Hour-to-hour variation in amino acid arterio-venous concentration differences across the lactating goat mammary gland

1974 ◽  
Vol 41 (1) ◽  
pp. 95-100 ◽  
Author(s):  
T. B. Mepham ◽  
J. L. Linzell
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Amino Acid ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Arterial Infusion ◽  
Amino Acid Synthesis ◽  
Lactating Goats ◽  
Arterial Concentration ◽  
Infusion Technique

SummaryArterio-venous (AV) blood plasma concentration differences of amino acids across the mammary glands of 2 lactating goats were measured at intervals throughout a day. One gland of each animal had been transplanted to the neck for experimental purposes. The variation throughout the day in arterial concentration of all amino acids was similar. The variation in AV differences was slight for most essential amino acids, greater for glutamic acid and proline and very marked for aspartic acid, alanine, glycine and citrulline. There was no statistical difference between the AV difference of any amino acid measured simultaneously across the 2 glands of either goat. The arterial concentrations of certain pairs of amino acids were significantly correlated. The implications of the results for estimation of rates of amino-acid synthesis in the mammary gland using the intra-arterial infusion technique are discussed.

Effects of intramammary arterial infusion of non-essential amino acids and glucose in the lactating goat

1974 ◽  
Vol 41 (1) ◽  
pp. 111-121 ◽  
Author(s):  
T. B. Mepham ◽  
J. L. Linzell
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Amino Acid ◽  
Milk Protein ◽  
Essential Amino Acids ◽  
Arterial Infusion ◽  
Lactating Goats ◽  
Arterial Plasma ◽  
Fourth Experiment ◽  
Amino Acid Concentrations

SummaryThree experiments were carried out on 2 lactating goats, in which mammary arterial plasma amino-acid concentrations were elevated by the infusion of a solution of non-essential amino acids into a carotid artery supplying a transplanted mammary gland. In a fourth experiment a solution of glucose was similarly infused. In some cases the increased arterial concentrations of amino acids resulted in their increased mammary uptake, and in a depression of glucose uptake. However, infusions of neither amino acids nor glucose resulted in increased milk protein yield. Infusion of [U-14C]glutamic acid in one experiment demonstrated gluconeogenesis from glutamate carbon within the mammary gland. The results are discussed in relation to data obtained in another laboratory, from which it has been claimed that non-essential amino acid supply may limit milk protein synthesis. The present results provide no confirmation for the claim.

Effects of intramammary arterial infusion of essential amino acids in the lactating goat

1974 ◽  
Vol 41 (1) ◽  
pp. 101-109 ◽  
Author(s):  
J. L. Linzell ◽  
T. B. Mepham
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Milk Protein ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Acid Uptake ◽  
Lactating Goats ◽  
Arterial Concentration ◽  
Arterial Plasma ◽  
Amino Acid Concentrations

SummaryExperiments were performed on 3 lactating goats, in which mammary arterial plasma amino-acid concentrations were elevated by the infusion of a solution of essential amino-acids into the carotid artery supplying a transplanted mammary gland. In 2 experiments there were marked elevations in the arterial concentrations of most essential amino acids, but in one case only did this result in significantly increased uptake of amino acids by the gland, the arterio-venous difference being significantly correlated with arterial concentration for all except one amino acid. In the experiment in which increased amino-acid uptake was observed, infusion also resulted in a significantly increased milk yield and increased milk protein yield. The results are discussed in relation to data from other laboratories and lead to the suggestion that milk protein synthesis may be limited by the availability of either methionine or tryptophan.

scholarly journals Energy Availability Determines Strategy of Microbial Amino Acid Synthesis in Volatile Fatty Acid–Fed Anaerobic Methanogenic Chemostats

2021 ◽  
Vol 12 ◽  
Author(s):  
Jian Yao ◽  
Yan Zeng ◽  
Miaoxiao Wang ◽  
Yue-Qin Tang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Public Goods ◽  
Functional Group ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Microbial Evolution ◽  
Community Level ◽  
Energy Availability ◽  
Amino Acid Synthesis

In natural communities, microbes exchange a variety of metabolites (public goods) with each other, which drives the evolution of auxotroph and shapes interdependent patterns at community-level. However, factors that determine the strategy of public goods synthesis for a given community member still remains to be elucidated. In anaerobic methanogenic communities, energy availability of different community members is largely varied. We hypothesized that this uneven energy availability contributed to the heterogeneity of public goods synthesis ability among the members in these communities. We tested this hypothesis by analyzing the synthetic strategy of amino acids of the bacterial and archaeal members involved in four previously enriched anaerobic methanogenic communities residing in thermophilic chemostats. Our analyses indicate that most of the members in the communities did not possess ability to synthesize all the essential amino acids, suggesting they exchanged these essential public goods to establish interdependent patterns for survival. Importantly, we found that the amino acid synthesis ability of a functional group was largely determined by how much energy it could obtain from its metabolism in the given environmental condition. Moreover, members within a functional group also possessed different amino acid synthesis abilities, which are related to their features of energy metabolism. Our study reveals that energy availability is a key driver of microbial evolution in presence of metabolic specialization at community level and suggests the feasibility of managing anaerobic methanogenic communities for better performance through controlling the metabolic interactions involved.

scholarly journals Biosynthesis of ‘essential’ amino acids by scleractinian corals

1997 ◽  
Vol 322 (1) ◽  
pp. 213-221 ◽  
Author(s):  
Lisa M. FITZGERALD ◽  
Alina M. SZMANT
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Reef Coral ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Acropora Cervicornis ◽  
Isoleucine Leucine ◽  
Amino Acid Synthesis ◽  
Protein Amino Acids

Animals rely on their diet for amino acids that they are incapable either of synthesizing or of synthesizing in sufficient quantities to meet metabolic needs. These are the so-called ‘essential amino acids’. This set of amino acids is similar among the vertebrates and many of the invertebrates. Previously, no information was available for amino acid synthesis by the most primitive invertebrates, the Cnidaria. The purpose of this study was to examine amino acid synthesis by representative cnidarians within the Order Scleractinia. Three species of zooxanthellate reef coral, Montastraea faveolata, Acropora cervicornis and Porites divaricata, and two species of non-zooxanthellate coral, Tubastrea coccinea and Astrangia poculata, were incubated with 14C-labelled glucose or with the 14C-labelled amino acids glutamic acid, lysine or valine. Radiolabel tracer was followed into protein amino acids. A total of 17 amino acids, including hydroxyproline, were distinguishable by the techniques used. Of these, only threonine was not found radiolabelled in any of the samples. We could not detect tryptophan or cysteine, nor distinguish between the amino acid pairs glutamic acid and glutamine, or aspartic acid and asparagine. Eight amino acids normally considered essential for animals were made by the five corals tested, although some of them were made only in small quantities. These eight amino acids are valine, isoleucine, leucine, tyrosine, phenylalanine histidine, methionine and lysine. The ability of cnidarians to synthesize these amino acids could be yet another indicator of a separate evolutionary history of the cnidarians from the rest of the Metazoa.

scholarly journals Molecular and Histologic Adaptation of Horned Gall Induced by the Aphid Schlechtendalia chinensis (Pemphigidae)

2021 ◽  
Vol 22 (10) ◽  
pp. 5166
Author(s):  
Qin Lu ◽  
Xiaoming Chen ◽  
Zixiang Yang ◽  
Nawaz Haider Bashir ◽  
Juan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Amino Acid ◽  
Host Plants ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Amino Acid Synthesis ◽  
Glucose Content ◽  
Anatomical Structures ◽  
Synthesis And Degradation

Chinese galls are the result of hyperplasia in host plants induced by aphids. The metabolism and gene expression of these galls are modified to accommodate the aphids. Here, we highlight the molecular and histologic features of horned galls according to transcriptome and anatomical structures. In primary pathways, genes were found to be unevenly shifted and selectively expressed in the galls and leaves near the galls (LNG). Pathways for amino acid synthesis and degradation were also unevenly shifted, favoring enhanced accumulation of essential amino acids in galls for aphids. Although galls enhanced the biosynthesis of glucose, which is directly available to aphids, glucose content in the gall tissues was lower due to the feeding of aphids. Pathways of gall growth were up-regulated to provide enough space for aphids. In addition, the horned gall has specialized branched schizogenous ducts and expanded xylem in the stalk, which provide a broader feeding surface for aphids and improve the efficiency of transportation and nutrient exchange. Notably, the gene expression in the LNG showed a similar pattern to that of the galls, but on a smaller scale. We suppose the aphids manipulate galls to their advantage, and galls lessen competition by functioning as a medium between the aphids and their host plants.

scholarly journals Petasis vs. Strecker Amino Acid Synthesis: Convergence, Divergence and Opportunities in Organic Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1707
Author(s):  
Wayiza Masamba
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Synthesis ◽  
Acid Synthesis ◽  
Physical Sciences ◽  
Amino Acid Synthesis

α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used. Both reactions are three-component reactions using the same starting materials, except the nucleophilic species. The differences and similarities between these two important reactions are highlighted in this review.

scholarly journals New aspects of amino acid metabolism in cancer

2019 ◽  
Vol 122 (2) ◽  
pp. 150-156 ◽  
Author(s):  
Lisa Vettore ◽  
Rebecca L. Westbrook ◽  
Daniel A. Tennant
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cancer Cells ◽  
Cancer Metabolism ◽  
Acid Synthesis ◽  
Response To Therapy ◽  
Direct Role ◽  
Amino Acid Synthesis ◽  
Metabolic Coupling ◽  
Abundant Supply

AbstractAn abundant supply of amino acids is important for cancers to sustain their proliferative drive. Alongside their direct role as substrates for protein synthesis, they can have roles in energy generation, driving the synthesis of nucleosides and maintenance of cellular redox homoeostasis. As cancer cells exist within a complex and often nutrient-poor microenvironment, they sometimes exist as part of a metabolic community, forming relationships that can be both symbiotic and parasitic. Indeed, this is particularly evident in cancers that are auxotrophic for particular amino acids. This review discusses the stromal/cancer cell relationship, by using examples to illustrate a number of different ways in which cancer cells can rely on and contribute to their microenvironment – both as a stable network and in response to therapy. In addition, it examines situations when amino acid synthesis is driven through metabolic coupling to other reactions, and synthesis is in excess of the cancer cell’s proliferative demand. Finally, it highlights the understudied area of non-proteinogenic amino acids in cancer metabolism and their potential role.

scholarly journals New Enzymatic Method of Chiral Amino Acid Synthesis by Dynamic Kinetic Resolution of Amino Acid Amides: Use of Stereoselective Amino Acid Amidases in the Presence of α-Amino-ε-Caprolactam Racemase

2007 ◽  
Vol 73 (16) ◽  
pp. 5370-5373 ◽  
Author(s):  
Shigenori Yamaguchi ◽  
Hidenobu Komeda ◽  
Yasuhisa Asano
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Kinetic Resolution ◽  
Acid Synthesis ◽  
Enzymatic Method ◽  
Ochrobactrum Anthropi ◽  
Dynamic Kinetic Resolution ◽  
Amino Acid Synthesis

ABSTRACT d- and l-amino acids were produced from l- and d-amino acid amides by d-aminopeptidase from Ochrobactrum anthropi C1-38 and l-amino acid amidase from Pseudomonas azotoformans IAM 1603, respectively, in the presence of α-amino-ε-caprolactam racemase from Achromobacter obae as the catalyst by dynamic kinetic resolution of amino acid amides.

scholarly journals Biosynthesis of Amino Acids in Xanthomonas oryzae pv. oryzae Is Essential to Its Pathogenicity

2019 ◽  
Vol 7 (12) ◽  
pp. 693 ◽  
Author(s):  
Ting Li ◽  
Zhaohong Zhan ◽  
Yunuan Lin ◽  
Maojuan Lin ◽  
Qingbiao Xie ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Growth ◽  
Acid Synthesis ◽  
Xanthomonas Oryzae ◽  
Host Responses ◽  
Amino Acid Synthesis ◽  
Rice Bacterial Blight ◽  
Nutrient Environment ◽  
Blight Disease

Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of rice bacterial blight disease, which causes a large reduction in rice production. The successful interaction of pathogens and plants requires a particular nutrient environment that allows pathogen growth and the initiation of both pathogen and host responses. Amino acid synthesis is essential for bacterial growth when bacteria encounter amino acid-deficient environments, but the effects of amino acid synthesis on Xoo pathogenicity are unclear. Here, we systemically deleted the essential genes (leuB, leuC, leuD, ilvC, thrC, hisD, trpC, argH, metB, and aspC) involved in the synthesis of different amino acids and analyzed the effects of these mutations on Xoo virulence. Our results showed that leucine, isoleucine, valine, histidine, threonine, arginine, tryptophan, and cysteine syntheses are essential to Xoo infection. We further studied the role of leucine in the interaction between pathogens and hosts and found that leucine could stimulate some virulence-related responses and regulate Xoo pathogenicity. Our findings highlight that amino acids not only act as nutrients for bacterial growth but also play essential roles in the Xoo and rice interaction.

scholarly journals Mechanism of De Novo Branched-Chain Amino Acid Synthesis as an Alternative Electron Sink in Hypoxic Aspergillus nidulans Cells

2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
De Novo ◽  
Acid Synthesis ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Lactate Dehydrogenase Activity ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.

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