CAdo组32只，致痫+生理盐水组32只。干预：按1．5mg／kg腹腔注射马桑内酯(由哈尔滨医科大学药理学部提供)建立动物癫痫模型，全部大鼠于注射后5min出现抽搐，持续时间一两分钟。致痫+2-CAdo组于马桑内酯注射前1h及抽搐后1h经尾静脉注射2-CAdo(由ICN公司提供)剂量为0．6mg／kg，致痫+生理盐水组于马桑内酯注射前1h及抽搐后1h经尾静脉注射等量的生理盐水。主要观察指标：海马CA1区bcl-2，Bax基因表达阳性细胞数。结果：癫痫发作后24h海马CA1区神经细胞bcl-2表达量增多，48h明显下降，72h仅有少量表达，7d时其表达量再度升高。而Bax表达则在癫痫发作24h开始增多，48h显著增多，72h表达达高峰，7d表达量最少。致痫+2．CAdo组各相应时间点bcl-2表达量较致痫组、致痫+生理盐水组明显增高(P&;lt;0．05)，Box表达量较致痫组、致痫+生理盐水组明显减少(P&;lt;0．05)，有统计学意义。结论：2-CAdo能够减少癫痫发作后海马神经细胞的凋亡，对神经细胞有一定的保护作用。     

GABAA受体γ2亚单位在海人酸颞叶癫痫大鼠海马内的表达

目的:探讨癫痫发作后GABAA受体γ2亚单位在海马各区的动态表达以及氯硝西泮干预对其表达的影响。方法:健康成年雄性SD大鼠40只,随机分为对照组5只,致痫组15只,干预组15只,干预对照组5只。大鼠海马CA3区注射海人酸建立颞叶癫痫模型,干预组大鼠在致痫前予以氯硝西泮灌胃。于致痫后6 h、12 h和1 d采用免疫组化法检测各组大鼠海马CA1及CA3区γ-氨基丁酸A受体γ2亚单位(GABAARγ2)的动态表达水平。结果:致痫组在海人酸给药后6 h、12 h及1 d,海马CA3区GABAARγ2蛋白表达均显著低于对照组(P0.01);CA1区GABAARγ2蛋白表达也下降,注射后1 d显著低于对照组(P0.01)。干预组在海人酸注射后1 d CA1和CA3区GABAARγ2蛋白表达低于对照组(P0.05);海人酸注射后6 h、12 h及1 d,CA3区GABAARγ2蛋白表达均高于同时间点致痫组(P0.05),CA1区于海人酸注射后1 d,GABAARγ2蛋白表达显著高于同时间点致痫组(P0.01)。结论:海人酸诱导的颞叶癫痫模型中,海马GABAARγ2蛋白表达减少,氯硝西泮可缓解颞叶癫痫导致的GABAARγ2蛋白表达减少。     

老龄大鼠脑缺血再灌注海马神经元线粒体形态计量分析

目的:探讨老龄大鼠脑缺血再灌注后海马神经元超微结构变化,以及线粒体形态改变程度及性质。方法:建立老年大鼠脑缺血动物模型,正常对照组(A组)、缺血30min再灌注6h(B组)、12h(C组)、24h(D组)、48h(E组)和7d组(F组),用透射电镜观察海马神经元的超微结构变化,通过计算机图像分析系统对线粒体形态计量分析。结果:B组海马神经元超微结构与A组相同,E组和F组海马神经元损伤较重;E组和F组线粒体体密度、数密度、比表面和嵴膜密度较A组明显减少(P<0.05),线粒体平均体积和平均截面积较A组明显增大(P<0.05)。结论:老龄大鼠脑缺血后产生延迟性神经元死亡,其线粒体的形态结构也发生明显变化,这些变化直接与脑缺血再灌注时程相关。     

唑尼沙胺对癫痫小鼠学习记忆及海马神经元的影响

目的探讨应用唑尼沙胺对癫痫小鼠空间学习、记忆能力的影响,并观察海马组织形态学的改变。方法60只小鼠随机分为正常对照组和模型组,模型组采用腹腔注射戊四氮(45 mg/kg)复制癫痫动物模型。筛选造模合格小鼠30只随机分为癫痫模型组、唑尼沙胺组,各15只。正常对照组、癫痫模型组每日经口腔灌胃0.9%的氯化钠溶液0.15 ml,唑尼沙胺组经口腔灌胃溶于0.9%氯化钠溶液的唑尼沙胺(75 mg/kg)。观察各组小鼠行为表现,2周后行Morris水迷宫实验5 d,结束后取海马组织切片行HE染色,光学镜下观察海马组织形态学变化。结果与癫痫模型组比较,唑尼沙胺组在定位航行和空间探索时间均有明显提升,差异有统计学意义(P0.05),而与正常组比较差异无统计学意义(P0.05);且唑尼沙胺能够减轻海马神经元细胞损伤。结论唑尼沙胺能够延长惊厥发作潜伏期,缩短发作持续时间,减少自发发作次数,降低致痫小鼠的惊厥发作级别,进而减轻脑组织神经元损伤程度,改善癫痫小鼠的认知功能。     

MCMV感染对小鼠海马[Ca2+]i及线粒体膜电位的影响

目的:观察鼠巨细胞病毒(MCMV)感染对小鼠海马细胞内游离Ca2+浓度(犤Ca2+犦i)及线粒体膜电位的影响。方法:将BALB/C乳鼠同母鼠随机分为实验对照组(24只)和病毒组(35只),感染后56d应用荧光分光光度计和流式细胞仪分别检测两组小鼠海马的犤Ca2+犦i及线粒体膜电位。结果:病毒感染组小鼠海马犤Ca2+犦i增高及线粒体膜电位明显下降,与实验对照组比较差异有显著性(P值均<0.01)。结论:巨细胞病毒感染所引起的小鼠海马犤Ca2+犦i及线粒体膜电位的改变可能是其导致神经系统功能紊乱的机制之一。     

红藻氨酸处理C57BL/6J小鼠癫痫发作后再次阈下注射形成敏感性的特性

目的:探讨红藻氨酸处理的C57BL/6J小鼠癫痫发作后癫痫发作敏感性能否形成及其机制。方法:实验于2004--03/06在大连医科大学生理学教研室进行。选用C57BL6J小鼠36只,实验分为盐水对照组(n=8)和红藻氨酸处理组(n=24),红藻氨酸处理组根据不同时间点又分为红藻氨酸处理后0.5h,2h,24h组,每组8只。盐水对照组为C57BL/6J小鼠颈部皮下注射0.2mL盐水,红藻氨酸处理组为C57BL/6J小鼠颈部皮下注射0.2mL惊厥剂量红藻氨酸(25mg/kg)诱导癫痫发作,分别在红藻氨酸处理后0.5,2,24h,用免疫组化技术检测海马内c-Jun免疫阳性神经元,作为神经元兴奋的形态功能指标来观察癫痫发作相关脑区的兴奋传递通路,同时检测海马门区γ-氨基丁酸免疫反应活性阳性神经元数目。红藻氨酸处理后7d,存活的C57BL/6J小鼠被给予皮下注射12.5mg/kg阈下剂量的红藻氨酸,以检测癫痫发作敏感性。结果:实验纳入36只C57BL/6J小鼠,中途有4只脱落,最终有32只进入结果分析。①惊厥剂量红藻氨酸诱发C57BL/6J小鼠(n=24)在30min内出现癫痫持续状态,并伴有全身强直阵挛性惊厥,其中4只在30min内死亡。②7d后阈下剂量未引起癫痫发作,即癫痫发作敏感性未形成。③脑内免疫组化显示,海马各部位γ-氨基丁酸免疫反应阳性神经元在检测各时间点内均未见任何脱失现象;与盐水对照组比较,红藻氨酸组诱发急性癫痫发作,红藻氨酸处理后,在海马齿状回颗粒细胞c-Jun免疫反应最早增强(P<0.05),CA3部位不增强,以CA1部位c-Jun免疫反应在24h显著性升高(P<0.001)。④与盐水对照组相比,惊厥剂量的红藻氨酸处理后0.5h,2h,24h,海马门区γ-氨基丁酸免疫阳性神经元的数目及染色程度未见明显改变(P>0.05)。结论:C57BL/6J小鼠具有对红藻氨酸引起癫痫急性发作的敏感,可能与CA1接受内嗅皮层海马穿通通路的直接投射有关,同时C57BL/6J小鼠海马对红藻氨酸引起的γ--氨基丁酸能神经元损伤不敏感,海马门区γ-氨基丁酸免疫反应阳性神经元的结构功能完整性可能在防止癫痫敏感性形成方面起着关键的作用。     

腺苷受体A1与A2A相互作用对小鼠大脑中动脉缺血/再灌注损伤区谷氨酸转运体GLT-1表达的影响

目的 探讨在不同A1受体活性状态下,腺苷A2A受体缺失对脑缺血/再灌注区GLT-1D的影响,并探讨其产生的缺血性脑保护的可能机制.方法 将腺苷A2A受体基因敲除小鼠(A2A R/KO)与野生型小鼠(A2AR/WR)制作成大脑中动脉缺血2 h/再灌注22 h模型,分别给予腺苷A1受体激动剂CPA及拮抗剂DPCPX,采用免疫组化、Western - blot方法检测缺血/再灌注区(纹状体区)谷氨酸转运体(GLT -1)的表达情况,同时观察对脑梗死体积和神经功能缺损程度的影响.结果 缺血2h/再灌注22 h后,KO小鼠的神经功能缺损程度均明显轻于同样干预的WT小鼠(P＜0.05),使用A1受体拮抗剂后,小鼠的神经缺损程度较非干预组明显加重,而使用A1受体激动剂后神经功能缺损程度较非干预组明显减轻;KO小鼠的梗死体积均明显小于同样干顶的WT小鼠(P＜0.01),A2AR - KO/A1拮抗剂组小鼠梗死体积较非干预小鼠明显增大,而A2AR - KO/A1激动剂组小鼠的梗死体积则明显缩小.在缺血/再灌注区,A1R激动剂CPA使小鼠的GLT -1表达明显高于非干预组,其中A2AR/KO小鼠的增加更为明显;而使用A1R拮抗剂DPCPX后,局部GLT -1的表达与非干预组相比无明显差异.结论 初步证明A2AR缺失产生的神经保护作用与A1受体功能激活,进而促进缺血/再灌注区GLT-1的表达增加有关.抑制A2AR,同时激活A1R能加强缺血性脑保护作用.     

腺苷受体A_1与A_（2A）相互作用对小鼠大脑中动脉缺血/再灌注损伤区谷氨酸转运体GLT-1表达的影响

目的探讨在不同A1受体活性状态下,腺苷A2A受体缺失对脑缺血/再灌注区GLT-1D的影响,并探讨其产生的缺血性脑保护的可能机制。方法将腺苷A2A受体基因敲除小鼠（A2AR/KO）与野生型小鼠（A2AR/WT）制作成大脑中动脉缺血2 h/再灌注22 h模型,分别给予腺苷A1受体激动剂CPA及拮抗剂DPCPX,采用免疫组化、Western-blot方法检测缺血/再灌注区（纹状体区）谷氨酸转运体（GLT-1）的表达情况,同时观察对脑梗死体积和神经功能缺损程度的影响。结果缺血2h/再灌注22 h后,KO小鼠的神经功能缺损程度均明显轻于同样干预的WT小鼠（P〈0.05）,使用A1受体拮抗剂后,小鼠的神经缺损程度较非干预组明显加重,而使用A1受体激动剂后神经功能缺损程度较非干预组明显减轻;KO小鼠的梗死体积均明显小于同样干预的WT小鼠（P〈0.01）,A2AR-KO/A1拮抗剂组小鼠梗死体积较非干预小鼠明显增大,而A2AR-KO/A1激动剂组小鼠的梗死体积则明显缩小。在缺血/再灌注区,A1R激动剂CPA使小鼠的GLT-1表达明显高于非干预组,其中A2AR/KO小鼠的增加更为明显;而使用A1R拮抗剂DPCPX后,局部GLT-1的表达与非干预组相比无明显差异。结论初步证明A2AR缺失产生的神经保护作用与A1受体功能激活,进而促进缺血/再灌注区GLT-1的表达增加有关。抑制A2AR,同时激活A1R能加强缺血性脑保护作用。     

A3 and P2Y2 receptors control the recruitment of neutrophils to the lungs in a mouse model of sepsis

We have recently shown that A3 adenosine receptors and P2Y2 purinergic receptors play an important role in neutrophil chemotaxis. Chemotaxis of neutrophils to sites of infections is critical for immune defense. However, excessive accumulation of neutrophils in the lungs can cause acute lung tissue damage. Here we assessed the role of A3 and P2Y2 receptors in neutrophil sequestration to the lungs in a mouse model of sepsis. Sepsis was induced by cecal ligation and puncture (CLP) using adult male C57BL/6J mice (wild type [WT]), homozygous A3 receptor knockout (A3KO) mice, and P2Y2 receptor knockout (P2Y2KO) mice. Animals were killed 2, 4, 6, or 8 h after CLP, and peritoneal lavage fluid and blood were collected. Lungs were removed, and neutrophil infiltration was evaluated using elastase as a marker. Leukocyte and bacterial counts in peritoneal lavage fluid and blood samples were determined. Survival after sepsis was determined in a separate group. Leukocyte counts in the peritoneum were lower in A3KO and P2Y2KO mice than in WT mice. Conversely, initial leukocyte counts in the peripheral blood were higher in KO mice than in WT mice. Neutrophil sequestration to the lungs reached a maximum 2 h after CLP and remained significantly higher in WT mice compared with A3KO and P2Y2KO mice (P < 0.001). Survival after 24 h was significantly lower in WT mice (37.5%) than in A3KO or P2Y2KO mice (82.5%; P < 0.05). These data suggest that A3 and P2Y2 receptors are involved in the influx of neutrophils into the lungs after sepsis. Thus, pharmaceutical approaches that target these receptors might be useful to control acute lung tissue injury in sepsis.     

Abnormal permeability of inner and outer mitochondrial membranes contributes independently to mitochondrial dysfunction in the liver during acute endotoxemia

OBJECTIVE: This study was designed to determine the role played by the mitochondrial permeability transition in the pathogenesis of mitochondrial damage and dysfunction in a representative systemic organ during the acute phase of endotoxemia. DESIGN: A well-established, normotensive feline model was employed to determine whether pretreatment with cyclosporine A, a potent inhibitor of the mitochondrial permeability transition, normalizes mitochondrial ultrastructural injury and dysfunction in the liver during acute endotoxemia. SETTING: The Ohio State University Medical Center research laboratory. SUBJECTS: Random source, adult, male conditioned cats. INTERVENTIONS: Hemodynamic resuscitation and maintenance of acid-base balance and tissue oxygen availability were provided, as needed, to minimize the potentially confounding effects of tissue hypoxia and/or acidosis on the experimental results. Treatment groups received isotonic saline vehicle (control; n = 6), lipopolysaccharide (3.0 mg/kg, intravenously; n = 8), or cyclosporine A (6.0 mg/kg, intravenously; n = 6) or tacrolimus (FK506, 0.1 mg/kg, intravenously; n = 4) followed in 30 mins by lipopolysaccharide (3.0 mg/kg, intravenously). Liver samples were obtained 4 hrs posttreatment, and mitochondrial ultrastructure, function, and cytochrome c, Bax, and ceramide contents were assessed. MEASUREMENTS AND MAIN RESULTS: As expected, significant mitochondrial injury was apparent in the liver 4 hrs after lipopolysaccharide treatment, despite maintenance of regional tissue oxygen availability. Namely, mitochondria demonstrated high-amplitude swelling and exhibited altered respiratory function. Cyclosporine A pretreatment attenuated lipopolysaccharide-induced mitochondrial ultrastructural abnormalities and normalized mitochondrial respiratory control, reflecting protection against inner mitochondrial membrane damage. However, an abnormal permeability of outer mitochondrial membranes to cytochrome c was observed in all lipopolysaccharide-treated groups and was associated with increased mitochondrial concentrations of Bax and ceramide. CONCLUSIONS: These studies confirm that liver mitochondria are early targets of injury during endotoxemia and that inner and outer mitochondrial membrane damage occurs through different mechanisms. Inner mitochondrial membrane damage appears to relate to the mitochondrial permeability transition, whereas outer mitochondrial membrane damage can occur independent of the mitochondrial permeability transition. Preliminary evidence suggests that Bax may participate in lipopolysaccharide-induced outer mitochondrial membrane damage, but further investigations are needed to confirm this.     

Mu-opioid receptors selectively regulate basal inhibitory transmission in the central amygdala: lack of ethanol interactions

Endogenous opioid systems are implicated in the actions of ethanol. For example, mu-opioid receptor (MOR) knockout (KO) mice self-administer less alcohol than the genetically intact counterpart wild-type (WT) mice (Roberts et al., 2000). MOR KO mice also exhibit less anxiety-like behavior than WT mice (Filliol et al., 2000). To investigate the neurobiological mechanisms underlying these behaviors, we examined the effect of ethanol in brain slices from MOR KO and WT mice using sharp-electrode and whole-cell patch recording techniques. We focused our study in the central nucleus of the amygdala (CeA) because it is implicated in alcohol drinking behavior and stress behavior. We found that the amplitudes of evoked inhibitory postsynaptic currents (IPSCs) or inhibitory postsynaptic potentials (IPSPs) were significantly greater in MOR KO mice than WT mice. In addition, the baseline frequencies of spontaneous and miniature GABA(A) receptor-mediated inhibitory postsynaptic currents were significantly greater in CeA neurons from MOR KO than WT mice. However, ethanol enhancements of evoked IPSP and IPSC amplitudes and the frequency of miniature IPSCs were comparable between WT and MOR KO mice. Baseline spontaneous and miniature excitatory postsynaptic currents (EPSCs) and ethanol effects on EPSCs were not significantly different between MOR KO and WT mice. Based on knowledge of CeA circuitry and projections, we hypothesize that the role of MOR- and GABA receptor-mediated mechanisms in CeA underlying reinforcing effects of ethanol operate independently, possibly through pathway-specific responses within CeA.     

Cl-IB-MECA [2-chloro-N6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide] reduces ischemia/reperfusion injury in mice by activating the A3 adenosine receptor

We used pharmacological agents and genetic methods to determine whether the potent A(3) adenosine receptor (AR) agonist 2-chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide (Cl-IB-MECA) protects against myocardial ischemia/reperfusion injury in mice via the A(3)AR or via interactions with other AR subtypes. Pretreating wild-type (WT) mice with Cl-IB-MECA reduced myocardial infarct size induced by 30 min of coronary occlusion and 24 h of reperfusion at doses (30 and 100 mug/kg) that concomitantly reduced blood pressure and stimulated systemic histamine release. The A(3)AR-selective antagonist MRS 1523 [3-propyl-6-ethyl-5[(ethylthio)carbonyl]-2-phenyl-4-propyl-3-pyridine-carboxylate], but not the A(2A)AR antagonist ZM 241385 [4-{2-7-amino-2-(2-furyl)[1,2,4]triazolo-[2,3-a][1,3,5]triazin-5-ylamino]ethyl}phenol], blocked the reduction in infarct size provided by Cl-IB-MECA, suggesting a mechanism involving the A(3)AR. To further examine the selectivity of Cl-IB-MECA, we assessed its cardioprotective effectiveness in A(3)AR gene "knock-out" (A(3)KO) mice. Cl-IB-MECA did not reduce myocardial infarct size in A(3)KO mice in vivo and did not protect isolated perfused hearts obtained from A(3)KO mice from injury induced by global ischemia and reperfusion. Additional studies using WT mice treated with compound 48/80 [condensation product of p-methoxyphenethyl methylamine with formaldehyde] to deplete mast cell contents excluded the possibility that Cl-IB-MECA was cardioprotective by releasing mediators from mast cells. These data demonstrate that Cl-IB-MECA protects against myocardial ischemia/reperfusion injury in mice principally by activating the A(3)AR.     

Lack of TRPV1 inhibits cystitis-induced increased mechanical sensitivity in mice

Transient receptor potential vanilloid 1 (TRPV1) is highly expressed in primary afferent neurons. Tissue damage generates an array of chemical mediators that activate and sensitize afferent nerve fibers, and sensitization of afferent nerve fibers plays an important role in development of visceral pain. We investigated participation of TRPV1 in visceral pain associated with bladder inflammation induced in mice by systemic treatment with cyclophosphamide or intravesical instillation of acrolein. The effects of experimental cystitis on bladder function (an indicator of visceral pain) and the threshold of response to mechanical or thermal stimuli of the hind paws were investigated using TRPV1 knock-out (KO) and congenic wild-type (WT) mice. We found that cystitis induced bladder mechanical hyperreactivity and increased mechanical sensitivity of hind paws in WT, but not in TRPV1 KO mice. Lack of functional TRPV1 did not inhibit development of histological evidence of bladder inflammation, or increased expression of mRNAs for nerve growth factor, endothelial nitric oxide synthase, cyclooxygenase-2 and bradykinin receptors in urothelium. Cystitis did not affect the threshold of response to thermal stimuli in WT or KO mice. These results suggest that TRPV1 is essential for cystitis-induced bladder mechanical hyperreactivity. Also, TRPV1 participates in development of visceral pain, as reflected by referred increased mechanosensitivity in peripheral tissues in the presence of visceral inflammation.     

在小鼠骨髓移植中CCR5与急性移植物抗宿主病的相关性研究

本研究评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用,为今后的异基因造血干细胞移植的临床应用提供科学依据.经过致死剂量照射的BALB/c小鼠接受异基因C57BL/6小鼠的骨髓移植.根据回输的细胞不同实验分为4组:B6 CCR5 KO组,受者接受C57BL/6 CCR5-/-小鼠骨髓和脾脏细胞;B6 WT组,受者接受野生型C57BL/6小鼠骨髓和脾脏细胞;B6 CCR5 KO BMC组,受者只接受C57BL/6 CCR5-/-小鼠骨髓细胞;B6 WT BMC组,受者只接受野生型C57BL/6小鼠骨髓细胞.结果表明:较之B6 WT组,B6 CCR5 KO组小鼠以更快的速度死于急性GVHD;其受者体内的CD8+T细胞更大量的增殖;其T细胞恢复后产生更多的INF-γ和TNF-α并且由于其T细胞有丝分裂原刀豆素水平处于较高水平,从而进一步促进T细胞的增殖,提示CCR5的作用之一是下调参与排异反应的供者CD8+T细胞的增殖.组织学评价提示,移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在有更为严重的病理变化.结论:剔除CCR5基因的异基因骨髓移植使GVHD发病率的增加,供者CD8+T细胞在受者体内增殖增加以及肝肾损害加重,这提示CCR5在异基因骨髓移植中起着重要作用.     

在小鼠骨髓移植中CCRS与急性移植物抗宿主病的相关性研究

本研究评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用，为今后的异基因造血干细胞移植的临床应用提供科学依据。经过致死剂量照射的BALB／c小鼠接受异基因C57BL／6小鼠的骨髓移植。根据回输的细胞不同实验分为4组：B6CCR5KO组，受者接受C57BL／6CCR5^-/-小鼠骨髓和脾脏细胞；B6WT组，受者接受野生型C57BL／6小鼠骨髓和脾脏细胞；B6CCR5KOBMC组，受者只接受C57BL／6CCR5^-/-小鼠骨髓细胞；B6、WT BMC组，受者只接受野生型C57BL／6小鼠骨髓细胞。结果表明：较之B6、WT组，B6CCR5KO组小鼠以更快的速度死于急性GVHD；其受者体内的CD8^＋T细胞更大量的增殖；其T细胞恢复后产生更多的INF-γ和TNF-α并且由于其T细胞有丝分裂原刀豆素水平处于较高水平，从而进一步促进T细胞的增殖，提示CCR5的作用之一是下调参与排异反应的供者CD8^＋T细胞的增殖。组织学评价提示，移植剔除CCR5基因受者细胞的小鼠肾脏出现了病理损伤并且肝脏存在有更为严重的病理变化。结论：剔除CCR5基因的异基因骨髓移植使GVHD发病率的增加，供者CD8^＋T细胞在受者体内增殖增加以及肝肾损害加重，这提示CCR5在异基因骨髓移植中起着重要作用。     

Burn-induced acute lung injury requires a functional Toll-like receptor 4

The role of the Toll-like receptor 4 (TLR4), a component of the innate immune system, in the development of burn-induced acute lung injury (ALI) has not been completely defined. Recent data suggested that an intact TLR4 plays a major role in the development of organ injury in sterile inflammation. We hypothesized that burn-induced ALI is a TLR4-dependent process. Male C57BL/6J (TLR4 wild-type [WT]) and C57BL/10ScN (TLR4 knockout [KO]) mice were subjected to a 30% total body surface area steam burn. Animals were killed at 6 and 24 h after the insult. Lung specimens were harvested for histological examination after hematoxylin-eosin staining. In addition, lung myeloperoxidase (MPO) and intercellular adhesion molecule 1 immunostaining was performed. Lung MPO was measured by an enzymatic assay. Total lung keratinocyte-derived chemoattractant (IL-8) content was measured by enzyme-linked immunosorbent assay. Western blot was performed to quantify phosphorylated IκBα, phosphorylated nuclear factor κB p65 (NF-κBp65), and high mobility group box 1 expression. Acute lung injury, characterized by thickening of the alveolar-capillary membrane, hyaline membrane formation, intraalveolar hemorrhage, and neutrophil infiltration, was seen in WT but not KO animals at 24 h. Myeloperoxidase and intercellular adhesion molecule 1 immunostaining of KO animals was also similar to sham but elevated in WT animals. In addition, a reduction in MPO enzymatic activity was observed in KO mice as well as a reduction in IL-8 levels compared with their WT counterparts. Burn-induced ALI develops within 24 h after the initial thermal insult in our model. Toll-like receptor 4 KO animals were clearly protected and had a much less severe lung injury. Our data suggest that burn-induced ALI is a TLR4-dependent process.