银杏类黄酮对大鼠脑损伤后机能改变的影响

观测了银杏类黄酮(flavonoid of Ginkgo biloba, FGb)对损伤大鼠运动皮层后机能改变过程的影响.结果表明:(1) FGb明显促进运动平衡能力的恢复;(2) 损伤后脑室水肿明显,FGb促进脑水肿症状的恢复;(3)挫伤3 h后脑内的游离氨基酸递质水平明显下降,FGb促进脑内氨基酸水平的恢复.这可能是银杏叶提取物促进脑损伤修复的机制之一.     

银杏类黄酮对大鼠脑损伤后机能改变的影响

观测了银杏类黄酮（flavonoid of Ginkgo biloba,FGb)对损伤大鼠运动皮层后机能改变过程的影响。结果表明：（1）FGb明显促进运动平均能力的恢复;（2）损伤后脑水肿明显,FGb促进脑水肿症状的恢复;（3）挫伤3h后脑内的游离氨基酸递质水平明显下降,FGb促进脑内氨基酸水平的恢复。这可能是银杏叶提取物促进脑损伤修复的机制之一。     

Wistar大鼠海马CA1区、CA3区和齿状回区的解剖分割

目的:在体视显微镜下分割Wistar大鼠海马CA1区、CA3区和齿状回(DG)区。方法:24只健康Wistar大鼠,分组如下:①6只大鼠取脑后硫堇染色,观察海马各区细胞形态;②6只大鼠分离出海马,体视显微镜下观察海马形态并分割CA1区、CA3区和DG区,各区分别切片后硫堇染色;③12只大鼠检测海马各区HSP 70的表达。结果:①大脑冠状切片硫堇染色清晰显示出海马CA1区、CA3区和DG区;②体视显微镜下,在海马腹侧面,沿着CA1区和DG区之间的海马沟可分割开CA1区和DG区,沿着CA3区和DG区之间的裂隙可分割开CA3区和DG区;分割后的海马各区细胞形态结构与整体大脑冠状切片上相对应区域的细胞形态结构一致;③Western blot结果显示:与对照组相比,脑缺血组HSP 70的表达在海马CA3+DG区明显上调、而在CA1无明显变化,这一结果与免疫组织化学结果一致。结论:上述方法可比较明确地分割Wistar大鼠海马CA1区、CA3区和DG区,分割得到的各区组织可用于蛋白质表达的检测。     

甲醛炎性痛增强大鼠海马NOS表达和NO生成

目的：观察甲醛炎性痛过程中大鼠痛行为、海马一氧化氮合酶（NOS）活性及一氧化氮（NO）含量的变化以及变化的时程及区域特征。方法：采用辐射热甩尾法测定大鼠痛阈变化;采用NADPH—d组织化学法和硝酸还原酶法分别测定大鼠海马NOS表达和No含量。结果：皮下注射甲醛溶液后,大鼠出现伤害性感受反应及痛阈降低。注射甲醛后6h,海马CA1、CA2～3区及DG区NOS阳性细胞数目、阳性细胞染色深度均显著增加。海马NO含量亦显著增加;注射甲醛后12h时这些改变最为显著,48h时恢复至对照组水平。结论：甲醛炎性痛可诱导海马NOS活性增强及NO生成增多．这种改变可发生在海马各区．并具有一定的时程特征。     

精氨酸酶Ⅰ参与环腺苷酸促进脑缺血再灌注大鼠的轴突再生

环腺苷酸（cAMP）作为细胞内的重要第二信使之一,主要通过激活下游cAMP依赖性蛋白激酶A（PKA）,进一步激活转录因子-cAMP效应元件结合蛋（CREB）,达到促进损伤轴突再生的作用.精氨酸酶Ⅰ主要是通过促进多胺的表达,从而克服髓鞘相关抑制因子对轴突再生的抑制作用,达到促进轴突再生的效果.在脑缺血中,cAMP促进轴突再生的过程是否有精氨酸酶Ⅰ的参与及其与RhoA信号通路的关系尚不清楚.本研究采用线栓法制备脑缺血再灌注模型（MACO）,采用Longa 5评分法对大鼠运动功能进行评分,利用逆转录聚合酶链反应（RT-PCR）和Western蛋白印迹方法分别检测缺血灶周边脑组织生长相关蛋白43（GAP-43）和RhoA的mRNA和蛋白表达,免疫组化法进行GAP-43的形态学检测,作为轴突再生的标志.通过尾静脉注射cAMP类似物db-cAMP增加脑缺血后大鼠脑组织内cAMP的浓度后发现：db-cAMP处理可明显降低MACO大鼠的运动功能评分,且可促进GAP-43 mRNA及蛋白的表达,抑制RhoA mRNA及蛋白的表达,由此可见db-cAMP处理可促进脑缺血后大鼠运动功能的恢复,且这一过程与抑制RhoA通路,进而促进轴突再生有关;通过在db-cAMP的基础上给予精氨酸酶Ⅰ拮抗剂NOHA来降低精氨酸酶Ⅰ的活性发现：给予NOHA的大鼠运动功能评分明显增加,这一变化趋势与RhoA mRNA及蛋白表达的变化趋势相一致,而与GAP-43 mRNA及蛋白表达的变化趋势相反. 因此可推断：精氨酸酶Ⅰ参与了db-cAMP促进轴突再生、改善脑缺血后大鼠运动功能的过程,且与钝化RhoA通路有关.     

癫痫大鼠海马NMDA受体亚基NR2A和BDNFmRNA水平的检测

目的通过锂一匹罗卡品癫痫模型（ithium—pilocarpine seizures rats model of epilepsy,LPS）,研究NMDA受体亚基NR2A、BDNF mRNA的表达,探讨NR2A、BDNF在LPS中的作用。方法建立氯化锂-匹罗卡品大鼠模型,运用原位杂交技术检测致痫后各组不同时间点海马CAI、CA3及DG区NR2A与BDNF mRNA的表达。结果LPS海马NR2A、BDNF mRNA在各观察时间点及部位模型组与正常对照组比较均有明显上调,且有显著统计学差异（P〈0．05）。模型组NR2A mRNA的表达上调7d达峰值（P〈0．05）;而BDNF mRNA表达上调14d达峰值。VPA干预组NR2A mRNA在大鼠海马不同时间及部位（除1d的CA3区）的表达较模型组明显下调（P〈0．05）;BDNF mRNA在大鼠海马不同时间及部位（除28d的DG区）的表达较模型组明显下调（P〈0．05）。结论锂－匹罗卡品腹腔注射可诱导大鼠海马NR2A和BDNF mRNA的表达明显上调;NR2A mRNA表达的增强可能是诱导调控BDNF mRNA表达增强的重要机制之一,说明NMDA受体亚基NR2A可能成为抑制癫痫发作的新靶点。     

产前束缚应激子代大鼠海马神经颗粒素表达降低

神经颗粒素（neurogranin,NG）是脑特异性突触后蛋白,参与在学习记忆功能中起核心作用的信号转导通路及突触可塑性。本研究旨在探讨产前束缚应激对子代大鼠海马NG表达的影响。连续7d对孕晚期大鼠进行束缚应激,建立产前束缚应激模型,分为对照雌、雄组,应激雌、雄组。采用免疫组化方法观察NG在产前束缚应激子代大鼠海马不同亚区的分布特点;采用蛋白免疫印迹方法检测产前束缚应激子代大鼠海马NG蛋白的表达。结果显示：各组子代大鼠海马各区均有NG蛋白表达,CA1和CA3区表达高于齿状回（dentate gyrus,DG）;应激组雌、雄子代大鼠海马NG的表达明显低于对照组（P〈0．01）,应激组雌性子代比雄性子代减少更显著,对照组雌、雄子代之间无差异。免疫组化与蛋白免疫印迹方法所得结果一致。上述结果表明,NG在产前束缚应激子代大鼠海马表达降低,并且雌性比雄性降低明显,NG对产前束缚应激子代大鼠有差异性调制,NG表达减少可能与产前束缚应激子代大鼠学习记忆能力下降有关。     

黄芪多糖对缺血性脑损伤大鼠的神经保护作用及其机制研究

目的:探究缺血性脑损伤后,黄芪多糖(AG)对海马CA1区神经元重塑中粘附分子(NCAM)以及c-fos表达的影响。方法:取Wistar雄性大鼠100只,随机分成假手术组(SOG)、模型组(MG-1d,3d,7d),低剂量黄芪多糖治疗组(L-AGTG-1d,3d,7d),高剂量黄芪多糖治疗组(H-AGTG-1d,3d,7d),每组10只。所有MG和AGTG组颈部切开阻断右侧大脑中动脉,造成缺血性脑损伤后,AGTG组腹腔注射AG(5 mg/kg和15 mg/kg)。于1 d,3 d和7 d分别脑血流再灌注,随即评分神经功能缺损情况后取材,测算神经元凋亡数,免疫组织化学法和RT-PCR法半定量分析检测海马CA1区神经元NCAM和c-fos的表达。结果:L-AGTG和H-AGTG的神经功能缺损评分和海马神经元凋亡数显著低于MG(P<0.05或P<0.01),海马CA1区NCAM和c-fos的表达显著高于MG(P<0.05或P<0.01)。结论:黄芪多糖改善缺血性脑损伤大鼠的神经功能,可能与促进海马NCAM和c-fos表达,而阻止或逆转海马神经元凋亡有关。     

糖尿病大鼠弓状核-海马肥胖抑素通路构成及对胃运动和胃排空的影响

目的: 探究糖尿病大鼠弓状核(ARC)-海马肥胖抑素(obestatin)神经通路构成,以及该通路对大鼠胃运动、胃排空的影响。方法: 健康雄性Wistar大鼠采用果糖溶液诱导胰岛素抵抗加腹腔注射链脲佐菌素的方法制备糖尿病模型,造模之后,随机分为5组:对照组(NS组)、0.1、1和10 pmol obestatin组、obestatin+NBI27914组,每组7只;各组通过置管分别向海马内注射0.5 μl 生理盐水(NS)、obestatin(0.1 pmol、1 pmol、10 pmol)和混合液(10 pmol obestatin + 60 pmol NBI27914),给药后立即记录大鼠胃运动,15 min后进行胃排空研究;通过荧光金(FG)逆行追踪及免疫组化方法比较正常及糖尿病大鼠ARC-海马obestatin神经通路构及ARC obestatin mRNA表达的异同。结果: 与正常大鼠相比,糖尿病大鼠ARC FG/obestatin双标神经元数目显著减少(P＜0.05),ARC obestatin mRNA表达量显著下降(P＜0.05);obestatin各组可剂量依赖性的抑制大鼠胃运动及胃排空(P＜0.05~0.01),obestatin的这些效应可被促肾上腺皮质激素受体1(CRFR1)阻断剂NBI27914部分阻断(P＜0.05);obestatin对糖尿病大鼠胃运动和胃排空的抑制效应显著减弱(P＜0.05)。结论: ARC-海马之间存在obestatin神经和功能通路,参与糖尿病大鼠胃运动及胃排空调控,且CRFR1信号通路参与该过程。该通路功能的减弱可能参与了糖尿病早期胃动力紊乱的发病。     

LPS诱导海马星形胶质细胞活化与活化的星形胶质细胞对海马神经元的影响

探讨脂多糖(Lipopolysaccharide,LPS)对长时间存活大鼠海马内星形胶质细胞的反应以及对神经元的影响。方法:本实验用10只健康成年雄性SD大鼠,海马CA3区注射LPS 10μ1．7和14d后,尼氏染色观察神经元的变化,免疫组织化学染色结合图像分析方法观察海马CA3区注射部位胶质纤维酸性蛋白(glial fibrillary acidic protein GFAP)、的表达变化。结果:脂多糖可促进海马星形胶质细胞的活化,但并不能引起海马区神经元的损伤。结论:星形胶质细胞在脑损伤后的脑内炎症反应起了一定的作用,但并不能引起神经元的损伤。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.