Modulation of absence seizures by branched-chain amino acids: correlation with brain amino acid concentrations

2001 ◽  
Vol 40 (3) ◽  
pp. 255-263 ◽  
Author(s):  
Franck Dufour ◽  
Katarzyna A Nalecz ◽  
Maciej J Nalecz ◽  
Astrid Nehlig
1983 ◽  
Vol 244 (2) ◽  
pp. E151-E158 ◽  
Author(s):  
J. T. Brosnan ◽  
K. C. Man ◽  
D. E. Hall ◽  
S. A. Colbourne ◽  
M. E. Brosnan

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.


Author(s):  
David G Le Couteur ◽  
David J Handelsman ◽  
Fiona Stanaway ◽  
Louise M Waite ◽  
Fiona M Blyth ◽  
...  

Abstract Although characteristic changes in amino acid concentrations occur in obesity and sarcopenia, amino acids concentrations have not been reported in sarcopenic obesity. We studied n=831 men aged 75 years and older from the five-year follow-up of the Concord Health and Ageing in Men Project (CHAMP). Sarcopenia was defined using the Foundation of the National Institutes of Health (FNIH) criteria and obesity was defined as >30% fat mass. There were 31 men (3.7%) who had sarcopenic obesity. Branched chain amino acids were elevated in the obese (but not sarcopenic) group (n=348) but reduced in both the sarcopenic (but not obese) (n=44) and the sarcopenic obese groups. Apart from this, most of the amino acid concentrations were between those for the obese and the sarcopenic groups. Yet despite low concentrations of branched chain amino acids, the sarcopenic obese group had indications of insulin resistance and diabetes mellitus (fasting glucose and insulin concentrations, homeostatic model assessment (HOMA-IR) and percentage of participants taking diabetes medications) that were similar to the obese group. In summary, sarcopenic obese subjects did not have a unique amino acid signature. In obesity, elevated branched chain amino acids are not a prerequisite for insulin resistance and diabetes if obesity is associated with sarcopenia.


1981 ◽  
Vol 50 (1) ◽  
pp. 41-44 ◽  
Author(s):  
G. L. Dohm ◽  
G. R. Beecher ◽  
R. Q. Warren ◽  
R. T. Williams

Levels of free amino acids in muscle, liver, and plasma were measured in rats that had either swum (1 or 2 h) or run (until exhausted). Exercise lowered alanine levels in all three tissues except for liver of exhausted rats. Exercise decreased the plasma levels of the acidic amino acids and their amides. Glutamate and glutamine levels were depressed in muscle, and the glutamine level was lowered in liver by exercise. Aspartate concentration was lowered by exercise in liver but elevated in muscle. The branched-chain amino acids were generally elevated by exercise as were tyrosine, phenylalanine, methionine, and lysine. Plasma 3-methylhistidine concentration was also elevated by an exercise bout. The changes observed in the amino acid contents of muscle, liver, and plasma are consistent with the increase in protein degradation during exercise that we previously reported. The lowered levels of some amino acids (e.g., alanine, glutamine, glutamate) seem to suggest that amino acid catabolism and/or gluconeogenesis is increased by exercise.


1986 ◽  
Vol 250 (4) ◽  
pp. E407-E413 ◽  
Author(s):  
R. A. Gelfand ◽  
M. G. Glickman ◽  
R. Jacob ◽  
R. S. Sherwin ◽  
R. A. DeFronzo

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.


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