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Use of deuterium oxide ( 2H 2O) to assess muscle protein synthesis in juvenile red drum (Sciaenops ocellatus) fed complete, and valine-deficient diets. Amino Acids 2021; 53:1431-1439. [PMID: 34232398 DOI: 10.1007/s00726-021-03036-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
The use of 2H2O in tank water to assess protein synthesis rates in fish is a relatively novel methodology that could allow for a better understanding of the effects of particular nutritional and environmental variables on rates of protein accretion. As such, this study involved an assessment and comparison of protein synthesis rates in the muscle of juvenile red drum fed a control diet (nutritionally complete) versus a valine (Val)-deficient diet. Six groups of 12 juvenile red drum, initially weighing ~ 4.5 g/fish, were stocked in six separate 38-L aquaria operating as a recirculating system. Fish were acclimatized to experimental conditions for 2 weeks while being fed the control diet. Just prior to initiating the protein synthesis assay, one aquarium of fish was fed the control diet while a second aquarium of fish was fed the Val-deficient diet. Immediately after consuming the experimental diets, each group of fish was moved to an independent aquarium containing 2H2O, and the fractional synthetic rate (FSR) of protein synthesis was obtained at 12, 24, 36 and 48 h after feeding by collecting two fish per treatment at each time point. This protein synthesis assay procedure was performed in three separate sessions, and considered as replicates over time (n = 3) for fish fed the control or Val-deficient diets immediately before initiating the session. Results indicated that a one-time feeding of a diet deficient in Val significantly reduced protein synthesis rates in the muscle of red drum. In addition, a significant effect of time after feeding was found, where observed FSR values peaked at 12 h after feeding and decreased as time progressed. In conclusion, deuterium methodologies were applicable to red drum, and this approach had the sensitivity to assess differences in protein synthesis rates when dietary perturbations were introduced.
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Abstract
Barramundi (Lates calcarifer) are a highly valued aquaculture species, and, as obligate carnivores, they have a demonstrated preference for dietary protein over lipid or starch to fuel energetic growth demands. In order to investigate how carnivorous fish regulate nutritional cues, we examined the metabolic effects of feeding two isoenergetic diets that contained different proportions of digestible protein or starch energy. Fish fed a high proportion of dietary starch energy had a higher proportion of liver SFA, but showed no change in plasma glucose levels, and few changes in the expression of genes regulating key hepatic metabolic pathways. Decreased activation of the mammalian target of rapamycin growth signalling cascade was consistent with decreased growth performance values. The fractional synthetic rate (lipogenesis), measured by TAG 2H-enrichment using 2H NMR, was significantly higher in barramundi fed with the starch diet compared with the protein diet (0·6 (se 0·1) v. 0·4 (se 0·1) % per d, respectively). Hepatic TAG-bound glycerol synthetic rates were much higher than other closely related fish such as sea bass, but were not significantly different (starch, 2·8 (se 0·3) v. protein, 3·4 (se 0·3) % per d), highlighting the role of glycerol as a metabolic intermediary and high TAG-FA cycling in barramundi. Overall, dietary starch significantly increased hepatic TAG through increased lipogenesis. Compared with other fish, barramundi possess a unique mechanism to metabolise dietary carbohydrates and this knowledge may define ways to improve performance of advanced formulated feeds.
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Treberg JR, Killen SS, MacCormack TJ, Lamarre SG, Enders EC. Estimates of metabolic rate and major constituents of metabolic demand in fishes under field conditions: Methods, proxies, and new perspectives. Comp Biochem Physiol A Mol Integr Physiol 2016; 202:10-22. [DOI: 10.1016/j.cbpa.2016.04.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 01/19/2023]
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4
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Kreitals NM, Hobson KA, Hoemsen BM, Crane AL, Wishingrad V, Sloychuk J, Pollock MS, Chivers DP, Phillips ID. Turnover of hydrogen isotopes in lake sturgeon blood: implications for tracking movements of wild populations. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2016; 52:592-602. [PMID: 26981716 DOI: 10.1080/10256016.2016.1147440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 11/28/2015] [Indexed: 06/05/2023]
Abstract
Naturally occurring deuterium ((2)H) in biota can be used to trace movement, migration and geographic origin of a range of organisms. However, to evaluate movements of animals using δ(2)H measurements of tissues, it is necessary to establish the turnover time of (2)H in the tissues and the extent of isotopic discrimination from different environmental (2)H sources to those tissues. We investigated the turnover of (2)H in lake sturgeon (Acipenser fulvescens) blood by manipulating both environmental water δ(2)H and diet δ(2)H over a four-month period. The half-life of deuterium in lake sturgeon blood was 37.9 days after an increase in the environmental water δ(2)H of +714 ‰. However, no clear turnover in blood (2)H occurred over the same period in a separate trial following a change of -63.8 ‰ or +94.2 ‰ in diet. These findings suggest that environmental water (2)H exchanges much faster with blood than diets and that blood δ(2)H values can be used to trace movements of sturgeon and other fish moving among isotopically distinct waters.
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Affiliation(s)
- Natasha M Kreitals
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
- b TRoutreach Saskatchewan, Saskatchewan Wildlife Federation , Saskatchewan , Canada
| | | | - Brittney M Hoemsen
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
- b TRoutreach Saskatchewan, Saskatchewan Wildlife Federation , Saskatchewan , Canada
| | - Adam L Crane
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
| | - Van Wishingrad
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
| | - Janelle Sloychuk
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
| | | | - Douglas P Chivers
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
| | - Iain D Phillips
- a Department of Biology , University of Saskatchewan , Saskatchewan , Canada
- b TRoutreach Saskatchewan, Saskatchewan Wildlife Federation , Saskatchewan , Canada
- d Water Security Agency , Saskatchewan , Canada
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5
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Determination of muscle protein synthesis rates in fish using 2H2O and 2H NMR analysis of alanine. Anal Biochem 2016; 509:111-114. [DOI: 10.1016/j.ab.2016.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/29/2016] [Accepted: 07/08/2016] [Indexed: 11/20/2022]
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6
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Viegas I, Jarak I, Rito J, Carvalho RA, Metón I, Pardal MA, Baanante IV, Jones JG. Effects of dietary carbohydrate on hepatic de novo lipogenesis in European seabass (Dicentrarchus labrax L.). J Lipid Res 2016; 57:1264-72. [PMID: 27247346 DOI: 10.1194/jlr.m067850] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 02/06/2023] Open
Abstract
Farmed seabass have higher adiposity than their wild counterparts and this is often attributed to carbohydrate (CHO) feeding. Whether this reflects a reduction in fat oxidation, increased de novo lipogenesis (DNL), or both, is not known. To study the effects of high CHO diets on hepatic TG biosynthesis, hepatic TG deuterium ((2)H) enrichment was determined following 6 days in (2)H-enriched tank water for fish fed with a no-CHO control diet (CTRL), and diets with digestible starch (DS) and raw starch (RS). Hepatic fractional synthetic rates (FSRs, percent per day(-1)) were calculated for hepatic TG-glyceryl and FA moieties through (2)H NMR analysis. Glyceryl FSRs exceeded FA FSRs in all cases, indicating active cycling. DS fish did not show increased lipogenic potential compared to CTRL. RS fish had lower glyceryl FSRs compared with the other diets and negligible levels of FA FSRs despite similar hepatic TG levels to CTRL. DS-fed fish showed higher activity for enzymes that can provide NADPH for lipogenesis, relative to CTRL in the case of glucose-6-phosphate dehydrogenase (G6PDH) and relative to RS for both G6PDH and 6-phosphogluconate dehydrogenase. This approach indicated that elevated hepatic adiposity from DS feeding was not attributable to increased DNL.
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Affiliation(s)
- Ivan Viegas
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal Center for Functional Ecology, Department Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Ivana Jarak
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - João Rito
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal Center for Functional Ecology, Department Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Rui A Carvalho
- Center for Functional Ecology, Department Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Isidoro Metón
- Secció de Bioquímica i Biologia Molecular, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Miguel A Pardal
- Center for Functional Ecology, Department Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Isabel V Baanante
- Secció de Bioquímica i Biologia Molecular, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - John G Jones
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
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7
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McCarthy ID, Owen SF, Watt PW, Houlihan DF. Individuals Maintain Similar Rates of Protein Synthesis over Time on the Same Plane of Nutrition under Controlled Environmental Conditions. PLoS One 2016; 11:e0152239. [PMID: 27018996 PMCID: PMC4809500 DOI: 10.1371/journal.pone.0152239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 03/10/2016] [Indexed: 11/27/2022] Open
Abstract
Consistent individual differences in animal performance drive individual fitness under variable environmental conditions and provide the framework through which natural selection can operate. Underlying this concept is the assumption that individuals will display consistent levels of performance in fitness-related traits and interest has focused on individual variation and broad sense repeatability in a range of behavioural and physiological traits. Despite playing a central role in maintenance and growth, and with considerable inter-individual variation documented, broad sense repeatability in rates of protein synthesis has not been assessed. In this study we show for the first time that juvenile flounder Platichthys flesus reared under controlled environmental conditions on the same plane of nutrition for 46 days maintain consistent whole-animal absolute rates of protein synthesis (As). By feeding meals containing 15N-labelled protein and using a stochastic end-point model, two non-terminal measures of protein synthesis were made 32 days apart (d14 and d46). As values (mass-corrected to a standard mass of 12 g) showed 2- to 3-fold variation between individuals on d14 and d46 but individuals showed similar As values on both days with a broad sense repeatability estimate of 0.684 indicating significant consistency in physiological performance under controlled experimental conditions. The use of non-terminal methodologies in studies of animal ecophysiology to make repeat measures of physiological performance enables known individuals to be tracked across changing conditions. Adopting this approach, repeat measures of protein synthesis under controlled conditions will allow individual ontogenetic changes in protein metabolism to be assessed to better understand the ageing process and to determine individual physiological adaptive capacity, and associated energetic costs of adaptation, to global environmental change.
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Affiliation(s)
- Ian D. McCarthy
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, United Kingdom
- Instituto Oceanográfico, Universidade de São Paulo, São Paulo, SP, Brazil
- * E-mail:
| | - Stewart F. Owen
- AstraZeneca, Alderley Park, Macclesfield, Cheshire, United Kingdom
| | - Peter W. Watt
- Sport and Exercise Science and Medicine, University of Brighton, Eastbourne, United Kingdom
| | - Dominic F. Houlihan
- School of Biological Sciences, Aberdeen University, Aberdeen, United Kingdom
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8
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Previs SF, Herath K, Castro-Perez J, Mahsut A, Zhou H, McLaren DG, Shah V, Rohm RJ, Stout SJ, Zhong W, Wang SP, Johns DG, Hubbard BK, Cleary MA, Roddy TP. Effect of Error Propagation in Stable Isotope Tracer Studies: An Approach for Estimating Impact on Apparent Biochemical Flux. Methods Enzymol 2015; 561:331-58. [PMID: 26358910 DOI: 10.1016/bs.mie.2015.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Stable isotope tracers are widely used to quantify metabolic rates, and yet a limited number of studies have considered the impact of analytical error on estimates of flux. For example, when estimating the contribution of de novo lipogenesis, one typically measures a minimum of four isotope ratios, i.e., the precursor and product labeling pre- and posttracer administration. This seemingly simple problem has 1 correct solution and 80 erroneous outcomes. In this report, we outline a methodology for evaluating the effect of error propagation on apparent physiological endpoints. We demonstrate examples of how to evaluate the influence of analytical error in case studies concerning lipid and protein synthesis; we have focused on (2)H2O as a tracer and contrast different mass spectrometry platforms including GC-quadrupole-MS, GC-pyrolysis-IRMS, LC-quadrupole-MS, and high-resolution FT-ICR-MS. The method outlined herein can be used to determine how to minimize variations in the apparent biology by altering the dose and/or the type of tracer. Likewise, one can facilitate biological studies by estimating the reduction in the noise of an outcome that is expected for a given increase in the number of replicate injections.
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Affiliation(s)
| | | | | | - Ablatt Mahsut
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Haihong Zhou
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | | | - Vinit Shah
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Rory J Rohm
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Steven J Stout
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | - Wendy Zhong
- Merck Research Laboratories, Kenilworth, New Jersey, USA
| | | | | | | | | | - Thomas P Roddy
- Merck Research Laboratories, Kenilworth, New Jersey, USA
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Fluckey JD, Lambert BS, Greene NP, Shimkus KL, Cardin JM, Riechman SE, Crouse SF. Reply to letter to the editor: to D2O or not to D2O? What are the reasons we D2O it at all? Am J Physiol Endocrinol Metab 2015; 308:E928-31. [PMID: 25980015 DOI: 10.1152/ajpendo.00136.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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10
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Lamarre SG, Saulnier RJ, Blier PU, Driedzic WR. A rapid and convenient method for measuring the fractional rate of protein synthesis in ectothermic animal tissues using a stable isotope tracer. Comp Biochem Physiol B Biochem Mol Biol 2014; 182:1-5. [PMID: 25481869 DOI: 10.1016/j.cbpb.2014.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/12/2014] [Accepted: 11/21/2014] [Indexed: 12/01/2022]
Abstract
A method was devised to measure the fractional rate of protein synthesis in fish using a stable isotope labelled tracer (ring-D5-phenylalanine) instead of radioactive phenylalanine. This modified flooding dose technique utilizes gas chromatography with mass spectrometry detection (GC-MS). The technique was validated by measuring the fractional rate of protein synthesis in the liver and white muscle of Arctic charr (Salvelinus alpinus) and then tested by comparing the fractional rate of protein synthesis of fed and starved Arctic charr. The modified technique met the assumptions of the flooding dose technique and was successfully used to detect alterations in the rate of protein synthesis in fed and starved fish. This modified technique allows for studies on protein metabolism to be carried out in situations where the use of radioactivity is difficult, if not impossible.
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Affiliation(s)
- S G Lamarre
- Département de Biologie, Université de Moncton, Moncton, NB, Canada, E1A 3E9; Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, Newfoundland, Canada, A1C 5S7.
| | - R J Saulnier
- Département de Biologie, Université de Moncton, Moncton, NB, Canada, E1A 3E9
| | - P U Blier
- Département de Biologie, Université du Québec à Rimouski, Rimouski, Québec, Canada, G5L 3A1
| | - W R Driedzic
- Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, Newfoundland, Canada, A1C 5S7
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11
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Viegas I, Caballero-Solares A, Rito J, Giralt M, Pardal MA, Metón I, Jones JG, Baanante IV. Expressional regulation of key hepatic enzymes of intermediary metabolism in European seabass (Dicentrarchus labrax) during food deprivation and refeeding. Comp Biochem Physiol A Mol Integr Physiol 2014; 174:38-44. [PMID: 24746983 DOI: 10.1016/j.cbpa.2014.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/04/2014] [Accepted: 04/07/2014] [Indexed: 11/18/2022]
Abstract
We hypothesized that the analysis of mRNA level and activity of key enzymes in amino acid and carbohydrate metabolism in a feeding/fasting/refeeding setting could improve our understanding of how a carnivorous fish, like the European seabass (Dicentrarchus labrax), responds to changes in dietary intake at the hepatic level. To this end cDNA fragments encoding genes for cytosolic and mitochondrial alanine aminotransferase (cALT; mALT), pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) were cloned and sequenced. Measurement of mRNA levels through quantitative real-time PCR performed in livers of fasted seabass revealed a significant increase in cALT (8.5-fold induction) while promoting a drastic 45-fold down-regulation of PK in relation to the levels found in fed seabass. These observations were corroborated by enzyme activity meaning that during food deprivation an increase in the capacity of pyruvate generation happened via alanine to offset the reduction in pyruvate derived via glycolysis. After a 3-day refeeding period cALT returned to control levels while PK was not able to rebound. No alterations were detected in the expression levels of G6PDH while 6PGDH was revealed to be more sensitive specially to fasting, as confirmed by a significant 5.7-fold decrease in mRNA levels with no recovery after refeeding. Our results indicate that in early stages of refeeding, the liver prioritized the restoration of systemic normoglycemia and replenishment of hepatic glycogen. In a later stage, once regular feeding is re-established, dietary fuel may then be channeled to glycolysis and de novo lipogenesis.
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Affiliation(s)
- Ivan Viegas
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, 3004-517 Coimbra, Portugal; CFE - Center for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martins de Freitas 3000-456 Coimbra, Portugal.
| | - Albert Caballero-Solares
- Departament d'Ecologia, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain
| | - João Rito
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, 3004-517 Coimbra, Portugal; CFE - Center for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martins de Freitas 3000-456 Coimbra, Portugal
| | - Marina Giralt
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - Miguel A Pardal
- CFE - Center for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martins de Freitas 3000-456 Coimbra, Portugal
| | - Isidoro Metón
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - John G Jones
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, 3004-517 Coimbra, Portugal
| | - Isabel V Baanante
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
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Nilsson MI, Dobson JP, Greene NP, Wiggs MP, Shimkus KL, Wudeck EV, Davis AR, Laureano ML, Fluckey JD. Abnormal protein turnover and anabolic resistance to exercise in sarcopenic obesity. FASEB J 2013; 27:3905-16. [PMID: 23804240 DOI: 10.1096/fj.12-224006] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Obesity may impair protein synthesis rates and cause anabolic resistance to growth factors, hormones, and exercise, ultimately affecting skeletal muscle mass and function. To better understand muscle wasting and anabolic resistance with obesity, we assessed protein 24-h fractional synthesis rates (24-h FSRs) in selected hind-limb muscles of sedentary and resistance-exercised lean and obese Zucker rats. Despite atrophied hind-limb muscles (-28% vs. lean rats), 24-h FSRs of mixed proteins were significantly higher in quadriceps (+18%) and red or white gastrocnemius (+22 or +38%, respectively) of obese animals when compared to lean littermates. Basal synthesis rates of myofibrillar (+8%) and mitochondrial proteins (-1%) in quadriceps were not different between phenotypes, while manufacture of cytosolic proteins (+12%) was moderately elevated in obese cohorts. Western blot analyses revealed a robust activation of p70S6k (+178%) and a lower expression of the endogenous mTOR inhibitor DEPTOR (-28%) in obese rats, collectively suggesting that there is an obesity-induced increase in net protein turnover favoring degradation. Lastly, the protein synthetic response to exercise of mixed (-7%), myofibrillar (+6%), and cytosolic (+7%) quadriceps subfractions was blunted compared to the lean phenotype (+34, +40, and +17%, respectively), indicating a muscle- and subfraction-specific desensitization to the anabolic stimulus of exercise in obese animals.
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Affiliation(s)
- Mats I Nilsson
- 1Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843-4243.
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Soto DX, Wassenaar LI, Hobson KA. Stable hydrogen and oxygen isotopes in aquatic food webs are tracers of diet and provenance. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12054] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David X. Soto
- Environment Canada 11 Innovation Boulevard Saskatoon SK S7N 3H5 Canada
| | | | - Keith A. Hobson
- Environment Canada 11 Innovation Boulevard Saskatoon SK S7N 3H5 Canada
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14
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Effects of alanine aminotransferase inhibition on the intermediary metabolism inSparus auratathrough dietary amino-oxyacetate supplementation. Br J Nutr 2011; 107:1747-56. [DOI: 10.1017/s000711451100496x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In liver, through the reaction catalysed by alanine aminotransferase (ALT), alanine becomes an effective precursor for gluconeogenesis. In the present study amino-oxyacetate (AOA) was used to evaluate its effect on liver ALT activity of the carnivorous fishSparus aurata. Moreover, the derived metabolic effects on metabolites and other key enzymes of glycolysis, gluconeogenesis and the pentose phosphate pathway were also studied. A dose-effect-dependent inhibition of AOA on hepatic cytosolic and mitochondrial ALT activity was observedin vitro.In vivo, AOA behaved as an inhibitor of hepatic cytosolic ALT activity. A long-term exposure to AOA increased pyruvate kinase activity in the liver irrespective of the composition of the diet supplied to fish.1H NMR studies showed that inclusion of AOA to the diet decreased the hepatic levels of alanine, glutamate and glycogen. Moreover,2H NMR analysis indicated a higher renewal rate for alanine in the liver of fish fed with a high-carbohydrate/low-protein diet, while AOA decreased alanine2H-enrichment irrespective of the diet. The present study indicates that AOA-dependent inhibition of the cytosolic ALT activity could help to increase the use of dietary carbohydrate nutrients.
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Analysis of glucose metabolism in farmed European sea bass (Dicentrarchus labrax L.) using deuterated water. Comp Biochem Physiol A Mol Integr Physiol 2011; 160:341-7. [PMID: 21777686 DOI: 10.1016/j.cbpa.2011.06.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 06/30/2011] [Accepted: 06/30/2011] [Indexed: 11/23/2022]
Abstract
Glucose metabolism in free-swimming fasted and fed seabass was studied using deuterated water ((2)H(2)O). After transfer to seawater enriched with 4.9% (2)H(2)O for 6-h or for 72-h, positional and mole percent enrichment (MPE) of plasma glucose and water were quantified by (2)H NMR and ESI-MS/MS. Plasma water (2)H-enrichment reached that of seawater within 6h. In both fasted and fed fish, plasma glucose MPE increased asymptotically attaining ~55% of plasma water enrichment by 72 h. The distribution of (2)H-enrichment between the different glucose positions was relatively uniform. The gluconeogenic contribution to glucose that was synthesized during (2)H(2)O administration was estimated from the ratio of position 5 and 2 glucose enrichments. For both fed and fasted fish, gluconeogenesis accounted for 98±1% of the glucose that was produced during the 72-h (2)H(2)O administration period. For fasted fish, gluconeogenic contributions measured after 6h were identical to 72-h values (94±3%). For fed fish, the apparent gluconeogenic contribution at 6-h was significantly lower compared to 72-h (79±5% versus 98±1%, p<0.05). This may reflect a brief augmentation of gluconeogenic flux by glycogenolysis after feeding and/or selective enrichment of plasma glucose position 2 via futile glucose-glucose-6-phosphate cycling.
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16
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Tomcik K, Ibarra RA, Sadhukhan S, Han Y, Tochtrop GP, Zhang GF. Isotopomer enrichment assay for very short chain fatty acids and its metabolic applications. Anal Biochem 2010; 410:110-7. [PMID: 21112315 DOI: 10.1016/j.ab.2010.11.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/05/2010] [Accepted: 11/22/2010] [Indexed: 10/18/2022]
Abstract
The present work illustrated an accurate GC/MS measurement for the low isotopomer enrichment assay of formic acid, acetic acid, propionic aicd, butyric acid, and pentanoic acid. The pentafluorobenzyl bromide derivatives of these very short chain fatty acids have high sensitivity of isotopoic enrichment due to their low natural isotopomer distribution in negative chemical ionization mass spectrometric mode. Pentafluorobenzyl bromide derivatization reaction was optimized in terms of pH, temperature, reaction time, and the amount of pentafluorobenzyl bromide versus sample. The precision, stability, and accuracy of this method for the isotopomer analysis were validated. This method was applied to measure the enrichments of formic acid, acetic acid, and propionic acid in the perfusate from rat liver exposed to Krebs-Ringer bicarbonate buffer only, 0-1mM [3,4-(13)C(2)]-4-hydroxynonanoate, and 0-2mM [5,6,7-(13)C(3)]heptanoate. The enrichments of acetic acid and propionic acid in the perfusate are comparable to the labeling pattern of acetyl-CoA and propionyl-CoA in the rat liver tissues. The enrichment of the acetic acid assay is much more sensitive and precise than the enrichment of acetyl-CoA by LC-MS/MS. The reversibility of propionyl-CoA from succinyl-CoA was confirmed by the low labeling of M1 and M2 of propionic acid from [5,6,7-(13)C(3)]heptanoate perfusates.
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Affiliation(s)
- Kristyen Tomcik
- Department of Nutrition, Case Western Reserve University, 10900 Euclid Avenue, W-G48, Cleveland, OH 44106-4954, USA
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Gasier HG, Fluckey JD, Previs SF. The application of 2H2O to measure skeletal muscle protein synthesis. Nutr Metab (Lond) 2010; 7:31. [PMID: 20409307 PMCID: PMC2873296 DOI: 10.1186/1743-7075-7-31] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 04/21/2010] [Indexed: 12/21/2022] Open
Abstract
Skeletal muscle protein synthesis has generally been determined by the precursor:product labeling approach using labeled amino acids (e.g., [13C]leucine or [13C]-, [15N]-, or [2H]phenylalanine) as the tracers. Although reliable for determining rates of protein synthesis, this methodological approach requires experiments to be conducted in a controlled environment, and as a result, has limited our understanding of muscle protein renewal under free-living conditions over extended periods of time (i.e., integrative/cumulative assessments). An alternative tracer, 2H2O, has been successfully used to measure rates of muscle protein synthesis in mice, rats, fish and humans. Moreover, perturbations such as feeding and exercise have been included in these measurements without exclusion of common environmental and biological factors. In this review, we discuss the principle behind using 2H2O to measure muscle protein synthesis and highlight recent investigations that have examined the effects of feeding and exercise. The framework provided in this review should assist muscle biologists in designing experiments that advance our understanding of conditions in which anabolism is altered (e.g., exercise, feeding, growth, debilitating and metabolic pathologies).
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Affiliation(s)
- Heath G Gasier
- Naval Submarine Medical Research Laboratory, Groton, CT, USA.
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