Postharvest changes in ammonium, amino acids and enzymes of amino acid metabolism in asparagus spear tips

1993 ◽  
Vol 63 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Paul L. Hurst ◽  
Christopher J. Clark
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism

Biochemische Aspekte des Aminosäuren-Stoffwechsels bei Psoriasis vulgaris / Biochemical Aspects of Amino Acid Metabolism in Psoriasis vulgaris

1973 ◽  
Vol 28 (7-8) ◽  
pp. 449-451 ◽  
Author(s):  
G. Peter ◽  
H. Angst ◽  
U. Koch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Psoriasis Vulgaris ◽  
Normal Subjects ◽  
Pathological Process

Free and protein-bound amino acids in serum and scales were investigated. In serum the bound amino acids of psoriatics are significantly higher with exception of Pro, Met, Tyr and Phe in contrast to normal subjects. For free amino acids the differences between normal subjects and psoriatics found in serum and scales are not significant. Results are discussed in relation to the single amino acids and the biochemical correlations are outlined which takes the pathological process as a basis.

scholarly journals The Diverse Functions of Non-Essential Amino Acids in Cancer

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 675 ◽  
Author(s):  
Bo-Hyun Choi ◽  
Jonathan L. Coloff
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cancer Therapy ◽  
Metabolic Pathways ◽  
Essential Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Essential Amino Acids ◽  
Redox Status ◽  
Antioxidant Systems

Far beyond simply being 11 of the 20 amino acids needed for protein synthesis, non-essential amino acids play numerous important roles in tumor metabolism. These diverse functions include providing precursors for the biosynthesis of macromolecules, controlling redox status and antioxidant systems, and serving as substrates for post-translational and epigenetic modifications. This functional diversity has sparked great interest in targeting non-essential amino acid metabolism for cancer therapy and has motivated the development of several therapies that are either already used in the clinic or are currently in clinical trials. In this review, we will discuss the important roles that each of the 11 non-essential amino acids play in cancer, how their metabolic pathways are linked, and how researchers are working to overcome the unique challenges of targeting non-essential amino acid metabolism for cancer therapy.

IDIOPATHIC HYPERGLYCINEMIA: A NEW DISORDER OF AMINO ACID METABOLISM

PEDIATRICS ◽  
1961 ◽  
Vol 27 (4) ◽  
pp. 539-550 ◽  
Author(s):  
William L. Nyhan ◽  
Margaret Borden ◽  
Barton Childs
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Oral Administration ◽  
Dietary Intake ◽  
Urinary Excretion ◽  
Cation Exchange ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Acute Illness ◽  
Progressive Decrease

The amino acids of blood and urine have been investigated using chromatography on cation exchange columns in the study of a patient with idiopathic hyperglycinemia. Marked increases in concentrations of glycine, serine, alanine, isoleucine and valine were found in the plasma. These changes were not reflected in increased excretion of these amino acids in the urine (with the exception of glycine). Restriction of the dietary intake of protein resulted in a decrease in the concentrations of glycine and other amino acids in the blood and urine, and there was a concomitant decrease in the frequency and severity of episodes of acute illness. The oral administration of leucine was found to induce a decrease in the levels of a number of amino acids in the patient and in controls. Continued decrease during the 3 hours of observation was noted for serine, isoleucine and valine. A mild but progressive decrease in threonine concentration was observed in the controls, while in the patient the concentration increased after the administration of leucine. Decreased levels at 1½ hours, returning toward the fasting levels at 3 hours, were observed for alanine, taurine and glycine. These apparently normal responses to leucine loads were not mediated through increase in the urinary excretion of the amino acids involved, and the data are interpreted to indicate entry of these amino acids into cells.

scholarly journals Glucose and amino acid metabolism in mice depend mutually on glucagon and insulin receptor signaling

2019 ◽  
Vol 316 (4) ◽  
pp. E660-E673 ◽  
Author(s):  
Katrine D. Galsgaard ◽  
Marie Winther-Sørensen ◽  
Jens Pedersen ◽  
Sasha A. S. Kjeldsen ◽  
Mette M. Rosenkilde ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Insulin Receptor ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Receptor Signaling ◽  
Cell Secretion ◽  
Glucagon Receptor ◽  
Insulin Receptor Signaling ◽  
Glucagon And Insulin

Glucagon and insulin are important regulators of blood glucose. The importance of insulin receptor signaling for alpha-cell secretion and of glucagon receptor signaling for beta-cell secretion is widely discussed and of clinical interest. Amino acids are powerful secretagogues for both hormones, and glucagon controls amino acid metabolism through ureagenesis. The role of insulin in amino acid metabolism is less clear. Female C57BL/6JRj mice received an insulin receptor antagonist (IRA) (S961; 30 nmol/kg), a glucagon receptor antagonist (GRA) (25-2648; 100 mg/kg), or both GRA and IRA (GRA + IRA) 3 h before intravenous administration of similar volumes of saline, glucose (0.5 g/kg), or amino acids (1 µmol/g) while anesthetized with isoflurane. IRA caused basal hyperglycemia, hyperinsulinemia, and hyperglucagonemia. Unexpectedly, IRA lowered basal plasma concentrations of amino acids, whereas GRA increased amino acids, lowered glycemia, and increased glucagon but did not influence insulin concentrations. After administration of GRA + IRA, insulin secretion was significantly reduced compared with IRA administration alone. Blood glucose responses to a glucose and amino acid challenge were similar after vehicle and GRA + IRA administration but greater after IRA and lower after GRA. Anesthesia may have influenced the results, which otherwise strongly suggest that both hormones are essential for the maintenance of glucose homeostasis and that the secretion of both is regulated by powerful negative feedback mechanisms. In addition, insulin limits glucagon secretion, while endogenous glucagon stimulates insulin secretion, revealed during lack of insulin autocrine feedback. Finally, glucagon receptor signaling seems to be of greater importance for amino acid metabolism than insulin receptor signaling.

scholarly journals Metabolic profile of in vitro derived human embryos is not affected by the mode of fertilization

2020 ◽  
Vol 26 (4) ◽  
pp. 277-287
Author(s):  
Christine Leary ◽  
Roger G Sturmey
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Metabolic Profile ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Human Embryos ◽  
Embryo Morphology ◽  
Male Factor ◽  
Triglyceride Content

Abstract The pattern of metabolism by early embryos in vitro has been linked to a range of phenotypes, including viability. However, the extent to which metabolic function of embryos is modified by specific methods used during ART has yet to be fully described. This study has sought to determine if the mode of fertilization used to create embryos affects subsequent embryo metabolism of substrates. A metabolic profile, including consumption of key substrates and the endogenous triglyceride content of individual IVF and ICSI supernumerary embryos, was assessed and compared. Embryo development and quality was also recorded. All embryos were donated at a single clinical IVF center, on Day 5, from 36 patients aged 18–38 years, The data revealed that consumption of glucose and pyruvate, and production of lactate, did not differ between embryos created by IVF or ICSI. Similarly, the mode of insemination did not impact on the triglyceride content of embryos. However, ICSI-derived embryos displayed a more active turnover of amino acids (P = 0.023), compared to IVF embryos. The specific amino acids produced in higher quantities from ICSI compared to IVF embryos were aspartate (P = 0.016), asparagine (P = 0.04), histidine (P = 0.021) and threonine (P = 0.009) while leucine consumption was significantly lower (P = 0.04). However, importantly neither individual nor collective differences in amino acid metabolism were apparent for sibling oocytes subjected to either mode of fertilization. Embryo morphology (the number of top grade embryos) and development (proportion reaching the blastocyst stage) were comparable in patients undergoing IVF and ICSI. In conclusion, the microinjection of spermatozoa into oocytes does not appear to have an impact on subsequent metabolism and viability. Observed differences in amino acid metabolism may be attributed to male factor infertility of the patients rather than the ICSI procedure per se.

scholarly journals Studies on Requirements for Amino Acids in Infants with Disorders of Amino Acid Metabolism. I. Effect of Alanine

1985 ◽  
Vol 19 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Drew G Kelts ◽  
Denise Ney ◽  
Carolyn Bay ◽  
Jean-Marie Saudubray ◽  
William L Nyhan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism

Amino acid metabolism of bovine blastocysts derived from parthenogenetically activated or in vitro fertilized oocytes

1998 ◽  
Vol 10 (3) ◽  
pp. 279 ◽  
Author(s):  
Y. G. Jung ◽  
T. Sakata ◽  
E. S. Lee ◽  
Y. Fukui
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Culture Medium ◽  
Acid Metabolism ◽  
Essential Amino Acids ◽  
Fluid Medium ◽  
Vitro Fertilization ◽  
Oviduct Fluid

The uptake and synthesis of 19 amino acids by fresh or frozen–thawed bovine blastocysts produced by parthenogenesis (PT) or in vitro fertilization (IVF) were compared in the present study. Fresh blastocysts, 180 h after IVF or PT activation, and frozen–thawed blastocysts, 168 h old and cultured for 12 h post-thawing, were cultured in synthetic oviduct fluid medium (SOFM) containing polyvinyl alcohol (PVA) with both essential and non-essential amino acids (EAA and NEAA, respectively) (Medium 1: M1) or SOFM containing PVA with only EAA (Medium 2: M2). In Experiment 1, when fresh or frozen–thawed PT blastocysts were cultured in M1, the uptake of glutamate (in fresh only), aspartate and arginine, and the synthesis of glutamine and alanine were significantly enhanced. In the culture with M2, serine, asparagine, glutamate, glutamine, glycine, arginine and alanine were significantly taken up. It was found that the glutamine concentrations was significantly higher (P < 0.001) in the culture medium drops containing embryos than in the drops without embryos. In Experiment 2, when PT blastocysts were cultured in M1, the uptake of aspartate and synthesis of alanine were greater (P < 0.01) than those by IVF blastocysts. When M2 was used, a significant (P < 0.01) production of serine, asparagine, glutamate, glutamine and alanine, and the uptake of arginine by PT blastocysts were observed. In Experiment 3, when IVF blastocysts were cultured in M1, fresh blastocysts depleted more aspartate and glutamate, and produced more glutamine and alanine than frozen–thawed blastocysts. When cultured in M2, frozen–thawed blastocysts depleted more threonine (P < 0.01) than fresh blastocysts. These results indicate that the uptake and synthesis of amino acids were different in fresh or frozen–thawed bovine blastocysts derived from PT or IVF. These differences in amino acid metabolism may be related to the viability of the blastocysts.

scholarly journals The case for regulating indispensable amino acid metabolism: the branched-chain α-keto acid dehydrogenase kinase-knockout mouse

2006 ◽  
Vol 400 (1) ◽  
Author(s):  
Susan M. Hutson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Essential Amino Acids ◽  
The Body ◽  
Keto Acid ◽  
Acid Dehydrogenase ◽  
Indispensable Amino Acid ◽  
Branched Chain

BCAAs (branched-chain amino acids) are indispensable (essential) amino acids that are required for body protein synthesis. Indispensable amino acids cannot be synthesized by the body and must be acquired from the diet. The BCAA leucine provides hormone-like signals to tissues such as skeletal muscle, indicating overall nutrient sufficiency. BCAA metabolism provides an important transport system to move nitrogen throughout the body for the synthesis of dispensable (non-essential) amino acids, including the neurotransmitter glutamate in the central nervous system. BCAA metabolism is tightly regulated to maintain levels high enough to support these important functions, but at the same time excesses are prevented via stimulation of irreversible disposal pathways. It is well known from inborn errors of BCAA metabolism that dysregulation of the BCAA catabolic pathways that leads to excess BCAAs and their α-keto acid metabolites results in neural dysfunction. In this issue of Biochemical Journal, Joshi and colleagues have disrupted the murine BDK (branched-chain α-keto acid dehydrogenase kinase) gene. This enzyme serves as the brake on BCAA catabolism. The impaired growth and neurological abnormalities observed in this animal show conclusively the importance of tight regulation of indispensable amino acid metabolism.

Renal serine production in vivo: effects of dietary manipulation of serine status

1989 ◽  
Vol 67 (9) ◽  
pp. 1058-1061 ◽  
Author(s):  
John T. Brosnan ◽  
Beatrice Hall
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Dietary Manipulation ◽  
In Vivo Effects ◽  
Crystalline Amino Acids ◽  
Arteriovenous Difference

Renal serine production in rats was quantitated by simultaneously measuring renal blood flow and the renal arteriovenous difference for this amino acid. The rate of synthesis was 0.24 ± 0.02 μmol∙min−1∙100 g−1 in rats fed a diet containing 12% casein. This rate was not altered by the inclusion of an additional 1% serine in the diet for 7 days or by acute infusion of serine, although both protocols increased blood serine by 50%. When rats were fed a diet in which protein was entirely replaced by crystalline amino acids the rate of renal serine production was also 0.25 ±0.05 μmol∙min−1∙100 g−1. Omission of serine or both serine and glycine from this diet did not alter the rate of renal serine synthesis. Renal serine production does not respond to the serine content of the diet.Key words: serine, glycine, kidney, amino acid metabolism.

Amino acid metabolism in the Zucker diabetic fatty rat: effects of insulin resistance and of type 2 diabetes

2004 ◽  
Vol 82 (7) ◽  
pp. 506-514 ◽  
Author(s):  
Enoka P Wijekoon ◽  
Craig Skinner ◽  
Margaret E Brosnan ◽  
John T Brosnan
Keyword(s):  
Insulin Resistance ◽  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Plasma Concentrations ◽  
Branched Chain Amino Acids ◽  
Insulin Resistant ◽  
Branched Chain

We investigated amino acid metabolism in the Zucker diabetic fatty (ZDF Gmi fa/fa) rat during the prediabetic insulin-resistant stage and the frank type 2 diabetic stage. Amino acids were measured in plasma, liver, and skeletal muscle, and the ratios of plasma/liver and plasma/skeletal muscle were calculated. At the insulin-resistant stage, the plasma concentrations of the gluconeogenic amino acids aspartate, serine, glutamine, glycine, and histidine were decreased in the ZDF Gmi fa/fa rats, whereas taurine, α-aminoadipic acid, methionine, phenylalanine, tryptophan, and the 3 branched-chain amino acids were significantly increased. At the diabetic stage, a larger number of gluconeogenic amino acids had decreased plasma concentrations. The 3 branched-chain amino acids had elevated plasma concentrations. In the liver and the skeletal muscles, concentrations of many of the gluconeogenic amino acids were lower at both stages, whereas the levels of 1 or all of the branched-chain amino acids were elevated. These changes in amino acid concentrations are similar to changes seen in type 1 diabetes. It is evident that insulin resistance alone is capable of bringing about many of the changes in amino acid metabolism observed in type 2 diabetes.Key words: plasma amino acids, liver amino acids, muscle amino acids, gluconeogenesis.

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