Branched-chain amino acids in liver diseases

Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of liver cancer cells in vitro,and are essential for lymphocyte proliferation and dendritic cell maturation.In patients with advanced chronic liver disease,BCAA concentrations are low,whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high,conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients.Based on these basic observations,patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines,with positive effects.

Impairment of innate immune responses in cirrhotic patients and treatment by branched-chain amino acids

It has been reported that host defense responses, such as phagocytic function of neutrophils and natural killer (NK) cell activity of lymphocytes, are impaired in cirrhotic patients. This review will concentrate on the impairment of innate immune responses in decompensated cirrhotic patients and the effect of the treatment by branched-chain amino acids (BCAA) on innate immune responses. We already reported that phagocytic function of neutrophils was significantly improved by 3-mo BCAA supplementation. In addition, the changes of NK activity were also significant at 3 mo of supplementation compared with before supplementation. Also, Fisher’s ratios were reported to be significantly increased at 3 mo of BCAA supplementation compared with those before oral supplementation. Therefore, administration of BCAA could reduce the risk of bacterial and viral infection in patients with decompensated cirrhosis by restoring impaired innate immune responses of the host. In addition, it was also revealed that BCAA oral supplementation could reduce the risk of development of hepatocellular carcinoma in cirrhotic patients. The mechanisms of the effects will also be discussed in this review article.

Synergistic renoprotective effect of a compiled branched-chain amino acids and Cymbopogon schoenanthus extract against experimentally induced oxido-nitrosative renal insult

Objective: To better investigate the protective role of branched-chain amino acids(BCAAs)and Cymbopogon schoenanthus(CS) extract against the potassium dichromate(PDC)-induced oxido-nitrosative nephrotoxic insult in the experimental rat model. Methods: Thirty male rats were randomly divided into five equal groups: The 1 st group served as control; the 2^(nd)was injected with a single dose of PDC(15 mg/kg b.w i.p.);the 3^(rd), 4^(th), and 5^(th) groups were respectively treated with BCAAs, CS, and their combination for 15 d prior to induction of renal insult via PDC single dose(15 mg/kg b.w s.c.). The experimental period was terminated in all groups 2 d after induction of renal insult. The harvested kdney samples were divided for biochemical assays and histological examination. Results: The PDC-induced nephrotoxic effect caused a depletion of renal oxidative scavengers glutathione, superoxide dismutase with consequent lipo-oxidative cellular membrane deterioration manifested by a rise in malonaldehyde, oxidized glutathione, myeloperoxidase and the concomitant increase in inflammatory response elements tumor necrosis factor α, nitric oxide, and interleukin 1 β.Moreover, the comet assay and increased 8-hydroxy-2-deoxyguanosine proved an accelerated apoptotic DNA fragmentation. These local renal changes were met with global altered blood biochemistry. The BCAAs and CS or their compiled administration showed an ameliorative effect against PDC-induced nephrotoxic in a synergistic pattern. Conclusions: Both BCAAs and CS or their combined administration afford potential competitors against renal insult induced by polyvalent anion pollutants in experimentally studied animals model. As a route for novel drug discovery, further investigation should be attempted to optimize their augmenting reno-protecting potential.

Effect of branched-chain amino acids in patients receiving intervention for hepatocellular carcinoma

AIM: To investigate the usefulness of branched-chain amino acids (BCAA) before transarterial chemoembolization (TACE) or radiofrequency ablation (RFA).

Herbicide-Resistant Mutations in Acetolactate Synthase Can Reduce Feedback Inhibition and Lead to Accumulation of Branched-Chain Amino Acids

The branched-chain amino acids (BCAAs) valine, leucine and isoleucine are essential amino acids that are critical for animal growth and development. Animals need to obtain BCAAs from their diet because they cannot synthesize them. Plants are the ultimate source of these amino acids. Acetolactate synthase (ALS) is the first common enzyme in the biosynthesis of BCAAs. The metabolic control of BCAA biosynthesis involves allosteric regulation of ALS by the end-products of the pathway, i.e., valine, leucine and isoleucine. ALS holoenzyme seems to consist of two large catalytic subunits and two small regulatory subunits. In a previous study, using homologous recombination dependent gene targeting we created rice plants in which W548Land S627I mutations were induced into the endogenous gene encoding the ALS catalytic subunit. These two amino acid substitutions conferred hypertolerance to the ALS-inhibiting herbicide bispyripac-sodium. In this study, we revealed that feedback regulation by valine and leucine was reduced by these two amino acid substitutions. Furthermore, in leaves and seeds of ALS mutants with W548Land/or S627I substitution, a 2- to 3-fold increase in BCAAs was detected. Our results suggest that the ALS catalytic subunit is also involved in feedback regulation of ALS, and that judicious modification of the regulatory and catalytic subunits of ALS-coding genes by gene targeting can lead to the efficient accumulation of BCAA in plants.

OPTICALLY ACTIVE AMINO ACIDS WITH HIGHLY BRANCHED SIDE CHAIN (I) SYNTHESIS OF D- AND L- 2-AMINO-5,5-DIMETHYLHEXANOIC ACID AND 2-AMINO-6,6-DIMETHYLHEPTANOIC ACID

The title compounds were prepared by the enzymatic resolution of the corresponding N-acetylated DL-amino acids methyl esters, which were obtained from t-butyl chloride via an 8-step synthesis.

Functional microbiomics reveals branched-chain amino acids depletion for alleviation of insulin resistance by berberine

Increased circulating branched-chain amino acids(BCAAs)have been involved in the pathogenesis of obesity and insulin resistance.However,evidence relating berberine(BBR),gut microbiota,BCAAs,and insulin resis⁃tance is limited.Here,we showed that BBR could effectively rectify steatohepatitis and glucose intolerance in high-fat diet(HFD)-fed mice.BBR reorganized gut microbiota populations under both the normal chow diet(NCD)and HFD.Particu⁃larly,BBR noticeably decreased the relative abundance of BCAA-producing bacteria,including order Clostridiales;fami⁃lies Streptococcaceae,Clostridiaceae,and Prevotellaceae;and genera Streptococcus and Prevotella.Compared with the HFD group,predictive metagenomics indicated a reduction in the proportion of gut microbiota genes involved in BCAA biosynthesis but the enrichment genes for BCAA degradation and transport by BBR treatment.Accordingly,the elevated serum BCAAs of HFD group were significantly decreased by BBR.Furthermore,the Western blotting results implied that BBR could promote the BCAA catabolism in the liver and epididymal white adipose tissues of HFD-fed mice by acti⁃vation of the multienzyme branched-chain α-ketoacid dehydrogenase complex,whereas by inhibition of the phosphoryla⁃tion state of BCKDHA(E1α subunit)and branched-chain α-ketoacid dehydrogenase kinase.The ex vivo assay further confirmed that BBR could increase BCAA catabolism in both AML12 hepatocytes and 3T3-L1 adipocytes.Finally,data from healthy subjects and diabetics confirmed that BBR could improve glycemic control and modulate circulating BCAAs.Besides,functional microbiomics integrated high-throughput microbial genomics,metabolomics and molecular biotechnology has also been successfully applied to reveal the anti-obesity mechanism of hydroxysafflor yellow A.

Diagnostic value of methylated branched chain amino acid transaminase 1/IKAROS family zinc finger 1 for colorectal cancer

BACKGROUND The diagnostic value of combined methylated branched chain amino acid transaminase 1(BCAT1)/IKAROS family zinc finger 1(IKZF1)in plasma for colorectal cancer(CRC)has been explored since 2015.Recently,several related studies have published their results and showed its diagnostic efficacy.AIM To analyze the diagnostic value of methylated BCAT1/IKZF1 in plasma for screening and postoperative follow-up of CRC.METHODS The candidate studies were identified by searching the PubMed,Embase,Cochrane Library,CNKI,and Wanfang databases from May 31,2003 to June 1,2023.Sensitivity,specificity,and diagnostic accuracy were calculated by merging ratios or means.RESULTS Twelve eligible studies were included in the analysis,involving 6561 participants.The sensitivity of methylated BCAT1/IKZF1 in plasma for CRC diagnosis was 60%[95%confidence interval(CI)53-67]and specificity was 92%(95%CI:90-94).The positive and negative likelihood ratios were 8.0(95%CI:5.8-11.0)and 0.43(95%CI:0.36-0.52),respectively.Diagnostic odds ratio was 19(95%CI:11-30)and area under the curve was 0.88(95%CI:0.85-0.91).The sensitivity and specificity for CRC screening were 64%(95%CI:59-69)and 92%(95%CI:91-93),respectively.The sensitivity and specificity for recurrence detection during follow-up were 54%CONCLUSION The detection of methylated BCAT1/IKZF1 in plasma,as a non-invasive detection method of circulating tumor DNA,has potential CRC diagnosis,but the clinical application prospect needs to be further explored.

鳜KLF6序列特征、组织表达及其对BCAAs代谢酶基因表达的影响

为研究鳜KLF6基因序列特征、组织表达及其对支链氨基酸代谢酶基因表达的影响,通过在线工具和软件对KLF6基因进行生物信息学分析,运用实时荧光定量PCR(RT-qPCR)技术,检测KLF6基因在鳜7个不同组织的表达丰度及用siRNA干扰后KLF6基因和BCAAs代谢相关酶基因的mRNA表达量。结果表明:鳜KLF6基因编码区全长为3791 bp(登录号:XM_044176560.1),其中5′端和3′端分别为271和2659 bp,开放阅读框860 bp,共编码氨基酸286个。与鳃棘鲈KLF6基因的亲缘关系最近(98.6%),与鲤鱼较远(82.3%)。KLF6有1个KLF6-N型结构域(2-204 aa)、1个COG5048结构域(194-268 aa)和3个Znf-C2H2结构域(分别位于203-227、233-257、263-285个氨基酸之间)。鳜KLF6蛋白二级结构由无规则卷曲(56.99%)、α-螺旋(26.22%)、延伸链(10.84%)和β-转角(5.94%)相互连接而成。RT-qPCR结果发现,KLF6基因在鳜组织的相对表达量大小由高到低依次为心脏、脾脏、脑、肾脏、肠道、肌肉、肝脏。其中,心脏的表达量显著高于肝脏(P<0.01)和肌肉(P<0.05),脾脏、脑、肾脏及肠道的表达量高于肝脏(P<0.05)。在KLF6基因的mRNA表达量受到抑制后,BCAAs代谢酶(BCKDHb、ACADM、MCCC1、MCCC2、MUT、IVD)基因的mRNA表达量显著上升(P<0.05)。本研究为KLF6基因在鳜肌肉BCAAs代谢的调控机制研究提供了依据。

Plasma Levels of Amino Acids in Japanese Men and Their Changes after the Administration of Glucose and Sucrose

Background: It is not known whether plasma amino acids levels are different between young and old men in Japan. No research has been reported about changes in plasma levels of amino acids after the administration of glucose or sucrose to young and aged men. Objective: We want to know whether there are age differences in plasma levels of amino acids and if the administration of glucose or sucrose influences their levels. Results: Old people had lower plasma levels of most of amino acids, especially essential and branched-chain amino acids than young men. Plasma levels of amino acids were measured after the administration of 50 grams of glucose or sucrose to young (18 - 22 years old) and aged (≥50 years old) male adults. Plasma levels of total amino acids decreased after the administration of glucose. Decrease in the total amino acid levels was significant in aged men after the administration of sucrose. A significant decrease in plasma levels of total non-essential amino acids was observed at 120 min after the administration of glucose but not sucrose in both aged and young men. Both glucose and sucrose administrations resulted in a significant decrease in the plasma levels of the total essential amino acid levels and branched amino acids in young and aged men. Conclusion: These results suggest that there are age differences in plasma levels of amino acids. Upon the administration of glucose or sucrose amino acids, particularly essential amino acids, decreased in plasma. These amino acids may be transported from the blood soon after the administration of sugar (glucose or sucrose) to the tissues, such as muscles, possibly due to an increase in the insulin levels.

妊娠期糖尿病患者血清BCAAs、SFRP5水平与产后糖代谢异常的关系

目的探讨妊娠期糖尿病(GDM)患者血清支链氨基酸(BCAAs)、分泌型卷曲相关蛋白5(SFRP5)水平与产后糖代谢异常(AGM)的关系。方法选取GDM患者204例作为GDM组,同期于本院分娩的健康孕妇102例作为对照组,根据产后3个月是否发生AGM将GDM患者分为AGM组和非AGM组。采用氨基酸分析仪测定血清BCAAs(缬氨酸、异亮氨酸、亮氨酸)水平,酶联免疫吸附法检测血清SFRP5水平。以产后AGM为因变量,建立多因素非条件Logistic回归模型确定GDM患者产后AGM的因素,并绘制受试者工作特征曲线,评价血清BCAAs、SFRP5水平对产后AGM的预测价值。结果与对照组比较,GDM组血清缬氨酸、异亮氨酸、亮氨酸、BCAAs水平升高,SFRP5水平降低(P均<0.05)。随访3个月,204例GDM患者产后AGM发生率为31.86%(65/204)。与非AGM组比较,AGM组血清缬氨酸、异亮氨酸、亮氨酸、BCAAs水平升高,SFRP5水平降低(P均<0.05)。糖尿病家族史、OGTT餐后2 h血糖水平升高、BCAAs水平升高为GDM患者产后AGM的独立危险因素,SFRP5水平升高为独立保护因素(P均<0.05)。血清BCAAs联合SFRP5水平预测GDM患者产后AGM的曲线下面积为0.861,大于血清BCAAs、SFRP5水平单独预测的0.783、0.787(P均<0.05)。结论GDM患者血清BCAAs水平升高,SFRP5水平降低,与产后AGM独立相关,血清BCAAs联合SFRP5水平对产后AGM有较高预测价值。

Supplementation of branched-chain amino acids in protein-restricted diets modulates the expression levels of amino acid transporters and energy metabolism associated regulators in the adipose tissue of growing pigs

This experiment was conducted to investigate the effects of branched-chain amino acids(BCAA)supplemented in protein-restricted diets on the growth performance and the expression profile of amino acid transporters and energy metabolism related regulators in the white adipose tissue(WAT)of different regional depots including dorsal subcutaneous adipose(DSA) and abdominal subcutaneous adipose(ASA), A total of 24 crossbred barrows(7.40 ± 0.70 kg) were randomly divided into 4 groups and were fed the following isocaloric diets for 33 days: 1) a recommended adequate protein diet(AP, 20% CP, as a positive control); 2) a low protein diet(LP, 17% CP); 3) the LP diet supplemented with BCAA(LP + B, 17% CP) to reach the same level of the AP diet group; 4) the LP diet supplemented with 2 times the amount of BCAA(LP + 2B, 17% CP). The daily gain and daily feed intake of the LP diet group were the lowest among all the treatments(P < 0.01). The feed conversion was improved markedly in the group of LP + B compared with the LP diet group(P < 0.05). No significant difference was noted for the serum biochemical parameter concentrations of glucose, triglyceride, nonesterified fatty acid and insulin among the groups(P > 0.05). Moreover, BCAA supplementation down-regulated the expression levels of amino acid transporters including L-type amino acid transporter 1 and sodium-coupled neutral amino acid transporter 2 in DSA, but up-regulated the expression level of Ltype amino acid transporter 4 in ASA(P < 0.05), Meanwhile, the energy sensor AMP-activated protein kinase α was activated in the DSA of pigs fed LP diet and in the ASA of the pigs fed AP or LP + 2B diets(P < 0.05). The mRNA expression profile of the selected mitochondrial component and mitochondrial biogenesis associated regulators in DSA and ASA also responded differently to dietary BCAA supplementation. These results suggested that the growth performance of growing pigs fed protein restricted diets supplemented with BCAA could catch up to that of the pigs fed AP diets. The results also partly demonstrated that the regulation mechanisms of BCAA are different in the adipose tissues of different depots.

Branched chain amino acids and metabolic regulation

Amino acids are fundamental nutrients required for protein synthesis. The branched chain amino acids (BCAAs) leucine, isoleucine, and valine are the most abundant of the essential amino acids. BCAAs have recently been recognized as having functions in processes other than simple nutrition. For example, metabolic diseases are characterized by higher levels of circulating BCAAs. Moreover, supplementation with or deficiency in BCAAs is closely related to the regulation of metabolic homeostasis. Indeed, leucine deprivation induces increased lipolysis and thermogenesis, which result in fat loss, as well as suppressed lipogenesis and enhanced insulin sensitivity in the liver. Accumulating evidence has indicated that several amino acid sensors, including GCN2, ATF4, mTOR, and AMPK, play pivotal roles in the regulation of lipid metabolism, glucose metabolism, and energy homeostasis. Furthermore, the hypothalamus is critical for sensing amino acid levels and mediates the metabolic adaptation of the body upon limitation of essential amino acids (EAAs) through regulating expression of the S6K1, MC4R, and CRH. In this review, we highlight recent studies investigating the cellular mechanisms linking amino acids, amino acid sensors, metabolic regulation, and metabolic diseases. Amino acid sensing and metabolic regulation have become research hotspots in the metabolic field.

慢性充血性心力衰竭患者血浆BCAAs水平的临床研究

目的:探讨研究慢性充血性心力衰竭(CHF)患者血浆支链氨基酸(BCAAs)水平的变化,及其与氨基末端脑钠尿肽前体(NT-pro-BNP)和左室射血分数(LVEF)的相关性。方法:共纳入168例诊断为CHF患者作为病例组,同时随机选择同期体检的41例健康成年人作为对照组。采用ELISA方法测定空腹血浆BCAAs水平、NT-pro-BNP,超声心动图检测LVEF值。比较两组血浆BCAAs水平及其与NT-pro-BNP、LVEF的关系。结果:两组受试者基线资料无明显差异;CHF患者血浆BCAA水平、LVEF均低于对照组,血浆NT-pro-BNP高于对照组(P<0.01);随着NYHA分级增加,NT-pro-BNP逐渐升高,LVEF逐渐降低(P<0.01),而BCAAs水平无明显变化;Spearson偏相关分析显示经性别、年龄、收缩压、舒张压、体质量指数校正后,CHF组BCAAs水平与NT-pro-BNP呈负相关(r=-0.168,P<0.05),而与LVEF无关(r=0.069,P>0.05)。结论:CHF患者血浆BCAAs水平明显低于正常对照组,与NT-pro-BNP水平呈负相关。

BCAAs和3-HIB与妊娠期糖尿病向2型糖尿病转变者胰岛素抵抗的关系

目的:探究支链氨基酸(BCAAs)、3-羟基异丁酸(3-HIB)与妊娠期糖尿病(GDM)向2型糖尿病(T2DM)转变的胰岛素抵抗(IR)关系。方法:前瞻性选择2013年10月—2014年10月本院收治的GDM患者103例为病例组,随访产后5年,根据GDM患者是否进展为T2DM分为未进展组(n=57)和进展组(n=46),同期产前检查正常妊娠60例为对照组,比较各组血清BCAAs、3-HIB水平,采用Pearson相关分析T2DM患者血清BCAAs、3-HIB水平与IR的相关性,采用多因素logistic回归分析GDM进展为T2DM的影响因素。结果:病例组血清BCAAs(56.77±6.11μmol/L)、3-HIB(0.05±0.03 mmol/L)水平高于对照组(52.20±5.32μmol/L、0.02±0.01 mmol/L),进展组(58.69±6.97μmol/L、0.07±0.03 mmol/L)高于未进展组(58.69±6.97μmol/L、0.04±0.02 mmol/L)(均P<0.05);T2DM患者血清BCAAs、3-HIB水平与IR均呈正相关,且血清BCAAs、3-HIB高水平是GDM进展为T2DM的危险因素(均P<0.05)。结论:BCAAs、3-HIB水平在妊娠期糖尿病向2型糖尿病转变过程中逐渐上升,并与该过程中胰岛素抵抗相关。

BCAAs对干旱和盐胁迫下亚麻荠种子萌发的影响

旨在为逆境条件下亚麻荠的种植和栽培提供理论依据和技术支持,明确干旱和盐胁迫下支链氨基酸(BCAAs)对亚麻荠种子萌发的影响,研究以亚麻荠SC-N16为材料,采用聚乙二醇6000(PEG)和氯化钠(NaCl)建立亚麻荠种子的干旱胁迫和盐胁迫模型,通过亮氨酸(Leu)、异亮氨酸(Ile)和缬氨酸(Val)溶液对亚麻荠种子进行浸种处理,统计分析BCAAs对亚麻荠种子萌发率、发芽势、发芽指数、根长、芽长、鲜质量、干质量等萌发指标的影响。结果表明,干旱胁迫模型为0.20 g/mL PEG和盐胁迫模型为150 mmol/L NaCl条件下,3种BCAAs都能改善亚麻荠种子的发芽能力;其中,100μmol/L Val浸种后的缓解效果最好,其发芽势和萌发率较干旱胁迫模型分别提高了164.78%和34.76%,比盐胁迫模型分别提高了36.98%和29.77%。进一步扩大Val的浓度为0~250μmol/L,随着Val浓度的增大,干旱和盐胁迫下Val对亚麻荠种子萌发的缓解作用均呈先上升后下降的趋势,100μmol/L Val为最佳处理;100μmol/L Val处理后根长、芽长、干质量和鲜质量较PEG干旱胁迫分别提高了19.61%、30.77%、28.66%和9.53%,较NaCl盐胁迫增幅分别为21.05%、38.63%、27.14%和7.83%。综上可见,干旱和盐胁迫下外源BCAAs为Val且浓度为100μmol/L时对亚麻荠种子萌发的缓解效果最好。

支链氨基酸有效预测慢性阻塞性肺病的急性加重

目的:探讨支链氨基酸(BCAAs)代谢在慢性阻塞性肺病(COPD)发生机制中的作用。方法:收集42例COPD稳定期患者纳入COPD组,40例COPD急性加重(AECOPD)期患者纳入AECOPD组,收集同期46例健康体检者为对照组,采集外周血,应用液相色谱-质谱分析检测BCAAs水平,酶联免疫吸附(ELISA)法检测炎症因子水平,并对二者的相关性进行分析。结果:与对照组比较,COPD组及AECOPD组患者血浆亮氨酸、缬氨酸水平更低,且AECOPD组低于COPD组;血浆白介素(IL)-8、C-反应蛋白(CRP)水平更高,且AECOPD组高于COPD组(P均<0.001)。血浆中亮氨酸、缬氨酸水平与IL-8、CRP水平呈负相关(r=-0.64、-0.71、-0.73、-0.73,P均<0.05)。结论:BCAAs代谢可能通过炎症反应参与COPD的发生,临床中BCAAs水平有可能成为检测COPD急性加重潜在的生物标志物。

支链氨基酸代谢与2型糖尿病关系的研究进展

支链氨基酸(BCAAs)是一类因存在脂肪烃链而得名的必需氨基酸,包括亮氨酸、异亮氨酸以及缬氨酸。BCAAs同胰岛素抵抗的关系于1964年被提出,该类氨基酸在膳食中常见,其循环水平通过对糖脂代谢和胰岛素分泌的调控对2型糖尿病(T2DM)病程发展起着重要的作用。作为一种发病率高、并发症严重的慢性代谢性疾病,糖尿病已经对全球人民生活生产造成了极大的困扰。其中T2DM作为糖尿病中占比最高的类型,正大幅度降低患者的生活质量。本文通过糖脂代谢以及其他相关机制,将BCAAs代谢分解过程与T2DM发生发展联系起来,从而为临床T2DM的治疗诊断提供更多思路。

支链氨基酸代谢物对风湿性心脏瓣膜病体外循环术后低心排血量的预测价值

目的:探讨支链氨基酸代谢物对风湿性心脏瓣膜病病人行体外循环术后发生低心排血量事件的预测价值。方法:选取2019年1月—2022年1月我院收治的风湿性心脏瓣膜病病人154例作为研究对象,根据体外循环术后是否出现低心排血量,将病人分为低心排血量组(52例)和非低心排血量组(102例)。对比分析两组病人情况,多因素Logistic回归分析低心排血量事件的影响因素。Cox比例风险模型调整混杂变量,分析支链氨基酸代谢物和传统标志物与低心排血量事件的关联性。GRACE风险评分探讨支链氨基酸和传统标志物结合后对低心排血量的预测能力。Cox回归评价支链氨基酸代谢物和传统标志物之间的交互作用。建立回归方程y=1-1/(1+e-z)预测模型并进行验证。结果:脑钠肽、肌钙蛋白I、亮氨酸、缬氨酸、异亮氨酸等是低心排血量事件的独立危险因素。随着脑钠肽、肌钙蛋白I、亮氨酸、缬氨酸、异亮氨酸水平的升高,与低心排血量事件的关联效应也更强。支链氨基酸代谢物和传统标志物结合,会提高GRACE风险评分对低心排血量的预测能力。异亮氨酸联合脑钠肽前体对低心排血量事件的预测效应最高。经Bootstrap自抽样,预测模型区分度、准确度较好。结论:支链氨基酸代谢物和低心排血量密切相关。支链氨基酸代谢物加入传统标志物中,会提高对低心排血量的预测能力,有助于改善风湿性心脏瓣膜病病人预后。

支链氨基酸的生理功能及其在反刍动物生产中的应用研究进展

支链氨基酸是维持动物机体生长发育、生命活动和生理功能的必需氨基酸。支链氨基酸由于其特殊的分子结构而具有特殊生理功能。近年来研究发现,支链氨基酸具有氧化供能、调节蛋白质代谢、调节脂肪代谢、调节激素分泌、调节免疫、缓解氧化应激等多种功能。本文综述了支链氨基酸的生理功能及其在反刍动物生产中的应用,旨在为支链氨基酸在反刍动物生产中的合理应用提供理论依据和参考。