scholarly journals Walking exercise alters protein digestion, amino acid absorption, and whole body protein kinetics in older adults with and without COPD

2020 ◽  
Author(s):  
Clayton L. Cruthirds ◽  
Nicolaas E.P. Deutz ◽  
Gerdien C. Ligthart-Melis ◽  
Sunday Y. Simbo ◽  
Marielle P.K.J. Engelen
Keyword(s):  
Amino Acid ◽  
Whole Body ◽  
Protein Digestion ◽  
Protein Kinetics ◽  
Body Protein ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
Copd Patients ◽  
Maximal Speed ◽  
Walking Exercise

Purpose: Gut symptoms and markers of gut dysfunction have been observed in patients with Chronic Obstructive Pulmonary disease (COPD). It remains unclear whether walking exercise induces disturbances in protein digestion and amino acid absorption and whole body protein kinetics in these subjects due to exercise induced hypoxia. Methods: Sixteen clinically stable patients with moderate to very severe COPD and 12 age matched control subjects completed the study. Protein digestion and amino acid absorption and whole body protein kinetics, in the postabsorptive state, were measured via a continuous infusion of stable tracers in combination with orally administered tracer sips during 20 minutes of walking exercise and up to 4 hours post-exercise. COPD patients completed one study day, walking at maximal speed, while healthy subjects completed two, one matched to the speed of a COPD patient and one walking at maximal speed. Results: The COPD patients tolerated 20 minutes of vigorous intensity walking despite elevated heart rate (P<0.001) and substantial desaturation (P<0.001). Relative to rest, protein digestion was increased during recovery from exercise (P<0.05) while amino acid absorption was reduced during (P<0.0001) and immediately after exercise (P<0.001). Whole body protein breakdown was reduced within 20 minutes after exercise (P<0.05) and stayed suppressed for four hours (P<0.0001). Whole body net protein breakdown was elevated for four hours post-exercise (P<0.001). Conclusion: Our data showed that 20 minutes of walking exercise is sufficient to cause substantial perturbations in gut function in older adults and COPD patients with hypoxia as a potential underlying factor.

Amino acid absorption and subsequent muscle protein accretion following graded intakes of whey protein in elderly men

2012 ◽  
Vol 302 (8) ◽  
pp. E992-E999 ◽  
Author(s):  
Bart Pennings ◽  
Bart Groen ◽  
Anneke de Lange ◽  
Annemie P. Gijsen ◽  
Antoine H. Zorenc ◽  
...  
Keyword(s):  
Amino Acid ◽  
Whey Protein ◽  
Muscle Protein ◽  
Older Men ◽  
Whole Body ◽  
Protein Digestion ◽  
Protein Balance ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
The Impact

Whey protein ingestion has been shown to effectively stimulate postprandial muscle protein accretion in older adults. However, the impact of the amount of whey protein ingested on protein digestion and absorption kinetics, whole body protein balance, and postprandial muscle protein accretion remains to be established. We aimed to fill this gap by including 33 healthy, older men (73 ± 2 yr) who were randomly assigned to ingest 10, 20, or 35 g of intrinsically l-[1-13C]phenylalanine-labeled whey protein ( n = 11/treatment). Ingestion of labeled whey protein was combined with continuous intravenous l-[ ring-2H5]phenylalanine and l-[ ring-2H2]tyrosine infusion to assess the metabolic fate of whey protein-derived amino acids. Dietary protein digestion and absorption rapidly increased following ingestion of 10, 20, and 35 g whey protein, with the lowest and highest (peak) values observed following 10 and 35 g, respectively ( P < 0.05). Whole body net protein balance was positive in all groups (19 ± 1, 37 ± 2, and 58 ± 2 μmol/kg), with the lowest and highest values observed following ingestion of 10 and 35 g, respectively ( P < 0.05). Postprandial muscle protein accretion, assessed by l-[1-13C]phenylalanine incorporation in muscle protein, was higher following ingestion of 35 g when compared with 10 ( P < 0.01) or 20 ( P < 0.05) g. We conclude that ingestion of 35 g whey protein results in greater amino acid absorption and subsequent stimulation of de novo muscle protein synthesis compared with the ingestion of 10 or 20 g whey protein in healthy, older men.

scholarly journals Protein Type, Protein Dose, and Age Modulate Dietary Protein Digestion and Phenylalanine Absorption Kinetics and Plasma Phenylalanine Availability in Humans

2020 ◽  
Vol 150 (8) ◽  
pp. 2041-2050 ◽  
Author(s):  
Stefan H M Gorissen ◽  
Jorn Trommelen ◽  
Imre W K Kouw ◽  
Andrew M Holwerda ◽  
Bart Pennings ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Digestion ◽  
Absorption Kinetics ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
Type Protein ◽  
Protein Ingestion

ABSTRACT Background Dietary protein ingestion stimulates muscle protein synthesis by providing amino acids to the muscle. The magnitude and duration of the postprandial increase in muscle protein synthesis rates are largely determined by dietary protein digestion and amino acid absorption kinetics. Objective We assessed the impact of protein type, protein dose, and age on dietary protein digestion and amino acid absorption kinetics in vivo in humans. Methods We included data from 18 randomized controlled trials with a total of 602 participants [age: 53 ± 23 y; BMI (kg/m2): 24.8 ± 3.3] who consumed various quantities of intrinsically l-[1-13C]-phenylalanine–labeled whey (n = 137), casein (n = 393), or milk (n = 72) protein and received intravenous infusions of l-[ring-2H5]-phenylalanine, which allowed us to assess protein digestion and phenylalanine absorption kinetics and the postprandial release of dietary protein–derived phenylalanine into the circulation. The effect of aging on these processes was assessed in a subset of 82 young (aged 22 ± 3 y) and 83 older (aged 71 ± 5 y) individuals. Results A total of 50% ± 14% of dietary protein–derived phenylalanine appeared in the circulation over a 5-h postprandial period. Casein ingestion resulted in a smaller (45% ± 11%), whey protein ingestion in an intermediate (57% ± 10%), and milk protein ingestion in a greater (65% ± 13%) fraction of dietary protein–derived phenylalanine appearing in the circulation (P &lt; 0.001). The postprandial availability of dietary protein–derived phenylalanine in the circulation increased with the ingestion of greater protein doses (P &lt; 0.05). Protein digestion and phenylalanine absorption kinetics were attenuated in older when compared with young individuals, with 45% ± 10% vs. 51% ± 14% of dietary protein–derived phenylalanine appearing in the circulation, respectively (P = 0.001). Conclusions Protein type, protein dose, and age modulate dietary protein digestion and amino acid absorption kinetics and subsequent postprandial plasma amino acid availability in vivo in humans. These trials were registered at clinicaltrials.gov as NCT00557388, NCT00936039, NCT00991523, NCT01317511, NCT01473576, NCT01576848, NCT01578590, NCT01615276, NCT01680146, NCT01820975, NCT01986842, and NCT02596542, and at http://www.trialregister.nl as NTR3638, NTR3885, NTR4060, NTR4429, and NTR4492.

scholarly journals Effects of Extrusion of Whole Horse Beans on Protein Digestion and Amino Acid Absorption in Dairy Cows

1994 ◽  
Vol 77 (5) ◽  
pp. 1360-1371 ◽  
Author(s):  
C. Benchaar ◽  
M. Vernay ◽  
C. Bayourthe ◽  
R. Moncoulon
Keyword(s):  
Amino Acid ◽  
Dairy Cows ◽  
Protein Digestion ◽  
Acid Absorption ◽  
Amino Acid Absorption

scholarly journals Jejunal Casein Feeding Is Followed by More Rapid Protein Digestion and Amino Acid Absorption When Compared with Gastric Feeding in Healthy Young Men

2015 ◽  
Vol 145 (9) ◽  
pp. 2033-2038 ◽  
Author(s):  
Joanna Luttikhold ◽  
Klaske van Norren ◽  
Nikki Buijs ◽  
Marjolein Ankersmit ◽  
Annemieke C Heijboer ◽  
...  
Keyword(s):  
Amino Acid ◽  
Young Men ◽  
Protein Digestion ◽  
Acid Absorption ◽  
Amino Acid Absorption ◽  
Gastric Feeding

scholarly journals Basal and Postprandial Myofibrillar Protein Synthesis Rates Do Not Differ between Lean and Obese Middle-Aged Men

2019 ◽  
Vol 149 (9) ◽  
pp. 1533-1542 ◽  
Author(s):  
Imre W K Kouw ◽  
Jan Willem van Dijk ◽  
Astrid M H Horstman ◽  
Irene Fleur Kramer ◽  
Joy P B Goessens ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Myofibrillar Protein ◽  
Whole Body ◽  
Protein Digestion ◽  
Body Protein ◽  
Postprandial Period ◽  
Protein Ingestion ◽  
Myofibrillar Protein Synthesis

ABSTRACT Background Excess lipid availability has been associated with the development of anabolic resistance. As such, obesity may be accompanied by impairments in muscle protein metabolism. Objective We hypothesized that basal and postprandial muscle protein synthesis rates are lower in obese than in lean men. Methods Twelve obese men [mean ± SEM age: 48 ± 2 y; BMI (in kg/m2): 37.0 ± 1.5; body fat: 32 ± 2%] and 12 age-matched lean controls (age: 43 ± 3 y; BMI: 23.4 ± 0.4; body fat: 21 ± 1%) received primed continuous L-[ring-2H5]-phenylalanine and L-[ring-3,5-2H2]-tyrosine infusions and ingested 25 g intrinsically L-[1-13C]-phenylalanine labeled whey protein. Repeated blood and muscle samples were obtained to assess protein digestion and amino acid absorption kinetics, and basal and postprandial myofibrillar protein synthesis rates. Results Exogenous phenylalanine appearance rates increased after protein ingestion in both groups (P < 0.001), with a total of 53 ± 1% and 53 ± 2% of dietary protein–derived phenylalanine appearing in the circulation over the 5-h postprandial period in lean and obese men, respectively (P = 0.82). After protein ingestion, whole-body protein synthesis and oxidation rates increased to a greater extent in lean men than in the obese (P-interaction < 0.05), resulting in a higher whole-body protein net balance in the lean than in the obese (7.1 ± 0.2 and 4.6 ± 0.4 µmol phenylalanine · h−1 · kg−1, respectively; P-interaction < 0.001). Myofibrillar protein synthesis rates increased from 0.030 ± 0.002 and 0.028 ± 0.003%/h in the postabsorptive period to 0.034 ± 0.002 and 0.035 ± 0.003%.h−1 in the 5-h postprandial period (P = 0.03) in lean and obese men, respectively, with no differences between groups (P-interaction = 0.58). Conclusions Basal, postabsorptive myofibrillar protein synthesis rates do not differ between lean and obese middle-aged men. Postprandial protein handling, including protein digestion and amino acid absorption, and the postprandial muscle protein synthetic response after the ingestion of 25 g whey protein are not impaired in obese men. This trial was registered at www.trialregister.nl as NTR4060.

Effect of Total Parenteral Nutrition on the Protein Kinetics of Patients with Cancer Cachexia

2000 ◽  
Vol 86 (5) ◽  
pp. 408-411 ◽  
Author(s):  
Federico Bozzetti ◽  
Cecilia Gavazzi ◽  
Paola Ferrari ◽  
Federica Dworzak
Keyword(s):  
Amino Acid ◽  
Cancer Patients ◽  
Metabolic Response ◽  
Whole Body ◽  
Protein Kinetics ◽  
Body Protein ◽  
Patients With Cancer ◽  
Mass Depletion ◽  
Muscle Compartment ◽  
The Impact

Aims and background The question of whether TPN is able to reverse lean body mass depletion in cachectic cancer patients and, in particular, its effect on protein kinetics is a matter of some controversy. This study investigates the impact of TPN on protein kinetics in patients with gastric cancer. Methods The study involved three patients with 14–30% weight loss. They were administered a TPN regimen including 33–40 kcal/kg/day and 1.4–1.7 g amino acid/kg/day. The protein metabolism was studied before and during TPN using a stable amino acid isotope. Results Whole body protein turnover and breakdown did not change during TPN, whereas whole body protein synthesis increased from 3.39 ± 1.04 to 6.05 ± 0.48 g/kg/day (P = 0.03). However, the net balance, which was slightly negative prior to TPN, became positive during nutritional support. In the skeletal muscle compartment the synthesis improved with TPN (from 9.38 ± 2.6 nmol/100 mL/min to 35.95 ± 3.4 nmol/100 mL/min; P = 0.0143), whereas breakdown did not change significantly. Conclusions TPN triggers a positive metabolic response in cachectic cancer patients. Whether this results in a clinical benefit for the patient requires further investigation.

scholarly journals Accelerated protein digestion and amino acid absorption after Roux-en-Y gastric bypass

2015 ◽  
Vol 102 (3) ◽  
pp. 600-607 ◽  
Author(s):  
Kirstine N Bojsen-Møller ◽  
Siv H Jacobsen ◽  
Carsten Dirksen ◽  
Nils B Jørgensen ◽  
Søren Reitelseder ◽  
...  
Keyword(s):  
Gastric Bypass ◽  
Amino Acid ◽  
Protein Digestion ◽  
Acid Absorption ◽  
Amino Acid Absorption

Amino Acid and Protein Metabolism in Hospitalized Patients as Measured by l-[U-14C]Tyrosine and l-[1-14C]Leucine

1983 ◽  
Vol 65 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Sukumar P. Desai ◽  
Lyle L. Moldawer ◽  
Bruce R. Bistrian ◽  
George L. Blackburn
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Chloride ◽  
Hospitalized Patients ◽  
Whole Body ◽  
Protein Kinetics ◽  
Body Protein ◽  
Sodium Chloride Solutions ◽  
Isotonic Sodium Chloride ◽  
Plasma Tyrosine

1. Plasma amino acid kinetics were determined in hospitalized patients receiving one of three intravenous solutions: isotonic amino acids, isotonic sodium chloride, or total parenteral nutrition. 2. Whole body amino acid appearance, oxidation and incorporation into protein were estimated with two different isotopically labelled amino acids: l-[1-14C]leucine and l-[U-14C]tyrosine. 3. A positive correlation was obtained between whole body amino acid appearance, oxidation and incorporation into protein with the two isotopically labelled amino acids. 4. Derivation of whole body protein kinetics with l-[U-14C]tyrosine consistently gave higher values than those obtained from l-[1-14C]leucine, presumably due in part to the contribution of phenylalanine hydroxylation to plasma tyrosine appearance. However, the percentages of amino acid appearance oxidized and used for protein synthesis were similar. 5. It can be concluded that estimates of whole body protein kinetics are qualitatively similar when measured with l-[U-14C]tyrosine and l-[1-14C]leucine in hospitalized patients receiving either isotonic sodium chloride solutions or balanced amino acid intakes.

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