Oxidation of branched-chain amino acids beyond α-decarboxylation in rat heart and skeletal muscle

1984 ◽  
Vol 86 (3) ◽  
pp. 233-234
Author(s):  
A.J.M. Wagenmakers ◽  
J.H. Veerkamp ◽  
H.J.M. Salden
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Rat Heart ◽  
Branched Chain Amino Acids ◽  
Branched Chain

Removal of infused amino acids by splanchnic and leg tissues in humans

1986 ◽  
Vol 250 (4) ◽  
pp. E407-E413 ◽  
Author(s):  
R. A. Gelfand ◽  
M. G. Glickman ◽  
R. Jacob ◽  
R. S. Sherwin ◽  
R. A. DeFronzo
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Branched Chain Amino Acids ◽  
Acid Uptake ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Significant Uptake ◽  
Branched Chain

To compare the contributions of splanchnic and skeletal muscle tissues to the disposal of intravenously administered amino acids, regional amino acid exchange was measured across the splanchnic bed and leg in 11 normal volunteers. Postabsorptively, net release of amino acids by leg (largely alanine and glutamine) was complemented by the net splanchnic uptake of amino acids. Amino acid infusion via peripheral vein (0.2 g X kg-1 X h-1) caused a doubling of plasma insulin and glucagon levels and a threefold rise in blood amino acid concentrations. Both splanchnic and leg tissues showed significant uptake of infused amino acids. Splanchnic tissues accounted for approximately 70% of the total body amino acid nitrogen disposal; splanchnic uptake was greatest for the glucogenic amino acids but also included significant quantities of branched-chain amino acids. In contrast, leg amino acid uptake was dominated by the branched-chain amino acids. Based on the measured leg balance, body skeletal muscle was estimated to remove approximately 25-30% of the total infused amino acid load and approximately 65-70% of the infused branched-chain amino acids. Amino acid infusion significantly stimulated both the leg efflux and the splanchnic uptake of glutamine (not contained in the infusate). We conclude that when amino acids are infused peripherally in normal humans, splanchnic viscera (liver and gut) are the major sites of amino acid disposal.

Interorgan metabolism of amino acids in streptozotocin-diabetic ketoacidotic rat

1983 ◽  
Vol 244 (2) ◽  
pp. E151-E158 ◽  
Author(s):  
J. T. Brosnan ◽  
K. C. Man ◽  
D. E. Hall ◽  
S. A. Colbourne ◽  
M. E. Brosnan
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Branched Chain Amino Acids ◽  
Diabetic Rats ◽  
Normal Rat ◽  
Diabetic Brain ◽  
Streptozotocin Diabetic Rats ◽  
Branched Chain ◽  
Amino Acid Concentrations

Amino acid concentrations in whole blood, liver, kidney, skeletal muscle, and brain were measured and arteriovenous differences calculated for head, hindlimb, kidney, gut, and liver in control and streptozotocin-diabetic rats. In the control rats, glutamine was released by muscle and utilized by intestine, intestine released citrulline and alanine, liver removed alanine, and the kidneys removed glycine and produced serine. In diabetic rats, the major changes from the pattern of fluxes seen in the normal rat were the release of many amino acids from muscle, with glutamine and alanine predominating, and the uptake of these amino acids by the liver. Glutamine removal by the intestine was suppressed in diabetes, but a large renal uptake of glutamine was evident. Branched-chain amino acids were removed by the diabetic brain, and consequently, brain levels of a number of large neutral amino acids were decreased in diabetes.

The effect of branched-chain amino acids on ammonia metabolism in rat skeletal muscle

2000 ◽  
Vol 118 (4) ◽  
pp. A774
Author(s):  
Honma Nobuko ◽  
Imagawa Yuriko ◽  
Kobayashi Tetsuo ◽  
Kadowaki Motoni ◽  
Takahashi Kazuyoshi
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Branched Chain Amino Acids ◽  
Rat Skeletal Muscle ◽  
Ammonia Metabolism ◽  
Branched Chain

scholarly journals Enzymic determination of branched-chain amino acids and 2-oxoacids in rat tissues. Transfer of 2-oxoacids from skeletal muscle to liver in vivo

1980 ◽  
Vol 188 (3) ◽  
pp. 705-713 ◽  
Author(s):  
G Livesey ◽  
P Lund
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Bacillus Subtilis ◽  
Branched Chain Amino Acids ◽  
Rat Tissues ◽  
Arterial Blood ◽  
Branched Chain ◽  
Arteriovenous Difference

1. A procedure is described for the purification of leucine dehydrogenase (EC 1.4.1.9) from Bacillus subtilis. 2. The preparation is suitable for the quantitative assay of branched-chain amino acids and their 2-oxoacid analogues. 3. The content of total branched-chain 2-oxoacids in freeze-clamped liver, kidney, heart or mammary gland of fed rats is less than 5 nmol/g fresh wt. Higher amounts are present in skeletal muscle and arterial blood (25 +/- 4 nmol per g fresh wt., and 33 +/- 6 nmol per ml respectively; means +/- S.D. of 3 and 11 animals respectively). The values are not significantly affected by starvation for 24 h. 4. Arteriovenous difference measurements show that considerable amounts of branched-chain 2-oxoacids are released by skeletal muscle into the circulation and similar amounts are removed by the liver (about 1 mmol/24 h in a 400 g rat).

scholarly journals Branched-chain Amino Acids: Catabolism in Skeletal Muscle and Implications for Muscle and Whole-body Metabolism

2021 ◽  
Vol 12 ◽  
Author(s):  
Gagandeep Mann ◽  
Stephen Mora ◽  
Glory Madu ◽  
Olasunkanmi A. J. Adegoke
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Chronic Diseases ◽  
Branched Chain Amino Acids ◽  
Whole Body ◽  
Management Options ◽  
Impaired Metabolism ◽  
Whole Body Metabolism ◽  
Branched Chain ◽  
The Impact

Branched-chain amino acids (BCAAs) are critical for skeletal muscle and whole-body anabolism and energy homeostasis. They also serve as signaling molecules, for example, being able to activate mammalian/mechanistic target of rapamycin complex 1 (mTORC1). This has implication for macronutrient metabolism. However, elevated circulating levels of BCAAs and of their ketoacids as well as impaired catabolism of these amino acids (AAs) are implicated in the development of insulin resistance and its sequelae, including type 2 diabetes, cardiovascular disease, and of some cancers, although other studies indicate supplements of these AAs may help in the management of some chronic diseases. Here, we first reviewed the catabolism of these AAs especially in skeletal muscle as this tissue contributes the most to whole body disposal of the BCAA. We then reviewed emerging mechanisms of control of enzymes involved in regulating BCAA catabolism. Such mechanisms include regulation of their abundance by microRNA and by post translational modifications such as phosphorylation, acetylation, and ubiquitination. We also reviewed implications of impaired metabolism of BCAA for muscle and whole-body metabolism. We comment on outstanding questions in the regulation of catabolism of these AAs, including regulation of the abundance and post-transcriptional/post-translational modification of enzymes that regulate BCAA catabolism, as well the impact of circadian rhythm, age and mTORC1 on these enzymes. Answers to such questions may facilitate emergence of treatment/management options that can help patients suffering from chronic diseases linked to impaired metabolism of the BCAAs.

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