scholarly journals Diurnal response in endogenous amino acid oxidation of meal-fed rats

1980 ◽  
Vol 190 (3) ◽  
pp. 663-671 ◽  
Author(s):  
R W Wannemacher ◽  
R E Dinterman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Protein ◽  
Normal Diet ◽  
Acid Oxidation ◽  
Body Protein ◽  
Amino Acid Oxidation ◽  
Collagen Protein ◽  
Meal Feeding ◽  
Endogenous Amino Acid

A model has been developed to measure the effects of dietary protein on daily fluctuations in the rate of endogenous amino acid oxidation in meal-fed and starved rats. In addition, N tau-methylhistidine and hydroxyproline were utilized to determine changes in the rate of degradation of myofibrillar and collagen proteins. In rats meal-fed a normal diet of 18% (w/w) casein, a diurnal response was observed in rate of oxidation of radioactive amino acids contained in endogenous labelled body protein, with a nadir 16—20 h and maximum 4—8 h after beginning the feeding. This observation in part may be related to alterations in flux of amino acids from non-hepatic tissues to site of oxidation in liver, as well as alterations in rates of amino acid oxidation after a protein meal. When meal-fed a 70% protein diet, the maximal rates of endogenous amino acid oxidation were significantly increased by 4—8 h after meal-feeding, with no change in fractional rates of degradation of myofibrillar- or collagen-protein breakdown. This could suggest increases in activities of enzymes involved in amino acid oxidation, in rats meal-fed 70% compared with 18% dietary protein. In contrast, meal-feeding of a protein-free diet muted the diurnal response in the rate of oxidation of endogenously labelled amino acids, which correlated with a decrease in the fractional rate of degradation of myofibrillar or collagen protein. Thus dietary protein is apparently responsible for the observed diurnal rhythm rhythms in the rate of amino acid oxidation, whereas carbohydrates tend to mute the response.

scholarly journals Development of the Indicator Amino Acid Oxidation Technique to Determine the Availability of Amino Acids from Dietary Protein in Pigs

2005 ◽  
Vol 135 (12) ◽  
pp. 2866-2870 ◽  
Author(s):  
Soenke Moehn ◽  
Robert F. P. Bertolo ◽  
Paul B. Pencharz ◽  
Ronald O. Ball
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Protein ◽  
Acid Oxidation ◽  
Amino Acid Oxidation

scholarly journals Metabolic Availability of Lysine in Milk and a Vegetarian Cereal–Legume Meal Determined by the Indicator Amino Acid Oxidation Method in Indian Men

2020 ◽  
Vol 150 (10) ◽  
pp. 2748-2754
Author(s):  
Sulagna Bandyopadhyay ◽  
Rebecca Kuriyan ◽  
Nirupama Shivakumar ◽  
Santu Ghosh ◽  
Rajendran Ananthan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Milk Powder ◽  
Cow Milk ◽  
Ratio Method ◽  
Acid Oxidation ◽  
Mixed Effect ◽  
Amino Acid Oxidation ◽  
Heat Treated ◽  
Spray Dried

ABSTRACT Background Lysine rich foods such as milk and legumes serve as important food additions to the lysine deficient cereal-based diets of vegetarian populations in low- and middle-income countries (LMICs) to alleviate the risk of quality corrected dietary protein inadequacy. Dietary protein quality can be determined by estimating the metabolic availability (MA) of lysine. Objectives The study aimed to estimate the MA of lysine in spray-dried cow milk powder (SMP), heat-treated spray-dried cow milk powder (HSMP), and a habitually consumed cereal-legume based vegetarian meal (VM), using the indicator amino acid oxidation (IAAO) slope-ratio method. Methods The MA of lysine in SMP, HSMP, and VM was estimated in 7 healthy young men aged 19–24 y with BMI of 21.5 ± 0.5 kg/m2 in a repeated measures design. The IAAO response slopes with 2 graded lysine intakes (10.5 and 15.0 mg·kg−1·d−1) from the SMP and VM were compared with the response slope generated with 3 graded crystalline lysine intakes (6.0, 10.5, and 15.0 mg·kg−1·d−1) at the subrequirement level. To produce HSMP, pasteurized cow milk was heat treated and spray dried. The MA of lysine in HSMP was tested at a single level of lysine intake (15 mg·kg−1·d−1). A total of 8 IAAO experiments were conducted on each participant in randomized order. The IAAO slopes were estimated using a linear mixed-effect regression model. Results The MA of lysine in SMP, HSMP, and VM was 91.9%, 69.9%, and 86.6% respectively. Conclusions Heat treatment reduced the MA of lysine by 22% in HSMP compared with SMP in healthy Indian adults. The lysine MA estimates can be used to optimize lysine limited cereal-based diets, with the addition of appropriately processed legumes and milk powder, to meet the protein requirement. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2019/08/020568.

Correction of acidosis in humans with CRF decreases protein degradation and amino acid oxidation

1993 ◽  
Vol 265 (2) ◽  
pp. E230-E235 ◽  
Author(s):  
D. Reaich ◽  
S. M. Channon ◽  
C. M. Scrimgeour ◽  
S. E. Daley ◽  
R. Wilkinson ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Amino Acid ◽  
Sodium Chloride ◽  
Sodium Bicarbonate ◽  
Acid Oxidation ◽  
Body Protein ◽  
Amino Acid Oxidation ◽  
Kinetics Of ◽  
Amino Acid Concentrations

The effect of correction of acidosis in chronic renal failure (CRF) was determined from the kinetics of infused L-[1-13C]leucine. Nine CRF patients were studied before (acid) and after two 4-wk treatment periods of sodium bicarbonate (NaHCO3) and sodium chloride (NaCl) (pH: acid 7.31 +/- 0.01, NaHCO3 7.38 +/- 0.01, NaCl 7.30 +/- 0.01). Leucine appearance from body protein (PD), leucine disappearance into body protein (PS) and leucine oxidation (O) decreased significantly with correction of acidosis (PD: acid 122.4 +/- 6.1, NaHCO3 88.3 +/- 6.9, NaCl 116.2 +/- 9.1 mumol.kg-1.h-1, acid vs. NaHCO3 P < 0.01, NaHCO3 vs. NaCl P < 0.01, acid vs. NaCl NS; PS: acid 109.4 +/- 5.6, NaHCO3 79.0 +/- 6.3, NaCl 101.3 +/- 7.7 mumol.kg-1.h-1, acid vs. NaHCO3 P < 0.01, NaHCO3 vs. NaCl P < 0.01, acid vs. NaCl NS; O: acid 13.0 +/- 1.2, NaHCO3 9.2 +/- 0.9, NaCl 15.0 +/- 1.9 mumol.kg-1.h-1, acid vs. NaHCO3 P < 0.05, NaHCO3 vs. NaCl P < 0.01, acid vs. NaCl NS). There were no significant changes in plasma amino acid concentrations. These results confirm that correction of acidosis in chronic renal failure removes a potential catabolic factor.

Quantitative analysis of amino acid oxidation and related gluconeogenesis in humans

1992 ◽  
Vol 72 (2) ◽  
pp. 419-448 ◽  
Author(s):  
R. L. Jungas ◽  
M. L. Halperin ◽  
J. T. Brosnan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Urea Cycle ◽  
Liver Mitochondria ◽  
Carbon Flow ◽  
Acid Oxidation ◽  
Peripheral Tissues ◽  
Amino Acid Oxidation ◽  
Atp Production ◽  
Acid Load

Significant gaps remain in our knowledge of the pathways of amino acid catabolism in humans. Further quantitative data describing amino acid metabolism in the kidney are especially needed as are further details concerning the pathways utilized for certain amino acids in liver. Sufficient data do exist to allow a broad picture of the overall process of amino acid oxidation to be developed along with approximate quantitative assessments of the role played by liver, muscle, kidney, and small intestine. Our analysis indicates that amino acids are the major fuel of liver, i.e., their oxidative conversion to glucose accounts for about one-half of the daily oxygen consumption of the liver, and no other fuel contributes nearly so importantly. The daily supply of amino acids provided in the diet cannot be totally oxidized to CO2 in the liver because such a process would provide far more ATP than the liver could utilize. Instead, most amino acids are oxidatively converted to glucose. This results in an overall ATP production during amino acid oxidation very nearly equal to the ATP required to convert amino acid carbon to glucose. Thus gluconeogenesis occurs without either a need for ATP from other fuels or an excessive ATP production that could limit the maximal rate of the process. The net effect of the oxidation of amino acids to glucose in the liver is to make nearly two-thirds of the total energy available from the oxidation of amino acids accessible to peripheral tissues, without necessitating that peripheral tissues synthesize the complex array of enzymes needed to support direct amino acid oxidation. As a balanced mixture of amino acids is oxidized in the liver, nearly all carbon from glucogenic amino acids flows into the mitochondrial aspartate pool and is actively transported out of the mitochondria via the aspartate-glutamate antiport linked to proton entry. In the cytoplasm the aspartate is converted to fumarate utilizing urea cycle enzymes; the fumarate flows via oxaloacetate to PEP and on to glucose. Thus carbon flow through the urea cycle is normally interlinked with gluconeogenic carbon flow because these metabolic pathways share a common step. Liver mitochondria experience a severe nonvolatile acid load during amino acid oxidation. It is suggested that this acid load is alleviated mainly by the respiratory chain proton pump in a form of uncoupled respiration.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Radiometric studies on the oxidation of (U-14C) L-amino acids by drug-susceptible and drug-resistant mycobacteria

1987 ◽  
Vol 29 (5) ◽  
pp. 312-316
Author(s):  
Edwaldo E. Camargo ◽  
Teresa M. Kopajtic ◽  
Glinda K. Hopkins ◽  
Nancy P. Cannon ◽  
Henry N. Wagner Jr
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Reaction System ◽  
Tuberculosis H37rv ◽  
Assay System ◽  
Acid Oxidation ◽  
Resistant Organism ◽  
Drug Resistant ◽  
Amino Acid Oxidation ◽  
Radiometric Assay

A radiometric assay system has been used to study oxidation patterns of (U-14C) L-amino acids by drug-susceptible and drug-resistant mycobacteria. Drug-susceptible M. tuberculosis (H37Rv TMC 102 and Erdman) along with the drug-resistant organism M. tuberculosis (H37 Rv TMC 303), M. bovis, M. avium, M. intracellulare, M. kansasii and M. chelonei were used. The organisms were inoculated into a sterile reaction system with liquid 7H9 medium and one of the (U-14C) L-amino acids. Each organism displayed a different pattern of amino acid oxidation, but these patterns were not distinctive enough for identification of the organism. Complex amino acids such as proline, phenylalanine and tyrosine were of no use in identification of mycobacteria, since virtually all organisms failed to oxidize them. There was no combination of substrates able to separate susceptible from resistant organisms.

scholarly journals Indicator amino acid oxidation protein requirement estimate in endurance-trained men 24 h postexercise exceeds both the EAR and current athlete guidelines

2019 ◽  
Vol 316 (5) ◽  
pp. E741-E748 ◽  
Author(s):  
Arash Bandegan ◽  
Glenda Courtney-Martin ◽  
Mahroukh Rafii ◽  
Paul B. Pencharz ◽  
Peter W. R. Lemon
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Protein Pattern ◽  
Training Session ◽  
Acid Mixture ◽  
Acid Oxidation ◽  
Institute Of Medicine ◽  
Protein Requirement ◽  
Amino Acid Oxidation ◽  
Protein Requirements

Despite studies indicating increased protein requirements in strength-trained or endurance-trained (ET) individuals, the Institute of Medicine has concluded that “no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise,” and the controversy regarding exercise effects on protein requirements continues. The objective of this study was to determine the dietary protein requirement of healthy young ET men (≥1 yr training experience) 24 h post exercise (to minimize any acute effects of the previous training session) by measuring the oxidation of ingested l-[1-13C]phenylalanine to 13CO2 in response to graded intakes of protein (indicator amino acid oxidation technique). Eight men [maximal oxygen consumption 64.1 ml·kg−1·min−1 (SD 3.7)] were each studied 24 h postexercise repeatedly with protein intakes ranging from 0.3 to 3.5 g·kg−1·day−1. Protein was fed as an amino acid mixture based on the protein pattern in egg, except for phenylalanine and tyrosine, which were maintained at constant amounts across all protein intakes. For 2 days before the study day, all participants consumed 1.6 g protein·kg−1·day−1. The estimated average requirement (EAR) for protein was determined by applying a nonlinear mixed-effects change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath), which identified a breakpoint in the F13CO2 in response to the graded amounts of protein. The EAR for protein and the upper 95% confidence interval were 2.1 and 2.6 g·kg−1·day−1, respectively. These data suggest that the protein EAR for ET men 24 h postexercise exceeds the Institute of Medicine EAR and established athlete guidelines by ~3.5- and 1.3-fold, respectively.

scholarly journals An Evaluation of Protein Intake for Metabolic Demands and the Quality of Dietary Protein in Rats Using an Indicator Amino Acid Oxidation Method

2011 ◽  
Vol 57 (6) ◽  
pp. 418-425 ◽  
Author(s):  
Aki OGAWA ◽  
Yuka NARUSE ◽  
Yasutaka SHIGEMURA ◽  
Yukiko KOBAYASHI ◽  
Isao SUZUKI ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Protein Intake ◽  
Acid Oxidation ◽  
Oxidation Method ◽  
Amino Acid Oxidation

Suppression of muscle protein turnover and amino acid degradation by dietary protein deficiency

1992 ◽  
Vol 263 (2) ◽  
pp. E317-E325 ◽  
Author(s):  
N. E. Tawa ◽  
A. L. Goldberg
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dietary Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Normal Diet ◽  
High Rate ◽  
Acid Uptake ◽  
Rapid Weight Gain

To define the adaptations that conserve amino acids and muscle protein when dietary protein intake is inadequate, rats (60-70 g final wt) were fed a normal or protein-deficient (PD) diet (18 or 1% lactalbumin), and their muscles were studied in vitro. After 7 days on the PD diet, both protein degradation and synthesis fell 30-40% in skeletal muscles and atria. This fall in proteolysis did not result from reduced amino acid supply to the muscle and preceded any clear decrease in plasma amino acids. Oxidation of branched-chain amino acids, glutamine and alanine synthesis, and uptake of alpha-aminoisobutyrate also fell by 30-50% in muscles and adipose tissue of PD rats. After 1 day on the PD diet, muscle protein synthesis and amino acid uptake decreased by 25-40%, and after 3 days proteolysis and leucine oxidation fell 30-45%. Upon refeeding with the normal diet, protein synthesis also rose more rapidly (+30% by 1 day) than proteolysis, which increased significantly after 3 days (+60%). These different time courses suggest distinct endocrine signals for these responses. The high rate of protein synthesis and low rate of proteolysis during the first 3 days of refeeding a normal diet to PD rats contributes to the rapid weight gain ("catch-up growth") of such animals.

PSX-A-17 Late-Breaking: Methionine and total sulfur amino acid requirements for pups (>14 wk to 9 months), adults, and senior Labrador Retrievers using the indicator amino acid oxidation (IAAO) technique

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 374-374
Author(s):  
Jessica L Varney ◽  
Charlene Watson ◽  
Nicole Colopy ◽  
John Moss ◽  
Jordan T Weil ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Control Diet ◽  
Age Groups ◽  
Isotope Ratio Mass Spectrometry ◽  
Co2 Production ◽  
Acid Oxidation ◽  
Total Sulfur ◽  
Amino Acid Oxidation ◽  
Labrador Retrievers

Abstract Methionine and cystine are often considered limiting amino acids in canine diets but limited requirement studies have been conducted especially for different life stages. Eighteen Labrador Retrievers (6 pups (&gt;14 wk-9 month), 6 adults, and 6 seniors [&gt;8yr)] were utilized in feeding studies to evaluate the changing requirements of methionine (Met) and total sulfur amino acids (TSAA) as canines age. For this study, the indicator amino acid oxidation (IAAO) technique was utilized to determine the amino acid (AA) requirements in each of the three age groups. Dogs were subjected to diets ranging from deficient to excess, with indispensable amino acids formulated at 1.6x NRC values. To allow for adaptation, a control diet with same dietary ingredients, protein and amino acid levels was fed for two days prior to feeding the test diets on the third day. On test day, a baseline breath sample was collected for determining CO2 production using a respiration mask (Oxymax, Columbus Instruments). A priming dose of L-[1-13C] phenylalanine (Cambridge Isotope Laboratories, Inc.) based on body weight was utilized, followed by [1-13C] Phe doses every 30 minutes, spanning a four hour period. After each dose 13CO2 was collected, and enrichment was determined by isotope ratio mass spectrometry (IRMS). Results for IRMS were converted to atom percent excess (APE) and analyzed using a piecewise model of best fit (JMP® Pro 16). A segmented line regression showed Met and TSAA mean and population requirements for pups (&gt;14 wk-9 mo.) were 0.78 ± 0.16 and 1.53 ± 0.21 g/1000kcal (mean ± 2SD), respectively. Meanwhile, for adults, mean and population requirements for Met and TSAA were estimated to be 0.68 ± 0.19 and 1.4 ± 0.30 g/1000kcal (mean ± 2SD), respectively, and for seniors, Met and TSAA mean and population requirements were determined to be 0.62 ± 0.17 and 1.27 ± 0.23 g/1000kcal (mean ± 2SD), respectively.

Sign in / Sign up

Export Citation Format

Share Document