急性分离的大鼠骶髓后连合核神经元由抑制性氨基酸诱导的电流反应(英文)

应用制霉菌素穿孔全细胞电压钳技术．在急性分离的大鼠骶髓后连合核（SDCN）神经元上，研究抑制性氨基酸诱导的反应的电生理学和药理学特性。当钳制电压为-40mV时，γ-氨基丁酸（GABA）、甘氨酸（Gly）和牛磺酸（Tau）均诱导产生内向电流。它们的EC50值分别是GABA5．2×10-5M，Gly4．0×10-5M及Tau1．6×10-4M。其Hill系数分别为GABA1．21，Gly1．27和Tau1．23。所有这些电流均在膜电位为-1．8mV左右时翻转。此外．Tau和Gly反应问还存在很强的交叉脱敏。结果提示，GABAA，Gly和Tau作为递质，通过受体Cl-通道复合体．在调节SDCN社经元伤害性传递中可能有重要作用。     

Generators of pathologically enhanced excitation as determinant structures in the spinal cord

With the aid of tetanus toxin, which disturbs various types of inhibition, generators of excitation were created in the left and right anterior horns of the lumbar spinal cord in rats. The regimes of activity of the generators differed: the left-sided generator, formed during the longer action of the toxin, in response to activation by trigger stimulation first produced tonic, and then intermittent activity, or individual spontaneous discharges, whereas the righ-sided generator produced only tonic activity. If one generator was blocked by glycine, the other continued to operate as before. Activation of one generator led to concomitant depression of the effects of the other. During separate activation of each generator, all the spinal and supraspinal motoneuron pools synchronously reproduced the character of activity of the generator functioning at that particular moment. The generator thus played the role of a determinant structure, determining the behavior of the system. The results are examined from the standpoint of the general concept of the role of determinant structures in the activity of the nervous system and the theory of generator mechanisms of neuropathological syndromes characterized by hyperactivity of systems.Laboratory of General Pathology of the Nervous System, Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 515–519, May, 1977.     

4-羟基-3,5-二甲氧基苯甲酰甘氨酸的合成研究

目的　合成 4 -羟基 - 3,5 -二甲氧基苯甲酰甘氨酸。方法　以丁香酸为起始原料 ,经乙氧羰基化、酰氯化、酰胺化、水解四步反应制得。结果　经波谱数据及元素分析认为合成的产物为目标产物。结论　所得化合物作为 N- (4 -羟基 - 3,5 -二甲氧基苯甲酰基 ) -甘氨酰正丁基胍的中间体 ,实验还需进一步探讨改进     

GAD67-GFP转基因小鼠三叉神经脊束核吻侧亚核和极间亚核内GABA和甘氨酸共存神经元的观察

本文以GAD67-GFP基因敲入小鼠为研究工具,利用免疫荧光组织化学双重染色技术观察了小鼠三叉神经脊束核(spi-nal trigeminalnucleus,V)的吻侧亚核(Vo)和极间亚核(Vi)神经元内谷氨酸脱羧酶67[GAD67,γ-氨基丁酸(GABA)能神经元的标识物质]和甘氨酸(glycine,Gly)的定位分布和共存情况。结果显示,在Vo和Vi内均有比较密集分布的GAD67和Gly阳性神经元。此外,在Vo和Vi内也可见一些GAD67阳性神经元同时呈Gly阳性反应,即存在GAD67/Gly双标神经元。结果表明,Vo和Vi内有GABA和Gly共存神经元,它们可能在初级传入信息的传递和调制中发挥重要作用。     

小鼠白细胞介素-12融合蛋白编码基因的构建与表达研究

目的 构建小鼠白细胞介素－１２的融合基因,并进行初号表达,方法 通过重叠序列引物的设计与多聚酶链反应（ＰＣＲ）技术,将小鼠ＩＬ－１２的４０ｋＰａ多肽链基因与３５ｋＤａ多肽链基因,以甘氨酸接头（Ｇｌｙ４Ｓｃｒ）３序列连接成为晤蛋白编码基因,构建融合蛋白表达载体现,转染小鼠成纤维细胞ＳＶＴ２,表达具有生物学活性的融合蛋白型ＩＬ－１２。结果 构建的小鼠ＩＬ－１２表达载体经测序无突变发生。以Ｇ４１８筛选转     

甘氨酸受体在甘氨酸抗心肌细胞缺氧/复氧损伤中的作用机制研究

目的：探讨甘氨酸受体在心脏保护中的作用及甘氨酸受体的性质。方法：利用原代培养的SD大鼠乳鼠心肌细胞建立心肌缺氧/复氧(A/R)模型，并用甘氨酸受体阻断法和消除细胞外氯离子法, 测定各组培养心肌细胞内超氧化物歧化酶（SOD）活性、丙二醛（MDA）及一氧化氮（NO）的含量、钙离子浓度和心肌细胞凋亡率。结果：A/R组用甘氨酸处理后SOD活性、NO含量升高，MDA含量、［Ca²⁺］_i、细胞凋亡率降低，与A/R组比较显著差异。分别用甘氨酸受体阻断剂士的宁和消除细胞外氯离子处理后，甘氨酸的上述保护作用明显减弱，与A/R组比较无显著差异。结论：甘氨酸能抑制缺氧/复氧乳鼠心肌细胞的自由基生成、抑制钙超载，减轻心肌细胞的凋亡并增加细胞内SOD等保护蛋白和NO的合成而发挥细胞保护作用。甘氨酸的细胞保护作用可能是通过甘氨酸受体发挥作用的，甘氨酸受体的本质可能是甘氨酸门控氯离子通道。     

Aged-related loss of temporal processing: Altered responses to amplitude modulated tones in rat dorsal cochlear nucleus

Loss of temporal processing is characteristic of age-related loss of speech understanding observed in the elderly. Inhibitory glycinergic circuits provide input onto dorsal cochlear nucleus (DCN) projection neurons which likely serve to modulate excitatory responses to time-varying complex acoustic signals. The present study sought to test the hypothesis that age-related loss of inhibition would compromise the ability of output neurons to encode sinusoidally amplitude modulated (SAM) tones. Extracellular recordings were obtained from young and aged FBN rat DCN putative fusiform cells. Stimuli were SAM tones at three modulation depths (100, 50, and 20%) at 30 dB hearing level with the carrier frequency set to the unit's characteristic frequency. Discharge rate and synchrony were calculated to describe SAM responses. There were significant age-related changes in the shape and peak vector strength [best modulation frequency (BMF)] of temporal modulation transfer functions (tMTFs), with no significant age-related changes in rate modulation transfer functions (rMTFs) at BMF. Young neurons exhibited band-pass tMTFs for most SAM conditions while aged fusiform cells exhibited significantly more low-pass or double-peaked tMTFs. There were significant differences in tMTFs between buildup, pauser-buildup, and wide-chopper temporal response types. Young and aged wide-choppers displayed significantly lower vector strength values than the other two temporal DCN response types. Age-related decreases in the number of pauser-buildup response types and increases in wide-chopper types reported previously, could account, in part, for the observed loss of temporal coding of the aged fusiform cell. Age-related changes in SAM coding were similar to changes observed with receptor blockade of glycinergic inhibition onto fusiform cells and consistent with previously observed age-related loss of endogenous glycine levels and changes in normal adult glycine receptor function. DCN changes in SAM coding could, in part, underpin temporal processing deficits observed in the elderly.     

低氧条件下载二甲基草酰甘氨酸电纺纤维促血管化及成骨性能研究

目的 通过聚L-丙交酯-己内酯电纺纤维（PLCL）负载二甲基草酰甘氨酸（DMOG）,研究其在低氧和常氧成骨诱导过程中对大鼠骨髓间充质干细胞（BMSC）的血管化和体外成骨分化的作用。方法 本研究经静电纺丝技术制备PLCL电纺纤维（P）和负载DMOG的PLCL电纺纤维（PD）,通过扫描电镜观察电纺纤维形貌;通过细胞骨架染色观察BMSC在不同电纺纤维上的黏附和生长状态;通过碱性磷酸酶和茜素红染色检测在不同电纺纤维上的BMSC经常氧和低氧成骨诱导7 d后的碱性磷酸酶表达和14 d时的钙沉积情况;通过RT-PCR检测在不同电纺纤维上的BMSC经常氧和低氧成骨诱导7 d和14 d时的成骨相关基因（ALP、Runx2、Col1和OCN）和促血管化相关基因（VEGF）的表达情况。结果 扫描电镜结果表明,P和PD具有纤维状形态并呈现为多孔结构。细胞实验表明,BMSC可在P和PD表面黏附生长,且低氧条件下在PD上表现出更好的形态。与常氧条件相比,在低氧条件下,P和PD在7 d时的碱性磷酸酶表达减少。但低氧条件成骨诱导14 d时PD仍能促进钙的沉积。在常氧条件下,电纺纤维P可上调ALP、Runx2、Col1、OCN和VEGF的表达,但低氧条件下其对上述基因的上调作用不明显。而电纺纤维PD在常氧和低氧条件下均可促进ALP、Runx2、Col1、OCN和VEGF的表达。结论 本研究制备的负载DMOG的PLCL电纺纤维在低氧条件下具有良好的体外促血管化和促成骨分化性能,预期可作为一种较好的成骨修复材料。     

肝硬变患者肝脏体积改变与肝功能的关系

本文应用放免法检测３４例肝炎后肝硬变血清ＨＡ、ＣＧ等肝功能指标结合测量ＣＴ片上肝脾体积改变以探讨两者的关系。结果显示随着肝硬变患者Ｃｈｉｌｄ分级增加，肝功能损害加重，表现为ＨＡ和ＣＧ浓度逐渐上升，ＰＴ时间延长和白蛋白浓度降低。肝脏体积缩小，与ＨＡ、ＣＧ及ＰＴ时间呈负相关（分别为ｒ＝－０．８０４、－０．８９３、－０．８７４、Ｐ＜０．０１）及与白蛋白呈正相关（ｒ＝０．７２２、Ｐ＜０．００１），而脾脏体积改变与上述指标相反，即与ＨＡ、ＣＧ呈正相关，与白蛋白呈负相关，且ＣｈｉｌｄＡ、Ｂ、Ｃ三级之间差异显著（Ｐ＜０．００１）。结果表明，在检测肝功能的同时测量肝脏及脾脏体积可能有助于对肝硬变患者判断预后及指导治疗。     

甘氨酸通过PTEN/Akt通路减轻脑出血大鼠神经损伤

探讨甘氨酸对脑出血大鼠神经损伤的保护作用及其机制。将48只大鼠随机分为假手术组、模型组、甘氨酸组(分别给予0.5 mg/kg或2 mg/kg甘氨酸)。采用侧脑室注射自体血建立大鼠脑出血模型;干湿重法检测脑组织含水量,甲酰胺法检测血脑屏障通透性,原位末端标记法(TUNEL)法检测脑组织细胞凋亡的情况,实时聚合酶链反应(Real-time PCR)检测蛋白激酶B(Akt)、磷酸酶与张力蛋白同源物基因(PTEN)mRNA的表达,免疫印迹(Western blot)法检测脑组织中Akt、PTEN蛋白的表达水平。结果显示,与模型组比较,2 mg/kg甘氨酸组大鼠脑组织含水量、EB含量、血肿块体积、凋亡细胞数量显著降低,Akt mRNA和蛋白的表达显著升高,PTEN mRNA和蛋白的表达水平显著降低(P＜0.05)。结果表明甘氨酸对大鼠脑出血造成的大鼠脑神经的损伤有一定的保护作用,这可能与甘氨酸干预的PTEN/Akt通路有关。