Effect of leucine—Isoleucine antagonism on the amino acid pattern of plasma and tissues of the rat

Tannous, R. I.; Rogers, Quinton R.; Harper, Alfred E.

doi:10.1016/0003-9861(66)90197-4

Cited by 58 publications

(27 citation statements)

References 12 publications

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“…Although precursor pool enrichments were maintained at clearly nontracer levels (39%), the synthesis rate of RSA determined by MIDA was 46%/day in ad libitum fed rats (Table 7) or a t 1/ 2 of 1.53 Ϯ 0.09 days. These values are consistent with several previously published estimates (25,33,35) of t 1/ 2 for RSA. Using an estimate for the exchangeable albumin pool size (270 mg albumin/100 g body wt) (18), we calculated the absolute rate of albumin synthesis to be 5.2 mg/h/100 g body wt in fed rats.…”

Section: Discussionsupporting

confidence: 92%

Measuring Protein Synthesis by Mass Isotopomer Distribution Analysis (MIDA)

Papageorgopoulos

Caldwell

Shackleton³

et al. 1999

Analytical Biochemistry

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Section: Discussionsupporting

confidence: 92%

Measuring Protein Synthesis by Mass Isotopomer Distribution Analysis (MIDA)

Papageorgopoulos

Caldwell

Shackleton³

et al. 1999

Analytical Biochemistry

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“…Nakagawa et al . (5,6) could not confirmed the findings of Gopalan et al Tannous et al (7,8) reported that an excess intake of L-leucine retarded the growth of rats fed on a low protein diet . They found that the growth retardation caused by a diet containing 5% leucine was completely overcome by addition of 0.5% isoleucine to the diet, and that a decrease in the plasma valine and isoleucine concentrations resulting from excess intake of leucine was completely overcome by supplementing the diet with small amounts of isoleucine and valine.…”

contrasting

confidence: 54%

Effects of excess leucine on growth and tryptophan and niacin metabolism in rats.

Ohguri

1980

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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SummaryThe effects of an excess intake of leucine, for a short period (3 to 4 weeks) and a long period (12 weeks), on growth and excretion of tryptophan and niacin metabolites in rats were studied. Excess intake of leucine (4 or 5%) for a short period did not affect increase in body weight or organ weight (liver, kidney and heart) compared with those of rats fed the control diet. Excess intake of leucine for a long period resulted in a decrease in body weight, and an increase in the relative weight of the liver and kidney. Urinary excretions of N1 methyl nicotinamide (N-MNA), N1-methyl-2-pyridone-5-carboxamide (2 Py), niacin, quinolinic acid and 5-hydroxyindole acetic acid did not differ in rats fed an excess-leucine diet and rats fed a control diet. In niacin deficiency, the excretions of N-MNA, 2-Py and NiA decreased. Excess leucine intake increased the plasma levels of leucine and alanine and decreased those of valine, isoleucine, tryptophan and cystine. Excess leucine intake decreased the levels of valine, isoleucine, methionine and leucine in the liver, but these changes were not observed in niacin deficient rats. Changes in the levels of nicotinamide mononucleotide (NMN), nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP) in erythrocytes, suggested to occur in pellagra, were not observed. These findings do not support the idea that an excess intake of leucine results in changes in metabolism similar to those observed in pellagra.

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“…Interestingly, alanine is effective in a range of concentrations (0.05-1 mmol/1) that corresponds to values measured in plasma samples of rats [3,9,13], dogs [14] and humans [1,2,5,15]. In contrast, the valine concentrations necessary to elicit a significant stimulation of glucose transport (0.3-1.5 mmol/l) lie above the physiological values in rats [16] and humans [2,5,15]. Further, the effects of alanine and valine are not additive (Table I).…”

Section: Effects Of L-alanine and L-valine On Glucose Transportmentioning

confidence: 58%

“…Moreover, valine only produced an increase in glucose transport at concentrations that markedly exceed the plasma values measured in rats [16] and humans [2,5,15]. The finding that alanine and valine do not act additively (Table I), along with the fact that branched-chain amino acids are the major source of nitrogen for pyruvate transamination [4,[21][22][23][24] suggest that the effect of valine may be secondary to alanine formation in myocytes.…”

Section: Discussionmentioning

confidence: 99%

Possible involvement of alanine and pyruvate in the regulation of glucose transport in heart muscle cells

1990

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In isolated rat heart muscle cells, addition of L-alanine (1.5 mmol/l) or of L-valine (3 mmol/l) resulted in either a ca 1.5-or 1.3-fold increase in glucose transport, resp. half-maximal stimulation was observed in the presence of L-alanine, but not of L-valine, within a physiological plasmatic range of concentrations. D-Alanine (1.5 mmol/1) was ineffective and the stimulating effect of L-alanine could be prevented by an excess of L-serine (15-30 mmol/1). L-Alanine produced an increase in 3-O-methyl-D-glucose transport Vmax (from 44.6 to 81.5 pmol's-~.mg protein-l) without affecting the Km (12.2 in control vs 12.8 mmol/l in alanine-treated cells). Pyruvate (1.5 mmol/1) inhibited glucose transport by 20% and prevented the stimulating action of L-alanine (1.5 mmol/1). These results suggest that the effect of L-alanine in cardiac myocytes occurs through the interaction with an intracellular site and that both alanine and pyruvate may play a role in the regulation of glucose transport in these cells.

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Effect of leucine—Isoleucine antagonism on the amino acid pattern of plasma and tissues of the rat

Cited by 58 publications

References 12 publications

Measuring Protein Synthesis by Mass Isotopomer Distribution Analysis (MIDA)

Measuring Protein Synthesis by Mass Isotopomer Distribution Analysis (MIDA)

Effects of excess leucine on growth and tryptophan and niacin metabolism in rats.

Possible involvement of alanine and pyruvate in the regulation of glucose transport in heart muscle cells

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