Effects of N-Acetyl Aspartate, Aspartate, and Glutamate on cAMP and cGMP Levels in Developing Rat Cerebral Cortex

N-Acetyl-aspartate (N-Ac-Asp) incubated with minced cerebral cortex caused a dose-dependent increase in the levels of cAMP and cGMP. This effect was followed during postnatal development. N-Ac-Asp elicits the greatest increase in cAMP in 5-day-old and in cGMP in 40-day-old rats. The levels of cyclic AMP were always higher than those of cGMP. We also studied the effects of L-aspartate (Asp) and L-glutamate (Glu) on the levels of cyclic nucleotides in the cerebral cortex minces of rats different ages, and observed that both amino acids produced the maximum increase in cAMP at 10 days, whereas in the case of cGMP the maximal effect of Asp occurs earlier than 20 days and of Glu after 40 days. In the adult rat, the N-Ac-Asp effect on cAMP was greater than that produced by either Asp or Glu, whereas the levels of cGMP were similarly affected by all three. The data show a peak response of cAMP and cGMP to N-Ac-Asp, Asp, and Glu during cortical maturation. Because this response varies with postnatal time, N-Ac-Asp, and Glu may act upon different receptor sites.     

Analysis of individual CNS protein synthesis

A procedure for labeling rat CNS proteins in vivo which is useful for behavioral and pharmacological studies has been developed. Intraventricular administration of³⁵S-methionine through bilateral indwelling cannulae provided reproducible and highly specific radiolabeling of proteins from frontal cortex (FC), parietal cortex (PC), occipital cortex (OC), striatum (ST), septal nuclei (SN), amygdala (AM), hippocampus (HIP), thalamus (TH), brain stem (BS) and cerebellum (CB). Relative rates of synthesis of over 200 individual proteins were subsequently analyzed by 2DGE. Regional analysis demonstrated increased labeling of a protein of MW 28 kD and pI 6.4 in the hippocampus that was barely detectable in striatum of control rats. In heat-shocked animals, there was increased relative synthesis of the 74 kD Heat Shock Protein in both the septal nuclei and hippocampus.     

Postmortem Changes in Catecholamines, Indoleamines, and Their Metabolites in Rat Brain Regions: Prevention with 10-kW Microwave Irradiation

Postmortem changes in catecholamines, indoleamines, and their metabolites in rat brain regions following decapitation were determined by LCEC. In the three regions studied neurotransmitter levels declined after decapitation, whereas the metabolite levels increased. Microwave irradiation at 10 kW rapidly inactivated brain enzymes and thus prevented the postmortem changes.     

MicroRNAs参与调控中枢神经系统的发育及脊髓损伤修复

microRNAs（miRNAs）不仅参与神经系统的生长发育、功能完善,还参与脊髓损伤病理及损伤后修复过程。miRNAs能使中枢神经系统按正确的时序性和空间性顺序进行发育和分化,在维持生物体记忆及生物钟方面起着重要作用。miRNAs异常表达同脊髓损伤病理过程相关。目前,体内及体外实验均已证实,miRNAs不仅能够维持神经干细胞增殖,而且可以促进神经元轴突伸长,从而为脊髓损伤的治疗带来新的治疗策略。     

大鼠血浆中洛伐他汀的HPLC测定及药动学研究

目的:探索采用高效液相色谱法测定大鼠血浆中洛伐他汀浓度的方法。方法:血浆样品采用环已烷-二氯甲烷(3.5:1,V/V)提取,HPLC条件为色谱柱采用XTerra(?)MSC18柱(150×2.1 mm,5μm),流动相为乙腈-水(63L37,V/V),柱温35℃,检测波长为238nm。结果:大鼠血浆中洛伐他汀在0.01～5μg/mL线性范围内线性关系良好,最低检测浓度为0.01～g/mL,方法的提取回收率为81%～95%,日内、日间RSD均小于9.55%;药代动力学结果表明洛伐他汀在雌雄大鼠体内的Tp、Cmax和AUC均有显著性差异(p<0.05)。结论:建立的HPLC方法简便、灵敏度高,重现性好,药动学研究表明洛伐他汀在大鼠体内存在性别差异。     

Organ culture of adult cockroach CNS: ultrastructural and physiological characteristics

The abdominal nerve cord of adult Periplaneta americana has been maintained in culture for up to 5 weeks. The ultrastructural appearance of in vitro cords resembles that of in vivo cords although some degeneration of glia may occur during the first 2 weeks in culture. The glial cells most affected are those which make up the perineurium. The blood-brain barrier, formed by the perineurium in vivo, breaks down in vitro. Despite this, normal action potentials were recorded from giant axons in 1 month old cultured connectives.     

HPLC法检测苦杏仁苷及其酶解产物

本文建立了一个快速高效的HPLC方法同时检测苦杏仁苷及其4个体外酶解产物,色谱分析系统为安捷伦液相色谱系统,自动进样器,迪马ODS C18色谱柱(250 mm×4.6 mm,5μm),柱温25℃,流动相30%甲醇,检测波长210 nm,进样量10μL。结果表明,苦杏仁苷、phenyl-(3,4,5-trihydroxy-6-methyl-tetrahydro-pyran-2-yloxy)-acetonitrile、野樱花苷、苯甲醛和杏仁腈的保留时间分别为5.087、13.836、16.357、22.775和3.307 min。该HPLC方法的重现性好,精确度和准确度高,当柱温低于30℃、pH值介于6.0~7.0时该方法结果稳定、重现性好。     

高效液相色谱法测定大鼠血浆中来那度胺的浓度及其药动学* 龚

摘要目的：建立高效液相色谱法测定大鼠血浆中来那度胺的浓度。方法：色谱柱采用Venusil ASB C18 column (4.6 mm× 250 mm, 5 μm) 购自于博纳艾杰尔科技有限公司。样品采用梯度洗脱,流动相为乙腈和0.05%甲酸溶液,流速为1.0 mL/min,检测波长为 254 nm,以沙利度胺为内标。结果：来那度胺血药浓度的线性范围为0.1-5 滋g/mL,最低检测限为0.1 μg/mL,三个浓度的QC 样品 (0.2, 1 and 5μg/mL)的提取回收率分别为78.8± 3.8, 80.1 ± 3.2 and 79.1 ± 7.6 %。结论：此方法准确、简便、灵敏度高,对来那度胺 的血药浓度测定和药物代谢动力学研究极具价值。     

A Semiautomated Analysis Method for Catecholamines, Indoleamines, and Some Prominent Metabolites in Microdissected Regions of the Nervous System: An Isocratic HPLC Technique Employing Coulometric Detection and Minimal Sample Preparation

The application of a commercially available coulometric electrochemical detector to the automated HPLC analysis of some monoamines and their metabolites in microdissected areas of the rat nervous system is described. Apart from the stability and high sensitivity of the system, other appealing features of the technique are the facile sample preparation and long-term sample storage characteristics which show minimal analyte degradation. Basal values of some regional monoamine and metabolite concentration are listed together with a brief appendix that serves as a user's guide to the operation and maintenance of the detection system.     

Stereoselective Degradation of alpha‐Cypermethrin and Its Enantiomers in Rat Liver Microsomes

Alpha‐cypermethrin (α‐CP), [(RS)‐a‐cyano‐3‐phenoxy benzyl (1RS)‐cis‐3‐(2, 2‐dichlorovinyl)‐2, 2‐dimethylcyclopropanecarboxylate], comprises a diastereoisomer pair of cypermethrin, which are (+)‐(1R‐cis‐αS)–CP (insecticidal) and (?)‐(1S‐cis‐αR)–CP (inactive). In this experiment, the stereoselective degradation of α‐CP was investigated in rat liver microsomes by high‐performance liquid chromatography (HPLC) with a cellulose‐tris‐ (3, 5‐dimethylphenylcarbamate)‐based chiral stationary phase. The results revealed that the degradation of (?)‐(1S‐cis‐αR)‐CP was much faster than (+)‐(1R‐cis‐αS)‐CP both in enantiomer monomers and rac‐α‐CP. As for the enzyme kinetic parameters, there were some variances between rac‐α‐CP and the enantiomer monomers. In rac‐α‐CP, the V_max and CL_int of (+)‐(1R‐cis‐αS)–CP (5105.22 ± 326.26 nM/min/mg protein and 189.64 mL/min/mg protein) were about one‐half of those of (?)‐(1S‐cis‐αR)–CP (9308.57 ± 772.24 nM/min/mg protein and 352.19 mL/min/mg protein), while the K_m of the two α‐CP enantiomers were similar. However, in the enantiomer monomers of α‐CP, the V_max and K_m of (+)‐(1R‐cis‐αS) ‐CP were 2‐fold and 5‐fold of (?)‐(1S‐cis‐αR)‐CP, respectively, which showed a significant difference with rac‐α‐CP. The CL_int of (+)‐(1R‐cis‐αS)–CP (140.97 mL/min/mg protein) was still about one‐half of (?)‐(1S‐cis‐αR)–CP (325.72 mL/min/mg protein) in enantiomer monomers. The interaction of enantiomers of α‐CP in rat liver microsomes was researched and the results showed that there were different interactions between the IC₅₀ of (?)‐ to (+)‐(1R‐cis‐αS)‐CP and (+)‐ to (?)‐(1S‐cis‐αR)‐CP(IC_50(?)/(+) / IC_50(+)/(?) = 0.61). Chirality 28:58–64, 2016. © 2015 Wiley Periodicals, Inc.     

An Immunoblot Study of Neurofilament Degradation In Situ and During Calcium-Activated Proteolysis

The degradation of neurofilament (NF) proteins was examined by immunoblot methods to identify, characterize, and monitor the appearance of immunoreactive breakdown products during the loss of NF triplet proteins. Individual NF proteins and their breakdown products were identified using polyclonal and monoclonal antibodies to NF proteins. NF degradation was compared during calcium-activated proteolysis of isolated rat NF, during an experimental influx of calcium into excised rat spinal nerve roots, and during NF breakdown in transected rat peripheral nerve. These different experimental conditions produced similar patterns of NF fragmentation, including the transient appearance of NF immunobands between Mr 150,000-200,000 and 110,000-120,000 as well as the appearance and accumulation of NF immunobands between Mr 45,000 and 65,000. Most immunoreactive NF fragments remained Triton-insoluble. Low levels of the same immunoreactive fragments were present in control neural tissues, suggesting that calcium-activated proteolysis may be operative in the turnover and/or processing of NF proteins in vivo. Very similar patterns of NF degradation during experimental calcium influxes into different CNS and PNS tissues are indicative of the widespread distribution of calcium-activated NF protease in neural tissues.     

Changes of Neurotransmitter Systems in Chronic Relapsing Experimental Allergic Encephalomyelitis in Rat Brain and Spinal Cord

Catecholamine and indoleamine neurotransmitters, together with some of their precursors and metabolites, were determined using HPLC in three brain and two spinal cord regions of Lewis rats with chronic relapsing allergic encephalomyelitis and of control rats injected with complete Freund's adjuvant. Three attacks and two recovery phases were investigated. Changes are found mainly in the spinal cord. In the lumbosacral region both 5-hydroxytryptamine and noradrenaline are reduced during the entire course of the disease, whereas in the craniothoracal region 5-hydroxytryptamine is unchanged and only noradrenaline is reduced during the attacks, returning to normal during the first recovery. The precursors tyrosine and tryptophan are greatly elevated during the first two attacks in both regions. The 5-hydroxytryptamine turnover marker 5-hydroxyindoleacetic acid is increased in the first attack in both regions, then it decreases in the later stages, indicating destruction of nerve fibers. On the fourth and seventh days after inoculation values are generally not significantly different from controls in all regions. The possible correlation of neurochemical results with neurological signs is discussed.     

三七地下部分皂甙成分的HPLC比较研究

应用HPLC定量分析方法,对三七(Panax notoginseng)地下部位的皂甙成分进行分析,通过比较人参皂甙Rg1,Rb1,Re,Rd和三七皂甙R1等5种主要皂甙成分和总皂甙的含量变化,探讨不同部位和组织中皂甙成分的分布规律。结果表明在三七药材的不同商品等级中,人参皂甙Rg1和Rb1的含量以主根60头为最高,5个主要皂甙的总含量也明显高于其他的等级;根茎的生物产量只为全根的18%,皂甙含量占25%以上;主根和根茎中韧皮部的生物产量和总皂甙的含量均高于木质部;二年生三七的生物产量及皂甙含量均较三年生三七低得多。不同表型三七的皂甙组成也有区别。     

An Engulfment Assay: A Protocol to Assess Interactions Between CNS Phagocytes and Neurons

Phagocytosis is a process in which a cell engulfs material (entire cell, parts of a cell, debris, etc.) in its surrounding extracellular environment and subsequently digests this material, commonly through lysosomal degradation. Microglia are the resident immune cells of the central nervous system (CNS) whose phagocytic function has been described in a broad range of conditions from neurodegenerative disease (e.g., beta-amyloid clearance in Alzheimer’s disease) to development of the healthy brain (e.g., synaptic pruning)^1-6. The following protocol is an engulfment assay developed to visualize and quantify microglia-mediated engulfment of presynaptic inputs in the developing mouse retinogeniculate system⁷. While this assay was used to assess microglia function in this particular context, a similar approach may be used to assess other phagocytes throughout the brain (e.g., astrocytes) and the rest of the body (e.g., peripheral macrophages) as well as other contexts in which synaptic remodeling occurs (e.g. ,brain injury/disease).     

白毛茛中生物碱的提取和HPLC分析

白毛茛根粉末经室温萃取后用HPLC分析其中的生物碱成分,色谱柱为Zorbax Eclipse XDBC18快速分离,该方法可准确测定白毛茛中主要的生物碱,包括小檗碱（berberine）和白毛莨碱（hydrastine）。萃取和HPLC分析还可用于其他几种生物碱的测定,包括氢化小蘖碱（canadine）、白毛莨分碱（hydrastinine）和巴马亭（palmatine）,也可以应用于其它含小檗碱的植物根。Eclipse XDBC18快速分离柱采用等梯度分离,所有组分在15min内获得了高的分离度。     

LASS1基因克隆及其在大鼠脑皮层的表达与神经元衰老的相关性初步研究

长寿保障基因LAG1是从酵母中克隆的与酵母寿命相关的基因,随酵母生命衰老而表达发生变化.对大鼠中同源基因LASS1进行克隆、测序和序列分析,发现其mRNA序列不同于GenBank中的预测序列,开放阅读框包含1 053碱基对,编码蛋白由350个氨基酸组成,内含Lag1蛋白家族保守的Lag1p motif和TLC结构域.从新生、1月龄、6月龄、12月龄和24月龄大鼠脑顶叶皮质提取总RNA,用半定量RT-PCR及RNA印迹方法对LASS1在大鼠脑皮质中的表达随年龄变化情况进行分析.结果表明,出生后LASS1表达量随年龄增加而增高,至6月龄达高峰,然后随年龄增加而逐渐下降,至24月老龄鼠达最低.衰老相关β半乳糖苷酶(SA-β-gal)对鼠脑皮层染色发现,神经元阳性染色随年龄增长明显增加.大鼠LASS1基因表达在正常衰老过程中发生变化,为进一步研究该基因的作用奠定了基础.     

Myelin-Deficient Rat: Analysis of Myelin Proteins

Myelin basic protein (BP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) activity were quantitated in the brains and spinal cords of normal and myelin-deficient (md) rats at 8, 12, 18, and 25 days of age. The levels of BP, MAG, and CNP in 25-day-old md brain were 1.1, 1.8, and 11% of those in controls, respectively. In spinal cord, the levels were higher, at 9, 15, and 12% of control values, respectively. Although BP content in the mutant rats was a lower percentage of the control level than MAG and CNPase contents at all ages, the absolute level of BP increased steadily between 8 and 25 days of age in both brain and spinal cord, whereas there was little change in the amounts of MAG and CNPase during this period. Immunoblotting analysis did not reveal an increased apparent Mr for MAG, as has been observed in quaking and trembler mice. There was little difference in the relative distributions of the 14K, 17K, 18.5K, and 21.5K forms of BP between control and md rat spinal cord homogenates at the ages examined. PLP content was reduced more than that of the other proteins in the md mutants, because it could not be detected by a technique capable of detecting 0.2% of the control brain level and 0.1% of control spinal cord level. This suggests that the expression of PLP may be preferentially affected in the md mutation.     

An Insight to Chiral Monolith for Enantioselective Nano and Micro HPLC: Preparation and Applications

This review gives an overview of chiral separation principles and their application in enantioselective nano/micro high performance liquid chromatography (n/μ‐HPLC) using chiral monolith. In particular, developments in silica and polymer chiral monolithic stationary phases are presented. The preparation and applications of chiral monoliths, the basic chiral separation principles and the mechanisms are discussed. Chirality 25:314–323, 2013. © 2013 Wiley Periodicals, Inc.     

Dynamics of CNS Barriers: Evolution,Differentiation, and Modulation

Summary 1. Three main barrier layers at the interface between blood and tissue protect the central nervous system (CNS): the endothelium of brain capillaries, and the epithelia of the choroid plexus (CP) and the arachnoid. The classical work on these barriers in situ until the 1970s laid the foundations for modern understanding. Techniques for brain endothelial cell isolation and culture pioneered by Ferenc Joó in the 1970s opened up new fields of examination, enabling study of mechanisms at the cellular and molecular level.2. Astrocytic glial cells are closely associated with the brain endothelial barrier. During evolution the barrier appears to have shifted from the glial to the endothelial layer, in parallel with the increasing importance of the microvasculature and its regulation. Vestiges of the barrier potential of glia remain in the modern mammalian CNS.3. Evolutionary evidence suggests that the advantage derived from ionic homeostasis around central synapses was the major selective pressure leading to refinement of CNS barrier systems. This is one element of the modern multitasking barrier function.4. While epithelia are constitutively able to form barriers at appropriate interfaces, the default condition for endothelia is more leaky; inductive influences from associated cells especially astrocytes are important in generating the full blood–brain barrier (BBB) phenotype in brain capillaries. The underlying mechanisms are being elucidated at the molecular and genomics level.5. The barrier layers of the nervous system can be modulated by a number of receptor-mediated processes, involving several signal transduction pathways, both calcium dependent and independent. Some agents acting as inducers in the long term can act as modulators in the short-term, with some overlap of signaling pathways. Modulating agents may be derived both from the blood and from cells associated with cerebral vessels. Less is known about the modulation of the CP.6. The challenge for the next era of CNS barrier studies will be to apply new knowledge from proteomics and genomics to understanding the in vivo condition in physiology and pathology.This revised article was published online in May 2005 with a February 2005 cover date.     

HPLC法测定烟草不同部位、不同提取方法茄尼醇的含量

为了建立烟草不同部位、不同烟草原料中茄尼醇的含量测定方法,本文取烟草不同部位经甲醇超声提取及烟草不同提取方法的提取物,分别用高效液相色谱法测定茄尼醇的含量。结果显示,烟草茎及叶柄中茄尼醇含量极低,烤烟中的茄尼醇的含量：中部烟〉上部烟〉下部烟,烟叶档次越高茄尼醇含量越高。提取溶媒为石油醚〉丙酮〉乙醇。