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。     

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     

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。     

花粉制剂对脑衰老动物各脑区的SOD和NO水平的影响

采用 D-半乳糖建立脑衰老动物模型 ,观察服用花粉制剂前后对脑衰老模型动物不同脑区组织中超氧化物歧化酶 ( SOD)活性、一氧化氮 ( NO)水平的影响。结果表明花粉制剂能明显升高脑衰老动物某些脑区 SOD活性和降低脑衰老动物某些脑区 NO水平。研究结果提示花粉制剂具有延缓衰老和增强记忆力等作用 ,其机制可能与其促进自由基的清除及减少 NO释放有关。     

Oxidative stress and aberrant signaling in aging and cognitive decline

Brain aging is associated with a progressive imbalance between antioxidant defenses and intracellular concentrations of reactive oxygen species (ROS) as exemplified by increases in products of lipid peroxidation, protein oxidation, and DNA oxidation. Oxidative conditions cause not only structural damage but also changes in the set points of redox-sensitive signaling processes including the insulin receptor signaling pathway. In the absence of insulin, the otherwise low insulin receptor signaling is strongly enhanced by oxidative conditions. Autophagic proteolysis and sirtuin activity, in turn, are downregulated by the insulin signaling pathway, and impaired autophagic activity has been associated with neurodegeneration. In genetic studies, impairment of insulin receptor signaling causes spectacular lifespan extension in nematodes, fruit flies, and mice. The predicted effects of age-related oxidative stress on sirtuins and autophagic activity and the corresponding effects of antioxidants remain to be tested experimentally. However, several correlates of aging have been shown to be ameliorated by antioxidants. Oxidative damage to mitochondrial DNA and the electron transport chain, perturbations in brain iron and calcium homeostasis, and changes in plasma cysteine homeostasis may altogether represent causes and consequences of increased oxidative stress. Aging and cognitive decline thus appear to involve changes at multiple nodes within a complex regulatory network.     

Dietary spermidine for lowering high blood pressure

Loss of cardiac macroautophagy/autophagy impairs heart function, and evidence accumulates that an increased autophagic flux may protect against cardiovascular disease. We therefore tested the protective capacity of the natural autophagy inducer spermidine in animal models of aging and hypertension, which both represent major risk factors for the development of cardiovascular disease. Dietary spermidine elicits cardioprotective effects in aged mice through enhancing cardiac autophagy and mitophagy. In salt-sensitive rats, spermidine supplementation also delays the development of hypertensive heart disease, coinciding with reduced arterial blood pressure. The high blood pressure-lowering effect likely results from improved global arginine bioavailability and protection from hypertension-associated renal damage. The polyamine spermidine is naturally present in human diets, though to a varying amount depending on food type and preparation. In humans, high dietary spermidine intake correlates with reduced blood pressure and decreased risk of cardiovascular disease and related death. Altogether, spermidine represents a cardio- and vascular-protective autophagy inducer that can be readily integrated in common diets.     

Casein kinase II activity in the brain of an insect,Acheta domesticus: Characterization and hormonal regulation

This study documented casein kinase II (CK II) activity in Acheta domesticus brain using specific antibodies and its regulation by polyamines. In control animals a transient decrease in CK II activity at day 3 after imaginal moult was observed in the brain but not in the fat body. If deprived of ecdysone by ovariectomy a different pattern was observed, with CK II activity being significantly higher on days 3 and 4 after emergence. After ecdysone injection in ovariectomized females, CK II activity decreased to levels similar to those in controls. The implications of ecdysone regulation of brain CK II activity are discussed. © 1997 Wiley-Liss, Inc.     

Comparison of lectin-binding patterns between young adult and older rat glycoproteins in the brain

Glycoproteins in the soluble fraction and in the membrane fraction of various portions of brains and spinal cords, obtained from 9-week-old rats and 29-month-old rats, were comparatively analyzed by SDS-polyacrylamide gel electrophoresis and lectin staining. The glycoprotein patterns of each brain part showed marked differences by the age of donors. The most prominent evidence in the soluble fractions of white matter, basal ganglia, and spinal cord detected by WGA is that the glycoproteins with an apparent molecular weight of 123K and 115K have increased in the aged rats. In addition, the reactivity of 115K with Con A and PNA has also increased in the aged rats. On the other hand, reactivity of an apparent molecular weight of 115K with WGA has increased in the membrane fractions of white matter, basal ganglia, hippocampus, cerebellum, and spinal cord from the aged rats. In contrast, by MAM, which is specific for Sia2®3Gal linkage, an apparent molecular weight of 115K has been detected only in the membrane fraction of cerebellum and it has decreased in the aged rats. Reactivity of an apparent molecular weight of 133K and 125K in the membrane fractions of white matter and basal ganglia with LCA has decreased in the aged rats. In contrast, reactivity of the front band with LCA and AAL has increased and that of 130K with AAL has decreased in spinal cord from the aged rats, respectively. These results indicate that the glycosylation state of the protein in the brain changes during aging.