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Wang Y, Zhang Z, Jiao W, Wang Y, Wang X, Zhao Y, Fan X, Tian L, Li X, Mi J. Ferroptosis and its role in skeletal muscle diseases. Front Mol Biosci 2022; 9:1051866. [PMID: 36406272 PMCID: PMC9669482 DOI: 10.3389/fmolb.2022.1051866] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Ferroptosis is characterized by the accumulation of iron and lipid peroxidation products, which regulates physiological and pathological processes in numerous organs and tissues. A growing body of research suggests that ferroptosis is a key causative factor in a variety of skeletal muscle diseases, including sarcopenia, rhabdomyolysis, rhabdomyosarcoma, and exhaustive exercise-induced fatigue. However, the relationship between ferroptosis and various skeletal muscle diseases has not been investigated systematically. This review’s objective is to provide a comprehensive summary of the mechanisms and signaling factors that regulate ferroptosis, including lipid peroxidation, iron/heme, amino acid metabolism, and autophagy. In addition, we tease out the role of ferroptosis in the progression of different skeletal muscle diseases and ferroptosis as a potential target for the treatment of multiple skeletal muscle diseases. This review can provide valuable reference for the research on the pathogenesis of skeletal muscle diseases, as well as for clinical prevention and treatment.
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Affiliation(s)
- Ying Wang
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Zepeng Zhang
- Research Center of Traditional Chinese Medicine, The First Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Weikai Jiao
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Yanyan Wang
- Department of Endocrinology, The First Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Xiuge Wang
- Department of Endocrinology, The First Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Yunyun Zhao
- Department of Endocrinology, The First Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Xuechun Fan
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Lulu Tian
- School of Life Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiangyan Li
- Northeast Asia Research Institute of Traditional Chinese Medicine, Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Changchun University of Chinese Medicine, Changchun, China
- *Correspondence: Xiangyan Li, ; Jia Mi,
| | - Jia Mi
- Department of Endocrinology, The First Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
- *Correspondence: Xiangyan Li, ; Jia Mi,
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Xiao R, Wei Y, Zhang Y, Xu F, Ma C, Gong Q, Gao J, Xu Y. Trilobatin, a Naturally Occurring Food Additive, Ameliorates Exhaustive Exercise-Induced Fatigue in Mice: Involvement of Nrf2/ARE/Ferroptosis Signaling Pathway. Front Pharmacol 2022; 13:913367. [PMID: 35814232 PMCID: PMC9263197 DOI: 10.3389/fphar.2022.913367] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/12/2022] [Indexed: 01/10/2023] Open
Abstract
Nrf2-mediated oxidative stress is a promising target of exhaustive exercise-induced fatigue (EEIF). Trilobatin (TLB) is a naturally occurring food additive with antioxidant effect and Nrf2 activation potency. The present study aimed to investigate the effect of TLB on EEIF and elucidate its underlying mechanism. Our results showed that TLB exerted potent anti-EEIF effect, as reflected by the rope climbing test and exhaustive swimming test. Moreover, TLB also effectively reduced the levels of lactate, creatine kinase, and blood urea nitrogen, and increased liver glycogen and skeletal muscle glycogen in mice after EEIF insult. Additionally, TLB also balanced the redox status as evidenced by decreasing the generation of reactive oxygen species and improving the antioxidant enzyme activities including superoxide dismutase, catalase, and glutathione peroxidase, as well as the level of glutathione both in the tissue of muscle and myocardium. Furthermore, TLB promoted nuclear factor erythroid 2-related factor 2 (Nrf2) from the cytoplasm to the nucleus, and upregulated its downstream antioxidant response element (ARE) including quinone oxidoreductase-1 and heme oxygenase-1. Intriguingly, TLB also upregulated the GPx4 protein expression and reduced iron overload in mice after EEIF insult. Encouragingly, the beneficial effect of TLB on EEIF-induced oxidative stress and ferroptosis were substantially abolished in Nrf2-deficient mice. In conclusion, our findings demonstrate, for the first time, that TLB alleviates EEIF-induced oxidative stress through mediating Nrf2/ARE/ferroptosis axis.
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Affiliation(s)
- Ran Xiao
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Yu Wei
- Department of Neurology, The Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Yueping Zhang
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Fan Xu
- Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Congjian Ma
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Qihai Gong
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Jianmei Gao
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Yingshu Xu
- School of Pharmacy, Zunyi Medical University, Zunyi, China
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
- *Correspondence: Yingshu Xu,
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Jung M, Ryu S, Kang M, Javadi AH, Loprinzi PD. Evaluation of the transient hypofrontality theory in the context of exercise: A systematic review with meta-analysis. Q J Exp Psychol (Hove) 2021; 75:1193-1214. [PMID: 34523365 DOI: 10.1177/17470218211048807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Accumulating research suggests that, as a result of reduced neural activity in the prefrontal cortex (PFC), higher-order cognitive function may be compromised while engaging in high-intensity acute exercise, with this phenomenon referred to as the transient hypofrontality effect. However, findings in this field remain unclear and lack a thorough synthesis of the evidence. Therefore, the purpose of this meta-analysis was to evaluate the effects of in-task acute exercise on cognitive function, and further, to examine whether this effect is moderated by the specific type of cognition (i.e., PFC-dependent vs. non-PFC-dependent). Studies were identified by electronic databases in accordance with the PRISMA guidelines. In total, 22 studies met our inclusion criteria and intercept only meta-regression models with robust variance estimation were used to calculate the weighted average effect sizes across studies. Acute exercise at all intensities did not influence cognitive function (β = -0.16, 95% CI = [-0.58, 0.27], p = .45) when exercise occurred during the cognitive task, and no significant moderation effects emerged. However, there was evidence that cognitive task type (PFC-dependent vs. non-PFC-dependent) moderated the effect of high-intensity acute exercise on a concomitant cognitive performance (β = -0.81, 95% CI = [-1.60, -0.02], p = .04). Specifically, our findings suggest that PFC-dependent cognition is impaired while engaging in an acute bout of high-intensity exercise, providing support for the transient hypofrontality theory. We discuss these findings in the context of reticular-activating and cognitive-energetic perspectives.
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Affiliation(s)
- Myungjin Jung
- Health and Sport Analytics Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS, USA.,Exercise & Memory Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS, USA
| | - Seungho Ryu
- Health and Sport Analytics Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS, USA
| | - Minsoo Kang
- Health and Sport Analytics Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS, USA
| | - Amir-Homayoun Javadi
- School of Psychology, University of Kent, Canterbury, UK.,Department of Experimental Psychology, Institute of Neuroscience, University College London, London, UK.,School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran
| | - Paul D Loprinzi
- Exercise & Memory Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS, USA
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Scheffer DDL, Latini A. Exercise-induced immune system response: Anti-inflammatory status on peripheral and central organs. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165823. [PMID: 32360589 PMCID: PMC7188661 DOI: 10.1016/j.bbadis.2020.165823] [Citation(s) in RCA: 172] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 04/07/2020] [Accepted: 04/25/2020] [Indexed: 12/13/2022]
Abstract
A wide array of molecular pathways has been investigated during the past decade in order to understand the mechanisms by which the practice of physical exercise promotes neuroprotection and reduces the risk of developing communicable and non-communicable chronic diseases. While a single session of physical exercise may represent a challenge for cell homeostasis, repeated physical exercise sessions will improve immunosurveillance and immunocompetence. Additionally, immune cells from the central nervous system will acquire an anti-inflammatory phenotype, protecting central functions from age-induced cognitive decline. This review highlights the exercise-induced anti-inflammatory effect on the prevention or treatment of common chronic clinical and experimental settings. It also suggests the use of pterins in biological fluids as sensitive biomarkers to follow the anti-inflammatory effect of physical exercise.
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Affiliation(s)
- Débora da Luz Scheffer
- Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
| | - Alexandra Latini
- Laboratório de Bioenergética e Estresse Oxidativo, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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Radel R, Tempest GD, Brisswalter J. The long and winding road: Effects of exercise intensity and type upon sustained attention. Physiol Behav 2018; 195:82-89. [DOI: 10.1016/j.physbeh.2018.07.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 12/22/2022]
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Dienel GA, Cruz NF. Aerobic glycolysis during brain activation: adrenergic regulation and influence of norepinephrine on astrocytic metabolism. J Neurochem 2016; 138:14-52. [DOI: 10.1111/jnc.13630] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/24/2016] [Accepted: 03/31/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Gerald A. Dienel
- Department of Cell Biology and Physiology; University of New Mexico; Albuquerque; New Mexico USA
- Department of Neurology; University of Arkansas for Medical Sciences; Little Rock Arkansas USA
| | - Nancy F. Cruz
- Department of Neurology; University of Arkansas for Medical Sciences; Little Rock Arkansas USA
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McDaniel J, Davuluri G, Hill EA, Moyer M, Runkana A, Prayson R, van Lunteren E, Dasarathy S. Hyperammonemia results in reduced muscle function independent of muscle mass. Am J Physiol Gastrointest Liver Physiol 2016; 310:G163-70. [PMID: 26635319 PMCID: PMC4971815 DOI: 10.1152/ajpgi.00322.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/14/2015] [Indexed: 01/31/2023]
Abstract
The mechanism of the nearly universal decreased muscle strength in cirrhosis is not known. We evaluated whether hyperammonemia in cirrhosis causes contractile dysfunction independent of reduced skeletal muscle mass. Maximum grip strength and muscle fatigue response were determined in cirrhotic patients and controls. Blood and muscle ammonia concentrations and grip strength normalized to lean body mass were measured in the portacaval anastomosis (PCA) and sham-operated pair-fed control rats (n = 5 each). Ex vivo contractile studies in the soleus muscle from a separate group of Sprague-Dawley rats (n = 7) were performed. Skeletal muscle force of contraction, rate of force development, and rate of relaxation were measured. Muscles were also subjected to a series of pulse trains at a range of stimulation frequencies from 20 to 110 Hz. Cirrhotic patients had lower maximum grip strength and greater muscle fatigue than control subjects. PCA rats had a 52.7 ± 13% lower normalized grip strength compared with control rats, and grip strength correlated with the blood and muscle ammonia concentrations (r(2) = 0.82). In ex vivo muscle preparations following a single pulse, the maximal force, rate of force development, and rate of relaxation were 12.1 ± 3.5 g vs. 6.2 ± 2.1 g; 398.2 ± 100.4 g/s vs. 163.8 ± 97.4 g/s; -101.2 ± 22.2 g/s vs. -33.6 ± 22.3 g/s in ammonia-treated compared with control muscle preparation, respectively (P < 0.001 for all comparisons). Tetanic force, rate of force development, and rate of relaxation were depressed across a range of stimulation from 20 to 110 Hz. These data provide the first direct evidence that hyperammonemia impairs skeletal muscle strength and increased muscle fatigue and identifies a potential therapeutic target in cirrhotic patients.
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Affiliation(s)
- John McDaniel
- 1Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio; ,2Department of Exercise Science, Kent State University Kent, Ohio;
| | | | | | - Michelle Moyer
- 1Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio;
| | - Ashok Runkana
- 3Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio; ,4Department of Medicine, Cleveland Clinic, Cleveland, Ohio;
| | - Richard Prayson
- 5Department of Pathology, Cleveland Clinic, Cleveland, Ohio;
| | - Erik van Lunteren
- 1Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio; ,6Case Western Reserve University Cleveland, Ohio
| | - Srinivasan Dasarathy
- Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio; Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio; and
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Falkowska A, Gutowska I, Goschorska M, Nowacki P, Chlubek D, Baranowska-Bosiacka I. Energy Metabolism of the Brain, Including the Cooperation between Astrocytes and Neurons, Especially in the Context of Glycogen Metabolism. Int J Mol Sci 2015; 16:25959-81. [PMID: 26528968 PMCID: PMC4661798 DOI: 10.3390/ijms161125939] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/27/2015] [Accepted: 10/16/2015] [Indexed: 01/15/2023] Open
Abstract
Glycogen metabolism has important implications for the functioning of the brain, especially the cooperation between astrocytes and neurons. According to various research data, in a glycogen deficiency (for example during hypoglycemia) glycogen supplies are used to generate lactate, which is then transported to neighboring neurons. Likewise, during periods of intense activity of the nervous system, when the energy demand exceeds supply, astrocyte glycogen is immediately converted to lactate, some of which is transported to the neurons. Thus, glycogen from astrocytes functions as a kind of protection against hypoglycemia, ensuring preservation of neuronal function. The neuroprotective effect of lactate during hypoglycemia or cerebral ischemia has been reported in literature. This review goes on to emphasize that while neurons and astrocytes differ in metabolic profile, they interact to form a common metabolic cooperation.
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Affiliation(s)
- Anna Falkowska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University, Broniewskiego 24, 71-460 Szczecin, Poland.
| | - Marta Goschorska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Przemysław Nowacki
- Department of Neurology, Pomeranian Medical University, Unii Lubelskiej 1, 71-225 Szczecin, Poland.
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland.
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Back C, Thiesen KL, Skovgaard K, Edvinsson L, Jensen LT, Larsen VA, Iversen HK. RAAS and stress markers in acute ischemic stroke: preliminary findings. Acta Neurol Scand 2015; 131:132-9. [PMID: 25214428 DOI: 10.1111/ane.12298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Angiotensin II type 1 receptor blockade has neuroprotective effects in animal stroke models, but no effects in clinical stroke trials. We evaluated cerebral and peripheral changes in the renin angiotensin aldosterone system (RAAS) and stress responses in acute ischemic stroke patients. MATERIALS AND METHODS Blood from a jugular and cubital vein was collected within 48 h of stroke onset, after 24 and 48 h, and renin, angiotensin I, angiotensin II, aldosterone, norepinephrine, epinephrine, and cortisol were measured. Post-stroke cubital vein samples were collected after 8 (4.7-10) months. RESULTS The acute systolic blood pressure was significantly increased, 148 (141-168) vs 140 (130-147) mmHg post-stroke. Angiotensin I, renin and aldosterone levels were significantly lower, angiotensin II was unchanged, and ACE activity was higher in the acute phase compared to post-stroke. No differences in RAAS were detected between jugular and cubital plasma levels. Jugular venous plasma levels of epinephrine and cortisol were elevated in the acute phase compared to cubital levels (P < 0.05). CONCLUSION Increased epinephrine and cortisol levels in the jugular vein blood may reflect a higher peripheral turnover. The observed changes in RAAS in the acute stroke phase are consistent with responses to increased blood pressure.
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Affiliation(s)
- C. Back
- Stroke Unit; Department of Neurology; Copenhagen University Hospital; Glostrup Denmark
- Translational Stroke Center; Copenhagen University Hospital; Glostrup Denmark
| | - K. L. Thiesen
- Department of Anesthesiology; Copenhagen University Hospital; Glostrup Denmark
| | - K. Skovgaard
- Department of Anesthesiology; Copenhagen University Hospital; Glostrup Denmark
| | - L. Edvinsson
- Glostrup Research Institute; Copenhagen University Hospital; Glostrup Denmark
| | - L. T. Jensen
- Department of Clinical Physiology; Copenhagen University Hospital; Glostrup Denmark
| | - V. A. Larsen
- Department of Radiology; Copenhagen University Hospital; Glostrup Denmark
| | - H. K. Iversen
- Stroke Unit; Department of Neurology; Copenhagen University Hospital; Glostrup Denmark
- Translational Stroke Center; Copenhagen University Hospital; Glostrup Denmark
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Kılıç M, Ulusoy Ö, Cırrık S, Hindistan İ, Özkaya Y. Effect of exercise intensity on cerebrospinal fluid interleukin-6 concentration during recovery from exhaustive exercise in rats. ACTA ACUST UNITED AC 2014; 101:21-31. [DOI: 10.1556/aphysiol.100.2013.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Temesi J, Arnal PJ, Davranche K, Bonnefoy R, Levy P, Verges S, Millet GY. Does Central Fatigue Explain Reduced Cycling after Complete Sleep Deprivation? Med Sci Sports Exerc 2013; 45:2243-53. [PMID: 23760468 DOI: 10.1249/mss.0b013e31829ce379] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Differential effects of differing intensities of acute exercise on speed and accuracy of cognition: A meta-analytical investigation. Brain Cogn 2012; 80:338-51. [DOI: 10.1016/j.bandc.2012.09.001] [Citation(s) in RCA: 278] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 07/19/2012] [Accepted: 09/03/2012] [Indexed: 01/28/2023]
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13
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Secher NH, Rasmussen P. Food for thought. J Physiol 2012; 590:1013. [DOI: 10.1113/jphysiol.2011.224337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Seifert T, Secher NH. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans. Prog Neurobiol 2011; 95:406-26. [PMID: 21963551 DOI: 10.1016/j.pneurobio.2011.09.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/13/2011] [Accepted: 09/19/2011] [Indexed: 11/26/2022]
Abstract
This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF as evidenced by pharmacological manipulation of adrenergic and cholinergic receptors. Cholinergic blockade by glycopyrrolate blocks the exercise-induced increase in the transcranial Doppler determined mean flow velocity (MCA Vmean). Conversely, alpha-adrenergic activation increases that expression of cerebral perfusion and reduces the near-infrared determined cerebral oxygenation at rest, but not during exercise associated with an increased cerebral metabolic rate for oxygen (CMRO(2)), suggesting competition between CMRO(2) and sympathetic control of CBF. CMRO(2) does not change during even intense handgrip, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non-oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade, but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced by increased release of brain-derived neurotrophic factor (BDNF) from the brain.
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Affiliation(s)
- Thomas Seifert
- Department of Anaesthesia and The Copenhagen Muscle Research Centre, Rigshospitalet 2041, University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
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Wilkinson DJ, Smeeton NJ, Castle PC, Watt PW. Absence of neuropsychological impairment in hyperammonaemia in healthy young adults; possible synergism in development of hepatic encephalopathy (HE) symptoms? Metab Brain Dis 2011; 26:203-12. [PMID: 21773808 DOI: 10.1007/s11011-011-9251-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 07/04/2011] [Indexed: 12/16/2022]
Abstract
The aetiology of minimal hepatic encephalopathy (mHE) remains unclear. It is generally accepted that hyperammonaemia plays a major role, however there are a multitude of metabolic perturbations present. To determine the contribution of hyperammonaemia to mHE symptom development, ten healthy males (Age:25 ± 5 yrs, BM:76.3 ± 7.1 kg, Height:178.6 ± 4.5 cm, mean ± SD) received two 4 h intravenous infusions of either a 2% ammonium chloride solution (AMM) or a placebo (PLA;0.9% sodium chloride) using a double blind cross-over design. Sensations of fatigue were measured at baseline, 2 and 4 h using the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) questionnaire. Learning & memory, motor control and cognition were assessed using Rey's Auditory Verbal Learning Test (AVL), Continuous Compensatory Tracking (COMPTRACK) Task and Inhibitory Control Test (ICT) respectively. Arterialised venous blood samples were collected every hour, and analysed for ammonia concentration. There was a significantly higher plasma ammonia concentration in the AMM trial than the PLA trial at every time point during the infusion, peaking at 2 h (57 ± 4 μmol/L PLA, 225 ± 14 μmol/L AMM; p < 0.05). At 2 h there were significantly higher sensations of general fatigue (Z = -2.527, p = 0.008, 2 tailed) and physical fatigue (Z = -2.156, p = 0.027, 2 tailed), and lower sensations of vigour (Z = -2.456, p = 0.012, 2 tailed) for the AMM trial. There were no significant effects on the performance of the psychological tasks. These results demonstrate that hyperammonaemia in the absence of other complications induces significant sensations of fatigue but does not cause the typically observed performance impairment in individuals with mHE. Supporting the hypothesis for synergism between ammonia and other co-factors in mHE.
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Affiliation(s)
- Daniel J Wilkinson
- Department of Sport and Exercise Science, Chelsea School, University of Brighton, 30 Carlisle Road, Eastbourne BN20 7SN, UK.
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Vigorous exercise increases brain lactate and Glx (glutamate+glutamine): a dynamic 1H-MRS study. Neuroimage 2011; 57:1324-30. [PMID: 21640838 DOI: 10.1016/j.neuroimage.2011.05.048] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 05/07/2011] [Accepted: 05/17/2011] [Indexed: 01/12/2023] Open
Abstract
Vigorous exercise increases lactate and glucose uptake by the brain in excess of the increase in brain oxygen uptake. The metabolic fate of this non-oxidized carbohydrate entering the brain is poorly understood, but accumulation of lactate in the brain and/or increased net synthesis of amino acid neurotransmitters are possible explanations. Previous proton magnetic resonance spectroscopy (1H-MRS) studies using conventional pulse sequences have not detected changes in brain lactate following exercise. This contrasts with 1H-MRS studies showing increased brain lactate when blood lactate levels are raised by an intravenous infusion of sodium lactate. Using a J-editing 1H-MRS technique for measuring lactate, we demonstrated a significant 19% increase in lactate in the visual cortex following graded exercise to approximately 85% of predicted maximum heart rate. However, the magnitude of the increase was insufficient to account for more than a small fraction of the non-oxidized carbohydrate entering the brain with exercise. We also report a significant 18% increase in Glx (combined signal from glutamate and glutamine) in visual cortex following exercise, which may represent an activity-dependent increase in glutamate. Future studies will be necessary to test the hypothesis that non-oxidized carbohydrate entering the brain during vigorous exercise is directed, in part, toward increased net synthesis of amino acid neurotransmitters. The possible relevance of these findings to panic disorder and major depression is discussed.
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Rasmussen P, Vedel JC, Olesen J, Adser H, Pedersen MV, Hart E, Secher NH, Pilegaard H. In humans IL-6 is released from the brain during and after exercise and paralleled by enhanced IL-6 mRNA expression in the hippocampus of mice. Acta Physiol (Oxf) 2011; 201:475-82. [PMID: 21083649 DOI: 10.1111/j.1748-1716.2010.02223.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AIM Plasma interleukin-6 (IL-6) increases during exercise by release from active muscles and during prolonged exercise also from the brain. The IL-6 release from muscles continues into recovery and we tested whether the brain also releases IL-6 in recovery from prolonged exercise in humans. Additionally, it was evaluated in mice whether brain release of IL-6 reflected enhanced IL-6 mRNA expression in the brain as modulated by brain glycogen levels. METHODS Nine healthy male subjects completed 4 h of ergometer rowing while the arterio-jugular venous difference (a-v diff) for IL-6 was determined. The IL-6 mRNA and the glycogen content were determined in mouse hippocampus, cerebellum and cortex before and after 2 h treadmill running (N = 8). RESULTS At rest, the IL-6 a-v diff was negligible but decreased to -2.2 ± 1.9 pg ml(-1) at the end of exercise and remained low (-2.1 ± 2.1 pg ml(-1) ) 1 h into the recovery (P < 0.05 vs. rest). IL-6 mRNA was expressed in the three parts of the brain with the lowest content in the hippocampus (P < 0.05) coupled to the highest glycogen content (3.2 ± 0.8 mmol kg(-1) ). Treadmill running increased the hippocampal IL-6 mRNA content 2-3-fold (P < 0.05), while the hippocampal glycogen content decreased to 2.6 ± 0.6 mmol kg(-1) (P < 0.05) with no significant changes in the two other parts of the brain. CONCLUSION Human brain releases IL-6 both during and in recovery from prolonged exercise and mouse data suggest that concurrent changes in IL-6 mRNA and glycogen levels make the hippocampus a likely source of the IL-6 release from the brain.
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Affiliation(s)
- P Rasmussen
- Department of Anesthesia, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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18
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Hecker JG, McGarvey M. Heat shock proteins as biomarkers for the rapid detection of brain and spinal cord ischemia: a review and comparison to other methods of detection in thoracic aneurysm repair. Cell Stress Chaperones 2011; 16:119-31. [PMID: 20803353 PMCID: PMC3059797 DOI: 10.1007/s12192-010-0224-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 08/16/2010] [Accepted: 08/17/2010] [Indexed: 12/14/2022] Open
Abstract
The heat shock proteins (HSPs) are members of highly conserved families of molecular chaperones that have multiple roles in vivo. We discuss the HSPs in general, and Hsp70 and Hsp27 in particular, and their rapid induction by severe stress in the context of tissue and organ expression in physiology and disease. We describe the current state of knowledge of the relationship and interactions between extra- and intracellular HSPs and describe mechanisms and significance of extracellular expression of HSPs. We focus on the role of the heat shock proteins as biomarkers of central nervous system (CNS) ischemia and other severe stressors and discuss recent and novel technologies for rapid measurement of proteins in vivo and ex vivo. The HSPs are compared to other proposed small molecule biomarkers for detection of CNS injury and to other methods of detecting brain and spinal cord ischemia in real time. While other biomarkers may be of use in prognosis and in design of appropriate therapies, none appears to be as rapid as the HSPs; therefore, no other measurement appears to be of use in the immediate detection of ongoing severe ischemia with the intention to immediately intervene to reduce the severity or risk of permanent damage.
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Affiliation(s)
- James G Hecker
- Department of Anesthesiology and Critical Care, University of Pennsylvania, 3620 Hamilton Walk, Philadelphia, PA 19104-6112, USA.
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19
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Seifert T, Fisher JP, Young CN, Hartwich D, Ogoh S, Raven PB, Fadel PJ, Secher NH. Experimental Physiology -Research Paper: Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans. Exp Physiol 2010; 95:1016-25. [DOI: 10.1113/expphysiol.2010.054346] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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20
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Alvarez P, Levine JD, Green PG. Eccentric exercise induces chronic alterations in musculoskeletal nociception in the rat. Eur J Neurosci 2010; 32:819-25. [PMID: 20726881 DOI: 10.1111/j.1460-9568.2010.07359.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Eccentric muscle exercise is a common cause of acute and chronic (lasting days to weeks) musculoskeletal pain. To evaluate the mechanisms involved, we have employed a model in the rat, in which eccentric hind limb exercise produces both acute mechanical hyperalgesia as well as long-term changes characterized by enhanced hyperalgesia to subsequent exposure to an inflammatory mediator. Eccentric exercise of the hind limb produced mechanical hyperalgesia, measured in the gastrocnemius muscle, which returned to baseline at 120 h post-exercise. When nociceptive thresholds had returned to baseline, intramuscular injection of prostaglandin E(2) (PGE(2) ) induced hyperalgesia that was unattenuated 240 h later, much longer than PGE(2) -induced hyperalgesia in unexercised rats (4 h). This marked prolongation of PGE(2) hyperalgesia induced by eccentric exercise was prevented by the spinal intrathecal injection of oligodeoxynucleotide antisense to protein kinase Cε, a second messenger in nociceptors implicated in the induction of chronic pain. Exercise-induced hyperalgesia and prolongation of PGE(2) hyperalgesia were inhibited by the spinal intrathecal administration of antisense for the interleukin-6 but not the tumor necrosis factor α type 1 receptor. These findings provide further insight into the mechanism underlying exercise-induced chronic muscle pain, and suggest novel approaches for the prevention and treatment of exercise- or work-related chronic musculoskeletal pain syndromes.
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Affiliation(s)
- Pedro Alvarez
- Department of Oral and Maxillofacial Surgery, University of California San Francisco, San Francisco, CA 94143-0440, USA
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21
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Rasmussen P, Foged EM, Krogh-Madsen R, Nielsen J, Nielsen TR, Olsen NV, Petersen NC, Sørensen TA, Secher NH, Lundby C. Effects of erythropoietin administration on cerebral metabolism and exercise capacity in men. J Appl Physiol (1985) 2010; 109:476-83. [DOI: 10.1152/japplphysiol.00234.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Recombinant human erythropoietin (EPO) increases exercise capacity by stimulating erythropoiesis and subsequently enhancing oxygen delivery to the working muscles. In a large dose, EPO crosses the BBB and may reduce central fatigue and improve cognition. In turn, this would augment exercise capacity independent of erythropoiesis. To test this hypothesis, 15 healthy young men (18–34 years old, 74 ± 7 kg) received either 3 days of high-dose (30,000 IU/day; n = 7) double-blinded placebo controlled or 3 mo of low-dose (5,000 IU/wk; n = 8) counter-balanced open but controlled administration of EPO. We recorded exercise capacity, transcranial ultrasonography-derived middle cerebral artery blood velocity, and arterial-internal jugular venous concentration differences of glucose and lactate. In addition, cognitive function, ratings of perceived exertion, ventilation, and voluntary activation by transcranial magnetic stimulation-induced twitch force were evaluated. Although EPO in a high dose increased cerebrospinal fluid EPO concentration ∼20-fold and affected ventilation and cerebral glucose and lactate metabolism ( P < 0.05), 3 days of high-dose EPO administration had no effect on cognition, voluntary activation, or exercise capacity, but ratings of perceived exertion increased ( P < 0.05). We confirmed that 3 mo of administration of EPO increases exercise capacity, but the improvement could not be accounted for by other mechanisms than enhanced oxygen delivery. In conclusion, EPO does not attenuate central fatigue or change cognitive performance strategy, suggesting that EPO enhances exercise capacity exclusively by increased oxygen delivery to the working muscles.
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Affiliation(s)
- P. Rasmussen
- Departments of 1Anesthesia, and
- Copenhagen Muscle Research Centre, and
- Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | | | - R. Krogh-Madsen
- Infectious Diseases,
- Centre of Inflammation and Metabolism, Rigshospitalet, Copenhagen
| | | | | | - N. V. Olsen
- Departments of 1Anesthesia, and
- Neuroscience and Pharmacology, and
| | - N. C. Petersen
- Exercise Sciences, University of Copenhagen, Denmark; and
| | | | - N. H. Secher
- Departments of 1Anesthesia, and
- Copenhagen Muscle Research Centre, and
| | - C. Lundby
- Copenhagen Muscle Research Centre, and
- Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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22
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Wilkinson DJ, Smeeton NJ, Watt PW. Ammonia metabolism, the brain and fatigue; revisiting the link. Prog Neurobiol 2010; 91:200-19. [PMID: 20138956 DOI: 10.1016/j.pneurobio.2010.01.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 01/27/2010] [Accepted: 01/29/2010] [Indexed: 12/15/2022]
Abstract
This review addresses the ammonia fatigue theory in light of new evidence from exercise and disease studies and aims to provide a view of the role of ammonia during exercise. Hyperammonemia is a condition common to pathological liver disorders and intense or exhausting exercise. In pathology, hyperammonemia is linked to impairment of normal brain function and the onset of the neurological condition, hepatic encephalopathy. Elevated blood ammonia concentrations arise due to a diminished capacity for removal via the liver and lead to increased exposure of organs, such as the brain, to the toxic effects of ammonia. High levels of brain ammonia can lead to deleterious alterations in astrocyte morphology, cerebral energy metabolism and neurotransmission, which may in turn impact on the functioning of important signalling pathways within the neuron. Such changes are believed to contribute to the disturbances in neuropsychological function, in particular the learning, memory, and motor control deficits observed in animal models of liver disease and also patients with cirrhosis. Hyperammonemia in exercise occurs as a result of an increased production by contracting muscle, through adenosine monophosphate (AMP) deamination (the purine nucleotide cycle) and branched chain amino acid (BCAA) deamination prior to oxidation. Plasma concentrations of ammonia during exercise often achieve or exceed those measured in liver disease patients, resulting in increased cerebral uptake. In this article we propose that exercise-induced hyperammonemia may lead to concomitant disturbances in brain function, potentially through similar mechanisms underpinning pathology, which may impact on performance as fatigue or reduced function, especially during extreme exercise.
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Affiliation(s)
- Daniel J Wilkinson
- Department of Sport and Exercise Science, Chelsea School, University of Brighton, 30 Carlisle Road, Eastbourne, UK.
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23
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Hecker JG, Sundram H, Zou S, Praestgaard A, Bavaria JE, Ramchandren S, McGarvey M. Heat shock proteins HSP70 and HSP27 in the cerebral spinal fluid of patients undergoing thoracic aneurysm repair correlate with the probability of postoperative paralysis. Cell Stress Chaperones 2008; 13:435-46. [PMID: 18418731 PMCID: PMC2673924 DOI: 10.1007/s12192-008-0039-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 10/22/2022] Open
Abstract
An understanding of the time course and correlation with injury of heat shock proteins (HSPs) released during brain and/or spinal cord cellular stress (ischemia) is critical in understanding the role of the HSPs in cellular survival, and may provide a clinically useful biomarker of severe cellular stress. We have analyzed the levels of HSPs in the cerebrospinal fluid (CSF) from patients who are undergoing thoracic aneurysm repair. Blood and CSF samples were collected at regular intervals, and CSF was analyzed by enzyme-linked immunosorbent assay for HSP70 and HSP27. These results were correlated with intraoperative somatosensory-evoked potentials measurements and postoperative paralysis. We find that the levels of these proteins in many patients are elevated and that the degree of elevation correlates with the risk of permanent paralysis. We hypothesize that sequential measurement intraoperatively of the levels of the heat shock proteins HSP70 and HSP27 in the CSF can predict those patients who are at greatest risk for paralysis during thoracic aneurysm surgery and will allow us to develop means of preventing or attenuating this severe and often fatal complication.
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Affiliation(s)
- James G Hecker
- Department of Anesthesia, University of Pennsylvania, Philadelphia, PA 19104-6112, USA.
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24
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Seifert TS, Brassard P, Jørgensen TB, Hamada AJ, Rasmussen P, Quistorff B, Secher NH, Nielsen HB. Cerebral non-oxidative carbohydrate consumption in humans driven by adrenaline. J Physiol 2008; 587:285-93. [PMID: 19015195 DOI: 10.1113/jphysiol.2008.162073] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
During brain activation, the decrease in the ratio between cerebral oxygen and carbohydrate uptake (6 O(2)/(glucose + (1)/(2) lactate); the oxygen-carbohydrate index, OCI) is attenuated by the non-selective beta-adrenergic receptor antagonist propranolol, whereas OCI remains unaffected by the beta(1)-adrenergic receptor antagonist metroprolol. These observations suggest involvement of a beta(2)-adrenergic mechanism in non-oxidative metabolism for the brain. Therefore, we evaluated the effect of adrenaline (0.08 microg kg(-1) min(-1) i.v. for 15 min) and noradrenaline (0.5, 0.1 and 0.15 microg kg(-1) min(-1) i.v. for 20 min) on the arterial to internal jugular venous concentration differences (a-v diff) of O(2), glucose and lactate in healthy humans. Adrenaline (n = 10) increased the arterial concentrations of O(2), glucose and lactate (P < 0.05) and also increased the a-v diff for glucose from 0.6 +/- 0.1 to 0.8 +/- 0.2 mM (mean +/- s.d.; P < 0.05). The a-v diff for lactate shifted from a net cerebral release to an uptake and OCI was lowered from 5.1 +/- 1.5 to 3.6 +/- 0.4 (P < 0.05) indicating an 8-fold increase in the rate of non-oxidative carbohydrate uptake during adrenaline infusion (P < 0.01). Conversely, noradrenaline (n = 8) did not affect the OCI despite an increase in the a-v diff for glucose (P < 0.05). These results support that non-oxidative carbohydrate consumption for the brain is driven by a beta(2)-adrenergic mechanism, giving neurons an abundant provision of energy when plasma adrenaline increases.
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Affiliation(s)
- Thomas S Seifert
- Department of Anaesthesia, The Copenhagen Muscle Research Centre, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Denmark.
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25
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Abstract
The human brain releases a small amount of lactate at rest, and even an increase in arterial blood lactate during anesthesia does not provoke a net cerebral lactate uptake. However, during cerebral activation associated with exercise involving a marked increase in plasma lactate, the brain takes up lactate in proportion to the arterial concentration. Cerebral lactate uptake, together with glucose uptake, is larger than the uptake accounted for by the concomitant O(2) uptake, as reflected by the decrease in cerebral metabolic ratio (CMR) [the cerebral molar uptake ratio O(2)/(glucose+(1/2) lactate)] from a resting value of 6 to <2. The CMR also decreases when plasma lactate is not increased, as during prolonged exercise, cerebral activation associated with mental activity, or exposure to a stressful situation. The CMR decrease is prevented with combined beta(1)- and beta(2)-adrenergic receptor blockade but not with beta(1)-adrenergic blockade alone. Also, CMR decreases in response to epinephrine, suggesting that a beta(2)-adrenergic receptor mechanism enhances glucose and perhaps lactate transport across the blood-brain barrier. The pattern of CMR decrease under various forms of brain activation suggests that lactate may partially replace glucose as a substrate for oxidation. Thus, the notion of the human brain as an obligatory glucose consumer is not without exceptions.
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Affiliation(s)
- Bjørn Quistorff
- Department of Biomedical Sciences, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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26
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Larsen TS, Rasmussen P, Overgaard M, Secher NH, Nielsen HB. Non-selective beta-adrenergic blockade prevents reduction of the cerebral metabolic ratio during exhaustive exercise in humans. J Physiol 2008; 586:2807-15. [PMID: 18403423 DOI: 10.1113/jphysiol.2008.151449] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Intense exercise decreases the cerebral metabolic ratio of oxygen to carbohydrates [O(2)/(glucose + (1/2)lactate)], but whether this ratio is influenced by adrenergic stimulation is not known. In eight males, incremental cycle ergometry increased arterial lactate to 15.3 +/- 4.2 mm (mean +/- s.d.) and the arterial-jugular venous (a-v) difference from -0.02 +/- 0.03 mm at rest to 1.0 +/- 0.5 mm (P < 0.05). The a-v difference for glucose increased from 0.7 +/- 0.3 to 0.9 +/- 0.1 mm (P < 0.05) at exhaustion and the cerebral metabolic ratio decreased from 5.5 +/- 1.4 to 3.0 +/- 0.3 (P < 0.01). Administration of a non-selective beta-adrenergic (beta(1) + beta(2)) receptor antagonist (propranolol) reduced heart rate (69 +/- 8 to 58 +/- 6 beats min(-1)) and exercise capacity (239 +/- 42 to 209 +/- 31 W; P < 0.05) with arterial lactate reaching 9.4 +/- 3.6 mm. During exercise with propranolol, the increase in a-v lactate difference (to 0.5 +/- 0.5 mm; P < 0.05) was attenuated and the a-v glucose difference and the cerebral metabolic ratio remained at levels similar to those at rest. Together with the previous finding that the cerebral metabolic ratio is unaffected during exercise with administration of the beta(1)-receptor antagonist metropolol, the present results suggest that the cerebral metabolic ratio decreases in response to a beta(2)-receptor mechanism.
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Affiliation(s)
- Thomas Seifert Larsen
- Department of Anaesthesia, Rigshospitalet 2041, Blegdamsvej 9, DK 2100, Copenhagen Ø, Denmark.
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27
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Secher NH, Seifert T, Van Lieshout JJ. Cerebral blood flow and metabolism during exercise: implications for fatigue. J Appl Physiol (1985) 2008; 104:306-14. [PMID: 17962575 DOI: 10.1152/japplphysiol.00853.2007] [Citation(s) in RCA: 248] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During exercise: the Kety-Schmidt-determined cerebral blood flow (CBF) does not change because the jugular vein is collapsed in the upright position. In contrast, when CBF is evaluated by 133Xe clearance, by flow in the internal carotid artery, or by flow velocity in basal cerebral arteries, a ∼25% increase is detected with a parallel increase in metabolism. During activation, an increase in cerebral O2 supply is required because there is no capillary recruitment within the brain and increased metabolism becomes dependent on an enhanced gradient for oxygen diffusion. During maximal whole body exercise, however, cerebral oxygenation decreases because of eventual arterial desaturation and marked hyperventilation-related hypocapnia of consequence for CBF. Reduced cerebral oxygenation affects recruitment of motor units, and supplemental O2 enhances cerebral oxygenation and work capacity without effects on muscle oxygenation. Also, the work of breathing and the increasing temperature of the brain during exercise are of importance for the development of so-called central fatigue. During prolonged exercise, the perceived exertion is related to accumulation of ammonia in the brain, and data support the theory that glycogen depletion in astrocytes limits the ability of the brain to accelerate its metabolism during activation. The release of interleukin-6 from the brain when exercise is prolonged may represent a signaling pathway in matching the metabolic response of the brain. Preliminary data suggest a coupling between the circulatory and metabolic perturbations in the brain during strenuous exercise and the ability of the brain to access slow-twitch muscle fiber populations.
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28
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Abstract
The metabolic response to brain activation in exercise might be expressed as the cerebral metabolic ratio (MR; uptake O2/glucose + 1/2 lactate). At rest, brain energy is provided by a balanced oxidation of glucose as MR is close to 6, but activation provokes a 'surplus' uptake of glucose relative to that of O2. Whereas MR remains stable during light exercise, it is reduced by 30% to 40% when exercise becomes demanding. The MR integrates metabolism in brain areas stimulated by sensory input from skeletal muscle, the mental effort to exercise and control of exercising limbs. The MR decreases during prolonged exhaustive exercise where blood lactate remains low, but when vigorous exercise raises blood lactate, the brain takes up lactate in an amount similar to that of glucose. This lactate taken up by the brain is oxidised as it does not accumulate within the brain and such pronounced brain uptake of substrate occurs independently of plasma hormones. The 'surplus' of glucose equivalents taken up by the activated brain may reach approximately 10 mmol, that is, an amount compatible with the global glycogen level. It is suggested that a low MR predicts shortage of energy that ultimately limits motor activation and reflects a biologic background for 'central fatigue'.
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Affiliation(s)
- Mads K Dalsgaard
- Department of Anaesthesia and The Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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29
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Mohr M, Rasmussen P, Drust B, Nielsen B, Nybo L. Environmental heat stress, hyperammonemia and nucleotide metabolism during intermittent exercise. Eur J Appl Physiol 2006; 97:89-95. [PMID: 16485104 DOI: 10.1007/s00421-006-0152-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2006] [Indexed: 11/25/2022]
Abstract
This study investigated the influence of environmental heat stress on ammonia (NH3) accumulation in relation to nucleotide metabolism and fatigue during intermittent exercise. Eight males performed 40 min of intermittent exercise (15 s at 306+/-22 W alternating with 15 s of unloaded cycling) followed by five 15 s all-out sprints. Control trials were conducted in a 20 degrees C environment while heat stress trials were performed at an ambient temperature of 40 degrees C. Muscle biopsies and venous blood samples were obtained at rest, after 40 min of exercise and following the maximal sprints. Following exercise with heat stress, the core and muscle temperatures peaked at 39.5+/-0.2 and 40.2+/-0.2 degrees C to be approximately 1 degrees C higher (P<0.05) than the corresponding control values. Mean power output during the five maximal sprints was reduced from 618+/-12 W in control to 558+/-14 W during the heat stress trial (P<0.05). During the hot trial, plasma NH3 increased from 31+/-2 microM at rest to 93+/-6 at 40 min and 151+/-15 microM after the maximal sprints to be 34% higher than control (P<0.05). In contrast, plasma K+ and muscle H+ accumulation were lower (P<0.05) following the maximal sprints with heat stress compared to control, while muscle glycogen, CP, ATP and IMP levels were similar across trials. In conclusion, altered levels of "classical peripheral fatiguing agents" does apparently not explain the reduced capacity for performing repeated sprints following intermittent exercise in the heat, whereas the augmented systemic NH3 response may be a factor influencing fatigue during exercise with superimposed heat stress.
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Affiliation(s)
- Magni Mohr
- Institute of Exercise and Sport Sciences, Department of Human Physiology, August Krogh Institute, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
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30
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Alexander GM, van Rijn MA, van Hilten JJ, Perreault MJ, Schwartzman RJ. Changes in cerebrospinal fluid levels of pro-inflammatory cytokines in CRPS. Pain 2005; 116:213-219. [PMID: 15964681 DOI: 10.1016/j.pain.2005.04.013] [Citation(s) in RCA: 203] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2004] [Revised: 03/23/2005] [Accepted: 04/07/2005] [Indexed: 11/17/2022]
Abstract
Complex Regional Pain Syndrome (CRPS) Types I and II are characterized by various combinations of sensory, autonomic and motor abnormalities. Pain disproportionate to the severity and duration of the inciting event is the most devastating symptom. In animal studies, conditions resulting in exaggerated pain states demonstrate elevated pro-inflammatory cytokines. In addition, pro-inflammatory cytokines have been shown to induce or increase neuropathic and inflammatory pain. Utilizing high sensitivity enzyme linked immunosorbent assay (ELISA), we compared the levels of the pro-inflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-alpha) in the cerebrospinal fluid (CSF) of patients afflicted with CRPS to CSF levels found in other patients with and without painful conditions. The results from this study demonstrated significant increases in IL-1beta and IL-6, but not TNF-alpha in the CSF of individuals afflicted with CRPS as compared to controls. CSF cytokine levels in controls with painful conditions did not differ from levels in controls without pain. These increases showed no correlation with the patient's gender or weight. These results are consistent with studies that suggest that the pathogenesis of CRPS is due in part to central neuroimmune activation.
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Affiliation(s)
- Guillermo M Alexander
- Department of Neurology, Drexel University College of Medicine, Mail Stop 423, 245 North 15th Street, Philadelphia, PA 19102, USA Department of Neurology, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
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31
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Nybo L, Dalsgaard MK, Steensberg A, Møller K, Secher NH. Cerebral ammonia uptake and accumulation during prolonged exercise in humans. J Physiol 2004; 563:285-90. [PMID: 15611036 PMCID: PMC1665558 DOI: 10.1113/jphysiol.2004.075838] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We evaluated whether peripheral ammonia production during prolonged exercise enhances the uptake and subsequent accumulation of ammonia within the brain. Two studies determined the cerebral uptake of ammonia (arterial and jugular venous blood sampling combined with Kety-Schmidt-determined cerebral blood flow; n = 5) and the ammonia concentration in the cerebrospinal fluid (CSF; n = 8) at rest and immediately following prolonged exercise either with or without glucose supplementation. There was a net balance of ammonia across the brain at rest and at 30 min of exercise, whereas 3 h of exercise elicited an uptake of 3.7 +/- 1.3 micromol min(-1) (mean +/-s.e.m.) in the placebo trial and 2.5 +/- 1.0 micromol min(-1) in the glucose trial (P < 0.05 compared to rest, not different across trials). At rest, CSF ammonia was below the detection limit of 2 microm in all subjects, but it increased to 5.3 +/- 1.1 microm following exercise with glucose, and further to 16.1 +/- 3.3 microm after the placebo trial (P < 0.05). Correlations were established between both the cerebral uptake (r2 = 0.87; P < 0.05) and the CSF concentration (r2 = 0.72; P < 0.05) and the arterial ammonia level and, in addition, a weaker correlation (r2 = 0.37; P < 0.05) was established between perceived exertion and CSF ammonia at the end of exercise. The results let us suggest that during prolonged exercise the cerebral uptake and accumulation of ammonia may provoke fatigue, e.g. by affecting neurotransmitter metabolism.
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Affiliation(s)
- Lars Nybo
- Department of Human Physiology, Institute of Exercise and Sport Sciences, August Krogh Institute, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark.
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32
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Dalsgaard MK, Ogoh S, Dawson EA, Yoshiga CC, Quistorff B, Secher NH. Cerebral carbohydrate cost of physical exertion in humans. Am J Physiol Regul Integr Comp Physiol 2004; 287:R534-40. [PMID: 15155282 DOI: 10.1152/ajpregu.00256.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Above a certain level of cerebral activation the brain increases its uptake of glucose more than that of O(2), i.e., the cerebral metabolic ratio of O(2)/(glucose + 12 lactate) decreases. This study quantified such surplus brain uptake of carbohydrate relative to O(2) in eight healthy males who performed exhaustive exercise. The arterial-venous differences over the brain for O(2), glucose, and lactate were integrated to calculate the surplus cerebral uptake of glucose equivalents. To evaluate whether the amount of glucose equivalents depends on the time to exhaustion, exercise was also performed with beta(1)-adrenergic blockade by metoprolol. Exhaustive exercise (24.8 +/- 6.1 min; mean +/- SE) decreased the cerebral metabolic ratio from a resting value of 5.6 +/- 0.2 to 3.0 +/- 0.4 (P < 0.05) and led to a surplus uptake of glucose equivalents of 9 +/- 2 mmol. beta(1)-blockade reduced the time to exhaustion (15.8 +/- 1.7 min; P < 0.05), whereas the cerebral metabolic ratio decreased to an equally low level (3.2 +/- 0.3) and the surplus uptake of glucose equivalents was not significantly different (7 +/- 1 mmol; P = 0.08). A time-dependent cerebral surplus uptake of carbohydrate was not substantiated and, consequently, exhaustive exercise involves a brain surplus carbohydrate uptake of a magnitude comparable with its glycogen content.
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Affiliation(s)
- Mads K Dalsgaard
- Department of Anesthesia, Rigshospitalet 2041, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
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