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Burke LM, Whitfield J. Ketogenic Diets Are Not Beneficial for Athletic Performance. Med Sci Sports Exerc 2024; 56:756-759. [PMID: 38079311 DOI: 10.1249/mss.0000000000003344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2024]
Affiliation(s)
- Louise M Burke
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, AUSTRALIA
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Burke LM, Whitfield J. Ketogenic Diets Are Not Beneficial for Athletic Performance: Response to Noakes. Med Sci Sports Exerc 2024; 56:763-765. [PMID: 38485731 DOI: 10.1249/mss.0000000000003346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Affiliation(s)
- Louise M Burke
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, AUSTRALIA
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McKay AKA, Anderson B, Peeling P, Whitfield J, Tee N, Zeder C, Zimmermann MB, Burke LM, Moretti D. Iron Absorption in Highly Trained Male Runners: Does it Matter When and Where You Eat Your Iron? Med Sci Sports Exerc 2024; 56:118-127. [PMID: 38098150 DOI: 10.1249/mss.0000000000003272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
PURPOSE We examined iron absorption and its regulation during two common scenarios experienced by endurance athletes. Our aims were to: (i) compare the effects of preexercise versus postexercise iron intake on iron absorption; and (ii) compare the impact of training at altitude (1800 m) on iron absorption preexercise. METHODS Male runners (n = 18) completed three exercise trials over a 5-wk period, each preceded by 24 h of standardized low-iron diets. First, athletes completed two 60-min treadmill running trials at 65% V̇O2max at near sea-level (580 m). In a randomized order, preexercise and postexercise test meals labeled with 4 mg of 57Fe or 58Fe were consumed 30 min before or 30 min after exercise. Then, the same exercise trial was performed after living and training at altitude (~1800 m) for 7 d, with the labeled test meal consumed 30 min preexercise. We collected venous blood samples preexercise and postexercise for markers of iron status and regulation, and 14 d later to measure erythrocyte isotope incorporation. RESULTS No differences in fractional iron absorption were evident when test meals were consumed preexercise (7.3% [4.4, 12.1]) or postexercise (6.2% [3.1, 12.5]) (n = 18; P = 0.058). Iron absorption preexercise was greater at altitude (18.4% [10.6, 32.0]) than at near sea-level (n = 17; P < 0.001) and hepcidin concentrations at altitude were lower at rest and 3 h postexercise compared with near sea level (P < 0.001). CONCLUSIONS In an acute setting, preexercise and postexercise iron absorption is comparable if consumed within 30 min of exercise. Preexercise iron absorption increases 2.6-fold at altitude compared with near sea-level, likely due to the homeostatic response to provide iron for enhanced erythropoiesis and maintain iron stores.
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Affiliation(s)
- Alannah K A McKay
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Vic, AUSTRALIA
| | | | | | - Jamie Whitfield
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Vic, AUSTRALIA
| | - Nicolin Tee
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Vic, AUSTRALIA
| | - Christophe Zeder
- Laboratory of Human Nutrition, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, SWITZERLAND
| | - Michael B Zimmermann
- Medical Research Council Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UNITED KINGDOM
| | - Louise M Burke
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Vic, AUSTRALIA
| | - Diego Moretti
- Nutrition Group, Health Department, Swiss Distance University of Applied Sciences (FFHS), Zürich, SWITZERLAND
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McKay AKA, Wallett AM, McKune AJ, Périard JD, Saunders P, Whitfield J, Tee N, Heikura IA, Ross MLR, Sharma AP, Costa RJS, Burke LM. The Impact of a Short-Term Ketogenic Low-Carbohydrate High-Fat Diet on Biomarkers of Intestinal Epithelial Integrity and Gastrointestinal Symptoms. Int J Sport Nutr Exerc Metab 2023; 33:305-315. [PMID: 37567573 DOI: 10.1123/ijsnem.2023-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 06/06/2023] [Accepted: 06/13/2023] [Indexed: 08/13/2023]
Abstract
Endurance exercise can disturb intestinal epithelial integrity, leading to increased systemic indicators of cell injury, hyperpermeability, and pathogenic translocation. However, the interaction between exercise, diet, and gastrointestinal disturbance still warrants exploration. This study examined whether a 6-day dietary intervention influenced perturbations to intestinal epithelial disruption in response to a 25-km race walk. Twenty-eight male race walkers adhered to a high carbohydrate (CHO)/energy diet (65% CHO, energy availability = 40 kcal·kg FFM-1·day-1) for 6 days prior to a Baseline 25-km race walk. Athletes were then split into three subgroups: high CHO/energy diet (n = 10); low-CHO, high-fat diet (LCHF: n = 8; <50 g/day CHO, energy availability = 40 kcal·kg FFM-1·day-1); and low energy availability (n = 10; 65% CHO, energy availability = 15 kcal·kg FFM-1·day-1) for a further 6-day dietary intervention period prior to a second 25-km race walk (Adaptation). During both trials, venous blood was collected pre-, post-, and 1 hr postexercise and analyzed for markers of intestinal epithelial disruption. Intestinal fatty acid-binding protein concentration was significantly higher (twofold increase) in response to exercise during Adaptation compared to Baseline in the LCHF group (p = .001). Similar findings were observed for soluble CD14 (p < .001) and lipopolysaccharide-binding protein (p = .003), where postexercise concentrations were higher (53% and 36%, respectively) during Adaptation than Baseline in LCHF. No differences in high CHO/energy diet or low energy availability were apparent for any blood markers assessed (p > .05). A short-term LCHF diet increased intestinal epithelial cell injury in response to a 25-km race walk. No effect of low energy availability on gastrointestinal injury or symptoms was observed.
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Affiliation(s)
- Alannah K A McKay
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC,Australia
| | - Alice M Wallett
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT,Australia
- Australian Institute of Sport, Canberra, ACT,Australia
| | - Andrew J McKune
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT,Australia
- Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban,South Africa
| | - Julien D Périard
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT,Australia
| | | | - Jamie Whitfield
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC,Australia
| | - Nicolin Tee
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC,Australia
| | - Ida A Heikura
- Canadian Sport Institute Pacific, Victoria, BC,Canada
- Exercise Science, Physical & Health Education, University of Victoria, Victoria, BC,Canada
| | - Megan L R Ross
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC,Australia
| | | | - Ricardo J S Costa
- Department of Nutrition, Dietetics and Food, Monash University, Notting Hill, VIC,Australia
| | - Louise M Burke
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC,Australia
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Whitfield J, Burke LM, Ross MLR, Tee N, Sharma AP, King AJ, Heikura IA, Morabito A, McKay AKA. Acute Low Energy Availability Exposure Alters Body Composition Of Elite Race Walkers But Does Not Hinder Performance. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000883456.01600.0a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Janzen NR, Whitfield J, Murray-Segal L, Kemp BE, Hawley JA, Hoffman NJ. Disrupting AMPK-Glycogen Binding in Mice Increases Carbohydrate Utilization and Reduces Exercise Capacity. Front Physiol 2022; 13:859246. [PMID: 35392375 PMCID: PMC8980720 DOI: 10.3389/fphys.2022.859246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
The AMP-activated protein kinase (AMPK) is a central regulator of cellular energy balance and metabolism and binds glycogen, the primary storage form of glucose in liver and skeletal muscle. The effects of disrupting whole-body AMPK-glycogen interactions on exercise capacity and substrate utilization during exercise in vivo remain unknown. We used male whole-body AMPK double knock-in (DKI) mice with chronic disruption of AMPK-glycogen binding to determine the effects of DKI mutation on exercise capacity, patterns of whole-body substrate utilization, and tissue metabolism during exercise. Maximal treadmill running speed and whole-body energy utilization during submaximal running were determined in wild type (WT) and DKI mice. Liver and skeletal muscle glycogen and skeletal muscle AMPK α and β2 subunit content and signaling were assessed in rested and maximally exercised WT and DKI mice. Despite a reduced maximal running speed and exercise time, DKI mice utilized similar absolute amounts of liver and skeletal muscle glycogen compared to WT. DKI skeletal muscle displayed reduced AMPK α and β2 content versus WT, but intact relative AMPK phosphorylation and downstream signaling at rest and following exercise. During submaximal running, DKI mice displayed an increased respiratory exchange ratio, indicative of greater reliance on carbohydrate-based fuels. In summary, whole-body disruption of AMPK-glycogen interactions reduces maximal running capacity and skeletal muscle AMPK α and β2 content and is associated with increased skeletal muscle glycogen utilization. These findings highlight potential unappreciated roles for AMPK in regulating tissue glycogen dynamics and expand AMPK’s known roles in exercise and metabolism.
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Affiliation(s)
- Natalie R. Janzen
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Lisa Murray-Segal
- St Vincent’s Institute of Medical Research and Department of Medicine, University of Melbourne, Fitzroy, VIC, Australia
| | - Bruce E. Kemp
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
- St Vincent’s Institute of Medical Research and Department of Medicine, University of Melbourne, Fitzroy, VIC, Australia
| | - John A. Hawley
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Nolan J. Hoffman
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
- *Correspondence: Nolan J. Hoffman,
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Merrick B, Noronha M, Batra R, Douthwaite S, Nebbia G, Snell L, Pickering S, Galao R, Whitfield J, Jahangeer A, Gunawardena R, Godfrey T, Laifa R, Webber K, Cliff P, Cunningham E, Neil S, Gettings H, Edgeworth J, Harrison H. Real-world deployment of lateral flow SARS-CoV-2 antigen detection in the emergency department to provide rapid, accurate and safe diagnosis of COVID-19. Infect Prev Pract 2021; 3:100186. [PMID: 34812417 PMCID: PMC8598289 DOI: 10.1016/j.infpip.2021.100186] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Point-of-care (POC) SARS-CoV-2 lateral-flow antigen detection (LFD) testing in the emergency department (ED) could inform rapid infection control decisions but requirements for safe deployment have not been fully defined. METHODS Review of LFD test results, laboratory and POC-RT-PCR results and ED-performance metrics during a two-week high SARS-CoV-2 prevalence period followed by several months of falling prevalence. AIM Determine whether LFD testing can be safely deployed in ED to provide an effective universal SARS-CoV-2 testing capability. FINDINGS 93% (345/371) of COVID-19 patients left ED with a virological diagnosis during the 2-week universal LFD evaluation period compared to 77% with targeted POC-RT-PCR deployment alone, on background of approximately one-third having an NHS Track and Trace RT-PCR test-result at presentation. LFD sensitivity and specificity was 70.7% and 99.1% respectively providing a PPV of 97.7% and NPV of 86.4% with disease prevalence of 34.7%. ED discharge-delays (breaches) attributable to COVID-19 fell to 33/3532 (0.94%) compared with the preceding POC-RT-PCR period (107/4114 (2.6%); p=<0.0001). Importantly, LFD testing identified 1 or 2 clinically-unsuspected COVID-19 patients/day. Three clinically-confirmed LFD false positive patients were appropriately triaged based on LFD action-card flowchart, and only 5 of 95 false-negative LFD results were inappropriately admitted to non-COVID-19 areas where no onward-transmission was identified. LFD testing was restricted to asymptomatic patients when disease prevalence fell below 5% and detected 1-3 cases/week. CONCLUSION Universal SARS-CoV-2 LFD testing can be safely and effectively deployed in ED alongside POC-RT-PCR testing during periods of high and low disease prevalence.
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Affiliation(s)
- B. Merrick
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - M. Noronha
- Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - R. Batra
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - S. Douthwaite
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - G. Nebbia
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - L.B. Snell
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - S. Pickering
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
| | - R.P. Galao
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
| | - J. Whitfield
- Guy's King's and Thomas' School of Medicine, King's College London, UK
| | - A. Jahangeer
- Guy's King's and Thomas' School of Medicine, King's College London, UK
| | - R. Gunawardena
- Guy's King's and Thomas' School of Medicine, King's College London, UK
| | - T. Godfrey
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
| | - R. Laifa
- Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | | | | | | | - S.J.D. Neil
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
| | - H. Gettings
- Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - J.D. Edgeworth
- Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, UK
- Directorate of Infection, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - H.L. Harrison
- Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK
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McKay AKA, Peeling P, Pyne DB, Tee N, Whitfield J, Sharma AP, Heikura IA, Burke LM. Six Days of Low Carbohydrate, Not Energy Availability, Alters the Iron and Immune Response to Exercise in Elite Athletes. Med Sci Sports Exerc 2021; 54:377-387. [PMID: 34690285 DOI: 10.1249/mss.0000000000002819] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To quantify the effects of a short-term (6-day) low carbohydrate (CHO) high fat (LCHF), and low energy availability (LEA) diet on immune, inflammatory, and iron-regulatory responses to exercise in endurance athletes. METHODS Twenty-eight elite male race walkers completed two 6-day diet/training phases. During phase 1 (Baseline), all athletes consumed a high CHO/energy availability (CON) diet (65% CHO and ~ 40 kcal·kg-1 fat free mass (FFM)·day-1). In phase 2 (Adaptation), athletes were allocated to either a CON (n = 10), LCHF (n = 8; <50 g·day-1 CHO and ~ 40 kcal·kg-1 FFM·day-1), or LEA diet (n = 10; 60% CHO and 15 kcal·kg-1 FFM·day-1). At the end of each phase, athletes completed a 25 km race walk protocol at ~75% VO2max. On each occasion, venous blood was collected before and after exercise for interleukin-6, hepcidin, cortisol and glucose concentrations, as well as white blood cell counts. RESULTS The LCHF athletes displayed a greater IL-6 (p = 0.019) and hepcidin (p = 0.011) response to exercise after Adaptation, compared to Baseline. Similarly, post-exercise increases in total white blood cell counts (p = 0.026) and cortisol levels (p < 0.001) were larger compared to Baseline following LCHF Adaptation. Decreases in blood glucose concentrations were evident post-exercise during Adaptation in LCHF (p = 0.049), whereas no change occurred in CON or LEA (p > 0.05). No differences between CON and LEA were evident for any of the measured biological markers (all p > 0.05). CONCLUSION Short-term adherence to a LCHF diet elicited small yet unfavorable iron, immune, and stress responses to exercise. In contrast, no substantial alterations to athlete health were observed when athletes restricted energy availability compared to athletes with adequate energy availability. Therefore, short-term restriction of CHO, rather than energy, may have greater negative impacts on athlete health.
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Affiliation(s)
- Alannah K A McKay
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia Western Australian Institute of Sport, Mt Claremont, WA, Australia School of Human Sciences (Exercise and Sport Science). The University of Western Australia, Crawley, WA, Australia Research Institute for Sport and Exercise, University of Canberra, Canberra, Australia Triathlon Australia, Burleigh Heads, Australia Canadian Sport Institute - Pacific, Victoria, British Columbia, Canada Exercise Science, Physical & Health Education, University of Victoria British Columbia, Canada
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Burke LM, Hall R, Heikura IA, Ross ML, Tee N, Kent GL, Whitfield J, Forbes SF, Sharma AP, Jones AM, Peeling P, Blackwell JR, Mujika I, Mackay K, Kozior M, Vallance B, McKay AKA. Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers. Nutrients 2021; 13:nu13082767. [PMID: 34444928 PMCID: PMC8398364 DOI: 10.3390/nu13082767] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/03/2021] [Accepted: 08/07/2021] [Indexed: 11/16/2022] Open
Abstract
Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes’ economy as well as the performance effects in elite groups.
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Affiliation(s)
- Louise M. Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- Correspondence: ; Tel.: +61-422-635-869
| | - Rebecca Hall
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Ida A. Heikura
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Megan L. Ross
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Nicolin Tee
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Georgina L. Kent
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
| | - Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
| | - Sara F. Forbes
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- UniSA Online, University of South Australia, Adelaide, SA 5000, Australia
| | - Avish P. Sharma
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- Triathlon Australia, Burleigh Heads, Gold Coast, QLD 4220, Australia
| | - Andrew M. Jones
- Sport and Health Sciences, University of Exeter, Heavitree Road, Exeter EX1 2LU, UK; (A.M.J.); (J.R.B.)
| | - Peter Peeling
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA 6009, Australia;
- West Australian Institute of Sport, Mt Claremont, Nedlands, WA 6010, Australia
| | - Jamie R. Blackwell
- Sport and Health Sciences, University of Exeter, Heavitree Road, Exeter EX1 2LU, UK; (A.M.J.); (J.R.B.)
| | - Iñigo Mujika
- Department of Physiology, Faculty of Medicine and Nursing, University of the Basque Country, 48940 Leioa, Basque Country, Spain;
- Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago 7501015, Chile;
| | - Karen Mackay
- Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago 7501015, Chile;
- School of Exercise & Nutrition Sciences, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - Marta Kozior
- Department of Physical Education & Sport Sciences, University of Limerick, V94 T9PX Limerick, Ireland;
| | - Brent Vallance
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia; (R.H.); (I.A.H.); (M.L.R.); (N.T.); (J.W.); (B.V.)
- Athletics Australia, South Melbourne, Melbourne, VIC 3205, Australia
| | - Alannah K. A. McKay
- Australian Institute of Sport, Bruce, Canberra, ACT 2616, Australia; (G.L.K.); (S.F.F.); (A.P.S.); (A.K.A.M.)
- School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, WA 6009, Australia;
- West Australian Institute of Sport, Mt Claremont, Nedlands, WA 6010, Australia
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Shamim B, Camera DM, Whitfield J. Corrigendum: Myofibre Hypertrophy in the Absence of Changes to Satellite Cell Content Following Concurrent Exercise Training in Young Healthy Men. Front Physiol 2021; 12:736848. [PMID: 34393834 PMCID: PMC8356794 DOI: 10.3389/fphys.2021.736848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022] Open
Affiliation(s)
- Baubak Shamim
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Donny M Camera
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Jamie Whitfield
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
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Shamim B, Camera DM, Whitfield J. Myofibre Hypertrophy in the Absence of Changes to Satellite Cell Content Following Concurrent Exercise Training in Young Healthy Men. Front Physiol 2021; 12:625044. [PMID: 34149439 PMCID: PMC8213074 DOI: 10.3389/fphys.2021.625044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 05/11/2021] [Indexed: 12/17/2022] Open
Abstract
Concurrent exercise training has been suggested to create an ‘interference effect,’ attenuating resistance training-based skeletal muscle adaptations, including myofibre hypertrophy. Satellite cells support myofibre hypertrophy and are influenced by exercise mode. To determine whether satellite cells contribute to the ‘interference effect’ changes in satellite cell and myonuclear content were assessed following a period of training in 32 recreationally active males (age: 25 ± 5 year; body mass index: 24 ± 3 kg⋅m–2; mean ± SD) who undertook 12-week of either isolated (3 d⋅w–1) resistance (RES; n = 10), endurance (END; n = 10), or alternate day (6 d⋅w–1) concurrent (CET, n = 12) training. Skeletal muscle biopsies were obtained pre-intervention and after 2, 8, and 12 weeks of training to determine fibre type-specific cross-sectional area (CSA), satellite cell content (Pax7+DAPI+), and myonuclei (DAPI+) using immunofluorescence microscopy. After 12 weeks, myofibre CSA increased in all training conditions in type II (P = 0.0149) and mixed fibres (P = 0.0102), with no difference between conditions. Satellite cell content remained unchanged after training in both type I and type II fibres. Significant correlations were observed between increases in fibre type-specific myonuclear content and CSA of Type I (r = 0.63, P < 0.0001), Type II (r = 0.69, P < 0.0001), and mixed fibres (r = 0.72, P < 0.0001). Resistance, endurance, and concurrent training induce similar myofibre hypertrophy in the absence of satellite cell and myonuclear pool expansion. These findings suggest that myonuclear accretion via satellite cell fusion is positively correlated with hypertrophy after 12 weeks of concurrent training, and that individuals with more myonuclear content displayed greater myofibre hypertrophy.
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Affiliation(s)
- Baubak Shamim
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Donny M Camera
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Jamie Whitfield
- Exercise and Nutrition Research Programme, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
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12
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Whitfield J, Harris RC, Broad EM, Patterson AK, Ross MLR, Shaw G, Spriet LL, Burke LM. Chronic pantothenic acid supplementation does not affect muscle coenzyme A content or cycling performance. Appl Physiol Nutr Metab 2020; 46:280-283. [PMID: 33075232 DOI: 10.1139/apnm-2020-0692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study determined if supplementation with pantothenic acid (PA) for 16 weeks could increase skeletal muscle coenzyme A (CoASH) content and exercise performance. Trained male cyclists (n = 14) were matched into control or PA (6 g·day-1) groups. At 0, 4, 8, and 16 weeks, subjects performed an incremental time to exhaustion cycle with muscle biopsies taken prior to and following exercise. Prolonged PA supplementation did not change skeletal muscle CoASH and acetyl-CoA contents or exercise performance. Novelty: Supplementation with pantothenic acid for 16 weeks had no effect on skeletal muscle CoASH and acetyl-CoA content or exercise performance in trained male cyclists.
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Affiliation(s)
- Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia
| | | | | | | | - Megan L R Ross
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia.,Australian Institute of Sport, Belconnen, ACT 2616, Australia
| | - Gregory Shaw
- Australian Institute of Sport, Belconnen, ACT 2616, Australia
| | - Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Louise M Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC 3000, Australia.,Australian Institute of Sport, Belconnen, ACT 2616, Australia
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13
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Burke LM, Whitfield J, Heikura IA, Ross MLR, Tee N, Forbes SF, Hall R, McKay AKA, Wallett AM, Sharma AP. Adaptation to a low carbohydrate high fat diet is rapid but impairs endurance exercise metabolism and performance despite enhanced glycogen availability. J Physiol 2020; 599:771-790. [PMID: 32697366 PMCID: PMC7891450 DOI: 10.1113/jp280221] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/14/2020] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS Brief (5-6 days) adaptation to a low carbohydrate high fat diet in elite athletes increased exercise fat oxidation to rates previously observed with medium (3-4 weeks) or chronic (>12 months) adherence to this diet, with metabolic changes being washed out in a similar time frame. Increased fat utilisation during exercise was associated with a 5-8% increase in oxygen cost at speeds related to Olympic Programme races. Acute restoration of endogenous carbohydrate (CHO) availability (24 h high CHO diet, pre-race CHO) only partially restored substrate utilisation during a race warm-up. Fat oxidation continued to be elevated above baseline values although it was lower than achieved by 5-6 days' keto adaptation; CHO oxidation only reached 61% and 78% of values previously seen at exercise intensities related to race events. Acute restoration of CHO availability failed to overturn the impairment of high-intensity endurance performance previously associated with low carbohydrate high fat adaptation, potentially due to the blunted capacity for CHO oxidation. ABSTRACT We investigated substrate utilisation during exercise after brief (5-6 days) adaptation to a ketogenic low-carbohydrate (CHO), high-fat (LCHF) diet and similar washout period. Thirteen world-class male race walkers completed economy testing, 25 km training and a 10,000 m race (Baseline), with high CHO availability (HCHO), repeating this (Adaptation) after 5-6 days' LCHF (n = 7; CHO: <50 g day-1 , protein: 2.2 g kg-1 day-1 ; 80% fat) or HCHO (n = 6; CHO: 9.7 g kg-1 day-1 ; protein: 2.2 g kg-1 day-1 ) diet. An Adaptation race was undertaken after 24 h HCHO and pre-race CHO (2 g kg-1 ) diet, identical to the Baseline race. Substantial (>200%) increases in exercise fat oxidation occurred in the LCHF Adaptation economy and 25 km tests, reaching mean rates of ∼1.43 g min-1 . However, relative V ̇ O 2 (ml min-1 kg-1 ) was higher (P < 0.0001), by ∼8% and 5% at speeds related to 50 km and 20 km events. During Adaptation race warm-up in the LCHF group, rates of fat and CHO oxidation at these speeds were decreased and increased, respectively (P < 0.001), compared with the previous day, but were not restored to Baseline values. Performance changes differed between groups (P = 0.009), with all HCHO athletes improving in the Adaptation race (5.7 (5.6)%), while 6/7 LCHF athletes were slower (2.2 (3.4)%). Substrate utilisation returned to Baseline values after 5-6 days of HCHO diet. In summary, robust changes in exercise substrate use occurred in 5-6 days of extreme changes in CHO intake. However, adaptation to a LCHF diet plus acute restoration of endogenous CHO availability failed to restore high-intensity endurance performance, with CHO oxidation rates remaining blunted.
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Affiliation(s)
- Louise M Burke
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.,Australian Institute of Sport, Canberra, Australia
| | - Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - Ida A Heikura
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.,Australian Institute of Sport, Canberra, Australia
| | - Megan L R Ross
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.,Australian Institute of Sport, Canberra, Australia
| | - Nicolin Tee
- Australian Institute of Sport, Canberra, Australia
| | | | - Rebecca Hall
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.,Australian Institute of Sport, Canberra, Australia
| | - Alannah K A McKay
- Australian Institute of Sport, Canberra, Australia.,School of Human Sciences (Exercise and Sport Science), University of Western Australia, Crawley, Australia.,Western Australian Institute of Sport, Mt, Claremont, Western Australia, Australia
| | - Alice M Wallett
- Australian Institute of Sport, Canberra, Australia.,University of Canberra Research Institute for Sport and Exercise, Canberra, Australia
| | - Avish P Sharma
- Australian Institute of Sport, Canberra, Australia.,Griffith Sports Physiology and Performance, School of Allied Health Sciences, Griffith University, Southport, Australia
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14
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Tachtsis B, Whitfield J, Hawley JA, Hoffman NJ. Omega-3 Polyunsaturated Fatty Acids Mitigate Palmitate-Induced Impairments in Skeletal Muscle Cell Viability and Differentiation. Front Physiol 2020; 11:563. [PMID: 32581844 PMCID: PMC7283920 DOI: 10.3389/fphys.2020.00563] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/07/2020] [Indexed: 12/15/2022] Open
Abstract
Accumulation of excess saturated free fatty acids such as palmitate (PAL) in skeletal muscle leads to reductions in mitochondrial integrity, cell viability and differentiation. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) counteract PAL-induced lipid accumulation. EPA and DHA, as well as the n-3 PUFA docosapentaenoic acid (DPA), may therefore mitigate PAL-induced lipotoxicity to promote skeletal muscle cell survival and differentiation. C2C12 myoblasts were treated with 50 μM EPA, DPA, or DHA in the absence or presence of 500 μM PAL for 16 h either prior to myoblast analysis or induction of differentiation. Myoblast viability and markers of apoptosis, endoplasmic reticulum (ER) stress and myotube differentiation capacity were investigated using fluorescence microscopy and immunoblotting. High-resolution respirometry was used to assess mitochondrial function and membrane integrity. PAL induced cell death via apoptosis and increased protein content of ER stress markers BiP and CHOP. EPA, DPA, and DHA co-treatment maintained cell viability, prevented PAL-induced apoptosis and attenuated PAL-induced increases in BiP, whereas only DPA prevented increases in CHOP. PAL subsequently reduced protein content of the differentiation marker myogenin and inhibited myotube formation, and all n-3 PUFAs promoted myotube formation in the presence of PAL. Furthermore, DPA prevented PAL-induced release of cytochrome c and maintained mitochondrial integrity. These findings demonstrate the n-3 PUFAs EPA, DPA and DHA elicit similar protective effects against PAL-induced impairments in muscle cell viability and differentiation. Mechanistically, the protective effects of DPA against PAL lipotoxicity are attributable in part to its ability to maintain mitochondrial respiratory capacity via mitigating PAL-induced loss of mitochondrial membrane integrity.
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Affiliation(s)
- Bill Tachtsis
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Jamie Whitfield
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - John A Hawley
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Nolan J Hoffman
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
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15
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McIlvenna LC, Muggeridge DJ, Whitfield J. Exploring the mechanisms by which nitrate supplementation improves skeletal muscle contractile function: one fibre at a time. J Physiol 2019; 598:25-27. [DOI: 10.1113/jp279118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Luke C. McIlvenna
- Institute for Health and SportVictoria University Melbourne Australia
| | - David J. Muggeridge
- Active Health Exercise LaboratoryDivision of Biomedical SciencesInstitute of Health Research and InnovationUniversity of the Highlands and Islands Inverness UK
| | - Jamie Whitfield
- Exercise and Nutrition Research ProgramMary MacKillop Institute for Health ResearchAustralian Catholic University Melbourne Australia
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16
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Hoffman N, Whitfield J, Janzen NR, Belhaj MR, Galic S, Murray-Segal L, Oakhill JS, Scott JW, Kemp BE, Hawley JA. Disruption of AMPK-glycogen binding in vivo reveals novel roles in whole-body and tissue metabolism. Obes Res Clin Pract 2019. [DOI: 10.1016/j.orcp.2018.11.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Alvis B, Hopper T, Polcz M, Hocking K, Whitfield J, Brophy C, Eagle S, Lindenfeld J. Non-Invasive Venous Waveform Analysis (NIVA) for Monitoring Pulmonary Capillary Wedge Pressure Post-Orthotopic Heart Transplantation: A Proof of Concept Study. J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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18
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Whitfield J, Heigenhauser GJF, van Loon LJC, Spriet LL, Tupling AR, Holloway GP. Response. Med Sci Sports Exerc 2018; 50:875. [PMID: 29547496 DOI: 10.1249/mss.0000000000001490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Jamie Whitfield
- Mary Mackillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, AUSTRALIA Department of Medicine, McMaster University, Hamilton, ON, CANADA Department of Human Movement Sciences, Nutrition and Toxicology Research Institute, Maastricht University, Maastricht, the NETHERLANDS Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA Department of Kinesiology, University of Waterloo, Waterloo, ON, CANADA Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
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19
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Whitfield J, Paglialunga S, Smith BK, Miotto PM, Simnett G, Robson HL, Jain SS, Herbst EAF, Desjardins EM, Dyck DJ, Spriet LL, Steinberg GR, Holloway GP. Ablating the protein TBC1D1 impairs contraction-induced sarcolemmal glucose transporter 4 redistribution but not insulin-mediated responses in rats. J Biol Chem 2017; 292:16653-16664. [PMID: 28808062 DOI: 10.1074/jbc.m117.806786] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/10/2017] [Indexed: 12/28/2022] Open
Abstract
TBC1 domain family member 1 (TBC1D1), a Rab GTPase-activating protein and paralogue of Akt substrate of 160 kDa (AS160), has been implicated in both insulin- and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase-mediated glucose transporter type 4 (GLUT4) translocation. However, the role of TBC1D1 in contracting muscle remains ambiguous. We therefore explored the metabolic consequence of ablating TBC1D1 in both resting and contracting skeletal muscles, utilizing a rat TBC1D1 KO model. Although insulin administration rapidly increased (p < 0.05) plasma membrane GLUT4 content in both red and white gastrocnemius muscles, the TBC1D1 ablation did not alter this response nor did it affect whole-body insulin tolerance, suggesting that TBC1D1 is not required for insulin-induced GLUT4 trafficking events. Consistent with findings in other models of altered TBC1D1 protein levels, whole-animal and ex vivo skeletal muscle fat oxidation was increased in the TBC1D1 KO rats. Although there was no change in mitochondrial content in the KO rats, maximal ADP-stimulated respiration was higher in permeabilized muscle fibers, which may contribute to the increased reliance on fatty acids in resting KO animals. Despite this increase in mitochondrial oxidative capacity, run time to exhaustion at various intensities was impaired in the KO rats. Moreover, contraction-induced increases in sarcolemmal GLUT4 content and glucose uptake were lower in the white gastrocnemius of the KO animals. Altogether, our results highlight a critical role for TBC1D1 in exercise tolerance and contraction-mediated translocation of GLUT4 to the plasma membrane in skeletal muscle.
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Affiliation(s)
- Jamie Whitfield
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Sabina Paglialunga
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Brennan K Smith
- Division of Endocrinology and Metabolism, Department of Medicine, and
| | - Paula M Miotto
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Genevieve Simnett
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Holly L Robson
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Swati S Jain
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Eric A F Herbst
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Eric M Desjardins
- Division of Endocrinology and Metabolism, Department of Medicine, and
| | - David J Dyck
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Lawrence L Spriet
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, and.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Graham P Holloway
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
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20
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Castellani LN, Peppler WT, Sutton CD, Whitfield J, Charron MJ, Wright DC. Glucagon receptor knockout mice are protected against acute olanzapine-induced hyperglycemia. Psychoneuroendocrinology 2017; 82:38-45. [PMID: 28500893 DOI: 10.1016/j.psyneuen.2017.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/17/2017] [Accepted: 05/01/2017] [Indexed: 12/22/2022]
Abstract
OBJECTIVES To determine if glucagon is involved in mediating the increase in blood glucose levels caused by the second-generation antipsychotic drug olanzapine. MATERIALS AND METHODS Whole body glucagon receptor deficient mice (Gcgr-/-) or WT littermate controls were injected with olanzapine (5mg/kg BW IP) and changes in blood glucose measured over the following 120min. Separate cohorts of mice were treated with olanzapine and changes in pyruvate tolerance, insulin tolerance and whole body substrate oxidation were determined. RESULTS Olanzapine treatment increased serum glucagon and lead to rapid increases in blood glucose concentrations in WT mice. Gcgr-/- mice were protected against olanzapine-induced increases in blood glucose but this was not explained by differences in terminal serum insulin concentrations, enhanced AKT phosphorylation in skeletal muscle, adipose tissue or liver or differences in RER. In both genotypes olanzapine induced an equivalent degree of insulin resistance as measured using an insulin tolerance test. Olanzapine treatment led to an exaggerated glucose response to a pyruvate challenge in WT but not Gcgr-/- mice and this was paralleled by reductions in the protein content of PEPCK and G6Pase in livers from Gcgr-/- mice. CONCLUSIONS Gcgr-/- mice are protected against olanzapine-induced increases in blood glucose. This is likely a result of reductions in liver glucose output, perhaps secondary to decreases in PEPCK and G6Pase protein content. Our findings highlight the central role of the liver in mediating olanzapine-induced disturbances in glucose homeostasis.
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Affiliation(s)
- Laura N Castellani
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Willem T Peppler
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Charles D Sutton
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jamie Whitfield
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Maureen J Charron
- Departments of Biochemistry, Obstetrics and Gynecology and Women's Health and Medicine (Endocrinology), Albert Einstein College of Medicine, Bronx, NY, USA
| | - David C Wright
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
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21
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Barbeau PA, Holloway TM, Whitfield J, Baechler BL, Quadrilatero J, van Loon LJC, Chabowski A, Holloway GP. α-Linolenic acid and exercise training independently, and additively, decrease blood pressure and prevent diastolic dysfunction in obese Zucker rats. J Physiol 2017; 595:4351-4364. [PMID: 28345766 DOI: 10.1113/jp274036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/23/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS α-linolenic acid (ALA) and exercise training both attenuate hyperlipidaemia-related cardiovascular derangements, however, there is a paucity of information pertaining to their mechanisms of action when combined. We investigated both the independent and combined effects of exercise training and ALA consumption in obese Zucker rats, aiming to determine the potential for additive improvements in cardiovascular function. ALA and exercise training independently improved cardiac output, end-diastolic volume, left ventricular fibrosis and mean blood pressure following a 4 week intervention. Combining ALA and endurance exercise yielded greater improvements in these parameters, independent of changes in markers of oxidative stress or endogenous anti-oxidants. We postulate that divergent mechanisms of action may explain these changes: ALA increases peripheral vasodilation, and exercise training stimulates angiogenesis. ABSTRACT Although α-linolenic acid (ALA) and endurance exercise training independently attenuate hyperlipidaemia-related cardiovascular derangements, there is a paucity of information pertaining to their mechanisms of action and efficacy when combined as a preventative therapeutic approach. Therefore, we used obese Zucker rats to investigate the independent and combined effects of these interventions on cardiovascular disease. Specifically, animals were randomly assigned to one of the following groups: control diet-sedentary, ALA supplemented-sedentary, control diet-exercise trained or ALA supplemented-exercise trained. Following a 4 week intervention, although the independent and combined effects of ALA and exercise reduced (P < 0.05) the serum free/esterified cholesterol ratio, only the ALA supplemented-exercise trained animals displayed a reduction in the content of both serum free and esterified cholesterol. Moreover, although ALA and endurance training individually increased cardiac output, stroke volume and end-diastolic volume, as well as reduced left ventricle fibrosis, mean blood pressure and total peripheral resistance, these responses were all greater following the combined intervention (ALA supplemented-exercise trained). These effects occurred independent of changes in oxidative phosphorylation proteins, markers of oxidative stress or endogenous anti-oxidant capacity. We propose that the beneficial effects of a combined intervention occur as a result of divergent mechanisms of action elicited by ALA and endurance exercise because only exercise training increased the capillary content in the left ventricle and skeletal muscle, and tended to decrease protein carbonylation in the left ventricle (P = 0.06). Taken together, our data indicate that combining ALA and endurance exercise provides additional improvements in cardiovascular disease risk reduction compared to singular interventions in the obese Zucker rat.
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Affiliation(s)
- Pierre-Andre Barbeau
- Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Tanya M Holloway
- Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.,NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, The Netherlands
| | - Jamie Whitfield
- Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Brittany L Baechler
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, The Netherlands
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Graham P Holloway
- Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Whitfield J, Heigenhauser GJF, Spriet LL, Holloway GP, Tupling AR. Beetroot Juice Increases Skeletal Muscle Force Production in Recreationally Active Subjects. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000487686.41551.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Whitfield J, Ludzki A, Heigenhauser GJF, Senden JMG, Verdijk LB, van Loon LJC, Spriet LL, Holloway GP. Beetroot juice supplementation reduces whole body oxygen consumption but does not improve indices of mitochondrial efficiency in human skeletal muscle. J Physiol 2015; 594:421-35. [PMID: 26457670 DOI: 10.1113/jp270844] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 09/29/2015] [Indexed: 12/23/2022] Open
Abstract
KEY POINTS Oral consumption of nitrate (NO3(-)) in beetroot juice has been shown to decrease the oxygen cost of submaximal exercise; however, the mechanism of action remains unresolved. We supplemented recreationally active males with beetroot juice to determine if this altered mitochondrial bioenergetics. Despite reduced submaximal exercise oxygen consumption, measures of mitochondrial coupling and respiratory efficiency were not altered in muscle. In contrast, rates of mitochondrial hydrogen peroxide (H2O2) emission were increased in the absence of markers of lipid or protein oxidative damage. These results suggest that improvements in mitochondrial oxidative metabolism are not the cause of beetroot juice-mediated improvements in whole body oxygen consumption. ABSTRACT Ingestion of sodium nitrate (NO3(-)) simultaneously reduces whole body oxygen consumption (V̇O2) during submaximal exercise while improving mitochondrial efficiency, suggesting a causal link. Consumption of beetroot juice (BRJ) elicits similar decreases in V̇O2 but potential effects on the mitochondria remain unknown. Therefore we examined the effects of 7-day supplementation with BRJ (280 ml day(-1), ∼26 mmol NO3(-)) in young active males (n = 10) who had muscle biopsies taken before and after supplementation for assessments of mitochondrial bioenergetics. Subjects performed 20 min of cycling (10 min at 50% and 70% V̇O2 peak) 48 h before 'Pre' (baseline) and 'Post' (day 5 of supplementation) biopsies. Whole body V̇O2 decreased (P < 0.05) by ∼3% at 70% V̇O2 peak following supplementation. Mitochondrial respiration in permeabilized muscle fibres showed no change in leak respiration, the content of proteins associated with uncoupling (UCP3, ANT1, ANT2), maximal substrate-supported respiration, or ADP sensitivity (apparent Km). In addition, isolated subsarcolemmal and intermyofibrillar mitochondria showed unaltered assessments of mitochondrial efficiency, including ADP consumed/oxygen consumed (P/O ratio), respiratory control ratios and membrane potential determined fluorometrically using Safranine-O. In contrast, rates of mitochondrial hydrogen peroxide (H2O2) emission were increased following BRJ. Therefore, in contrast to sodium nitrate, BRJ supplementation does not alter key parameters of mitochondrial efficiency. This occurred despite a decrease in exercise V̇O2, suggesting that the ergogenic effects of BRJ ingestion are not due to a change in mitochondrial coupling or efficiency. It remains to be determined if increased mitochondrial H2O2 contributes to this response.
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Affiliation(s)
- J Whitfield
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - A Ludzki
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - G J F Heigenhauser
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada, L8N 3Z5
| | - J M G Senden
- Department of Human Movement Sciences, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, 6200 MD, Maastricht, The Netherlands
| | - L B Verdijk
- Department of Human Movement Sciences, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, 6200 MD, Maastricht, The Netherlands
| | - L J C van Loon
- Department of Human Movement Sciences, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, 6200 MD, Maastricht, The Netherlands
| | - L L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - G P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
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Abstract
PURPOSE Dietary nitrate supplementation with beetroot juice (BR) has received widespread attention as an ergogenic aid. However, recent evidence in well-trained cyclists has not consistently reported improved cycling economy or performance. The present study examined the effects of acute and chronic BR supplementation on V˙O2 during submaximal running and 1500-m time trial (TT) performance of elite distance runners. METHODS Eight male 1500-m runners (V˙O2peak, 80 ± 5 mL·kg·min; 1500-m personal best, 3:56 ± 9 s) participated in this study. In a randomized, double-blind, crossover design, subjects supplemented with BR or a nitrate-free BR placebo (PL) for 8 d separated by at least 1 wk. On days 1 (acute) and 8 (chronic), subjects ingested 210 mL of BR (19.5-mmol nitrate) or PL and completed a submaximal treadmill run and 1500-m TT on an indoor 200-m track. RESULTS Plasma nitrate increased from 37 ± 15 to 615 ± 151 μM (acute) and 870 ± 259 μM (chronic) after BR supplementation. There were no V˙O2 differences between conditions at 50%, 65%, and 80% V˙O2peak (acute PL, 4194 ± 90 mL·min; chronic PL, 4216 ± 95 mL·min; acute BR, 4192 ± 113 mL·min; chronic BR, 4299 ± 92 mL·min). The 1500-m TT was unaffected by acute or chronic BR supplementation (acute PL, 4:10.4 min:s ± 2.5 s; chronic PL, 4:11.4 min:s ± 2.7 s; acute BR, 4:10.7 min:s ± 1.5 s; chronic BR, 4:10.5 min:s ± 2.2 s). However, two subjects improved their TT performance after acute (5.8 and 5.0 s) and chronic BR supplementation (7.0 and 0.5 s). CONCLUSIONS Acute and chronic BR supplementation did not reduce running V˙O2 or improve 1500-m TT performance of a group of elite distance runners, but two responders to BR were identified.
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Affiliation(s)
- Robert K Boorsma
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
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Monaco C, Whitfield J, Jain SS, Spriet LL, Bonen A, Holloway GP. Activation of AMPKα2 Is Not Required for Mitochondrial FAT/CD36 Accumulation during Exercise. PLoS One 2015; 10:e0126122. [PMID: 25965390 PMCID: PMC4429092 DOI: 10.1371/journal.pone.0126122] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/30/2015] [Indexed: 12/30/2022] Open
Abstract
Exercise has been shown to induce the translocation of fatty acid translocase (FAT/CD36), a fatty acid transport protein, to both plasma and mitochondrial membranes. While previous studies have examined signals involved in the induction of FAT/CD36 translocation to sarcolemmal membranes, to date the signaling events responsible for FAT/CD36 accumulation on mitochondrial membranes have not been investigated. In the current study muscle contraction rapidly increased FAT/CD36 on plasma membranes (7.5 minutes), while in contrast, FAT/CD36 only increased on mitochondrial membranes after 22.5 minutes of muscle contraction, a response that was exercise-intensity dependent. Considering that previous research has shown that AMP activated protein kinase (AMPK) α2 is not required for FAT/CD36 translocation to the plasma membrane, we investigated whether AMPK α2 signaling is necessary for mitochondrial FAT/CD36 accumulation. Administration of 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) induced AMPK phosphorylation, and resulted in FAT/CD36 accumulation on SS mitochondria, suggesting AMPK signaling may mediate this response. However, SS mitochondrial FAT/CD36 increased following acute treadmill running in both wild-type (WT) and AMPKα 2 kinase dead (KD) mice. These data suggest that AMPK signaling is not required for SS mitochondrial FAT/CD36 accumulation. The current data also implicates alternative signaling pathways that are exercise-intensity dependent, as IMF mitochondrial FAT/CD36 content only occurred at a higher power output. Taken altogether the current data suggests that activation of AMPK signaling is sufficient but not required for exercise-induced accumulation in mitochondrial FAT/CD36.
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Affiliation(s)
- Cynthia Monaco
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Jamie Whitfield
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Swati S. Jain
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Lawrence L. Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Arend Bonen
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Graham P. Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
- * E-mail:
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26
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Ellis R, Osborne S, Whitfield J, Parmar P, Hing W. Examining the influence of seated spinal postures (slump versus upright) upon longitudinal sciatic nerve excursion during neural mobilisation exercises. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Roke K, Zulyniak M, Gerling C, Whitfield J, Spriet L, Mutch D. Cardiometabolic Profiles and Gene Expression Following Fish Oil Supplementation: Is There a Role for FADS Genotypes? FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.917.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kaitlin Roke
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
| | - Michael Zulyniak
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
| | - Christopher Gerling
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
| | - Jamie Whitfield
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
| | - Lawrence Spriet
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
| | - David Mutch
- Human Health and Nutritional Sciences University of GuelphGuelphOntarioCanada
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Whitfield J, Ludzki A, Heigenhauser G, Spriet L, Holloway G. Beetroot Juice Supplementation Does Not Improve Mitochondrial Efficiency or ADP Sensitivity in Humans. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.824.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jamie Whitfield
- Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Alison Ludzki
- Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | | | - Lawrence Spriet
- Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Graham Holloway
- Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
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Abstract
PURPOSE OF REVIEW To discuss the recent work examining the importance of taurine in skeletal muscle and outline the discrepancy that exists between research findings in rodent vs. human skeletal muscle. RECENT FINDINGS There is clear evidence that a normal taurine level is important for the normal functioning of skeletal muscle. Taurine is believed to be involved in many cellular functions, but in skeletal muscle its main roles are to facilitate Ca2+ dependent excitation-contraction processes, contribute to the regulation of cellular volume, and aid in antioxidant defense from stress responses. Most research has studied the importance of taurine in rodent skeletal muscle by downregulating and upregulating the muscle taurine content and examining the effects on the functioning of skeletal muscle at rest and during the stress of contractions (exercise). One successful research approach is to supplement the diet with taurine, which leads to increases in muscle taurine content and contractile function in rodents. However, this approach does not work in human skeletal muscle as the processes involved in the transport of taurine into the muscle are resistant to large and prolonged increases in plasma taurine following oral taurine supplementation. At present, attempts to influence muscle function with taurine supplementation can only occur through interactions outside the muscle cell in humans. SUMMARY Future research should target the mechanisms responsible for the transport of taurine into human skeletal muscle and determine why the muscle defends the normal taurine content in the face of elevated plasma taurine levels, as opposed to the results in rodent muscle. This may lead to more fruitful usage of taurine as a skeletal muscle enhancing nutrient in athletic and clinical populations.
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Affiliation(s)
- Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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30
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Nederveen JP, Leckie JR, Whitfield J, Doherty TJ, Paterson DH, Rossiter HB, Spriet LL, Kowalchuk JM. Adjustment of O2 Uptake and Skeletal Muscle Metabolism during Exercise Transitions from Differing Metabolic Rates. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000493449.90202.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Leckie JR, Nederveen JP, Whitfield J, Doherty TJ, Paterson DH, Spriet LL, Kowalchuk JM. Skeletal Muscle PDH Activity And Pulmonary VO2 Kinetics are Attenuated After A Low Carbohydrate Diet. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000493453.82578.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Whitfield J, Leckie JR, Nederveen JP, Doherty TJ, Paterson DH, Kowalchuk JM, Spriet LL. Skeletal Muscle PDH Activity at the Onset of High Intensity Cycling Following a High-fat Diet. Med Sci Sports Exerc 2014. [DOI: 10.1249/01.mss.0000495382.97528.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Gerling CJ, Whitfield J, Mukai K, Spriet LL. Variable effects of 12 weeks of omega-3 supplementation on resting skeletal muscle metabolism. Appl Physiol Nutr Metab 2014; 39:1083-91. [PMID: 25054452 DOI: 10.1139/apnm-2014-0049] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Omega-3 supplementation has been purported to improve the function of several organs in the body, including reports of increased resting metabolic rate (RMR) and reliance on fat oxidation. However, the potential for omega-3s to modulate human skeletal muscle metabolism has received little attention. This study examined the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on whole-body RMR and the content of proteins involved in fat metabolism in human skeletal muscle. Recreationally active males supplemented with 3.0 g/day of EPA and DHA (n = 21) or olive oil (n = 9) for 12 weeks. Resting muscle biopsies were sampled in a subset of 10 subjects before (pre) and after (post) omega-3 supplementation. RMR significantly increased (5.3%, p = 0.040) following omega-3 supplementation (Pre, 1.33 ±0.05; Post, 1.40 ±0.04 kcal/min) with variable individual responses. When normalizing for body mass, this effect was lost (5.2%, p = 0.058). Omega-3s did not affect whole-body fat oxidation, and olive oil did not alter any parameter assessed. Omega-3 supplementation did not affect whole muscle, sarcolemmal, or mitochondrial FAT/CD36, FABPpm, FATP1 or FATP4 contents or mitochondrial electron chain and PDH proteins, but did increase the long form of UCP3 by 11%. In conclusion, supplementation with a high dose of omega-3s for 12 weeks increased RMR in a small and variable manner in a group of healthy young men. Omega-3 supplementation also had no effect on several proteins involved in skeletal muscle fat metabolism and did not cause mitochondrial biogenesis.
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Affiliation(s)
- Christopher J Gerling
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
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34
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Herbst EAF, Paglialunga S, Gerling C, Whitfield J, Mukai K, Chabowski A, Heigenhauser GJF, Spriet LL, Holloway GP. Omega-3 supplementation alters mitochondrial membrane composition and respiration kinetics in human skeletal muscle. J Physiol 2014; 592:1341-52. [PMID: 24396061 DOI: 10.1113/jphysiol.2013.267336] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Studies have shown increased incorporation of omega-3 fatty acids into whole skeletal muscle following supplementation, although little has been done to investigate the potential impact on the fatty acid composition of mitochondrial membranes and the functional consequences on mitochondrial bioenergetics. Therefore, we supplemented young healthy male subjects (n = 18) with fish oils [2 g eicosapentaenoic acid (EPA) and 1 g docosahexanoic acid (DHA) per day] for 12 weeks and skeletal muscle biopsies were taken prior to (Pre) and following (Post) supplementation for the analysis of mitochondrial membrane phospholipid composition and various assessments of mitochondrial bioenergetics. Total EPA and DHA content in mitochondrial membranes increased (P < 0.05) ∼450 and ∼320%, respectively, and displaced some omega-6 species in several phospholipid populations. Mitochondrial respiration, determined in permeabilized muscle fibres, demonstrated no change in maximal substrate-supported respiration, or in the sensitivity (apparent Km) and maximal capacity for pyruvate-supported respiration. In contrast, mitochondrial responses during ADP titrations demonstrated an enhanced ADP sensitivity (decreased apparent Km) that was independent of the creatine kinase shuttle. As the content of ANT1, ANT2, and subunits of the electron transport chain were unaltered by supplementation, these data suggest that prolonged omega-3 intake improves ADP kinetics in human skeletal muscle mitochondria through alterations in membrane structure and/or post-translational modification of ATP synthase and ANT isoforms. Omega-3 supplementation also increased the capacity for mitochondrial reactive oxygen species emission without altering the content of oxidative products, suggesting the absence of oxidative damage. The current data strongly emphasize a role for omega-3s in reorganizing the composition of mitochondrial membranes while promoting improvements in ADP sensitivity.
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Affiliation(s)
- E A F Herbst
- Human Health and Nutritional Sciences, University of Guelph, 491 Gordon St., Guelph, ON N1G 2W1, Canada.
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35
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O'Donovan DS, MacFhearraigh S, Whitfield J, Swigart LB, Evan GI, Mc Gee MM. Sequential Cdk1 and Plk1 phosphorylation of protein tyrosine phosphatase 1B promotes mitotic cell death. Cell Death Dis 2013; 4:e468. [PMID: 23348582 PMCID: PMC3563996 DOI: 10.1038/cddis.2012.208] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 11/09/2012] [Accepted: 11/12/2012] [Indexed: 01/20/2023]
Abstract
Mitotic cell death following prolonged arrest is an important death mechanism that is not completely understood. This study shows that Protein Tyrosine Phosphatase 1B (PTP1B) undergoes phosphorylation during mitotic arrest induced by microtubule-targeting agents (MTAs) in chronic myeloid leukaemia cells. Inhibition of cyclin-dependent kinase 1 (Cdk1) or polo-like kinase 1 (Plk1) during mitosis prevents PTP1B phosphorylation, implicating these kinases in PTP1B phosphorylation. In support of this, Cdk1 and Plk1 co-immunoprecipitate with endogenous PTP1B from mitotic cells. In addition, active recombinant Cdk1-cyclin B1 directly phosphorylates PTP1B at serine 386 in a kinase assay. Recombinant Plk1 phosphorylates PTP1B on serine 286 and 393 in vitro, however, it requires a priming phosphorylation by Cdk1 at serine 386 highlighting a novel co-operation between Cdk1 and Plk1 in the regulation of PTP1B. Furthermore, overexpression of wild-type PTP1B induced mitotic cell death, which is potentiated by MTAs. Moreover, mutation of serine 286 abrogates the cell death induced by PTP1B, whereas mutation of serine 393 does not, highlighting the importance of serine 286 phosphorylation in the execution of mitotic cell death. Finally, phosphorylation on serine 286 enhanced PTP1B phosphatase activity. Collectively, these data reveal that PTP1B activity promotes mitotic cell death and is regulated by the co-operative action of Cdk1 and Plk1 during mitotic arrest.
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Affiliation(s)
- D S O'Donovan
- UCD School of Biomolecular and Biomedical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - S MacFhearraigh
- UCD School of Biomolecular and Biomedical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - J Whitfield
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - L B Swigart
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - G I Evan
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - M M Mc Gee
- UCD School of Biomolecular and Biomedical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Paczesny S, Braun T, Vander Lugt M, Harris A, Fiema B, Hernandez J, Choi S, Kitko C, Magenau J, Yanik G, Peres E, Pawarode A, Mineishi S, Whitfield J, Jones D, Couriel D, Pavan R, Hanash S, Ferrara J, Levine J. A Three Biomarker Panel at Days 7 and 14 Can Predict Development of Grade II-IV Acute Graft-Versus-Host Disease. Biol Blood Marrow Transplant 2011. [DOI: 10.1016/j.bbmt.2010.12.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Choi S, Stiff P, Braun T, Ferrara J, Cooke K, Khaled Y, Kitko C, Lay-Luskin J, Mineishi S, Nickoloff B, Paczesny S, Pawarode A, Peres E, Reddy P, Richardson J, Rodriguez T, Smith S, Yanik G, Whitfield J, Levine J. TNF-Inhibition With Etanercept For GVHD Prevention In Alternative Donor HCT: Lower TNFR1 Levels Correlate With Better Outcomes. Biol Blood Marrow Transplant 2010. [DOI: 10.1016/j.bbmt.2009.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Dimitrievska S, Whitfield J, Hacking SA, Bureau MN. Novel carbon fiber composite for hip replacement with improvedin vitroandin vivoosseointegration. J Biomed Mater Res A 2009; 91:37-51. [DOI: 10.1002/jbm.a.32175] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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39
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Paczesny S, Levine J, Hogan J, Crawford J, Braun T, Wang H, Faca V, Zhang Q, Pitteri S, Chin A, Choi S, Kitko C, Krijanovski O, Reddy P, Mineishi S, Whitfield J, Jones D, Hanash S, Ferrara J. Elafin is a Biomarker of Graft Versus Host Disease of the Skin. Biol Blood Marrow Transplant 2009. [DOI: 10.1016/j.bbmt.2008.12.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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40
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Levine J, Adepoju L, Molitor M, McEwen E, Hutchinson R, Mody R, Mouro D, Whitfield J, Yanik G, Geiger J. A Pilot Study of Tumor Lysate-Pulsed Dendritic Cell Vaccine in Pediatric High-Risk Solid Tumor Patients Following HCT: Preliminary Results. Biol Blood Marrow Transplant 2009. [DOI: 10.1016/j.bbmt.2008.12.078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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41
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Kitko C, Mineishi S, Braun T, Choi S, Jones D, Harris A, Khaled Y, Krijanovski O, Paczesny S, Peres E, Yanik G, Whitfield J, Ferrara J, Levine J. Day7 TNFR1 Levels Following Reduced Intensity Allogeneic Hematopoietic Stem Cell Transplant (HCT) Predict For Acute GVHD. Biol Blood Marrow Transplant 2009. [DOI: 10.1016/j.bbmt.2008.12.395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
In the Hymenoptera, single locus complementary sex determination (sl-CSD) describes a system where males develop either from unfertilized haploid eggs or from fertilized diploid eggs that are homozygous at a single polymorphic sex locus. Diploid males are often inviable or sterile, and are produced more frequently under inbreeding. Within families where sl-CSD has been demonstrated, we predict that sl-CSD should be more likely in species with solitary development than in species where siblings develop gregariously (and likely inbreed). We examine this prediction in the parasitoid wasp genus Cotesia, which contains both solitary and gregarious species. Previous studies have shown that sl-CSD is absent in two gregarious species of Cotesia, but present in one gregarious species. Here, we demonstrate CSD in the solitary Cotesia vestalis, using microsatellite markers. Diploid sons are produced by inbred, but not outbred, females. However, frequencies of diploid males were lower than expected under sl-CSD, suggesting that CSD in C. vestalis involves more than one locus.
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Affiliation(s)
- J G De Boer
- Department of Entomology, University of Minnesota, St Paul, MN 55108, USA.
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Kitko C, Paczesny S, Yanik G, Braun T, Jones D, Whitfield J, Choi S, Hutchinson R, Ferrara J, Levine J. 5: Changes in TNFR1 ratios in the first week post-myeloablative allogeneic BMT correlate with GVHD, TRM and OS in children. Biol Blood Marrow Transplant 2007. [DOI: 10.1016/j.bbmt.2006.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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45
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Wurst FM, Watson B, Haber PS, Whitfield J, Wallace C, Lauer J, Weinmann W, Conigrave K. Alcohol consumption patterns amongst hepatitis C positive people receiving opioid maintenance treatment. Pharmacopsychiatry 2005. [DOI: 10.1055/s-2005-918878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chung P, Ajitanand NN, Alexander JM, Anderson M, Best D, Brady FP, Case T, Caskey W, Cebra D, Chance JL, Cole B, Crowe K, Das AC, Draper JE, Gilkes ML, Gushue S, Heffner M, Hirsch AS, Hjort EL, Holzmann W, Huo L, Issah M, Justice M, Kaplan M, Keane D, Kintner JC, Klay J, Krofcheck D, Lacey RA, Lauret J, Lisa MA, Liu H, Liu YM, Milan J, McGrath R, Milosevich Z, Odyniec G, Olson DL, Panitkin S, Porile NT, Rai G, Ritter HG, Romero JL, Scharenberg R, Srivastava B, Stone NTB, Symons TJM, Taranenko A, Whitfield J, Wienold T, Witt R, Wood L, Zhang WN, Oeschler H. Near-threshold production of the multistrange Xi- hyperon. Phys Rev Lett 2003; 91:202301. [PMID: 14683356 DOI: 10.1103/physrevlett.91.202301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2003] [Indexed: 05/24/2023]
Abstract
The yield for the multistrange Xi(-) hyperon has been measured in 6A GeV Au+Au collisions via reconstruction of its decay products pi(-) and Lambda, the latter also being reconstructed from its daughter tracks of pi(-) and p. The measurement is rather close to the threshold for Xi(-) production and therefore provides an important test of model predictions. The measured yield for Xi(-) and Lambda are compared for several centralities. In central collisions the Xi(-) yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multistrange hadron production approaches chemical equilibrium in high baryon density nuclear matter.
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Affiliation(s)
- P Chung
- Departments of Chemistry and Physics, SUNY at Stony Brook, New York 11794-3400, USA
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Chung P, Ajitanand NN, Alexander JM, Anderson M, Best D, Brady FP, Case T, Caskey W, Cebra D, Chance JL, Cole B, Crowe K, Das AC, Draper JE, Gilkes ML, Gushue S, Heffner M, Hirsch AS, Hjort EL, Holzmann W, Huo L, Issah M, Justice M, Kaplan M, Keane D, Kintner JC, Klay J, Krofcheck D, Lacey RA, Lauret J, Lisa MA, Liu H, Liu YM, McGrath R, Milosevich Z, Odyniec G, Olson DL, Panitkin S, Porile NT, Rai G, Ritter HG, Romero JL, Scharenberg R, Srivastava B, Stone NTB, Symons TJM, Taranenko A, Whitfield J, Witt R, Wood L, Zhang WN, Brown D, Pratt S, Wang F, Danielewicz P. Comparison of source images for protons, pi-'s, and lambda's in 6A GeV Au+Au collisions. Phys Rev Lett 2003; 91:162301. [PMID: 14611394 DOI: 10.1103/physrevlett.91.162301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2002] [Indexed: 05/24/2023]
Abstract
Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs p Lambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p. These observations suggest important differences in the space-time emission histories for protons, pions, and neutral strange baryons produced in the same events.
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Affiliation(s)
- P Chung
- Department of Chemistry, SUNY, Stony Brook, New York 11794-3400, USA
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Klay JL, Ajitanand NN, Alexander JM, Anderson MG, Best D, Brady FP, Case T, Caskey W, Cebra D, Chance JL, Chung P, Cole B, Crowe K, Das AC, Draper JE, Gilkes ML, Gushue S, Heffner M, Hirsch AS, Hjort EL, Huo L, Justice M, Kaplan M, Keane D, Kintner JC, Krofcheck D, Lacey RA, Lauret J, Law C, Lisa MA, Liu H, Liu YM, McGrath R, Milosevich Z, Odyniec G, Olson DL, Panitkin SY, Pinkenburg C, Porile NT, Rai G, Ritter HG, Romero JL, Scharenberg R, Schroeder L, Srivastava B, Stone NTB, Symons TJM, Wang S, Wells R, Whitfield J, Wienold T, Witt R, Wood L, Zhang WN. Longitudinal flow of protons from (2-8)A GeV central Au+Au collisions. Phys Rev Lett 2002; 88:102301. [PMID: 11909348 DOI: 10.1103/physrevlett.88.102301] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2001] [Indexed: 05/23/2023]
Abstract
Rapidity distributions of protons from central 197Au+197Au collisions measured by the E895 Collaboration in the energy range from (2-8)A GeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, <betagamma>(L), as a function of the logarithm of beam energy.
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Affiliation(s)
- J L Klay
- University of California, Davis, California 95616, USA
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Parkinson DB, Dong Z, Bunting H, Whitfield J, Meier C, Marie H, Mirsky R, Jessen KR. Transforming growth factor beta (TGFbeta) mediates Schwann cell death in vitro and in vivo: examination of c-Jun activation, interactions with survival signals, and the relationship of TGFbeta-mediated death to Schwann cell differentiation. J Neurosci 2001; 21:8572-85. [PMID: 11606645 PMCID: PMC6762809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
In some situations, cell death in the nervous system is controlled by an interplay between survival factors and negative survival signals that actively induce apoptosis. The present work indicates that the survival of Schwann cells is regulated by such a dual mechanism involving the negative survival signal transforming growth factor beta (TGFbeta), a family of growth factors that is present in the Schwann cells themselves. We analyze the interactions between this putative autocrine death signal and previously defined paracrine and autocrine survival signals and show that expression of a dominant negative c-Jun inhibits TGFbeta-induced apoptosis. This and other findings pinpoint activation of c-Jun as a key downstream event in TGFbeta-induced Schwann cell death. The ability of TGFbeta to kill Schwann cells, like normal Schwann cell death in vivo, is under a strong developmental regulation, and we show that the decreasing ability of TGFbeta to kill older cells is attributable to a decreasing ability of TGFbeta to phosphorylate c-Jun in more differentiated cells.
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies, Blocking/pharmacology
- Apoptosis/drug effects
- Apoptosis/physiology
- Autocrine Communication/physiology
- Axotomy
- Cell Count
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cell Survival/drug effects
- Cell Survival/physiology
- Cells, Cultured
- Dose-Response Relationship, Drug
- Gene Expression Regulation, Developmental
- JNK Mitogen-Activated Protein Kinases
- Laminin/pharmacology
- Mitogen-Activated Protein Kinases/metabolism
- Neuregulin-1/metabolism
- Peptides/pharmacology
- Phosphorylation/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Growth Factor/genetics
- Receptors, Growth Factor/metabolism
- Schwann Cells/cytology
- Schwann Cells/drug effects
- Schwann Cells/metabolism
- Sciatic Nerve/drug effects
- Sciatic Nerve/physiology
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Transcription, Genetic/drug effects
- Transfection
- Transforming Growth Factor beta/genetics
- Transforming Growth Factor beta/metabolism
- Transforming Growth Factor beta/pharmacology
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Affiliation(s)
- D B Parkinson
- Department of Anatomy, University College London, London WC1E 6BT, United Kingdom
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