衰老大鼠的某些脑区组织中游离氨基酸水平的改变

使用D 半乳糖建立衰老大鼠模型组与同龄、同饲的正常对照组大鼠的某些脑区游离氨基酸 (FAA)水平的比较发现 :( 1 )衰老模型组的海马、纹状体以及皮层等脑区中谷氨酸 (Glu)、天门冬氨酸 (Asp)水平明显降低 ;( 2 )γ 氨基丁酸 (GABA)水平在衰老模型组大鼠的海马 ,纹状体以及小脑等脑区中明显升高 ;( 3)衰老模型组的皮层、小脑、海马、纹状体等脑区的牛磺酸 (Tau)水平明显下降。以此探讨动物衰老与脑区游离氨基酸水平的关系     

衰老对大鼠脑区氨基酸水平的影响

本文测定了正常青龄组（３月龄）和老龄组（２０月龄）大鼠不同脑区（皮层、小脑海马、纹状体和下丘脑）谷氨酸、天门冬氨酸、甘氨酸、ｒ－氨基丁酸和牛磺酸的含量。结果表明：在衰老过程中大鼠某些脑区谷氨酸、天门冬氨酸、甘氨酸和牛磺酸水平显著降低;而纹状体γ－氨基丁酸含量则显著升高。     

多胺与植物衰老关系研究进展

多胺作为生理活性物质与植物衰老关系密切。本文综述了近十年来多胺对衰老的调控作用,从调节细胞膜的理化性质,生物大分子合成作用以及多胺与乙烯的关系等方面阐述了多胺延缓衰老的机制,比较了多胺和影响衰老的植物激素在信号转导过程中的作用。     

多胺与植物衰老关系研究进展

多胺作为生理活性物质与植物衰老关系密切。本文综述了近十多年来多胺对衰老的调控作用,从调节细胞膜的理化性质、生物大分子合成作用以及多胺与乙烯的关系等方面阐述了多胺延缓衰老的机制,比较了多胺和影响衰老的植物激素在信号转导过程中的作用。     

花生叶片衰老中多胺代谢酶活性及游离多胺含量变化（简报）

花生叶片衰老过程中,多胺代谢酶精氨酸脱羧酶（ADC）、鸟氨酸脱羧酶（ODC）和多胺氧化酶（PAO）活性逐渐下降,而腐胺（Put）含量迅速上升,精胺（SPm）、亚精胶（Spd）含量下降,致使衰老期间Put／（Spd＋Spm）迅速上升。     

多效唑对花生叶片多胺含量及衰老的调节作用

通过对大田条件下生殖生长期花生喷施不同浓度的多效唑,研究了多效唑对叶片内源多受及其它衰老指标的影响,结果证明多效唑对内源多胺的影响较复杂,多效唑降低了幼嫩叶片的多胺含量,却提高了成熟叶片衰老阶段的多胺含量,并起到延缓衰老的作用,讨论了多效唑影响多胺含量的可能原因。     

月季切花衰老过程中多胺与乙烯的关系

月季切花瓶插过程中,内源腐胺在前２天略有增加,内源亚精胺,精胺、多胺总量则呈下降趋势,乙烯释放速率在第３天达到最高峰;多胺抑制剂甲基乙醛－双咪腙处理抑制了亚精胺,精胺的合成,增加了乙烯的释放速率;乙烯抑制剂氨氧乙酸处理推迟腐胺高峰的到来,降低了乙烯的释放速率,而且在瓶插期的前２天内业精胺、精胺含量较高,结果表明,具乙烯跃变型特征的月季切花衰老过程中,多与乙烯在其生物合成过程中相互竞争Ｓ－腺苷甲硫氨     

月季切花衰老过程中多胺与膜脂过氧化的关系

以月季切花为材料,研究了月季切花瓶插过程中多胺含量的变化,外源多胺处理对月季药花体内多胺含量的影响以及多胺与膜脂过氧化的关系。结果表明,月季切花瓶插衰老过程中腐胺在前2d略有增加,亚精胺和精胺均呈下降趋势;外源亚精胺和精胺处理均能增加切花体内多胺含量,并能延缓切花衰老和改善切花品质;且亚精胺和精胺处理降低了MDA含量的积累和膜相对透性的上升趋势。     

豇豆叶片衰老过程中多胺氧化酶活性的变化（简报）

豇豆幼苗的连体和离体叶片衰老过程中多胺氧化酶（PAO）活性与叶绿素和蛋白质的含量都呈下降趋势,它们的降幅依次是：PAO活性大于叶绿素含量大于蛋白质含量;用氨基胍抑制离体叶圆片PAO活性,不能延缓叶绿素和蛋白质的含量下降。     

铅损伤对新生鼠脑组织中多胺的影响

将新生Wistar大鼠按腹腔注射醋酸铅的剂量 ,随机分为正常、低铅组、高铅组。各组注射剂量分别为 0 ,2 0 ,6 0mg/kg。定期测量体重 ,采用薄板层析法测脑中精脒的含量。结果显示正常组出生后体重增长迅速 ;与正常组相比 ,高、低铅组分别于出生 5、10天后体重增长明显落后 ;脑重、脑精脒含量均显著低于正常组 ,并且与铅损伤的剂量有明显的负相关 (r =- 0 .793,P <0 .0 1)。研究表明脑中多胺的量是反映铅神经毒性程度的有用指标     

Energy-Metabolising Enzymes in Brain Regions of Adult and Aging Rats

Abstract: The regional enzyme activities of glucose metabolism in the rat brain were investigated. Hexokinase (EC 2.7.1.1) and pyruvate dehydrogenase (EC 1.2.4.1), key enzymes for glucose metabolism, showed no changes in activity in all the regions studied of the aging brain as compared with the adult brain. However, the activity of d -3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) is low throughout the adult brain and, in contrast with hexokinase and pyruvate dehydrogenase, its activity decreases significantly during aging. Other enzymes that showed significant decreases during aging are aldolase (EC 4.1.2.13), lactate dehydrogenase (EC 1.1.1.27), citrate synthase (EC 4.1.3.7), and NAD⁺-linked isocitrate dehydrogenase (EC 1.1.1.41). The catabolic enzyme in cholinergic metabolism, acetylcholinesterase (EC 3.1.1.7), selected as an example of a non-energy-metabolising enzyme, also showed significant decreases in all regions of the brain in aging, although its highest activity remained in the striatum. These results are discussed with respect to the energy metabolism in various brain regions and their status with aging.     

The Aging Astrocyte Transcriptome from Multiple Regions of the Mouse Brain

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脑细胞的基因及其表达与衰老

概述了脑与衰老在神经分子生物学方面的研究进展 ,包括 :细胞衰老分子机制的主要进展 ,衰老脑在基因及其表达水平的研究进展 ;阿尔茨海默病 (AlzheimerDisease ,AD)相关基因研究进展 ,帕金森病 (porkinsondisease ,PD)相关基因研究进展[7] 。这些研究成果对脑与衰老的关系、对脑在基因及其表达水平上衰老机制认识的加深乃至对衰老脑的基因治疗均具有理论意义和应用价值。     

Cystathionine Accumulation in Various Regions of Brain of DL-Propargylglycine-Treated Rats

The contents of cystathionine and taurine, as well as cystathionine beta-synthase activity in various regions of the brains of normal and DL-propargylglycine-treated rats, were measured. The content of cystathionine in each region of brain increased gradually from 0.5 mg to 20 mg/200 g body weight in relation to the dose of DL-propargylglycine. Cystathionine was found to be unevenly distributed in brains of both normal and DL-propargylglycine-treated rats. On the other hand, the activity of cystathionine beta-synthase was evenly distributed in various regions of normal rat brain, and was unaltered following treatment of rats with DL-propargylglycine. The concentration of taurine was similarly unaffected by DL-propargylglycine injection.     

Lipid Compositions of Different Regions of the Human Brain During Aging

The neutral and phospholipid compositions of various regions of the human brain were analyzed using autopsy material covering the life period between 33 and 92 years of age. The protein content was also measured and, on a weight basis, this content is unchanged in the cerebellum, pons, and medulla oblongata, whereas in the 90-year-old group it decreases in the hippocampus, gray matter, and nucleus caudatus. In white matter, the protein content decreases continuously with age. The phospholipid composition is characteristic of the region investigated, but remains unchanged during aging. The total phospholipid content exhibits only a 5-10% decrease in the oldest age group. The content of dolichol and its polyisoprenoid pattern are also characteristic of the region analyzed. Between 33 and 92 years of age, the amount of dolichol in all portions of the brain increases three- to fourfold, but the isoprenoid pattern remains constant. The level of dolichyl-P varies between different regions, but only a moderate increase is seen with age. Ubiquinone content is highest in the nucleus caudatus, gray matter, and hippocampus, and in all areas this content is decreased to a great extent in the oldest age groups. All regions of the human brain are rich in cholesterol, but alterations in the amount of this lipid are highly variable during aging, ranging from no change to a 40% decrease.     

豇豆初生叶多胺氧化酶的催化特性

从豇豆幼苗 (6d苗龄 )初生叶提纯得到的多胺氧化酶 (EC 1 .4.3 .6 )属于二胺氧化酶 ,最有效的底物是 1 ,4 二胺丁烷 (腐胺 )、1 ,5 二胺戊烷 (尸胺 )、1 ,6 二胺己烷、1 ,1 0 二胺癸烷等α 二胺 ,其催化活性随二胺类底物碳链的增长而相应减弱。豇豆多胺氧化酶对亚精胺和精胺也具有较高的催化活性。另外 ,底物腐胺和尸胺的浓度超过 2mmol/L或亚精胺和精胺浓度超过 3mmol/L时会对酶活性有抑制效应。以腐胺和尸胺为底物时 ,酶的最适 pH约为7.0 ,而以亚精胺和精胺为底物时其最适pH为 6 .5。该酶的催化活性还随反应介质的离子强度增加而降低。K ,Ca2 和Mg2 (皆为 1 0mmol/L)对酶活性无明显抑制作用 ,而同样浓度的Mn2 ,Zn2 ,Fe2 ,Co2 和Cd2 则对酶活性有不同程度的抑制作用。金属螯合剂EDTA(1 0mmol/L)和腺苷蛋氨酸脱羧酶抑制剂甲基乙二醛 双脒腙 (0 .1mmol/L)可抑制酶活性约 80 % ,而铜结合剂KCN(1 .0mmol/L)、羰基试剂羟胺 (0 .1mmol/L)和氨基胍 (0 .1mmol/L)可导致该酶完全失活     

多胺生物合成抑制剂结合热处理后番茄冷害、多胺含量的变化及其相关性分析

以“佳粉15”和“粉红908”番茄为试材,分别采用热空气处理和多胺生物合成抑制剂(D-精氨酸和二环己胺)处理,然后于2℃(冷害温度)下贮藏。结果表明,热处理和2种多胺抑制剂处理都可以降低番茄的冷害指数和呼吸速率,抑制呼吸高峰的出现,并抑制多胺的合成。腐胺含量与冷害之间相关性分析的结果表明,多胺合成抑制剂结合热处理是通过改变果实腐胺的生物合成或分解代谢实现其减轻冷害作用的。     

百合小鳞茎离体发生过程中内源多胺水平和多胺氧化酶活性的变化

以百合小鳞茎离体发生为实验系统,研究了鳞片(外植体)内多胺和多胺氧化酶活性的变化与小鳞茎发生之间的相关性。随着细胞脱分化、愈伤组织形成、小鳞茎发生等过程,内源腐胺、亚精胺和精胺的含量均失上升后下降,变化曲线为“钟形”,其含量达最高峰的时间为肉眼可见小鳞茎出现之前。多胺氧化酶活性在小鳞茎发生初期逐渐下降,6d后开始上升,并在小鳞茎突起时达最大值。由于内源多胺水平和多胺氧化酶活性的变化与小鳞茎发生有密切关系,可作为这一形态发生过程的生化指示。