内源性硫化氢和胱硫醚-β-合成酶mRNA在支气管哮喘大鼠中的表达及意义

目的观察支气管哮喘（简称哮喘）大鼠胱硫醚-β-合成酶（eystathionine-β-synthase,CBS）tuRNA及硫化氢（hydrogensulfide,HzS）的表达变化,探讨CBS与HzS的相关性。方法采用哮喘大鼠模型,将30只SD大鼠随机分成哮喘组、对照组、地塞米松组,分光光度法测定血浆H2S含量,RT—PCR法检测肺组织CBSmRNA的表达水平。结果血浆中H2S含量哮喘组显著低于对照组,地塞米松组与哮喘组、对照组相比差异无统计学意义。肺组织CBSmRNA的表达水平哮喘组、地塞米松组显著低于对照组,地塞米松组显著高于哮喘组。肺组织CBSmRNA和血浆中Hzs的表达水平呈显著正相关。结论哮喘大鼠血浆中H2S的含量和肺组织CBSmRNA的表达下降,两者呈正相关,提示可能参与了哮喘的炎症过程。地塞米松改善哮喘炎症可能部分通过H2S／CBS体系而起作用。     

内源性硫化氢和胱硫醚-β-合成酶mRNA在支气管哮喘大鼠中的表达及意义

目的 观察支气管哮喘(简称哮喘)大鼠胱硫醚-β-合成酶(cystathionine-β-synthase,CBS)mRNA及硫化氢(hydrogen sulfide,H2S)的表达变化,探讨CBS与H2S的相关性.方法 采用哮喘大鼠模型,将30只SD大鼠随机分成哮喘组、对照组、地塞米松组,分光光度法测定血浆H2S含量,RT-PCR法检测肺组织CBS mRNA的表达水平.结果 血浆中H2S含量哮喘组显著低干对照组,地寒米松组与哮喘组、对照组相比差异无统计学意义.肺组织CBS mRNA的表达水平哮喘组、地塞米松组显著低于对照组,地塞米松组显著高于哮喘组.肺组织CBS mRNA和血浆中H2S的表达水平呈显著正相关.结论 哮喘大鼠血浆中H2S的含量和肺组织CBS mRNA的表达下降,两者呈正相关,提示可能参与了哮喘的炎症过程.地塞米松改善哮喘炎症可能部分通过H2S/CBS体系而起作用.     

丁苯酞对慢性酒精中毒大鼠海马内硫化氢和纤维状肌动蛋白的影响

目的探究丁苯酞(NBP)对慢性酒精中毒大鼠学习记忆能力、海马内硫化氢(H2S)和纤维状肌动蛋白(F-actin)含量的影响。方法将50只SD雄性大鼠随机分为5组,除对照组外,将含酒的水作为大鼠唯一水来源,并逐渐增加酒精含量,采用自由饮用方法建立慢性酒精中毒模型。42 d后按慢性酒精中毒大鼠戒断评分表于末次饮酒后6 h检测大鼠模型,NBP低、中、高剂量组大鼠灌胃不同剂量NBP(大约14 d),饮酒结束后利用Y型电迷宫测试酒精中毒大鼠的学习记忆能力,随后检测海马组织H2S和F-actin的含量。结果与对照组大鼠学习记忆成绩(40.38±5.97)、H2S含量(23.25±3.61)和F-actin在阳性细胞中的表达相比,模型组大鼠学习记忆成绩(83.25±5.47)和H2S含量(43.86±6.95)均升高,F-actin的阳性表达降低(P<0.01)。与模型组大鼠相比,NBP中、高剂量组大鼠学习记忆成绩(64.75±4.71)、(70.00±4.72)和H2S含量(32.21±5.32)、(36.78±7.29)nmol/g均降低,F-actin的阳性表达升高(P<0.01)。结论 NBP能够减轻慢性酒精中毒大鼠对酒精的依赖,缓解酒精对大鼠学习记忆能力的影响,可能与NBP影响H2S和F-actin的含量有关。     

β-淀粉样蛋白对大鼠海马S100β表达及学习记忆的影响

目的　探讨 β-淀粉样蛋白 (Aβ)沉积与大鼠海马 S1 0 0 β表达的相关性及其在大鼠学习记忆中的作用。方法　采用不同浓度的 Aβ2 5-35选择大鼠海马 CA1区进行定位注射 ,通过行为学测试、光镜形态学观察 ,免疫组化染色的方法 ,观测大鼠学习记忆、海马 CA1区神经元和 S1 0 0β阳性细胞形态、数目的变化。结果　术后 7d,随着 Aβ2 5- 35脑内注射浓度的增加 ,实验组较对照组大鼠的学习记忆能力明显下降 (P<0 .0 5) ,海马CA1区神经元数目明显减少 (P<0 .0 5) ,而 S1 0 0β阳性细胞数则显著增多 (P<0 .0 5)。结论　 Aβ2 5- 35可以明显上调 S1 0 0β的表达 ,两者之间存在剂量效应关系 ;Aβ2 5- 35具有神经毒性作用 ,可以引起海马神经元丢失 ,造成大鼠学习记忆下降 ;S1 0 0 β的高水平表达可能与海马 CA1区神经元丢失以及大鼠的学习记忆下降有密切关系。     

增龄对大鼠阴茎海绵体内硫化氢信号通路的影响

目的研究增龄对大鼠阴茎海绵体组织中硫化氢(H_2S)信号通路的影响从而进一步明确老年性勃起功能障碍(ED)的发病机制。方法随机分别挑选3、9、18月龄雄性健康Wistar大鼠(相同月龄组体重相近)各10只并按3、9、18月龄依次分为A、B、C组。三组适应性喂养2 w后行阴茎海绵体内压/平均颈动脉压(ICPmax/MAP)值的检测,而后采血以测定血浆H_2S浓度,处死大鼠取阴茎组织以检测阴茎组织H2S含量及生成率,各组阴茎海绵体组织内胱硫醚-β-合成酶(CBS)与胱硫醚-γ-裂解酶(CSE)的含量用Western印迹法测出。结果随着月龄增长,ICPmax/MAP(5、7 V)值均依次显著减小(P0.05),血浆H_2S浓度、阴茎海绵体组织H_2S含量及生成率均依次显著性降低(P0.05),阴茎组织内CSE和CBS的含量也分别明显减低(P0.05)。结论增龄中,大鼠阴茎组织内CSE和CBS表达减弱,内源性H_2S减少,这可能是大鼠老年性ED致病机制之一。     

亚甲基四氢叶酸还原酶和胱硫醚-β-合成酶基因多态与唐氏综合征发生的关系

目的探讨母体5,10-亚甲基四氢叶酸还原酶(MTHFR)基因和胱硫醚-β-合成酶(CβS)基因多态性与唐氏综合征(DS)发生的关系。方法应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测70例DS患儿母亲和117例对照女性的MTHFR两个多态位点(C677T、A1298C),利用SHEsis在线分析软件进行单体型和连锁不平衡分析;PCR法检测CβS 844Ins68基因型。Pearsonχ2检验各基因和基因型频率分布的差异。计算比值比评价相对危险度。结果 MTHFR基因两个多态位点及CβS 844Ins68突变基因频率和基因型频率在病例组和对照组中分布无显著差异(P0.05)。MTHFR 677T/T/1298(C/C+C/A)联合基因型显著地增加DS发生风险(OR=8.46,95%CI:0.90~79.51,P0.05)。MTHFR两个多态位点存在连锁不平衡(D'=0.68);677T-1298C单体型与DS发生显著相关(OR=5.22,95%CI:1.37~19.94,P0.01)。结论 MTHFR两个位点变异联合分析及677T-1298C单体型可能是DS发生的风险因素,不能排除叶酸代谢酶基因多态在DS发生中的作用。     

何首乌对D-gal致衰大鼠学习记忆能力及海马内突触素含量的影响

目的　探讨何首乌对致衰大鼠学习记忆能力及海马内突触素含量的影响。方法　选用Wistar大鼠 ,用D 半乳糖 (D gal)制成亚急性衰老模型 ,并观察药物对学习记忆能力的影响 ;通过免疫组化和计算机图象分析研究药物对致衰大鼠海马内突触素含量的影响。结果　何首乌可使致衰大鼠Y 迷宫分辨学习的正确次数明显增加 ,明暗箱被动回避反应的步入潜伏期也显著延长。何首乌可使致衰大鼠海马内突触素免疫反应产物的校正光密度值 (COD)显著高于D gal模型组。结论　何首乌能改善D gal致衰大鼠学习记忆能力及提高海马内突触素的含量。     

氨基羟乙酸对慢性酒精中毒大鼠海马线粒体及纤维状肌动蛋白的影响

目的探究氨基羟乙酸(AOAA)对慢性酒精中毒大鼠学习记忆能力、海马硫化氢、线粒体形态结构、线粒体ATP酶活性和纤维状肌动蛋白(F-actin)含量的影响。方法将60只SD雄性大鼠随机平均分为3组,除正常对照(NC)组外,每组饮含6%(V/V)酒精水溶液28 d,酒精溶液每日9∶00配制,置换。14 d后,AOAA(剂量为5 mg/kg)溶解在1 ml生理盐水中,AOAA治疗(AR)组每日腹腔注射一次,连续14 d。NC组每日腹腔注射1 ml生理盐水。结束后采用Y型电迷宫测试大鼠的学习记忆能力,随后检测海马组织H2S含量、ATP酶活性及F-actin表达,并在电镜下观察海马组织细胞内线粒体形态结构。结果与NC组相比,模型(M)组学会所需训练次数和H2S含量均升高,线粒体ATP酶活性和海马组织区F-actin阳性表达均降低,有极显著性差异(P0. 01);与M组相比,AR组学会所需训练次数和H2S含量均降低,ATP酶活性和海马组织F-actin阳性表达均升高,有极显著性差异(P0. 01)。结论 AOAA能够减轻慢性酒精中毒大鼠的症状,改善学习记忆能力,可能与AOAA影响H2S的含量、线粒体结构、Factin的含量有关。     

β-淀粉样蛋白对大鼠大脑α7尼古丁受体表达和学习记忆能力的影响

目的研究β-淀粉样蛋白(Aβ1~42)对大鼠大脑神经型尼古丁受体α7亚单位表达及学习记忆能力的影响,探讨这些改变在阿尔茨海默病(AD)发病机制中的作用。方法用立体定向法将Aβ1~42(1mg/ml,5μl)注入Wistar大鼠侧脑室,用免疫组化方法测定大鼠大脑中Aβ1~42的沉积,用Western印迹法和RT-PCR方法分别测定神经型尼古丁受体α7亚单位在蛋白和基因水平的表达,用水迷宫法检测大鼠的学习记忆能力。结果与对照组比较,经Aβ1~42侧脑室注射后的大鼠大脑皮层出现明显Aβ1~42沉积;神经型尼古丁受体α7亚单位蛋白质表达水平明显降低;α7亚单位mRNA表达水平明显升高;大鼠学习记忆能力明显降低。结论Aβ1~42引起神经型尼古丁受体α7亚单位的表达明显改变,并导致大鼠学习记忆力降低,可能是AD发病机制中的重要因素。     

α-亚麻酸对大鼠学习记忆功能和海马神经元的影响

目的 探讨α-亚麻酸对第二代大鼠学习记忆功能和海马神经元的影响.方法 以富含α-亚麻酸的青花椒籽油饲料饲喂SD大鼠两代,Morris水迷宫测定仔代大鼠的学习记忆能力,电子显微镜观察仔代大鼠海马神经元超微结构的变化.结果 青花椒籽油组大鼠学习记忆能力有一定程度提高;青花椒籽油组海马神经元蛋白质合成增强,细胞分化程度增加.结论 富含α-亚麻酸的青花椒籽油对大鼠大脑具有一定的营养和保健作用.     

促红细胞生成素对慢性脑缺血大鼠认知障碍及海马星形胶质细胞的影响

目的 观察促红细胞生成素干预后慢性脑缺血大鼠的空间学习记忆功能及海马星形胶质细胞的变化.方法 结扎大鼠双侧颈总动脉建立慢性脑缺血模型,治疗组术后给予EP01 000 U/kg腹腔内注射5d.术后第8周时3组大鼠Morris水迷宫测试后断头取脑做免疫组化检测观察CA1区胶质纤维酸性蛋白(GFAP)表达.结果 缺血组水迷宫表现同假手术组和EPO治疗组相比有显著差异(P＜0.01).EPO干预能改善慢性脑缺血大鼠的空间学习记忆能力(P＜0.01).缺血组海马CA1区GFAP表达较假手术组相比明显增多,而EPO组海马CA1区GFAP表达同缺血组相比明显降低(P＜0.01).海马CA1区GFAP阳性细胞数与学习记忆能力呈负相关.结论 EPO能显著改善慢性脑缺血大鼠认知障碍,机制可能与减少海马星形胶质细胞增生有关.     

Selective impairment of hippocampal neurogenesis by chronic alcoholism: protective effects of an antioxidant

A major pathogenic mechanism of chronic alcoholism involves oxidative burden to liver and other cell types. We show that adult neurogenesis within the dentate gyrus of the hippocampus is selectively impaired in a rat model of alcoholism, and that it can be completely prevented by the antioxidant ebselen. Rats fed for 6 weeks with a liquid diet containing moderate doses of ethanol had a 66.3% decrease in the number of new neurons and a 227-279% increase in cell death in the dentate gyrus as compared with paired controls. Neurogenesis within the olfactory bulb was not affected by alcohol. Our studies indicate that alcohol abuse, even for a short duration, results in the death of newly formed neurons within the adult brain and that the underlying mechanism is related to oxidative or nitrosative stress. Moreover, these findings suggest that the impaired neurogenesis may be a mechanism mediating cognitive deficits observed in alcoholism.     

左归丸、右归丸对老年大鼠海马、杏仁核氨基酸类和单胺类神经递质含量变化的影响

目的 观察左归丸、右归丸对老年大鼠海马、杏仁核氨基酸类神经递质Asp、Glu、Gly、GABA和单胺类神经递质5-HT、NE含量变化的影响，探讨老年机体神经元的神经递质的变化，以及左归丸、右归丸延缓老年大鼠神经内分泌调控退化的作用机制。方法 以自然衰老大鼠为动物模型，分设4组：青年对照组、老年对照组、老年左归丸组、老年右归丸组。采用HPLC-荧光法，检测各组大鼠海马、杏仁核Asp、Glu、gly、GABA含量变化；采用ELISA法，检测5-HT、NE含量变化。结果 与青年对照组相比，老年对照组大鼠海马、杏仁核Asp、Glu、Gly、GABA含量有不同程度升高，而与老年对照组相比，两用药组含量有不同程度降低。同时，老年对照组大鼠海马NE含量减少，左归丸组能提高老年大鼠海马NE含量。而各组大鼠5-HT含量无明显差异。结论 左归丸、右归丸通过不同程度地纠正老年大鼠海马和杏仁核脑区氨基酸类和单胺类神经递质的紊乱状态，使兴奋性和抑制性神经递质趋向平衡，从而有助于改善大脑边缘系统，延缓机体衰老。     

Effects of chronic alcohol and repeated deprivations on dopamine D1 and D2 receptor levels in the extended amygdala of inbred alcohol-preferring rats

BACKGROUND: Dopaminergic (DA) activity in the extended amygdala (EA) has been known to play a pivotal role in mediating drug and alcohol addiction. Alterations of DA activity within the EA after chronic exposure to alcohol or substances of abuse are considered a major mechanism for the development of alcoholism and addiction. To date, it is not clear how different patterns of chronic alcohol drinking affect DA receptor levels. Therefore, the current studies investigated the effects of chronic ethanol consumption, with or without deprivations, on D1 and D2 receptor densities within the EA. METHODS: Inbred alcohol-preferring (iP) rats were divided into 3 groups with the following treatments: (1) water for 14 weeks; (2) continuous alcohol (C-Alc) for 14 weeks [24-hour concurrent access to 15 and 30% (v/v) ethanol]; or (3) repeatedly deprived of alcohol (RD-Alc) (24-hour concurrent access to 15 and 30% ethanol for 6 weeks, followed by 2 cycles of 2 weeks of deprivation of and 2 weeks of reexposure to ethanol access). At the end of 14 weeks, the rats were killed for autoradiographic labeling of D1 and D2 receptors. RESULTS: Compared with the water control group, both the C-Alc and the RD-Alc groups displayed increases in D1 receptor binding density in the anterior region of the Acb core, whereas the RD-Alc group displayed additional increases in D1 receptor binding density in anterior regions of the lateral and intercalated nuclei of the amygdala. Additionally, both C-Alc and RD-Alc rats displayed increases in D2 receptor binding density in anterior regions of the Acb shell and core, whereas RD-Alc rats displayed additional increases in D2 receptor binding density in the dorsal striatum. CONCLUSION: The results of this study indicate that 14-week extended alcohol drinking with continuous chronic or repeated deprivations increase binding sites of D1 and D2 receptors in specific regions of the EA with greater sensitivity in the anterior regions. The repeated deprivation has greater effect on altering D1 and D2 receptor binding sites in the Acb, dorsal striatum, and subamygdala regions. The current result indicates that the two drinking paradigms may have common as well as differential mechanisms on alteration of dopamine receptor-binding sites in specific regions of the EA.     

Effects of ultrasound-combined microbubbles on hippocampal AchE fibers in rats

Objective:To investigate the protective effect of ultrasound-combined microbubbles on hippocampal acetylcholinesterase(AchE) fibers in rats.Methods:According to random digits table,60 SD rats were divided into two groups,marrow stromal cells(MSCs) intracranial transplantation group and MSCs intracranial transplantation + ultrasonic microbubbles group.Marrow stromal cells were cultivated and isolated in vitro;12 weeks after transplantation,spatial learning and memorizing abilities of rats were assessed by Morris water maze;AchE staining method was used to observe changes in density and appearance of AchE staining positive fibers in hippocampal CA1 region.Results:There was asignificant increase in spatial learning and memorizing abilities of rats in MSCs intracranial transplantation + ultrasonic microbubbles group.Hippocampal AchE staining suggested an increase in the density of AchE staining positive fibers in MSCs intracranial transplantation group;the fibers were regular,intact and dense.Density of hippocampal AchE positive fibers was negatively correlated with the escape latent period and was positively correlated with percentage of the time needed to cross each platform quadrant.Conclusions:Better promotion of spatial learning and memorizing abilities of rats in MSCs intracranial transplantation + ultrasonic microbubbles group may be related with the protective effect of ultrasound-combined microbubbles on hippocampal acetylcholine fibers.     

Effects of chronic choline and lecithin on mouse hippocampal dendritic spine density

Dendritic spines, which project from the dendrites of central neurons, are thought to contribute to the amount of contact area available for synaptic connections. The density of these spines has been found to correlate with learning and memory function, and there is a progressive decrease in dendritic spine density with aging. In addition, experimental animals given a choline-enriched diet have an increase in neocortical spine density compared to controls. In this study, the dendritic spine density of hippocampal pyramidal cells was examined in aged mice which had received life-long choline enriched, choline deficient or lecithin enriched diets. These treatments had no effect on hippocampal dendritic spine density compared to control. The results indicate that dietary supplementation may have different effects in different brain areas and that the relative increase in learning and memory function in aged animals given a choline or lecithin enriched diet is not due to an increase in hippocampal dendritic spine density.     

Beta-adrenergic modulation of emotional memory-evoked human amygdala and hippocampal responses

Human emotional experience is typically associated with enhanced episodic memory. We have used functional magnetic resonance imaging to demonstrate that successful encoding of emotional, compared to neutral, verbal stimuli evokes increased human amygdala responses. Items that evoke amygdala activation at encoding evoke greater hippocampal responses at retrieval compared to neutral items. Administration of the beta-adrenergic antagonist propranolol at encoding abolishes the enhanced amygdala encoding and hippocampal retrieval effects, despite propranolol being no longer present at retrieval. Thus, memory-related amygdala responses at encoding and hippocampal responses at recognition for emotional items depend on beta-adrenergic engagement at encoding. Our results suggest that human emotional memory is associated with a beta-adrenergic-dependent modulation of amygdala-hippocampal interactions.