1
|
Matthews DE. Review of Lysine Metabolism with a Focus on Humans. J Nutr 2020; 150:2548S-2555S. [PMID: 33000162 DOI: 10.1093/jn/nxaa224] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/15/2020] [Accepted: 07/08/2020] [Indexed: 11/14/2022] Open
Abstract
Lysine cannot be synthesized by most higher organisms and, therefore, is an indispensable amino acid (IAA) that must be consumed in adequate amounts to maintain protein synthesis. Although lysine is an abundant amino acid in body proteins, lysine is limited in abundance in many important food sources (e.g. grains). Older observations assigned importance to lysine because animals fed a lysine-deficient diet did not lose weight as fast as animals placed upon other IAA-deficient diets, leading to the theory that there may be a special pool of lysine or metabolites that could be converted to lysine. The first step in the lysine catabolic pathway is the formation of saccharopine and then 2-aminoadipic acid, processes that are mitochondrial. The catabolism of 2-aminoadipic acid proceeds via decarboxylation to a series of CoA esters ending in acetyl-CoA. In mammals, the liver appears to be the primary site of lysine catabolism. In humans, the metabolic and oxidative response of lysine to diets either restricted in protein or in lysine is consistent with what has been measured for other IAAs with isotopically labeled tracers. Intestinal microflora are known to metabolize urea to ammonia and scavenge nitrogen (N) for the synthesis of amino acids. Studies feeding 15N-ammonium chloride or 15N-urea to animals and to humans, demonstrate the appearance of 15N-lysine in gut microbial lysine and in host lysine. However, the amount of 15N-lysine transferred to the host is difficult to assess directly using current methods. It is important to understand the role of the gut microflora in human lysine metabolism, especially in conditions where dietary lysine intake may be limited, but better methods need to be devised.
Collapse
Affiliation(s)
- Dwight E Matthews
- Departments of Chemistry and Medicine, University of Vermont, Burlington, VT, USA
| |
Collapse
|
2
|
Induced lung inflammation and dietary protein supply affect nitrogen retention and amino acid metabolism in growing pigs. Br J Nutr 2015; 113:414-25. [PMID: 25604632 DOI: 10.1017/s0007114514003821] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
It is hypothesised that during immune system activation, there is a competition for amino acids (AA) between body protein deposition and immune system functioning. The aim of the present study was to quantify the effect of immune system activation on N retention and AA metabolism in growing pigs, depending on dietary protein supply. A total of sixteen barrows received an adequate (Ad) or restricted (Res) amount of dietary protein, and were challenged at day 0 with intravenous complete Freund's adjuvant (CFA). At days - 5, 3 and 8, an irreversible loss rate (ILR) of eight AA was determined. CFA successfully activated the immune system, as indicated by a 2- to 4-fold increase in serum concentrations of acute-phase proteins (APP). Pre-challenge C-reactive protein concentrations were lower (P< 0·05) and pre- and post-challenge albumin tended to be lower in Res-pigs. These findings indicate that a restricted protein supply can limit the acute-phase response. CFA increased urinary N losses (P= 0·04) and tended to reduce N retention in Ad-pigs, but not in Res-pigs (P= 0·07). The ILR for Val was lower (P= 0·05) at day 8 than at day 3 in the post-challenge period. The ILR of most AA, except for Trp, were strongly affected by dietary protein supply and positively correlated with N retention. The correlations between the ILR and APP indices were absent or negative, indicating that changes in AA utilisation for APP synthesis were either not substantial or more likely outweighed by a decrease in muscle protein synthesis during immune system activation in growing pigs.
Collapse
|
3
|
Rietman A, Schwarz J, Tomé D, Kok FJ, Mensink M. High dietary protein intake, reducing or eliciting insulin resistance? Eur J Clin Nutr 2014; 68:973-9. [DOI: 10.1038/ejcn.2014.123] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/13/2014] [Accepted: 05/21/2014] [Indexed: 02/07/2023]
|
4
|
Xie G, Zhong W, Zheng X, Li Q, Qiu Y, Li H, Chen H, Zhou Z, Jia W. Chronic ethanol consumption alters mammalian gastrointestinal content metabolites. J Proteome Res 2013; 12:3297-306. [PMID: 23763674 PMCID: PMC5672944 DOI: 10.1021/pr400362z] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chronic ethanol consumption is associated with not only the alteration of metabolic profiles in biofluids but also the composition of the gut microbiome. Our understanding of the importance of the intestinal microbiota as well as the disturbances elicited by ethanol intervention is limited by the fact that previous analyses have primarily focused on biofluids and liver tissue metabolome; the metabolic profiles of the gastrointestinal (GI) contents are rarely investigated. In this study, we applied a metabonomics approach using a high performance liquid chromatography-time-of-flight mass spectrometry (HPLC-TOF MS) and gas chromatography-mass spectrometry (GC-MS) to characterize the metabolic alterations of the contents within the GI tract (stomach, duodenum, jejunum, ileum, cecum, colon, and rectum) in male Sprague-Dawley rats following 8 weeks of ethanol exposure. We obtained a snapshot of the distinct changes of the intestinal content metabolite composition in rats with ethanol exposure, which indicated a profound impact of ethanol consumption on the intestinal metabolome. Many metabolic pathways that are critical for host physiology were affected, including markedly altered bile acids, increased fatty acids and steroids, decreased carnitines and metabolites involved in lipid metabolism, a significant decrease of all amino acids and branched chain amino acids, and significantly decreased short chain fatty acids except for acetic acid, which rapidly elevated as a product of ethanol metabolism. These results provide an improved understanding of the systemic alteration of intestinal content metabolites in mammals and the interplay between the host and its complex resident microbiota and may aid in the design of new therapeutic strategies that target these interactions.
Collapse
Affiliation(s)
- Guoxiang Xie
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
- Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
- University of Hawaii Cancer Center, Honolulu, Hawaii 96813, USA
| | - Wei Zhong
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Xiaojiao Zheng
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Qiong Li
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Yunping Qiu
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Houkai Li
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Huiyuan Chen
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Zhanxiang Zhou
- Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, North Carolina 28081, USA
| | - Wei Jia
- Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
- University of Hawaii Cancer Center, Honolulu, Hawaii 96813, USA
| |
Collapse
|
5
|
Rodriguez NA, Jeschke MG, Williams FN, Kamolz LP, Herndon DN. Nutrition in burns: Galveston contributions. JPEN J Parenter Enteral Nutr 2011; 35:704-14. [PMID: 21975669 PMCID: PMC3778650 DOI: 10.1177/0148607111417446] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Aggressive nutrition support is recommended following severe burn injury. Initially, such injury results in a prolonged and persistent hypermetabolic response mediated by a 10- to 20-fold elevation in plasma catecholamines, cortisol, and inflammatory mediators. This response leads to twice-normal metabolic rates, whole-body catabolism, muscle wasting, and severe cachexia. Thus, it is relevant to review the literature on nutrition in burns to adjust/update treatment. Failure to meet the increased substrate requirements may result in impaired wound healing, multiorgan dysfunction, increased susceptibility to infection, and death. Therefore, aggressive nutrition support is essential to ensure adequate burn care, attenuate the hypermetabolic response, optimize wound healing, minimize devastating catabolism, and reduce morbidity and mortality. Here, the authors provide nutrition recommendations gained from prospective trials, retrospective analyses, and expert opinions based on the authors' practices in Galveston, Texas, and Vienna, Austria.
Collapse
Affiliation(s)
- Noe A. Rodriguez
- Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children–Galveston, Galveston, Texas
| | - Marc G. Jeschke
- Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children–Galveston, Galveston, Texas
- Department of Surgery, University of Toronto, Toronto, Canada
| | - Felicia N. Williams
- Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children–Galveston, Galveston, Texas
| | - Lars-Peter Kamolz
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
- Section of Plastic and Reconstructive Surgery, Department of Surgery, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - David N. Herndon
- Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children–Galveston, Galveston, Texas
| |
Collapse
|
6
|
Williams FN, Branski LK, Jeschke MG, Herndon DN. What, how, and how much should patients with burns be fed? Surg Clin North Am 2011; 91:609-29. [PMID: 21621699 DOI: 10.1016/j.suc.2011.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hypermetabolic response to severe burn injury is characterized by hyperdynamic circulation and profound metabolic, physiologic, catabolic, and immune system derangements. Failure to satisfy overwhelming energy and protein requirements after, and during, severe burn injury results in multiorgan dysfunction, increased susceptibility to infection, and death. Attenuation of the hypermetabolic response by various pharmacologic modalities is emerging as an essential component of the management of patients with severe burn injury. This review focuses on the more recent advances in therapeutic strategies to attenuate the hypermetabolic response and its postburn-associated insulin resistance.
Collapse
Affiliation(s)
- Felicia N Williams
- Department of Surgery, Shriners Hospital for Children and University of Texas Medical Branch, 815 Market Street, Galveston, TX 77550, USA
| | | | | | | |
Collapse
|
7
|
Chee S, Iji P, Choct M, Mikkelsen L, Kocher A. Functional interactions of manno-oligosaccharides with dietary threonine in chicken gastrointestinal tract. I. Growth performance and mucin dynamics. Br Poult Sci 2010; 51:658-66. [DOI: 10.1080/00071668.2010.517251] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
8
|
Williams FN, Herndon DN, Jeschke MG. The hypermetabolic response to burn injury and interventions to modify this response. Clin Plast Surg 2009; 36:583-96. [PMID: 19793553 PMCID: PMC3776603 DOI: 10.1016/j.cps.2009.05.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severe burn injury is followed by a profound hypermetabolic response that persists up to 24 months after injury. It is mediated by up to 50-fold elevations in plasma catecholamines, cortisol, and inflammatory cells that lead to whole-body catabolism, elevated resting energy expenditures, and multiorgan dysfunction. All of these metabolic and physiologic derangements prevent full rehabilitation and acclimatization of burn survivors back into society. Modulation of the response by early excision and grafting of burn wounds, thermoregulation, early and continuous enteral feeding with high-protein high-carbohydrate feedings, and pharmacologic treatments have markedly decreased morbidity.
Collapse
Affiliation(s)
- Felicia N Williams
- NIH Research Fellow, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
| | - David N Herndon
- Professor, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
- Shriners Hospitals for Children, Galveston, Texas
| | - Marc G Jeschke
- Associate Professor, Department of Surgery, The University of Texas Medical Branch, Galveston, Texas
- Shriners Hospitals for Children, Galveston, Texas
| |
Collapse
|
9
|
Williams FN, Jeschke MG, Chinkes DL, Suman OE, Branski LK, Herndon DN. Modulation of the hypermetabolic response to trauma: temperature, nutrition, and drugs. J Am Coll Surg 2009; 208:489-502. [PMID: 19476781 PMCID: PMC3775552 DOI: 10.1016/j.jamcollsurg.2009.01.022] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Accepted: 01/14/2009] [Indexed: 12/21/2022]
Affiliation(s)
- Felicia N Williams
- Department of Surgery, The University of Texas Medical Branch, Galveston, TX, USA
| | | | | | | | | | | |
Collapse
|
10
|
Juillet B, Fouillet H, Bos C, Mariotti F, Gausserès N, Benamouzig R, Tomé D, Gaudichon C. Increasing habitual protein intake results in reduced postprandial efficiency of peripheral, anabolic wheat protein nitrogen use in humans. Am J Clin Nutr 2008; 87:666-78. [PMID: 18326606 DOI: 10.1093/ajcn/87.3.666] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The postprandial retention of dietary protein decreases when the prevailing protein intake increases. OBJECTIVE We investigated the influence of the prevailing protein intake on the regional utilization and anabolic use of wheat protein during the postprandial non-steady state in humans. DESIGN Healthy adults (n = 8) were adapted for 7 d, first to a normal-protein diet (NP: 1 g x kg(-1) x d(-1)) and then to a high-protein diet (HP: 2 g x kg(-1) x d(-1)). After each adaptation period, the subjects received the same single, solid mixed meal containing [15N]-labeled wheat protein. The postprandial kinetics of dietary nitrogen were then measured for 8 h in blood and urine. These data were further analyzed by using a multicompartmental model to predict the postprandial kinetics of dietary nitrogen in unsampled pools. RESULTS The postprandial whole-body retention of wheat protein nitrogen, measured 8 h after meal ingestion, decreased by 10% when the subjects switched from the NP diet to the HP diet. According to modeling results, this resulted from an increased splanchnic utilization of dietary nitrogen for urea production, whereas its incorporation into splanchnic proteins was unchanged, leading to a 20-30% decrease in peripheral availability and anabolic use in HP-adapted compared with NP-adapted subjects having ingested the same protein load. CONCLUSIONS By combining clinical experimentation with compartmental modeling, we provide a global overview of postprandial dietary protein metabolism. Increasing prior protein intake was shown to reduce the postprandial retention of wheat protein nitrogen, mainly by diminishing the efficiency of its peripheral availability and anabolic use.
Collapse
Affiliation(s)
- Barbara Juillet
- INRA, AgroParisTech, UMR914 Nutrition Physiology and Ingestive Behavior, CRNH-IdF, Paris, France
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Karlsson A, Eliason EJ, Mydland LT, Farrell AP, Kiessling A. Postprandial changes in plasma free amino acid levels obtained simultaneously from the hepatic portal vein and the dorsal aorta in rainbow trout (Oncorhynchus mykiss). ACTA ACUST UNITED AC 2007; 209:4885-94. [PMID: 17142677 DOI: 10.1242/jeb.02597] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
For the first time, changes in plasma concentrations of free amino acid (AA) and their metabolites were followed simultaneously in pre- and post-hepatic blood following a single meal in non-anaesthetized and free-swimming fish. Rainbow trout (Oncorhynchus mykiss), kept in 10 degrees C water and fitted with cannulae in the hepatic portal vein (HPV) and the dorsal aorta (DA), were force-fed 1% of their body mass and blood samples were taken from both cannulae at 0, 3, 6, 12, 24 and 48 h postprandially to follow the free AA profile. Almost all free AAs increased rapidly within the first 3 h and only a few free AAs did not change significantly over time. By 6 h, the total free AA concentration had peaked in blood taken from both the DA (7107+/-369 nmol ml(-1)) and HPV (9999+/-572 nmol ml(-1)). However, individual free AAs showed three main profiles beyond this time: for type I, a peak concentration occurred only at 6 h; for type II, there was a more gradual rise in concentration to a peak at 24 h; and for type III there were two peaks, at 6 h and 24 h. All free AAs returned to or were lower than baseline levels within 48 h, with the exception of threonine and proline. The total free AA concentrations were consistently higher (P<0.05) in the HPV than in the DA at 3 h, 6 h, 12 h and 24 h. Our data provide clear evidence that, during the first pass through the liver, hepatic modification altered individual free AA concentrations as indicated by variable ratios among the simultaneous blood samples. Furthermore, the elevation of ammonium and urea in the HPV indicates intestinal catabolism of ingested free AA before release into the HPV. In conclusion, the dual HPV and DA cannulation shows promise as a useful technique for qualitative and quantitative investigations of absorption and turnover of nutrients, especially if the measurements can be combined with reliable estimates of blood flow and labelled substances.
Collapse
Affiliation(s)
- Anders Karlsson
- Aquaculture Protein Centre, Centre of Excellence, Norwegian University of Life Sciences, PO Box 5003, N-1432 Aas, Norway
| | | | | | | | | |
Collapse
|
12
|
Abstract
Since the in vitro study of Buse and Reid in 1975 showing a stimulatory effect of leucine upon rat muscle protein synthesis and reduction in proteolysis, a similar effect has been sought in humans. In 1978, Sherwin demonstrated in humans an improvement in N balance with infusion of leucine in obese subjects fasting to lose weight. A variety of subsequent studies have been performed in humans where leucine alone or the BCAAs have been administered in varying amounts and durations, and the effect upon protein metabolism has been measured. Measurements of changes in muscle amino acid metabolism were made by arteriovenous difference measurements and by biopsies. An anabolic effect of leucine and the branched-chain amino acids (BCAAs) on reduction of muscle protein breakdown was found in these studies, with no measured effect upon muscle protein synthesis. Later studies using stable isotope tracers to define both whole-body protein turnover and leg or arm protein metabolism have similarly concluded that leucine administration specifically induces a reduction in protein breakdown without increasing protein synthesis. This anabolic effect, produced through a reduction of protein breakdown in vivo in humans by leucine is contrary to in vitro studies of rat muscle where stimulation of protein synthesis, has been demonstrated by leucine. Likewise an increase in protein synthesis has also been demonstrated by insulin in rat muscle that is not seen in humans. Of the various studies administering BCAAs or leucine to humans for varying periods of time and amount, the results have been consistent. In addition, no untoward effects have been reported in any of these studies from infusion of the BCAAs at upward 3 times basal flux or 6 times normal dietary intake during the fed portion of the day.
Collapse
Affiliation(s)
- Dwight E Matthews
- Department of Medicine, University of Vermont, Burlington, 05405, USA.
| |
Collapse
|
13
|
Bos C, Stoll B, Fouillet H, Gaudichon C, Guan X, Grusak MA, Reeds PJ, Tomé D, Burrin DG. Intestinal lysine metabolism is driven by the enteral availability of dietary lysine in piglets fed a bolus meal. Am J Physiol Endocrinol Metab 2003; 285:E1246-57. [PMID: 12851176 DOI: 10.1152/ajpendo.00150.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous steady-state continuous-feeding studies have shown that the gut mucosa removes substantial amounts of both dietary and systemic amino acids. However, enteral nutrition is often given under non-steady-state conditions as a bolus meal, and this has been shown to influence systemic metabolism. Therefore, our aim was to quantify the relative metabolism of dietary and systemic lysine by the portal-drained viscera (PDV) under non-steady-state conditions after a single bolus meal. Five 28-day-old piglets implanted with arterial, venous, and portal catheters and with an ultrasonic portal flow probe were given an oral bolus feeding of a milk formula containing a trace quantity of intrinsically 15N-labeled soy protein and a continuous intravenous infusion of [U-13C]lysine for 8 h. Total lysine use by the PDV was maximal 1 h after the meal (891 micromol x kg(-1) x h(-1)) and was predominantly of dietary origin (89%), paralleling the enteral delivery of dietary lysine. Intestinal lysine use returned to a low level after 4 h postprandially and was derived exclusively from the arterial supply until 8 h. Cumulative systemic appearance of dietary lysine reached 44 and 80% of the ingested amount 4 and 8 h after the meal, respectively, whereas the PDV first-pass use of dietary lysine was 55 and 32% of the intake for these two periods, respectively. We conclude that the first-pass utilization rate of dietary lysine by the PDV is directly increased by the enteral lysine availability and that it is higher with a bolus than with continuous oral feeding.
Collapse
Affiliation(s)
- Cécile Bos
- Department of Nutrition Physiology and Feeding Control, National Institute for Agricultural Research, Unité Mixte de Recherche, Paris, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Fouillet H, Gaudichon C, Mariotti F, Bos C, Huneau JF, Tomé D. Energy nutrients modulate the splanchnic sequestration of dietary nitrogen in humans: a compartmental analysis. Am J Physiol Endocrinol Metab 2001; 281:E248-60. [PMID: 11440900 DOI: 10.1152/ajpendo.2001.281.2.e248] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We used a previously developed compartmental model to assess the postprandial distribution and metabolism of dietary nitrogen (N) in the splanchnic and peripheral areas after the ingestion of a single meal containing milk protein either alone (MP) or with additional sucrose (SMP) or fat (FMP). The addition of fat was predicted to enhance splanchnic dietary N anabolism only transiently, without significantly affecting the global kinetics of splanchnic retention and peripheral uptake. In contrast, the addition of sucrose, which induced hyperinsulinemia, was predicted to enhance dietary N retention and anabolism in the splanchnic bed, thus leading to reduced peripheral dietary amino acid availability and anabolism. The incorporation of dietary N into splanchnic proteins was thus predicted to reach 18, 24, and 35% of ingested N 8 h after MP, FMP, and SMP, respectively. Such a model provides insight into the dynamics of the system in the nonsteady postprandial state and constitutes a useful, explanatory tool to determine the region-specific utilization of dietary N under different nutritional conditions.
Collapse
Affiliation(s)
- H Fouillet
- Unité Mixte de Recherche de Physiologie de la Nutrition et du Comportement Alimentaire, Institut National de la Recherche Agronomique-Institut National Agronomique Paris-Grignon, F-75231 Paris, France.
| | | | | | | | | | | |
Collapse
|
15
|
Boza JJ, Dangin M, Moënnoz D, Montigon F, Vuichoud J, Jarret A, Pouteau E, Gremaud G, Oguey-Araymon S, Courtois D, Woupeyi A, Finot PA, Ballèvre O. Free and protein-bound glutamine have identical splanchnic extraction in healthy human volunteers. Am J Physiol Gastrointest Liver Physiol 2001; 281:G267-74. [PMID: 11408280 DOI: 10.1152/ajpgi.2001.281.1.g267] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The objectives of the present study were to determine the splanchnic extraction of glutamine after ingestion of glutamine-rich protein ((15)N-labeled oat proteins) and to compare it with that of free glutamine and to determine de novo glutamine synthesis before and after glutamine consumption. Eight healthy adults were infused intravenously in the postabsorptive state with L-[1-(13)C]glutamine (3 micromol x kg(-1) x h(-1)) and L-[1-(13)C]lysine (1.5 micromol x kg(-1) x h(-1)) for 8 h. Four hours after the beginning of the infusion, subjects consumed (every 20 min) a liquid formula providing either 2.5 g of protein from (15)N-labeled oat proteins or a mixture of free amino acids that mimicked the oat-amino acid profile and contained L-[2,5-(15)N(2)]glutamine and L-[2-(15)N]lysine. Splanchnic extraction of glutamine reached 62.5 +/- 5.0% and 66.7 +/- 3.9% after administration of (15)N-labeled oat proteins and the mixture of free amino acids, respectively. Lysine splanchnic extraction was also not different (40.9 +/- 11.9% and 34.9 +/- 10.6% for (15)N-labeled oat proteins and free amino acids, respectively). The main conclusion of the present study is that glutamine is equally bioavailable when given enterally as a free amino acid and when protein bound. Therefore, and taking into consideration the drawbacks of free glutamine supplementation of ready-to-use formulas for enteral nutrition, protein sources naturally rich in this amino acid are the best option for providing stable glutamine.
Collapse
Affiliation(s)
- J J Boza
- Nestlé Research Center, Vers-Chez-Les-Blanc, 1000 Lausanne 26, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
van Goudoever JB, Stoll B, Henry JF, Burrin DG, Reeds PJ. Adaptive regulation of intestinal lysine metabolism. Proc Natl Acad Sci U S A 2000; 97:11620-5. [PMID: 11016965 PMCID: PMC17250 DOI: 10.1073/pnas.200371497] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The metabolism of dietary essential amino acids by the gut has a direct effect on their systemic availability and potentially limits growth. We demonstrate that, in neonatal pigs bearing portal and arterial catheters and fed a diet containing 23% protein [high protein (HP) diet], more than half the intake of essential amino acids is metabolized by the portal-drained viscera (PDV). Intraduodenal or i.v. infusions of [U-(13)C]-lysine were used to measure the appearance across and the use of the tracer by the PDV. In HP-fed pigs, lysine use by the PDV was derived almost entirely from the arterial input. In these animals, the small amount of dietary lysine used in first pass was oxidized almost entirely. Even so, intestinal lysine oxidation (24 micromol/kg per h) accounted for one-third of whole-body lysine oxidation (77 micromol/kg per h). Total lysine use by the PDV was not affected by low protein (LP) feeding (HP, 213 micromol/kg per h; LP,186 micromol/kg per h). In LP-fed pigs, the use of lysine by the PDV accounted for more than 75% of its intake. In contrast to HP feeding, both dietary and arterial lysines were used by the PDV of LP-fed pigs in nearly equal amounts. Intestinal lysine oxidation was suppressed completely. We conclude that the PDV are key organs with respect to amino acid metabolism and that the intestines use a disproportionately large amount of the dietary supply of amino acids during protein restriction.
Collapse
Affiliation(s)
- J B van Goudoever
- United States Department of Agriculture/Agricultural Research Service (DOA) Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA
| | | | | | | | | |
Collapse
|
17
|
Metges CC, El-Khoury AE, Selvaraj AB, Tsay RH, Atkinson A, Regan MM, Bequette BJ, Young VR. Kinetics of L-[1-(13)C]leucine when ingested with free amino acids, unlabeled or intrinsically labeled casein. Am J Physiol Endocrinol Metab 2000; 278:E1000-9. [PMID: 10827001 DOI: 10.1152/ajpendo.2000.278.6.e1000] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In two groups of five adults, each adapted to two different dietary regimens for 6 days, the metabolic fate of dietary [1-(13)C]leucine was examined when ingested either together with a mixture of free amino acids simulating casein (extrinsically labeled; condition A), along with the intact casein (extrinsically labeled; condition B), or bound to casein (intrinsically labeled; condition C). Fed state leucine oxidation (Ox), nonoxidative leucine disposal (NOLD), protein breakdown, and splanchnic uptake have been compared using an 8-h oral [1-(13)C]leucine and intravenous [(2)H(3)]leucine tracer protocol while giving eight equal hourly mixed meals. Lower leucine Ox, increased NOLD, and net protein synthesis were found with condition C compared with condition A (19.3 vs. 24.9; 77 vs. 55.8; 18.9 vs. 12.3 micromol. kg(-1). 30 min(-1); P < 0.05). Ox and NOLD did not differ between conditions B and C. Splanchnic leucine uptake calculated from [1-(13)C]- and [(2)H(3)]leucine plasma enrichments was between 24 and 35%. These findings indicate that the form in which leucine is consumed affects its immediate metabolic fate and retention by the body; the implications of these findings for the tracer balance technique and estimation of amino acid requirements are discussed.
Collapse
Affiliation(s)
- C C Metges
- Clinical Research Center and Laboratory of Human Nutrition, School of Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrère B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A 1997; 94:14930-5. [PMID: 9405716 PMCID: PMC25140 DOI: 10.1073/pnas.94.26.14930] [Citation(s) in RCA: 898] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The speed of absorption of dietary amino acids by the gut varies according to the type of ingested dietary protein. This could affect postprandial protein synthesis, breakdown, and deposition. To test this hypothesis, two intrinsically 13C-leucine-labeled milk proteins, casein (CAS) and whey protein (WP), of different physicochemical properties were ingested as one single meal by healthy adults. Postprandial whole body leucine kinetics were assessed by using a dual tracer methodology. WP induced a dramatic but short increase of plasma amino acids. CAS induced a prolonged plateau of moderate hyperaminoacidemia, probably because of a slow gastric emptying. Whole body protein breakdown was inhibited by 34% after CAS ingestion but not after WP ingestion. Postprandial protein synthesis was stimulated by 68% with the WP meal and to a lesser extent (+31%) with the CAS meal. Postprandial whole body leucine oxidation over 7 h was lower with CAS (272 +/- 91 micromol.kg-1) than with WP (373 +/- 56 micromol.kg-1). Leucine intake was identical in both meals (380 micromol.kg-1). Therefore, net leucine balance over the 7 h after the meal was more positive with CAS than with WP (P < 0.05, WP vs. CAS). In conclusion, the speed of protein digestion and amino acid absorption from the gut has a major effect on whole body protein anabolism after one single meal. By analogy with carbohydrate metabolism, slow and fast proteins modulate the postprandial metabolic response, a concept to be applied to wasting situations.
Collapse
Affiliation(s)
- Y Boirie
- Laboratoire de Nutrition Humaine, Université Clermont Auvergne, Centre de Recherche en Nutrition Humaine, BP 321, 63009 Clermont-Ferrand Cedex 1, France
| | | | | | | | | | | |
Collapse
|