Ferraro T N, Hare T A
Brain Res. 1985 Jul 8;338(1):53-60. doi: 10.1016/0006-8993(85)90247-1.
An extended baseline characterization of amino acids (AAs) and related amino compounds in CSF is reported. Thirty-one amino compounds were measured in deproteinized CSF before and after acid hydrolysis using a triple-column HPLC/fluorometric analyzer. CSF specimens were collected under strictly controlled conditions from neurologically normal myelogram patients and carefully pooled with regard to subject age and sex. Consideration was given to factors which may produce artifactual alterations in AA levels during CSF collection, storage and handling. Conjugated AAs were determined as the difference between levels of free AAs (measured in CSF prior to hydrolysis) and total AAs (measured in hydrolyzed CSF) and are taken as an index of total CSF peptide AAs. Results documented conjugated forms of all non-acid-labile CSF AAs except citrulline and ethanolamine. In general, ratios of conjugated to free AAs were relatively low, however for the neurotransmitter AAs aspartate, glutamate, glycine and GABA as well as for beta-alanine hydrolysis produced marked increases indicating that these compounds are present predominantly in bound form in CSF. Results also revealed the significant influence of both age and sex on levels of a number of CSF free and conjugated AAs. Compared to younger individuals (those less than 40 years of age), older individuals exhibited significantly higher levels of free aspartate, glycine, alpha-aminobutyric acid, valine, isoleucine, leucine, phenylalanine and 3-methylhistidine as well as significantly lower levels of free phosphoethanolamine, serine, GABA, homocarnosine, conjugated GABA and conjugated beta-alanine. Additionally, significantly higher levels of free tyrosine, ethanolamine, arginine and conjugated aspartate were documented in males compared to females.(ABSTRACT TRUNCATED AT 250 WORDS)
本文报道了脑脊液中氨基酸（AAs）及相关氨基化合物的扩展基线特征。使用三柱高效液相色谱/荧光分析仪，对脱蛋白脑脊液在酸水解前后的31种氨基化合物进行了测定。脑脊液样本是在严格控制的条件下，从神经学正常的脊髓造影患者中采集的，并根据受试者的年龄和性别进行了仔细汇集。研究考虑了脑脊液采集、储存和处理过程中可能导致氨基酸水平出现人为改变的因素。结合氨基酸的测定方法是，用游离氨基酸水平（水解前脑脊液中测量值）与总氨基酸水平（水解后脑脊液中测量值）的差值来确定，并将其作为脑脊液总肽氨基酸的指标。结果记录了除瓜氨酸和乙醇胺外，所有脑脊液中对酸不稳定的氨基酸的结合形式。一般来说，结合氨基酸与游离氨基酸的比例相对较低，然而对于神经递质氨基酸天冬氨酸、谷氨酸、甘氨酸和γ-氨基丁酸以及β-丙氨酸，水解后显著增加，这表明这些化合物在脑脊液中主要以结合形式存在。结果还揭示了年龄和性别对许多脑脊液游离和结合氨基酸水平的显著影响。与年轻个体（年龄小于40岁者）相比，年长个体的游离天冬氨酸、甘氨酸、α-氨基丁酸、缬氨酸、异亮氨酸、亮氨酸、苯丙氨酸和3-甲基组氨酸水平显著更高，而游离磷酸乙醇胺、丝氨酸、γ-氨基丁酸、同肌肽、结合γ-氨基丁酸和结合β-丙氨酸水平显著更低。此外，与女性相比，男性的游离酪氨酸、乙醇胺、精氨酸和结合天冬氨酸水平显著更高。（摘要截选至250字）
