烧伤患者血浆和红细胞游离氨基酸变化及输注氨基酸对其变化的影响

动态测定烧伤患者血浆及红细胞内游离氨基酸的含量 ,探讨输入外源性氨基酸后对血及红细胞内游离氨基酸的影响。以日立 835— 5 0型氨基酸自动分析仪测定烧伤患者血浆及红细胞内游离氨基酸含量。结果发现烧伤患者血浆总游离氨基酸浓度从伤后到 2 1天均显著降低 (P <0 .0 5～ 0 .0 1) ;赖、苯丙和苯丙 酪氨酸比值显著升高 (P <0 .0 5～ 0 .0 1) ;色、组、精、丙、甘、苏、脯和丝氨酸比值显著降低 (P <0 .0 5～ 0 .0 1) ;缬、亮、异亮、酪、胱和支链氨基酸伤后早期降低。烧伤患者红细胞内总游离氨基酸含量不同程度降低 ,其中 1、3、7天降低显著 (P <0 .0 5～ 0 .0 1) ;红细胞内苯丙和苯丙 酪氨酸比值未见显著性升高 ;色、蛋、精、脯氨酸含量很低或基本未测出。输注复合氨基酸注射液后未能显著改善患者血及红细胞内游离氨基酸含量。结果提示烧伤患者红细胞内游离氨基酸含量的变化趋势与血浆游离氨基酸变化趋势基本一致 ;烧伤后红细胞内苯丙氨酸及苯丙 酪氨酸比值有别于血浆变化。本研究条件下补充外源性氨基酸未能显著改变烧伤患者血浆及红细胞内游离氨基酸的含量     

平衡型氨基酸透析液对维持性血液透析患者血浆游离氨基酸含量的影响

目的:研究一种平衡型氨基酸透析液,探讨其对维持性血透患者血游离氨基酸含量的影响。方法:实验采用自身对照设计,应用蛋白水解法测定、分析应用氨基酸透析液血透前后患者血浆氨基酸含量,并同时测定应用碳酸盐透析液患者及健康人血浆游离氨基酸作为比较。结果:经碳酸盐透析后,患者血浆大多数游离氨基酸和总氨基酸含量显著降低。给予平衡氨基酸透析液能不同程度改善患者血浆游离氨基酸的含量。结论:平衡型氨基酸透析液能减少血中部分氨基酸的丢失。     

富含谷氨酰胺和支链氨基酸的肠外制剂对创伤大鼠的效用

研究普通氨基酸注射液 (17AA)与富含谷氨酰胺及支链氨基酸注射液 (2 0AA)对创伤大鼠的营养效用。以Wistar大鼠为创伤模型 ,分别输注两种配方的氨基酸注射液 ,以日立L - 85 0 0氨基酸自动分析仪测定动物血浆游离氨基酸 ,并测定创伤处海绵内羟脯氨酸含量。结果显示创伤后大鼠血浆牛磺酸、谷氨酸、谷氨酰胺和支链氨基酸含量较术前下降 ,但 2 0AA组血浆氨基酸恢复优于 17AA组 ,创伤处海绵内羟脯氨酸含量 2 0AA组显著高于 17AA组 (1.2 9± 0 .2 1vs 0 .83± 0 .16mg/块海绵 ,P <0 .0 5 )。提示 ,创伤后给予富含谷氨酰胺和支链氨基酸的营养制剂能提高血浆氨基酸浓度并有利于创伤的恢复     

某些内科系统疾病患者血浆游离氨基酸的变化及意义

为了解某些内科系统疾病的血氨基酸代谢特点。测定１７０例９种内科系统急慢性疾病患者血浆游离氨基酸浓度,并分别与５８例健康人血浆氨基酸浓度作对比分析。９种疾病的血浆胱氨基酸浓度不同程度升高,以尿毒症病人最为显著,炎症性病人血浆苯丙、蛋、赖氨酸和苯丙／酪比值显著升高,丙、组、精、脯氨酸和支／芳比值显著降低;糖尿病和甲亢病人血浆总游离氨基酸、谷、丙、酪、赖和支链氨酸显著升高;糠尿病病人支／芳比值显著升高,表明不同疾病的血氨基酸浓度有特征性变化,炎症是导致血氨基酸代谢紊乱的重要因素     

血浆中氨基酸检测技术探讨

在血浆中检测游离氨基酸含量是临床诊断的重要手段之一。本文讨论了液相色谱法、氨基酸分析法、液质联用技术等几种血浆中氨基酸的检测技术,并介绍这些技术在氨基酸检测中的应用,为建立血浆中游离氨基酸的分析方法提供参考依据。     

氨基酸代谢调控在大鳞副泥鳅应对氨暴露中的作用

将大鳞副泥鳅(Paramisgurnus dabryanus)暴露于30 mmol/L NH4Cl溶液中以研究高浓度环境氨对其血浆、肝脏及肌肉组织中游离氨基酸含量的影响。氨暴露会显著影响大鳞副泥鳅血浆、肝脏及肌肉组织中游离氨基酸含量(P0.05)。随着氨暴露时间的延长,大鳞副泥鳅血浆中丙氨酸的含量显著增加,且显著高于对照组(P0.05)。在氨暴露12h后,其肝脏组织中游离谷氨酸含量显著上升(P0.05),而在暴露72h后迅速下降(P0.05)。而游离丙氨酸含量在氨暴露的前24h内基本保持恒定,随后开始显著上升(P0.05)并持续至72h。在氨暴露大鳞副泥鳅12h后,肌肉中游离谷氨酸含量显著上升(P0.05),随后快速下降至初始水平并持续到实验结束(P0.05),且在暴露72h和96h时显著低于对照组(P0.05)。肌肉中游离丙氨酸含量随着氨暴露时间的延长呈现先上升后降低的趋势,并在暴露12h和48h时出现2个峰值,且显著高于对照组(P0.05)。在氨暴露下,其血浆、肝脏及肌肉中游离谷氨酸含量显著降低,且谷氨酰胺含量和谷氨酰胺合成酶活性显著提高,说明在高环境氨条件下,大鳞副泥鳅会利用谷氨酰胺合成酶将谷氨酸和NH_4~+合成无毒的谷氨酰胺以降低氨毒性。随着氨暴露时间的延长,大鳞副泥鳅血浆和组织有明显的丙氨酸累积且游离谷氨酸、精氨酸和脯氨酸含量显著降低,说明其可通过代谢这些特定氨基酸生成丙氨酸以降低体内氨的累积。     

休克期切痂猪血浆氨基酸的变化

观察烧伤休克期切痂后猪血浆游离氨基酸的变化规律 ,探讨焦痂毒素对全血氨基酸浓度的影响。以日历83 5 5 0型氨基酸自动分析仪 ,测定TBSA3 5 %Ⅲ度实验用小型猪血浆游离氨基酸 ,同时分析相关指标 (血LPS、GPT和TNF)的变化 ,结果显示休克期切痂组血浆游离氨基酸 (除个别氨基酸的个别时间点有变化外 )无显著性变化 ;在伤后 6d和 1 0d苯丙氨酸显著降低 ,血LPS、GPT和TNF也较对照组低 ,提示焦痂的存在对肝脏代谢有一定的影响     

长期缺硒对大鼠血浆氨基酸的影响

目的：探讨长期缺硒对大鼠血浆氨基酸的影响。方法：选取20只SPF级3 w龄雄性断乳Sprague-Dawley大鼠随机分为2组：对照组喂养正常饲粮（0.18 mg Se/kg）、缺硒组喂养低硒饲粮（0.02 mg Se/kg）。应用L-8900氨基酸分析仪检测血浆氨基酸水平。结果：第300天缺硒组大鼠血浆磷酸丝氨酸、牛磺酸、天门冬氨酸含量显著降低;第532天缺硒组大鼠血浆丝氨酸、缬氨酸、异亮氨酸、亮氨酸、苯丙氨酸、组氨酸含量显著升高,甘氨酸含量显著降低。结论：长期缺硒引起大鼠氨基酸代谢发生显著变化。     

氮、磷、钾营养对膜荚黄芪幼苗根系活力和游离氨基酸含量的影响

运用水培试验法研究不同营养水平对黄芪幼苗根系活力和游离氨基酸组成及含量的影响。结果表明:缺素显著降低黄芪根系活力,不同营养处理游离氨基酸含量差异显著,游离氨基酸总量的变化规律为叶片>根,各处理游离氨基酸总量为-K>-P>NPK>-N。全素处理与缺素处理相比,能提高根系活力、协调根冠比。黄芪幼苗通过提高体内游离氨基酸含量以增强对营养胁迫逆境的适应能力。     

不同施肥水平对不同品种小麦籽粒蛋白质和地上器官游离氨基酸含量的影响

研究了小麦不同品种开花后各地上器官游离氨基酸含量的变化动态及其与籽粒蛋白质含量的关系,以及氮素营养的调节作用。结果表明,小麦叶片和颖壳十穗轴游离氨基酸含量均在开花后持续增加,至花后14d达到最大值,之后开始下降。茎和叶鞘游离氨基酸含量则在开花后上升较缓慢,至花后21d达最大值。籽粒游离氨基酸含量一般在开花后就持续降低。各地上器官游离氨基酸含量与成熟期籽粒蛋白质含量均呈显著或极显著正相关,说明源器宫中游离氨基酸供应充足,有利于籽粒蛋白质积累。增施氮肥能够提高各地上器官中的游离氨基酸含量,进而促进籽粒蛋白质的合成,提高籽粒蛋白质含量。品种之间籽粒蛋白质含量的差异,是由各地上营养器官向籽粒运输氨基酸的综合作用所造成的。     

羊胎素中氨基酸测定与评价

用日立L-8800型氨基酸自动分析仪测定了羊胎素中的氨基酸含量。结果表明羊胎素中18种氨基酸总量、必需氨基酸及药效氨基酸含量较高,提示羊胎素在营养学和医学上都有很高的研究价值。     

Free amino acids in some sponges

Most invertebrates, particularly those of marine origin, have relatively high concentrations of free amino acids which are considered an important constituent of their osmoregulatory mechanisms [1]. Very little information is available on the free amino acid distribution in Porifera [2,3]. Common amino acids in some sponges were recognised by paper chromatography by Inskip and Cassidy [4] and Ackermann et al. [5,6] included a few sponges in their survey of the occurence of nitrogen compounds in marine invertebrates. More recently Bergquist and Hartman [7] surveyed semiquantitatively the distribution of free amino acids in several sponges. In the present paper we report on the amino acid composition of 12 species of sponges belonging to the class Demospongiae as a part of a study on the metabolites of Porifera [8]. Fresh sponges were extracted with aqueous ethanol. The organic solvent was removed and the aqueous solution, after removal of the ether soluble compounds, was separated into cationic, anionic and neutral fractions by ion-exchange chromatography. The cation fraction was analysed for amino acids using an automatic amino acid analyser. The results, which are presented in Table 1, show that all species of sponges examined have a similar composition in common amino acids. Glycine almost always appears as the dominant protein amino acid, followed by high concentrations of alanine and glutamic acid, whereas relatively lower concentrations of basic amino acids are present. In Axinella cannabina, Chondrosia reniformis, Chondrilla nucula, Cliona viridis and Hymeniacidon sanguinea, glycine represents more than 77% of the total amino acids. The high percentage of free glycine (90.4%) in Chondrosia reniformis is noteworthy. The anionic and the neutral fractions were examined for sulfur-containing amino acids using PC. Taurine (Table 2) was detected in all the Porifera examined; this is in agreement with previous observations [5–7]. N-Methyltaurine was identified in some of the species examined, whereas neither N,N-dimethyltaurine nor N,N,N-trimethyltaurine were found.     

Effect of Impact Trauma on Neurotransmitter and Nonneurotransmitter Amino Acids in Rat Spinal Cord

N-Methyl-D-aspartate (NMDA) administration exacerbates neurological dysfunction after traumatic spinal cord injury in rats, whereas NMDA antagonists improve outcome in this model. These observations suggest that release of excitatory amino acids contributes to secondary tissue damage after traumatic spinal cord injury. To further examine this hypothesis, concentrations of free amino acids were measured in spinal cord samples from anesthetized rats subjected to various degrees of impact trauma to the T9 spinal segment. Levels of excitatory and inhibitory neurotransmitter amino acids [gamma-aminobutyric acid (GABA), glutamate, aspartate, glycine, taurine] and levels of nonneurotransmitter amino acids (asparagine, glutamine, alanine, threonine, serine) were determined at 5 min, 4 h, and 24 h posttrauma. Uninjured surgical (laminectomy) control animals showed modest but significant declines in aspartate and glutamate levels, but not in other amino acids, at all time points. In injured animals, the excitatory amino acids glutamate and aspartate were significantly decreased by 5 min posttrauma, and remained depressed at 4 h and 24 h as compared with corresponding laminectomy controls. In contrast, the inhibitory amino acids, glycine, GABA, and taurine, were decreased at 5 min postinjury, had partially recovered at 4 h, and were almost fully recovered at 24 h. The nonneurotransmitter amino acids were unchanged at 5 min posttrauma and significantly increased at 4 h, with partial recovery at 24 h. At 4 h postinjury, severe trauma caused significantly greater decreases in aspartate and glutamate than did either mild or moderate injury. These findings are consistent with the postulated role of excitatory amino acids in CNS trauma.     

Changes with aging in the levels of amino acids in rat CNS structural elements II. Taurine and small neutral amino acids

Taurine (Tau) and the small neutral amino acids glycine (Gly), serine (Ser), threonine (Thr), and alanine (Ala) were measured in 53 brain areas of 3- and 29-month-old male Fisher 344 rats. The ratio of highest to lowest level was 34 for Tau, 9.1 for Thr, 7.6 for Gly and Ser, and 6.5 for Ala. The heterogeneity was found in numerous areas; for example, Tau levels were more than 90 nmol/mg protein in 6 areas, and less than 20 nmol/mg protein in 10 areas. Similar heterogeneity was found with the other amino acids. The relative distribution of the small neutral amino acids showed several similarities; Tau distribution was different. With age, four amino acids decreased in 10–18 areas, and increased in only 1–3, while Thr increased in more areas than it decreased. The five amino acids of this paper, and the four of the previous paper, are among the amino acids at highest level in the brain; the sequence in their levels shows considerable regional heterogeneity.     

Lipophilicity of amino acids

Summary The lipophilicity (or hydrophobicity) of amino acids is an important property relevant for protein folding and therefore of great interest in protein engineering. For peptides or peptidomimetics of potential therapeutic interest, lipophilicity is related to absorption and distribution, and thus indirectly relates to their bioactivity. A rationalization of peptide lipophilicity requires basic knowledge of the lipophilicity of the constituting amino acids. In the present contribution we will review methods to measure or calculate the lipophilicities of amino acids, including unusual amino acids, and we will make a comparison between various lipophilicity scales.     

皱肋文蛤氨基酸含量及脂肪酸组成分析

测定了皱肋文蛤(Meretrix lyrata)软体部分的氨基酸含量与脂肪酸组成.共检出17种氨基酸,总含量为软体部干重的52.26%;4种呈味氨基酸(天门冬氨酸、谷氨酸、甘氨酸和丙氨酸)的含量为22.07%,占氨基酸总量的42.23%;必需氨基酸(EAA)总含量为20.72%,其必需氨基酸的构成比例基本符合FAO/W...     

Sugar amino acids in designing new molecules

Emulating the basic principles followed by Nature to build its vast repertoire of biomolecules, organic chemists are developing many novel multifunctional building blocks and using them to create ‘nature-like’ and yet unnatural organic molecules. Sugar amino acids constitute an important class of such polyfunctional scaffolds where the carboxyl, amino and hydroxyl termini provide an excellent opportunity to organic chemists to create structural diversities akin to Nature’s molecular arsenal. This article describes some of our works on various sugar amino acids and many other related building blocks, like furan amino acids, pyrrole amino acids etc. used in wide-ranging peptidomimetic studies. Published in 2005.Based on the invited lecture presented at the XVII International Symposium on Glycoconjugates held in January 12–16, 2003 at Bangalore, India.     

麦苗中氨基酸测定与评价

用日立L-8800型氨基酸自动分析仪测定了麦苗中的氨基酸含量.结果表明麦苗中18种氨基酸总量、必需氨基酸及药效氨基酸含量较高,提示麦苗在营养学和医学上都有很高的研究价值.     

柴达木盆地西伯利亚白刺和唐古特白刺的氨基酸含量及其营养评价

对柴达木盆地的西伯利亚白刺和唐古特白刺不同部位中氨基酸含量作了分析比较 ,并进行了营养评价。白刺中富含蛋白质 ,含有 18种氨基酸 ,其中有人体必需的 8种氨基酸 ,白刺果汁中的必需氨基酸含量远高于沙棘果汁。两种白刺的蛋白质和各氨基酸在各部位中含量分布相似 ,但因种的差异 ,第一限制性氨基酸稍有差别。     

海南产螺旋藻粉蛋白质氨基酸

采用Tecator自动定氮仪和Waters PICO-TAG氨基酸自动分析仪测定了海南螺旋藻粉中蛋白质含量和17种氨基酸含量。结果显示海南螺旋藻粉中蛋白质含量达63.3%,总氨基酸含量达60.88%,其中必需氨基酸含量超过40%,比例平衡,符合FA0标准,可与国外产品媲美。