抗氧化剂TA9901抑制加速老化鼠脑淀粉样颗粒的沉积

目的　观察抗氧化剂TA990 1对加速老化鼠P 8(SAM P 8)脑中淀粉样颗粒 (MSG)沉积的影响 ,为临床治疗阿尔采默病 (AD)提供科学依据。　方法　 2 5月龄雄性SAM P 8小鼠随机分为对照组、TA1组、TA2组和VE组 ,分别给予正常饮食、0 0 5 %TA990 1、0 5 %TA990 1和特制VitaminE(VE)饲料 (5 0 0mgVE kg)喂养 3 5个月。用Go mori六胺银法显示淀粉样颗粒 ,对海马CA1区的银染颗粒 (MSG)的体视学参数和分布进行图像分析。　结果　MSG为圆形和卵圆形 ,主要分布于海马、皮质深层和小脑 ;海马内MSG主要成群分布于各层。各组海马CA1区MSG颗粒数比较 ,差异均无显著性 (P >0 0 5 ) ,但TA1组、TA2组和VE组的MSG颗粒直径和面积均较对照组明显减小 (P <0 0 5 ) ,以TA2和VE组更为显著 (P <0 0 1) ;各实验组MSG的平均灰度均较对照组降低 (P <0 0 1) ;对照、TA1、TA2和VE组的低密度颗粒区分别占 12 0 5 %、36 5 2 %、4 7 91%和 4 4 6 5 % ,实验组在低密度区的颗粒数明显增多。　结论　TA990 1减少了SAM P 8脑中淀粉样颗粒的大小和密度 ,显示TA990 1对脑内淀粉样颗粒沉积有抑制作用     

抗氧化剂TA9901对加速老化鼠(SAM-P/8)行为学的影响

目的　观察抗氧化剂TA990 1对实验动物学习记忆功能的影响 ,为其临床应用提供实验依据。方法　用加速老化鼠 (SAM) P/ 8小鼠 2 0只随机分为对照组、TA1组 (0 0 5 %TA990 1)、TA2组 (0 5 %TA990 1)、和VE组 (5 0 0mgVE/kg饲料 ) ,分别进行Morris水迷宫行为学测试 ,观察TA990 1对SAM P/ 8小鼠的作用。结果　对照组平均逃避潜伏期是 (6 2 78± 8 75 )sec ,TA1组、TA2组和VE组的逃避潜伏期分别为 (5 3 94± 5 79)、(36 38± 4 77)和 (40 2 2± 5 5 1)sec。与对照组相比 ,TA2组和VE组逃避潜伏期减少均具有显著性意义 (P <0 0 5 ) ,TA1组和TA2组比较也有显著性差异 (P <0 0 5 )。空间探索试验结果以平台象限的游泳距离占总的游泳距离的百分比判断动物的空间学习记忆能力 ,对照组、TA1组、TA2组和VE组小鼠的平台象限游泳距离所占的百分比分别为 (11 33± 2 5 1)、(15 0 9± 4 0 2 )、(2 4 35± 7 89)和 (2 0 93± 5 0 2 ) % ,对照组与TA2组和VE组相比 ,差异均具有显著性 (P <0 0 5 ) ,TA1组与TA2组之间差异也有显著性 (P <0 0 5 )。结论　TA990 1能显著改善SAM P/ 8的学习记忆能力 ,初步显示TA990 1有改善学习记忆功能及抗痴呆的药理作用。     

出生前后胆碱乙酰转移酶在大鼠脑内定位的研究

为探讨大鼠胚胎及生后发育期间脑内胆碱乙酰转移酶(choline acetyltransferase,ChAT)的变化规律,本研究采用免疫组织化学方法,观察了胚胎和生后大鼠脑内ChAT样(ChAT-like immunoreactive,ChAT-LI)神经元表达的数量和灰度值。结果显示:ChAT-LI产物主要表达在细胞体、纤维及其末梢。ChAT-LI神经元最先在胚胎第12d(embryonic day12,E12),出现于端脑;E14时可见于隔核和中缝核;E16时内嗅区出现ChAT-LI神经元;E18时出现于视前区节细胞层;E20时,海马内部可见部分ChAT-LI纤维;生后第0d(postnatal day0,P0),少量带有生长锥的ChAT-LI纤维出现于海马;P5时,海马内出现ChAT-LI神经元,且ChAT-LI纤维进一步增加;P10时,海马、内嗅区和穹隆等结构中都可见ChAT-LI神经元胞体及纤维。上述结果提示:胆碱能神经元在出生前后的大鼠脑内,尤其是在海马记忆回路的发育过程中存在一定的变化规律,它们可能是学习记忆等功能的结构基础。     

抗衰益智方Ⅰ对小鼠学习记忆能力以及海马胆碱乙酰转移酶表达的影响

目的：观察抗衰益智方Ⅰ（KYFⅠ）对正常小鼠学习记忆能力和中枢胆碱乙酰转移酶表达的影响。方法:各组小鼠除正常对照组灌服双蒸水外,中药组(分为低、中、高剂量组）灌服相应剂量KYFⅠ,连续灌胃40 d。从第35 d起灌胃结束后进行Morris水迷宫测试,连续5 d。水迷宫测试结束后检测小鼠海马组织胆碱乙酰转移酶（ChAT）和乙酰胆碱酯酶（AChE）的活性,并分别用免疫组化和Western blotting方法观察小鼠海马ChAT阳性神经元的数量变化以及ChAT蛋白的表达。结果:与对照组比较,KYFⅠ高剂量组小鼠水迷宫学习成绩较好;同时,KYFⅠ高剂量组小鼠海马组织内ChAT活性明显增高,AChE活力降低;免疫组化和Western blotting结果显示KYFⅠ高剂量组小鼠海马CA1区ChAT阳性神经元数量增加,ChAT蛋白表达升高。结论:高剂量KYFⅠ可以提高正常小鼠学习记忆能力,其机制可能与KYFⅠ抑制小鼠海马组织AChE活性,提高ChAT活性、升高ChAT蛋白的表达,从而促进脑内乙酰胆碱（ACh）的合成有关。     

空间学习记忆引起脑内胆碱乙酰转移酶活性的变化

空间学习记忆引起脑内胆碱乙酰转移酶活性的变化△左萍萍刘娜陈纪君张世仪（中国医学科学院基础医学研究所，中国协和医科大学基础医学院，北京１００００５）已有资料表明，中枢乙酰胆碱是参与学习记忆的重要神经递质。主要证据是Ｍ－胆碱受体阻断剂（如东莨菪碱和阿托品...     

异动症大鼠基底节谷氨酸脱羧酶和胆碱乙酰转移酶表达的变化

观察左旋多巴诱发异动症(LID)大鼠模型基底节区谷氨酸脱羧酶(GAD)和胆碱乙酰转移酶(CAT)表达的变化,探讨LID发生过程中纹状体神经元的可塑性。间断性给帕金森病(PD)大鼠腹腔注射左旋多巴28d(每天1次)制备LID大鼠模型,应用免疫组织化学方法观察基底节区GAD和CAT的表达。结果发现模型复制成功后出现了与人类LID相似的对侧上肢、躯干和口面部异常不自主运动(AIM)。与正常组比较尾壳核及苍白球区GAD明显增加,黑质网状部GAD明显减少。尾壳核区CAT明显减少。提示慢性间断性给PD大鼠左旋多巴能复制出LID大鼠模型,其纹状体区GABA能投射神经元及胆碱能中间神经元功能发生了改变,与LID的发生可能有关。     

面神经损伤的针刺效应与面神经核胆碱乙酰转移酶的关系

目的:揭示针刺促进损伤面神经再生修复的机制。方法:大耳白兔分为假手术组、模型组、西药组、传统针刺组、电针刺激组,每组又分为术后4个时间点,应用神经卡压法造成面神经损伤模型,观察各组家兔面神经核中胆碱乙酰转移酶(ChAT)的变化。结果:术后细胞核核仁偏位,术后2、3、4周时模型组胞体肿胀,截面积均明显大于假手术组、西药组、传统针刺组、电针刺激组,尼氏体明显减少,随治疗时间延长,西药组、传统针刺组、电针刺激组均有不同程度的尼氏体增多,其中电针刺激组增多较明显。电针刺激组ChAT于各时间点均明显好于其他对照组,西药组、传统针刺组、电针刺激组均有随治疗时间延长ChAT表达增多的趋势,且有显著性差异。结论:穴位针刺可提高家兔面神经核中ChAT的表达,并对损伤面神经修复有促进作用。     

氨甲酰胆碱引起的促钠排泄反应和下丘脑室旁核胆碱乙酰转移酶免疫阳性反应变化

本研究选用清醒SD雄性大鼠,通过在体实验和免疫组化方法,观察大鼠侧脑室注射胆碱能激动剂氨甲酰胆碱(carbachol)0.5μg后,肾钠排泄量变化与室旁核胆碱乙酰转移酶(ChAT)表达的变化。结果显示侧脑室注射氨甲酰胆碱后40min,肾钠排泄量显著增加,室旁核的ChAT免疫反应阳性神经元数目明显增多(P<0.05),免疫染色强度明显增强(P<0.05);阿托品预处理后钠排泄量显著减少,下丘脑室旁核的ChAT免疫阳性反应(ChATIR)明显下降(P<0.05)。上述结果提示,侧脑室注射氨甲酰胆碱后,促钠排泄反应增强,下丘脑室旁核胆碱能神经元活性增强,阻断胆碱能受体后可下调氨甲酰胆碱诱导的上述变化。     

乙酰胆碱酯酶阳性神经元在鼠脑的分布和形态特征

本文用乙酰胆碱酯酶(AChE)再生技术,研究AChE阳性神经元在鼠脑的分布和形态特征。按其染色程度,可见强度、中度和轻度三种染色细胞。强染色细胞多数是较大的多极细胞,主要分布于纹状体、基底前脑、下丘脑、黑质、红核、蓝斑,腹侧被盖区、臂旁核、桥被盖核和脑神经运动核。本文将AChE染色结果和胆碱乙酰转移酶(ChAT)免疫组织化学资料进行了比较,对AChE和胆碱能神经元的关系,以及AChE阳性神经元的性质和意义,进行了讨论。     

当归芍药散对SAM-P8小鼠海马CA1区、齿状回锥体细胞的影响

目的观察当归芍药散(DSS)对快速老化小鼠海马CA1区、齿状回锥体细胞数量的影响。方法选用雌性SAM-P8鼠36只,分成4组:预防组(3月龄)、预防对照组(3月龄)、治疗组(6月龄)、治疗对照组(6月龄),治疗组以DSS(浓度为0.5g/mL)灌胃1个月,预防组自由饮用DSS(0.02%,v/v)4个月,对照组给予冷开水,给药结束后取脑、冰冻切片、尼氏染色,Leica图像分析系统分析海马CA1区、齿状回锥体细胞层尼氏染色的平均灰度。结果海马CA1区锥体细胞层尼氏染色的平均灰度各组间差异不明显(P>0.05)。预防组齿状回锥体细胞层尼氏染色的平均灰度明显多于其余各组(P<0.05)。结论低剂量长期服用DSS可增加老年性痴呆模型SAM-P8小鼠的齿状回锥体细胞数量。     

Choline Acetyltransferase Activity in the Denervated Urinary Bladder of the Rat

After extirpation of the pelvic ganglia the choline acetyltransferase activity decreased markedly indicating that most of the postganglionic cholinergic neurones of the bladder take this route. A small decrease in the activity of this enzyme was found after section of the hypogastric nerves, showing that these nerves contribute to some extent to the cholinergic innervation. The residual enzyme activity found after a combination of the two surgical procedures suggests that neurones relay distal to the level of the section of the hypogastric nerves and pass outside the pelvic ganglia and (or) that neurones pass the pelvic ganglia and relay distal to them. Electrical stimulation of the hypogastric nerves after extirpation of the pelvic ganglia and the use of blocking drugs showed on the existence of cholinergic neurones passing outside the pelvic ganglia, some of them relaying distal to the point of stimulation.     

Distinct Localization of Peripheral and Central Types of Choline Acetyltransferase in the Rat Cochlea

We previously discovered a splice variant of choline acetyltransferase (ChAT) mRNA, and designated the variant protein pChAT because of its preferential expression in peripheral neuronal structures. In this study, we examined the immunohistochemical localization of pChAT in rat cochlea and compared the distribution pattern to those of common ChAT (cChAT) and acetylcholinesterase. Some neuronal cell bodies and fibers in the spiral ganglia showed immunoreactivity for pChAT, predominantly the small spiral ganglion cells, indicating outer hair cell type II neurons. In contrast, cChAT- and acetylcholinesterase-positive structures were localized to fibers and not apparent in ganglion cells. After ablation of the cochlear nuclei, many pChAT-positive cochlear nerve fibers became clearly visible, whereas fibers immunopositive for cChAT and acetylcholine esterase disappeared. These results suggested that pChAT and cChAT are localized in different systems of the rat cochlea; pChAT in the afferent and cChAT in the efferent structures.     

Acetylcholinesterase Activity,Choline Acetyltransferase and Vesicular Acetylcholine Transporter Immunoreactivities in the Rat Adrenal Gland During Postnatal Development

From postnatl‐day‐0 to postnatal‐day‐2, a few acetylcholinesterase (AChE)‐active and choline acetytransferase (ChAT)‐immunoreactive nerve fibers and relatively numerous vesicular acetylcholine transporter (VAChT)‐immunoreactive puncta were observed in the rat adrenal medulla. Despite relatively numerous clear vesicles in the nerve fibers, the synthesis and hydrolysis of acetylcholine may not be fully activated until postnatal‐day‐2. The number of AChE‐active and ChAT‐immunoreactive nerve fibers dramatically increased and that of VAChT‐immunoreactive puncta gradually increased from postnatal‐day‐3 to postnatal‐week‐1. The synthesis and hydrolysis of acetylcholine may be dramatically activated in the nerve fibers of the medulla until postnatal‐week‐1. From postnatal‐week‐2 to postnatal‐week‐3, the number of AChE‐active and the ChAT‐immunoreactive nerve fibers gradually increased and reached the adult levels. The VAChT‐immunoreactive puncta per unit area was maximum number at postnatal‐week‐2. The synthesis and hydrolysis of acetylcholine in the nerve fibers of the medulla may be completed between postnatal‐week‐2 to postnatal‐week‐3. The diameter of the VAChT‐immunoreactive puncta gradually increased from postnatal‐day‐0 with aging. However, the number of the VAChT‐immunoreactive puncta gradually decreased from postnatal‐week‐2 onwards. In electron‐microscopy, the VAChT‐immunoreactive deposits were seen in clusters of clear vesicles, and the diameter of the nerve fibers and the number of clear vesicles at postnatal‐week‐8 increased compared with those at postnatal‐week‐2. The AChE‐active, ChAT‐immunoreactive, and VAChT‐immunoreactive nerve fibers observed around noradrenaline (NA) cells were denser than those around adrenaline (A) cells in the medulla at postnatal‐week‐8. These suggest that the preferential innervation of NA and A cells may cause the differential secretion NA and A. Anat Rec, 292:371–380, 2009. © 2009 Wiley‐Liss, Inc.     

Choline acetyltransferase immunohistochemistry in brains of alzheimer's disease patients and controls

Choline acetyltransferase (ChAT)-containing neuronal structures of the basal forebrain were studied by ChAT immunohistochemistry in the brains of persons dying with Alzheimer's disease (SDAT), as well as age-matched controls dying without neurological disorder. A loss of >50% in ChAT-containing neurons was found in the substantia innominata in the SDAT group. In contrast, there was no reduction in the number of ChAT-containing neurons of the putamen as compared with controls. The data confirm the reason for the reduction of ChAT as measured biochemically in the neocortex of SDAT cases, and support the cholinergic hypothesis of memory.     

FT-IR光谱法研究TA9902抑制Aβ1-42聚集的分子机制

目的：研究TA9902引起Aβ1-42二级结构变化，了解其抑制Aβ聚集和纤维形成的机制。 方法： 用傅里叶变换红外光谱法（FT-IR）曲线拟合定量分析和特征频谱分析Aβ老化后及TA9902干预后二级结构的变化。 结果： 1 700-1 600 cm-1之间的酰胺I带分析，Aβ1-42单独孵育30 min时，β-折叠片为46.53％；Aβ1-42老化72 h，β-折叠片为65.13％，β-折叠片增加了19.4％。TA9902与Aβ1-42作用β-折叠片为29.04％；与Aβ1-42老化72 h相比，TA9902的存在明显减少β折叠片的含量(下降了36.09％)，β-转角的含量明显升高(升高57.56％)，α-螺旋也略有升高（2.93％）。呈现出明显的β折叠片向β-转角的转化。其它基团特征峰位显示，TA9902中有酮类尤其是饱和链状酮或α-二酮和烷烃类的-CH2和-CH参与了Aβ1-42的分子变构。 结论： TA9902明显抑制Aβ1-42β-折叠的形成，同时也使Aβ1-42肽的侧链基团发生了化学修饰，提示Aβ的聚集和纤维形成与其分子β-折叠的形成和侧链基团发生了化学修饰有关。     

三七总皂苷对SAM-P/8小鼠海马中衰老相关基因表达的影响

目的探讨三七总皂苷对SAM-P/8小鼠海马中10个衰老相关基因表达的影响。方法采用RT-PCR技术检测10个衰老相关基因在各组小鼠海马中的表达及变化情况。结果各基因在海马中均有表达,成年三七组与成年对照组比较,SCN2B表达显著增加;老年三七组与老年对照组比较,MAP2、Sortilin-1、Rab6A、Calcineurin-B和MAPKK4的表达减少;MAP1B、Calmodulin-1、Regucalcin和RAP2A基因的表达在各组之间比较均没有变化。结论三七总皂苷可能通过调节部分衰老相关基因的表达来发挥其抗衰老的作用,但早期的预防比晚期治疗更加重要。     

Compensatory Increase in Choline Acetyltransferase Activity in Salivary Glands and Diaphragm Muscle of the Rat

When the function of salivary glands was abolished by applying ligatures to their ducts and the function of one half of the diaphragm muscle was abolished by sectioning of its phrenic nerve, the choline acetyltransferase activity was found to be increased in not duct-ligated glands and in the intact hemidiaphragm 4 weeks later. The increase was not seen within the first week. The increase in activity appears to be particularly manifested in the nerve endings, since it was seen in the hemidiaphragm but not in the phrenic nerve. Increased stream of impulses in the efferent nerves is thought to be the cause of this increase in choline acetyltransferase activity.     

Choline acetyltransferase activity and [3H]quinuclidinylbenzilate binding in brains of scrapie-infected hamsters

Choline acetyltransferase (ChAT) activity and [3H]quinuclidinylbenzilate binding were studied in the brain of scrapie-infected hamsters and sham inoculated controls. Although scrapie-infected hamsters showed no reduction of ChAT activity compared to the controls, they showed a decrease in the affinity and maximum number of post-synaptic muscarinic receptors. Scrapie virus thus alters the cholinergic system at the post-synaptic rather than at the pre-synaptic level.