scholarly journals The isotopic N turnover rate as a proxy to evaluate in the long-term the protein turnover in growing ruminants

2019 ◽  
Author(s):  
Gonzalo Cantalapiedra-Hijar ◽  
Hélène Fouillet ◽  
Céline Chantelauze ◽  
Nadezda Khodorova ◽  
Lahlou Bahloul ◽  
...  
Keyword(s):  
Protein Turnover ◽  
Plasma Proteins ◽  
Farm Animals ◽  
Whole Body ◽  
Synthesis Rate ◽  
Non Invasive ◽  
Depletion Rate ◽  
Fractional Synthesis ◽  
Large Farm

ABSTRACTProtein turnover is an energy-consuming process essential for ensuring the maintenance of living organisms. Gold standard methods for protein turnover measurement are based on intravenous infusions of stable isotopes. Although accurate they have inherent drawbacks precluding their generalization for large farm animals and during long time periods. We proposed here a non-invasive proxy of the whole-body fractional protein degradation (WBFPDR; protein turnover for a growing animal) in the long term and in a large number of beef cattle. The proxy is based on the rate at which urine-N and plasma proteins are progressively depleted in 15N after a slight decrease in the isotopic N composition of diet (i.e. diet-switch). We aimed to test the ability of this proxy to adequately discriminate the WBFPDR of 36 growing-fattening young bulls assigned to different dietary treatments known to impact the protein turnover rate: the protein content and amino acid profile. To achieve this objective, the experimental diets were enriched with 15N labeled-urea during 35 days while the animals were adapted to diets. After stopping the 15N labeled-urea administration the animals were thereafter sampled for spot urines (n = 13) and blood (n = 10) over 5 months and analyzed for their 15N enrichments in total N and plasma proteins, respectively. Adequately fitting the 15N kinetics in plasma proteins and urines required mono- and bi-exponential models, respectively, and the model parameters were compared across dietary conditions using a non-linear mixed effect model. The single 15N depletion rate found in plasma proteins represented their fractional synthesis rate, whereas the slowest depletion rate found in urines was interpreted as a proxy of the WBFPDR. The proxy here tested in urines suggested different WBFPDR values between Normal vs High protein diets but not between balanced vs unbalanced methionine diets. In contrast, the proxy tested in plasma indicated that both dietary conditions affected the fractional synthesis rate of plasma proteins. We consider that the rate at which urines are progressively 15N-depleted following an isotopic diet-switch could be proposed as a non-invasive proxy of the long-term whole-body fractional protein degradation rate for large farm animals.

The isotopic nitrogen turnover rate as a proxy to evaluate in the long-term the protein turnover in growing ruminants

2019 ◽  
Vol 157 (9-10) ◽  
pp. 701-710
Author(s):  
Gonzalo Cantalapiedra-Hijar ◽  
Hélène Fouillet ◽  
Céline Chantelauze ◽  
Nadezda Khodorova ◽  
Lahlou Bahloul ◽  
...  
Keyword(s):  
Protein Turnover ◽  
Plasma Proteins ◽  
Farm Animals ◽  
Synthesis Rate ◽  
Fractional Synthesis Rate ◽  
Non Invasive ◽  
Depletion Rate ◽  
Fractional Synthesis ◽  
Large Farm ◽  
Diet Switch

AbstractProtein turnover is an energy-consuming process that is essential for ensuring the maintenance of living organisms. Gold standard methods for whole-body protein turnover (WBPT) measurement have inherent drawbacks precluding their generalization for large farm animals and use during long periods. Here, we proposed a non-invasive proxy for the WBPT over a long period of time and in a large number of beef cattle. The proxy is based on the rate at which urine-N and plasma proteins are progressively depleted in terms of 15N after a slight decrease in the isotopic N composition of the diet (i.e. diet switch). We aimed to test the ability of this proxy to adequately discriminate the WBPT of 36 growing-fattening young bulls assigned to different dietary treatments known to impact the WBPT rate, with different protein contents (normal v. high) and amino acid profiles (balanced v. unbalanced in methionine). The 15N depletion rate found in plasma proteins represented their fractional synthesis rate, whereas the slow depletion rate found in urine was interpreted as a proxy of the WBPT. The proxy tested in urine suggested different WBPT values between the normal- and high-protein diets but not between the balanced and unbalanced methionine diets. In contrast, the proxy tested in plasma indicated that both dietary conditions affected the fractional synthesis rate of plasma proteins. We considered that the rate at which urine is progressively 15N-depleted following an isotopic diet switch could be proposed as a non-invasive proxy of the WBPT rate in large farm animals.

337 Efficient RFI Bulls Presented Lower Fractional Synthesis Rates of Plasma Proteins When Fed Corn but Not Grass Based Diets

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 188-189
Author(s):  
Pablo Guarnido Lopez ◽  
Isabelle Ortigues Marty ◽  
Pascal Faure ◽  
Chantelauze Celine ◽  
Cantalapiedra-Hijar Gonzalo
Keyword(s):  
Skeletal Muscle ◽  
Plasma Proteins ◽  
High Energy ◽  
Whole Body ◽  
Net Energy ◽  
Lower Plasma ◽  
N Turnover ◽  
Depletion Rate ◽  
Fractional Synthesis ◽  
Total Urine

Abstract Protein turnover (PT), the continual synthesis and degradation of body proteins not leading to protein gain, is an essential high energy-demanding process. We assumed that PT might explain the between-animal variations of residual feed intake (RFI). The objective was to measure PT in extreme RFI cattle fed two contrasted diets (grass or corn-based). We conducted a RFI test for 84 days with 100 Charolais bulls and we selected the 32 most extreme (8 per diet and RFI group) for PT measurements using 1) the urinary 3-methyl-histidine to creatinine ratio, as a biomarker of the fractional protein degradation rate (FDR) of skeletal-muscle and 2) the isotopic N turnover rate measured in urine and plasma, as a proxy, respectively, of the whole-body FDR and the fractional protein synthesis rates (FSR) of plasma proteins. The 3-methyl-histidine and creatinine were determined from 10 d total urine collection. Isotopic N turnover in urine and plasma was evaluated by modelling the 15N depletion rate over 112 d following an isotopic N dietary change. Higher plasma FSR and higher skeletal-muscle and whole-body FDR were observed with corn-vs-grass diets (≥11%; P ≤ 0.03), in line with higher metabolizable protein and net energy intakes (≥10%, P = 0.001). Differences between extreme RFI animals were noted with the corn diets only, where efficient animals presented significant lower plasma FSR (-10%; P = 0.04) and numerically lower skeletal-muscle and whole-body FDR (-13% and - 8.9%; P > 0.16 respectively) than non-efficient. Non-significant differences were probably due to an insufficient size of our experimental setup. Plasma FSR is related to the PS of hepatic exportation, hence the lower plasma FSR observed in efficient RFI animals fed corn diets may reflect a lower organs to carcass ratio. Altogether results suggests that efficient RFI bulls fed corn diets had a lower hepatic PT with no-significant changes of whole-body and skeletal muscle PT.

Protein kinetics in stable heart failure patients

2003 ◽  
Vol 94 (1) ◽  
pp. 295-300 ◽  
Author(s):  
Charles W. Cortes ◽  
Paul D. Thompson ◽  
Niall M. Moyna ◽  
Margaret D. Schluter ◽  
Maria J. Leskiw ◽  
...  
Keyword(s):  
Protein Metabolism ◽  
Protein Turnover ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Bed Rest ◽  
Whole Body ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Body Protein ◽  
Fractional Synthesis

Heart failure (HF) is a slow progressive syndrome characterized by low cardiac output and peripheral metabolic, biochemical, and histological alterations. Protein loss and reduced protein turnover occur with aging, but the consequences of congestive HF (CHF) superimposed on the normal aging response are unknown. This study has two objectives: 1) to determine whether there was a difference between older age-matched controls and those with stable HF (i.e., ischemic pathology) in whole body protein turnover and 2) to determine whether protein metabolism in liver and skeletal muscle protein turnover is impacted by CHF. We measured the whole body protein synthesis rate with a U-15N-labeled algal protein hydrolysate in 10 patients with CHF and in 10 age-matched controls. Muscle fractional synthesis rate of lateral vastus muscle was determined with [U-13C]alanine on muscle biopsies obtained by a standard percutaneous needle biopsy technique. Fractional synthesis rates of five plasma proteins of hepatic origin (fibrinogen, complement C-3, ceruloplasmin, transferrin, and very low-density lipoprotein apoliprotein B-100) were determined by using2H5-labeled l-phenylalanine as tracer. Results showed that whole body protein synthesis rate was reduced in CHF patients (3.09 ± 0.19 vs. 2.25 ± 0.71 g protein · kg−1 · day−1, P < 0.05) as was muscle fractional synthesis rate (3.02 ± 0.58 vs. 1.33 ± 0.71%/day, P < 0.05) and very low-density lipoprotein apoliprotein B-100 (265 ± 25 vs. 197 ± 16%/day, P < 0.05). CHF patients were hyperinsulinemic (9.6 ± 3.1 vs. 47.0 ± 7.8 μU/ml, P < 0.01). The results were compared with those found with bed rest patients. In conclusion, protein turnover is depressed in CHF patients, and both skeletal muscle and liver are impacted. These results are similar to those found with bed rest, which suggests that inactivity is a factor in depressed protein metabolism.

scholarly journals The effects of breed and level of nutrition on whole-body and muscle protein metabolism in pure-bred Aberdeen Angus and Charolais beef steers

2000 ◽  
Vol 84 (3) ◽  
pp. 275-284 ◽  
Author(s):  
G. E. Lobley ◽  
K. D. Sinclair ◽  
C. M. Grant ◽  
L. Miller ◽  
D. Mantle ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Live Weight ◽  
Whole Body ◽  
Synthesis Rate ◽  
Eating Quality ◽  
Eye Muscle ◽  
Fractional Synthesis Rate ◽  
Fractional Synthesis

Eighteen pure-bred steers (live weight 350 kg) from each of two breeds, Aberdeen Angus (AA) and Charolais (CH), were split into three equal groups (six animals each) and offered three planes of nutrition during a 20-week period. The same ration formulation was offered to all animals with amounts adjusted at 3-week intervals to give predicted average weight gains of either 1·0 kg/d (M/M group) or 1·4 kg/d (H/H group). The remaining group (M/H) were offered the same amount of ration as the M/M group until 10 weeks before slaughter when the ration was increased to H. Data on animal performance, carcass characteristics and fibre-type composition in skeletal muscle are presented elsewhere (; ). On three occasions (17, 10 and 2 weeks before slaughter) the animals were transferred to metabolism stalls for 1 week, during which total urine collection for quantification of Nτ-methylhistidine (Nτ-MeH) elimination was performed for 4 d. On the last day, animals were infused for 11 h with [2H5] phenylalanine with frequent blood sampling (to allow determination of whole-body phenylalanine flux) followed by biopsies from m. longissimus lumborum and m. vastus lateralis to determine the fractional synthesis rate of mixed muscle protein. For both breeds, the absolute amount of Nτ-MeH eliminated increased with animal age or weight (P < 0·001) and was significantly greater for CH steers, at all intake comparisons, than for AA (P < 0·001). Estimates of fractional muscle breakdown rate (FBR; calculated from Nτ-MeH elimination and based on skeletal muscle as a fixed fraction of live weight) showed an age (or weight) decline for M/M and H/H groups of both breeds (P < 0·001). FBR was greater for the H/H group (P = 0·044). The M/H group also showed a lower FBR for the first two measurement periods (both at M intake) but increased when intake was raised to H. When allowance was made for differences in lean content (calculated from fat scores and eye muscle area in carcasses at the end of period 3), there were significant differences in muscle FBR with intake (P = 0·012) but not between breed. Whole-body protein flux (WBPF; g/d) based on plasma phenylalanine kinetics increased with age or weight (P < 0·001) and was similar between breeds. The WBPF was lower for M/M compared with H/H (P < 0·001) based on either total or per kg live weight0·75. Muscle protein fractional synthesis rate (FSR) declined with age for both breeds and tended to be higher at H/H compared with M intakes (intake × period effects, P < 0·05). Changing intake from M to H caused a significant increase (P < 0·001) in FSR. The FSR values for AA were significantly greater than for CH at comparable ages (P = 0·044). Although FSR and FBR responded to nutrition, these changes in protein metabolism were not reflected in differences in meat eating quality (Sinclair et al. 2000).

scholarly journals Contribution of whole-body protein synthesis to basal metabolism in layer and broiler chickens

1987 ◽  
Vol 57 (2) ◽  
pp. 269-277 ◽  
Author(s):  
T. Muramatsu ◽  
Y. Aoyagi ◽  
J. Okumura ◽  
I. Tasaki
Keyword(s):  
Protein Synthesis ◽  
Broiler Chickens ◽  
Whole Body ◽  
Synthesis Rate ◽  
Body Protein ◽  
Fractional Synthesis Rate ◽  
Degradation Rates ◽  
Fractional Synthesis ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

1. The effect of starvation on whole-body protein synthesis and on the contribution of protein synthesis to basal metabolic rate was investigated in young chickens (Expt 1). Strain differences between layer and broiler chickens in whole-body protein synthesis and degradation rates were examined when the birds were starved (Expt 2).2. In Expt 1, 15-d-old White Leghorn male chickens were used, while in Expt 2 Hubbard (broiler) and White Leghorn (layer) male chickens at 14 d of age were used. They were starved for 4 d, and heat production was determined by carcass analysis after 2 and 4 d of starvation. Whole-body protein synthesis rates were measured on 0, 2 and 4 d of starvation (Expt 1), and on 0 and 4 d of starvation (Expt 2).3. The results showed that starving reduced whole-body protein synthesis in terms of fractional synthesis rate and the amount synthesized. Whole-body protein degradation was increased by starvation both in terms of fractional synthesis rate and the amount degraded on a per kg body-weight basis.4. Reduced fractional synthesis rate of protein in the whole body was accounted for by reductions in both protein synthesis per unit RNA and RNA:protein ratio.5. In the fed state, whole-body protein synthesis and degradation rates, whether expressed as fractional rates or amounts per unit body-weight, tended to be higher in layer than in broiler chickens. In the starved state, the difference in the rate of protein synthesis between the two strains virtually disappeared, while the degradation rates were higher in layer than in broiler birds.6. Based on the assumed value of 3.56 kJ/g protein synthesized (Waterlow et al. 1978), the heat associated with whole-body protein synthesis in the starved state was calculated to range from 14 to 17% of the basal metabolic rate with no strain difference between layer and broiler chickens.

scholarly journals Protein turnover in skeletal muscle of piglets

1974 ◽  
Vol 31 (1) ◽  
pp. 35-45 ◽  
Author(s):  
H. N. Perry
Keyword(s):  
Protein Turnover ◽  
Plasma Proteins ◽  
Hind Limb ◽  
Acid Metabolism ◽  
Specific Activity ◽  
Whole Body ◽  
Myofibrillar Proteins ◽  
Sarcoplasmic Proteins ◽  
Sarcoplasmic Protein ◽  
Suckling Piglets

1. Rates of protein synthesis and catabolism were measured in longissimus dorsi and hind-limb muscles of suckling piglets.2. Half-lives for synthesis and catabolism for mixed sarcoplasmic proteins were 4.8 and 9.4 d respectively. The corresponding values for mixed myofibrillar proteins were 5.7 and 16.4 d.3. The half-lives for synthesis of sarcoplasmic proteins were significantly different from those of myofibrillar proteins and were not confounded by contamination of the sarcoplasmic protein fraction with plasma proteins of higher specific activity.4. Individual myofibrillar proteins were synthesized and catabolized at rates which were not statistically significantly different. Intramuscular connective tissue also appeared to turnover rapidly, the half-life for synthesis being 8 d and that for catabolism 20 d.5. Values obtained for the specific radioactivities of aspartate + glutamate in mixed plasma proteins support the view that, in so far as the young of animals larger in mature body size than rats or mice are concerned, muscle assumes a more important role relative to liver in regulating whole body amino acid metabolism.

scholarly journals Correction of acidosis in hemodialysis decreases whole-body protein degradation.

1997 ◽  
Vol 8 (4) ◽  
pp. 632-637 ◽  
Author(s):  
K A Graham ◽  
D Reaich ◽  
S M Channon ◽  
S Downie ◽  
T H Goodship
Keyword(s):  
Renal Failure ◽  
Protein Degradation ◽  
Protein Turnover ◽  
Whole Body ◽  
Body Protein ◽  
Chronic Metabolic Acidosis ◽  
Optimal Correction ◽  
Kinetics Of ◽  
Amino Acid Concentrations

Correction of acidosis in hemodialysis (HD) decreases protein degradation. The effect of the correction of chronic metabolic acidosis in chronic renal failure patients treated with HD was determined from the kinetics of infused L-[1-(13)C]leucine. Six HD patients were studied before (acid) and after (bicarbonate) correction of acidosis (pH: acid 7.36 +/- 0.01, bicarbonate 7.40 +/- 0.01, P < 0.005). Leucine appearance from body protein (PD) and leucine disappearance into body protein (PS) decreased significantly with correction of acidosis (PD: acid 180.6 +/- 7.3, bicarbonate 130.9 +/- 7.2 mumol.kg-1.h-1, P < 0.005; PS: acid 172.3 +/- 6.8, bicarbonate 122.0 +/- 6.8 mumol.kg-1.h-1, P < 0.005). There was no significant change in leucine oxidation or plasma amino acid concentrations. These results demonstrate that optimal correction of acidosis in HD is beneficial in terms of protein turnover and may improve long-term nutritional status in HD.

Measurement of plasma protein synthesis rate in infant pig: an investigation of alternative tracer approaches

1994 ◽  
Vol 267 (1) ◽  
pp. R221-R227 ◽  
Author(s):  
F. Jahoor ◽  
D. G. Burrin ◽  
P. J. Reeds ◽  
M. Frazer
Keyword(s):  
Protein Synthesis ◽  
Plasma Protein ◽  
Apolipoprotein B ◽  
Plasma Proteins ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Isotopic Equilibrium ◽  
Fractional Synthesis

To devise a new method to measure plasma protein synthesis, we tested the hypothesis that, when [U-13C]glucose is used to produce [U-13C]alanine, plasma pyruvate and alanine will be in isotopic equilibrium with the alanine used to synthesize plasma proteins. The incorporation of labeled leucine, lysine, and alanine into very-low-density lipoprotein (VLDL) apolipoprotein B (apoB)-100, albumin, and fibrinogen was measured in seven infant pigs by infusing [U-13C]glucose, [2H3]leucine, and [2H4]lysine. The plateau enrichments of plasma alanine (2.29 +/- 0.29), pyruvate (2.5 +/- 0.33), and apoB-alanine (2.33 +/- 0.25) were not different. The fractional synthesis rates of fibrinogen and albumin calculated using the isotopic enrichments of apoB-bound lysine, leucine, and alanine as the precursor were similar to those based on plasma alanine. These results suggest that the intrahepatic precursor alanine pool and plasma alanine were in isotopic equilibrium. Thus plasma protein synthesis can be measured by infusing [U-13C]glucose and using plasma alanine as precursor.

scholarly journals Protein synthesis in rat lung. Measurements in vivo based on leucyl-tRNA and rapidly turning-over procollagen I

1984 ◽  
Vol 222 (1) ◽  
pp. 77-83 ◽  
Author(s):  
J Kelley ◽  
W S Stirewalt ◽  
L Chrin
Keyword(s):  
Plasma Proteins ◽  
Specific Radioactivity ◽  
Young Male ◽  
Male Rats ◽  
Synthesis Rate ◽  
Vascular Perfusion ◽  
Fractional Synthesis ◽  
Free Serum ◽  
Procollagen Iii

The relationships of the specific radioactivities of leucine in serum, leucine acylated to tRNA and leucine in procollagen I, procollagen III and total protein in lungs of unanaesthetized young male rats in vivo were assessed as a function of time during constant intravenous infusion of radiolabelled leucine. The specific radioactivity of free leucine in plasma reached a steady-state plateau value within 30 min of initiation of [3H]leucine infusion. Leucine acylated to tRNA isolated from lungs had the same specific radioactivity as free serum leucine. Leucine in procollagen I rapidly achieved a specific radioactivity equal to that of serum leucine and leucyl-tRNA, indicating that serum leucine and leucyl-tRNA isolated from total lung were in rapid equilibrium with the precursor leucine pool for procollagen I synthesis. On the basis of leucyl-tRNA or free serum leucine as the precursor, half-times of fractional conversion of procollagen I and III were calculated as 9 and 38 min respectively. The incorporation of leucine into mixed lung proteins calculated from the tracer studies was 6.8 mumol/day for the first 30 min of the infusion, after which the calculated rate increased to 15.0 mumol/day. This apparent increase correlated with the appearance of rapidly labelled plasma proteins trapped in the lungs. On the basis of short infusions lasting 30 min or less, followed by vascular perfusion of the lung, the average fractional synthesis rate of mixed pulmonary proteins in young male rats was 20%/day.

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