Interrelationship between hepatic ureagenesis and gluconeogenesis in early sepsis

1991 ◽  
Vol 260 (3) ◽  
pp. E453-E458 ◽  
Author(s):  
Y. Ohtake ◽  
M. G. Clemens
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Preference ◽  
Hormone Sensitivity ◽  
Urea Production ◽  
Urea Release ◽  
Amino Acid Levels ◽  
Early Sepsis ◽  
Septic Group

This study was performed to investigate the interrelationship between gluconeogenesis and ureagenesis during sepsis. In isolated perfused livers, gluconeogenesis was assessed using either lactate or a combination of lactate, glutamine, and alanine as substrate. Ureagenesis was assessed using either NH4Cl or glutamine plus alanine as substrate. NH4Cl stimulated urea production in livers from both septic and sham-operated control rats. Urea release was approximately 1.2 and 2.0 mg urea nitrogen.g-1.h-1 for 1 and 5 mM NH4Cl, respectively, and was equal for both groups. With amino acids as substrate, urea production was significantly greater in livers from septic animals compared with controls. Phenylephrine stimulated urea production in the sham-operated group by about twofold, whereas in the septic group urea release was slightly inhibited. Gluconeogenesis from lactate was inhibited by NH4Cl (1 and 5 mM) in both groups, with no difference between groups. In contrast to enhanced ureagenesis from amino acids in septic rats, gluconeogenesis was decreased by approximately 24% (P less than 0.5). Similarly, phenylephrine (1 microM) stimulated gluconeogenesis by 13 +/- 1 mumol.g-1.h-1 in sham-operated rats but only by 9 +/- 1 mumol.g-1.h-1 in septic rats (P less than 0.02). These results suggest that hepatic gluconeogenic and ureagenic pathways are intact in sepsis but that altered substrate preference and hormone sensitivity may result in decreased gluconeogenesis in the presence of elevated amino acid levels.

scholarly journals Amino acids whose intracellular levels change most during aging alter chronological lifespan of fission yeast

2020 ◽  
Author(s):  
Charalampos Rallis ◽  
Michael Mülleder ◽  
Graeme Smith ◽  
Yan Zi Au ◽  
Markus Ralser ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fission Yeast ◽  
Yeast Cells ◽  
Total Amino Acid ◽  
Wild Type ◽  
Chronological Lifespan ◽  
Biomarkers Of Aging ◽  
Concentration Changes ◽  
Amino Acid Levels

AbstractAmino acid deprivation or supplementation can affect cellular and organismal lifespan, but we know little about the role of concentration changes in free, intracellular amino acids during aging. Here, we determine free amino-acid levels during chronological aging of non-dividing fission yeast cells. We compare wild-type with long-lived mutant cells that lack the Pka1 protein of the protein kinase A signalling pathway. In wild-type cells, total amino-acid levels decrease during aging, but much less so in pka1 mutants. Two amino acids strongly change as a function of age: glutamine decreases, especially in wild-type cells, while aspartate increases, especially in pka1 mutants. Supplementation of glutamine is sufficient to extend the chronological lifespan of wild-type but not of pka1Δ cells. Supplementation of aspartate, on the other hand, shortens the lifespan of pka1Δ but not of wild-type cells. Our results raise the possibility that certain amino acids are biomarkers of aging, and their concentrations during aging can promote or limit cellular lifespan.

Effect of free fatty acids on blood amino acid levels in human

1986 ◽  
Vol 250 (6) ◽  
pp. E686-E694 ◽  
Author(s):  
E. Ferrannini ◽  
E. J. Barrett ◽  
S. Bevilacqua ◽  
R. Jacob ◽  
M. Walesky ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Insulin ◽  
Plasma Free Fatty Acid ◽  
Blood Levels ◽  
Experimental Conditions ◽  
Lipid Infusion ◽  
Amino Acid Levels ◽  
Branched Chain

Raised plasma free fatty acid (FFA) levels effectively impede glucose uptake in vivo, thereby conserving plasma glucose and sparing glycogen. To test whether FFA have any effect on blood amino acid levels, we infused Intralipid plus heparin or saline into healthy volunteers under four different experimental conditions: A) overnight fast; B) euglycemic hyperinsulinemia (approximately 100 microU/ml); C) hyperglycemic (approximately 200 mg/100 ml) hyperinsulinemia (approximately 50 microU/ml); and D) hyperglycemic (approximately 300 mg/100 ml) normoinsulinemia (approximately 20 microU/ml). In the fasting state (A), lipid infusion was associated with lower blood levels of most amino acids, both branched chain and glucogenic. This effect, however, could not be ascribed to lipid infusion alone, because plasma insulin levels were also stimulated. The clamp studies (B, C, and D) allowed to assess the influence of lipid on blood amino acid levels at similar plasma insulin and glucose levels. It was thus observed that lipid infusion has a significant hypoaminoacidemic effect of its own under both euglycemic (B) and hyperglycemic (C) conditions; this effect involved many glucogenic amino acids (alanine, glycine, phenylalanine, serine, threonine, and cystine) but none of the branched-chain amino acids (leucine, isoleucine, and valine). In marked contrast, normoinsulinemic hyperglycemia (D), with or without lipid infusion, caused no change in the blood level of any measured amino acid. We conclude that lipid infusion has a hypoaminoacidemic action. We also suggest that this action is permitted by insulin and may involve specific metabolic interactions (e.g., reduced availability of glucose-derived pyruvate or glycerophosphate) as well as enhanced uptake by the liver.

scholarly journals Diet, Physical Activity and Adiposity as Determinants of Circulating Amino Acid Levels in a Multiethnic Asian Population

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2603 ◽  
Author(s):  
Samuel H. Gunther ◽  
Chin Meng Khoo ◽  
Xueling Sim ◽  
E Shyong Tai ◽  
Rob M. van Dam
Keyword(s):  
Physical Activity ◽  
Amino Acids ◽  
Amino Acid ◽  
Multiple Testing ◽  
Asian Population ◽  
Lifestyle Factors ◽  
Health Examination ◽  
Activity Data ◽  
Study Program ◽  
Amino Acid Levels

Profiles of circulating amino acids have been associated with cardiometabolic diseases. We investigated the associations between dietary protein intake, physical activity and adiposity and serum amino acid profiles in an Asian population. We used data from 3009 male and female participants from the Singapore Prospective Study Program cohort. Dietary and physical activity data were obtained from validated questionnaires; anthropometric measurements were collected during a health examination; and fasting concentrations of 16 amino acids were measured using targeted LC-MS. The association between lifestyle factors and amino acid levels was modeled using multiple linear regression with adjustment for other sociodemographic and lifestyle factors and correction for multiple testing. We observed significant associations between seafood intake (β-coefficient 0.132, 95% CI 0.006, 0.257 for a 100% increment), physical activity (β-coefficient −0.096, 95% CI −0.183, −0.008 in the highest versus lowest quartile) and adiposity (BMI β-coefficient 0.062, 95% CI 0.054, 0.070 per kg/m2; waist circumference β-coefficient 0.034, 95% CI 0.031, 0.037 per cm) and branched-chain amino acid levels (expressed per-SD). We also observed significant interactions with sex for the association between meat and seafood and total intakes and BCAA levels (P for interaction 0.007), which were stronger in females than in males. Our findings suggest novel associations between modifiable lifestyle factors and amino acid levels in Asian populations.

Amino Acid Absorption following Intraperitoneal Administration in CAPD Patients

1981 ◽  
Vol 2 (3) ◽  
pp. 124-130 ◽  
Author(s):  
Paul F. Williams ◽  
Errol B. Marliss ◽  
G. Harvey Anderson ◽  
Arie Oren ◽  
Arthur N. Stein ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Solution ◽  
Intraperitoneal Administration ◽  
Amino Acid Solution ◽  
Dialysis Solution ◽  
Term Administration ◽  
Osmotic Agent ◽  
Amino Acid Levels

Six non-diabetic CAPD patients were infused over six hours with two litres of a dialysis solution containing 2 g/ dl amino acids (a mixture of essentials and non-essentials). The osmolality of the solution and the amount of ultrafiltration it induced were simiiar to that of a 4.25 g% dextrose Dianeal solution (control), suggesting that an amino acid solution is an efficient osmotic agent. By the end of the six-hour infusion, 80 to 90% of the amino acids present in the dialysis solution had been absorbed. One hour after the infusion was instituted, plasma amino acid levels increased threefold and subsequently decreased to near the initial value by the sixth hour. The amino acid solution was as effective as the dextrose solution in removing urea nitrogen, creatinine and potassium. Our data indicate that intraperitoneal administration of amino acids is effective and well-tolerated in patients on CAPD. We believe further work should be done to determine whether long-term administration of amino acids by this route will improve the nutritional status of these patients and prevent the side effects of daily absorption of large amounts of glucose.

Variations in the concentrations of free amino acids in the plasma of the dairy cow at parturition

1972 ◽  
Vol 39 (3) ◽  
pp. 355-364 ◽  
Author(s):  
R. Verbeke ◽  
E. Roets ◽  
G. Peeters
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Milk Protein ◽  
Sampling Period ◽  
Aminobutyric Acid ◽  
Amino Acid Utilization ◽  
Amino Acid Levels ◽  
The Mean ◽  
Peak Value

SummaryThe plasma levels of individual amino acids were studied in 6 dairy cows from 4 days before to 3 days after calving. During this sampling period, the concentrations of 13 amino acids showed significant changes. The levels of several amino acids were depressed markedly in the sample collected immediately before calving. Following parturition, the concentration of most amino acids gradually returned to values obtained 3 days before calving. The glutamine and alanine contents of the plasma rose to a peak value 1 day after calving and subsequently decreased. The mean concentrations of glycine and α-aminobutyric acid did not change before parturition but rose significantly thereafter. These observations are discussed in terms of amino-acid utilization for milk protein synthesis and gluconeogenesis at the onset of lactation. The changes in plasma amino acid levels appear to be synchronized with those reported for prolactin and progesterone in the 24 h before parturition. This may indicate an important influence of both hormones on the lactogenic process in the cow. The highly significant correlations obtained between the concentrations of 14 individual amino acids are discussed.

EFFECT OF CORTISOL TREATMENT ON FREE AMINO ACID LEVELS IN RATS

1973 ◽  
Vol 59 (1) ◽  
pp. 57-63 ◽  
Author(s):  
W. DE LOECKER ◽  
M. L. STAS
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Protein Turnover ◽  
Free Amino Acids ◽  
Free Amino ◽  
Experimental Period ◽  
Amino Acid Levels ◽  
Amino Acid Concentrations

SUMMARY Changes in the concentrations of free amino acids in intracellular fluids and blood plasma were measured in rats treated with cortisol. Increasing age raised the concentrations of free amino acids in plasma, while in liver, with the exception of glycine and alanine, decreased concentrations were observed. Cortisol treatment reduced free amino acid levels in plasma and liver which suggested a progressive catabolism of body proteins and increased protein synthesis in the liver. In skeletal muscle of control rats the free amino acid concentrations increased during the experimental period. Cortisol increased the concentration of certain amino acids and decreased that of others due to an increased protein turnover in muscle.

scholarly journals Experimental evolution recapitulates natural evolution

2000 ◽  
Vol 355 (1403) ◽  
pp. 1677-1684 ◽  
Author(s):  
H. A. Wichman ◽  
L. A. Scott ◽  
C. D. Yarber ◽  
J. J. Bull
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Experimental Evolution ◽  
Laboratory Culture ◽  
Culture Conditions ◽  
Natural Evolution ◽  
Amino Acid Variation ◽  
Experimental Line ◽  
Amino Acid Levels ◽  
A Site

Genomes of the closely related bacteriophages ϕX174 and S13 are 5386 bases long and differ at 114 nucleotides, affecting 28 amino acids. Both parental phages were adapted to laboratory culture conditions in replicate lineages and analysed for nucleotide changes that accumulated experimentally. Of the 126 experimental substitutions, 90% encoded amino–acid changes, and 62% of the substitutions occurred in parallel in more than one experimental line. Furthermore, missense changes at 12 of the experimental sites were at residues differing between the parental phages; in ten cases the ϕX174 experimental lineages were convergent with the S13 parent, or vice versa, at both the nucleotide and amino–acid levels. Convergence at a site was even obtained in both directions in three cases. These results point to a limited number of pathways taken during evolution in these viruses, and also raise the possibility that much of the amino–acid variation in the natural evolution of these viruses has been selected.

Influence of plasma amino acid level on urine volume in the alligator

1962 ◽  
Vol 202 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Roland A. Coulson ◽  
Thomas Hernandez
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Amino Acid ◽  
Ammonia Synthesis ◽  
Amino Acid Level ◽  
Urine Volume ◽  
Plasma Amino Acid ◽  
Protein Catabolism ◽  
Degree Of Hydration ◽  
Amino Acid Levels

Growth hormone, hydrocortisone, and a mixture of the two were injected daily into small alligators for periods up to 2 weeks. Although plasma amino acid levels increased only slightly after either growth hormone or hydrocortisone, injection of the combined hormones doubled the concentrations. In all cases increases in plasma amino acids were associated with an augmented renal ammonia synthesis and an increased urine volume. When the degree of hydration was maintained at a nearly constant level, the urine volume was directly related to the quantity of amino acids available for renal deamination. Insulin, a hormone which lowers the concentration of extracellular amino acids, decreased the rate of renal ammonia synthesis and therefore the rate of urine flow. The oliguria produced by insulin could be counteracted by the injection of glycine, a known precursor of urinary ammonia. Evidence is presented which suggests that in the "diabetes" caused by a combined injection of growth hormone and hydrocortisone, protein catabolism is enhanced and fat catabolism is inhibited. A negative nitrogen balance occurred as a result of the delivery of more amino acids for renal deamination.

Sign in / Sign up

Export Citation Format

Share Document