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Yang Y, Feng Z, Luo YH, Chen JM, Zhang Y, Liao YJ, Jiang H, Long Y, Wei B. Exercise-Induced Central Fatigue: Biomarkers, and Non-Medicinal Interventions. Aging Dis 2024:AD.2024.0567. [PMID: 39012671 DOI: 10.14336/ad.2024.0567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 06/27/2024] [Indexed: 07/17/2024] Open
Abstract
Fatigue, commonly experienced in daily life, is a feeling of extreme tiredness, shortage or lack of energy, exhaustion, and difficulty in performing voluntary tasks. Central fatigue, defined as a progressive failure to voluntarily activate the muscle, is typically linked to moderate- or light-intensity exercise. However, in some instances, high-intensity exercise can also trigger the onset of central fatigue. Exercise-induced central fatigue often precedes the decline in physical performance in well-trained athletes. This leads to a reduction in nerve impulses, decreased neuronal excitability, and an imbalance in brain homeostasis, all of which can adversely impact an athlete's performance and the longevity of their sports career. Therefore, implementing strategies to delay the onset of exercise-induced central fatigue is vital for enhancing athletic performance and safeguarding athletes from the debilitating effects of fatigue. In this review, we discuss the structural basis, measurement methods, and biomarkers of exercise-induced central fatigue. Furthermore, we propose non-pharmacological interventions to mitigate its effects, which can potentially foster improvements in athletes' performances in a healthful and sustainable manner.
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Affiliation(s)
- Ying Yang
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Zhi Feng
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Yu-Hang Luo
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Jue-Miao Chen
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Yu Zhang
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Yi-Jun Liao
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Hui Jiang
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
| | - Yinxi Long
- Department of Neurology, Affiliated Hengyang Hospital of Hunan Normal University &;amp Hengyang Central Hospital, Hengyang, 421001, China
| | - Bo Wei
- Institute of Translational Medicine, School of Basic Medical, Department of Special Medicine, School of Public Health, Hengyang Medical College, University of South China, Hengyang, 421001, China
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Faria VS, Manchado-Gobatto FB, Scariot PPM, Zagatto AM, Beck WR. Melatonin Potentiates Exercise-Induced Increases in Skeletal Muscle PGC-1 α and Optimizes Glycogen Replenishment. Front Physiol 2022; 13:803126. [PMID: 35557975 PMCID: PMC9087193 DOI: 10.3389/fphys.2022.803126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Compelling evidence has demonstrated the effect of melatonin on exhaustive exercise tolerance and its modulatory role in muscle energy substrates at the end of exercise. In line with this, PGC-1α and NRF-1 also seem to act on physical exercise tolerance and metabolic recovery after exercise. However, the literature still lacks reports on these proteins after exercise until exhaustion for animals treated with melatonin. Thus, the aim of the current study was to determine the effects of acute melatonin administration on muscle PGC-1α and NRF-1, and its modulatory role in glycogen and triglyceride contents in rats subjected to exhaustive swimming exercise at an intensity corresponding to the anaerobic lactacidemic threshold (iLAn). In a randomized controlled trial design, thirty-nine Wistar rats were allocated into four groups: control (CG = 10), rats treated with melatonin (MG = 9), rats submitted to exercise (EXG = 10), and rats treated with melatonin and submitted to exercise (MEXG = 10). Forty-eight hours after the graded exercise test, the animals received melatonin (10 mg/kg) or vehicles 30 min prior to time to exhaustion test in the iLAn (tlim). Three hours after tlim the animals were euthanized, followed by muscle collection for specific analyses: soleus muscles for immunofluorescence, gluteus maximus, red and white gastrocnemius for the assessment of glycogen and triglyceride contents, and liver for the measurement of glycogen content. Student t-test for independent samples, two-way ANOVA, and Newman keuls post hoc test were used. MEXG swam 120.3% more than animals treated with vehicle (EXG; p < 0.01). PGC-1α and NRF-1 were higher in MEXG with respect to the CG (p < 0.05); however, only PGC-1α was higher for MEXG when compared to EXG. Melatonin reduced the triglyceride content in gluteus maximus, red and white gastrocnemius (F = 6.66, F = 4.51, and F = 6.02, p < 0.05). The glycogen content in red gastrocnemius was higher in MEXG than in CG (p = 0.01), but not in EXG (p > 0.05). In conclusion, melatonin was found to enhance exercise tolerance, potentiate exercise-mediated increases in PGC-1α, decrease muscle triglyceride content and increase muscle glycogen 3 h after exhaustive exercise, rapidly providing a better cellular metabolic environment for future efforts.
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Affiliation(s)
- Vinícius Silva Faria
- Laboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos-UFSCar, São Carlos, Brazil
| | | | - Pedro Paulo Menezes Scariot
- Laboratory of Applied Sport Physiology, School of Applied Sciences, University of Campinas-UNICAMP, Limeira, Brazil
| | - Alessandro Moura Zagatto
- Laboratory of Physiology and Sports Performance, Department of Physical Education, School of Science-Bauru Campus, São Paulo State University-UNESP, Bauru, Brazil
| | - Wladimir Rafael Beck
- Laboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos-UFSCar, São Carlos, Brazil
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Effect of a Prolonged Maximal Bout of Exercise on Visual Performance. Asian J Sports Med 2022. [DOI: 10.5812/asjsm.119406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Despite it being purported that acute, prolonged maximal periods of exercise may impair visual performance, little/no research on this topic is forthcoming. In fact, research has demonstrated that sub-maximal and maximal acute exercise may actually improve cognitive and sensory tasks and thus possibly improve visual performance. Objectives: This study aimed to ascertain the influence of an acute, prolonged maximal bout of exercise on visual performance. Methods: A quantitative study was undertaken with 60 untrained males being divided into a control group (CON; n = 30) or treatment group (TRE; n = 30). Both groups completed a baseline vision test battery consisting of accommodation facility, saccadic eye movement, speed of recognition, peripheral awareness, visual memory, and hand-eye coordination using the following tests; Hart Near Far Rock, saccadic eye movement, evasion, accumulator, flash memory and Ball Wall Toss tests. Two weeks later, participants returned for follow-up testing using the same vision test battery, with the TRE participants first engaging in a standardized incremental maximal treadmill protocol immediately prior to their vision testing. Results: Following the incremental maximal treadmill protocol, statistical analyses indicated that statistically significant (P ≤ 0.05) differences existed for accommodation facility, saccadic eye movements, speed of recognition, hand-eye coordination, peripheral awareness, and visual memory between pre-test and after the aerobic treatment (P = 0.00 for all measures). Conclusions: This study indicates that an acute, prolonged maximal bout of running improves visual performance. As such, an appropriate prolonged maximal warm-up may be required as opposed to a standardized and general warm-up when preparing an athlete for visual skills training or for participation in an athletic event that requires optimal visual performance.
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Faria VS, Pejon TMM, Gobatto CA, de Araujo GG, Cornachione AS, Beck WR. Acute melatonin administration improves exercise tolerance and the metabolic recovery after exhaustive effort. Sci Rep 2021; 11:19228. [PMID: 34584111 PMCID: PMC8478932 DOI: 10.1038/s41598-021-97364-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/24/2021] [Indexed: 02/08/2023] Open
Abstract
The present study investigated the effects of acute melatonin administration on the biomarkers of energy substrates, GLUT4, and FAT/CD36 of skeletal muscle and its performance in rats subjected to exhaustive swimming exercise at an intensity corresponding to the maximal aerobic capacity (tlim). The incremental test was performed to individually determine the exercise intensity prescription and 48 h after, the animals received melatonin (10 mg·kg-1) or vehicles 30 min prior to tlim. Afterwards, the animals were euthanized 1 or 3 h after the exhaustion for blood and muscles storage. The experiment 1 found that melatonin increased the content of glycogen and GLUT4 in skeletal muscles of the animals that were euthanized 1 (p < 0.05; 22.33% and 41.87%) and 3 h (p < 0.05; 37.62% and 57.87%) after the last procedures. In experiment 2, melatonin enhanced the tlim (p = 0.01; 49.42%), the glycogen content (p < 0.05; 40.03%), GLUT4 and FAT/CD36 in exercised skeletal muscles (F = 26.83 and F = 25.28, p < 0.01). In summary, melatonin increased energy substrate availability prior to exercise, improved the exercise tolerance, and accelerated the recovery of muscle energy substrates after the tlim, possibly through GLUT4 and FAT/CD36.
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Affiliation(s)
- Vinícius Silva Faria
- grid.411247.50000 0001 2163 588XLaboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905 Brazil
| | - Taciane Maria Melges Pejon
- grid.411247.50000 0001 2163 588XLaboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905 Brazil
| | - Claudio Alexandre Gobatto
- grid.411087.b0000 0001 0723 2494Laboratory of Applied Sport Physiology, School of Applied Sciences, University of Campinas, Limeira, SP 13484-350 Brazil
| | - Gustavo Gomes de Araujo
- grid.411247.50000 0001 2163 588XLaboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905 Brazil
| | - Anabelle Silva Cornachione
- grid.411247.50000 0001 2163 588XMuscle Physiology and Biophysics Laboratory, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905 Brazil
| | - Wladimir Rafael Beck
- grid.411247.50000 0001 2163 588XLaboratory of Endocrine Physiology and Physical Exercise, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP 13565-905 Brazil
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Hwang DJ, Kwon KC, Choi DH, Song HK, Kim KS, Jung YS, Hwang DY, Cho JY. Comparison of intrinsic exercise capacity and response to acute exercise in ICR (Institute of Cancer Research) mice derived from three different lineages. Lab Anim Res 2021; 37:21. [PMID: 34348800 PMCID: PMC8335942 DOI: 10.1186/s42826-021-00094-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND As a laboratory animal resource, the ICR mouse is commonly used in a variety of research fields. However, information on differences in exercise-related characteristics in ICR mice derived from different lineages and the underlying mechanisms remains to be elucidated. In this study, we investigated the intrinsic exercise capacity and a magnitude of response to acute exercise, and sought to identify mechanisms contributing to difference in Korl:ICR (a novel ICR lineage recently established by the National Institute of Food and Drug Safety Evaluation, Korea) and two commercialized ICR lineages derived from different origins (viz., A:ICR mouse from Orient Bio Com, the United States, and B:ICR mouse from Japan SLC Inc., Japan). RESULTS Results showed that despite no significant difference in body weight and weight-proportioned tissue mass of heart and skeletal muscles among groups, the relatively low intrinsic exercise capacity and exaggerated response to acute exercise were identified in B:ICR comparted with Korl:ICR and A:ICR, as reflected by total work and lactate threshold (LT). Also, the mitochondrial efficiency expressed as the complex 1 and complex 1 + 2 respiratory control ratio (RCR) values for cardiac mitochondrial O2 consumption in B:ICR was significantly lower than that in Korl:ICR with higher level of state 2 respiration by glutamate/malate and UCP3 expression in cardiac muscle. CONCLUSIONS Taken together, these results indicate that the intrinsic exercise capacity of ICR mouse varies according to lineages, suggesting the role of cardiac mitochondrial coupling efficiency as a possible mechanism that might contribute to differences in the intrinsic exercise capacity and magnitude of response to exercise.
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Affiliation(s)
- Dong-Joo Hwang
- Exercise Biochemistry Laboratory, Korea National Sport University, Yangjae-daero, Songpa-gu, Seoul, Republic of Korea
| | - Ki-Chun Kwon
- Exercise Biochemistry Laboratory, Korea National Sport University, Yangjae-daero, Songpa-gu, Seoul, Republic of Korea
| | - Dong-Hun Choi
- Exercise Biochemistry Laboratory, Korea National Sport University, Yangjae-daero, Songpa-gu, Seoul, Republic of Korea
| | - Hyun-Keun Song
- Department of Microbiology and Immunology, INJE University College of Medicine, Inje-ro, Gimhae-si, Gyeongsangnam-do, Republic of Korea
| | - Kil-Soo Kim
- College of Veterinary Medicine, Kyungpook National University, Daehak-ro, Buk-gu, Daegu, Republic of Korea
| | - Young-Suk Jung
- College of Pharmacy, Pusan National University, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, Republic of Korea
| | - Dae-Youn Hwang
- Department of Biomaterials Science, College of Natural Resources and Life Science/Life and Industry Convergence Research Institute, Pusan National University, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, Republic of Korea
| | - Joon-Yong Cho
- Exercise Biochemistry Laboratory, Korea National Sport University, Yangjae-daero, Songpa-gu, Seoul, Republic of Korea.
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Huang Z, Zhang Y, Zhou R, Yang L, Pan H. Lactate as Potential Mediators for Exercise-Induced Positive Effects on Neuroplasticity and Cerebrovascular Plasticity. Front Physiol 2021; 12:656455. [PMID: 34290615 PMCID: PMC8287254 DOI: 10.3389/fphys.2021.656455] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/09/2021] [Indexed: 01/22/2023] Open
Abstract
The accumulated evidence from animal and human studies supports that exercise is beneficial to physical health. Exercise can upregulate various neurotrophic factors, activate neuroplasticity, and play a positive role in improving and enhancing cerebrovascular function. Due to its economy, convenience, and ability to prevent or ameliorate various aging-related diseases, exercise, a healthy lifestyle, is increasingly popularized by people. However, the mechanism by which exercise performs this function and how it is transmitted from muscles to the brain remains incompletely understood. Here, we review the beneficial effects of exercise with different intensities on the brain with a focus on the positive effects of lactate on neuroplasticity and cerebrovascular plasticity. Based on these recent studies, we propose that lactate, a waste previously misunderstood as a by-product of glycolysis in the past, may be a key signal molecule that regulates the beneficial adaptation of the brain caused by exercise. Importantly, we speculate that a central protective mechanism may underlie the cognitive benefits induced by exercise.
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Affiliation(s)
- Zhihai Huang
- Cognitive and Sports Neuroscience Laboratory, National Demonstration Center for Experimental Sports Science Education, College of Physical Education and Sports Science, South China Normal University, Guangzhou, China
| | - Yulan Zhang
- Cognitive and Sports Neuroscience Laboratory, National Demonstration Center for Experimental Sports Science Education, College of Physical Education and Sports Science, South China Normal University, Guangzhou, China
| | - Ruixue Zhou
- Cognitive and Sports Neuroscience Laboratory, National Demonstration Center for Experimental Sports Science Education, College of Physical Education and Sports Science, South China Normal University, Guangzhou, China
| | - Luodan Yang
- Cognitive and Sports Neuroscience Laboratory, National Demonstration Center for Experimental Sports Science Education, College of Physical Education and Sports Science, South China Normal University, Guangzhou, China
| | - Hongying Pan
- Cognitive and Sports Neuroscience Laboratory, National Demonstration Center for Experimental Sports Science Education, College of Physical Education and Sports Science, South China Normal University, Guangzhou, China
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Liu QH, Tang JW, Wen PB, Wang MM, Zhang X, Wang L. From Prokaryotes to Eukaryotes: Insights Into the Molecular Structure of Glycogen Particles. Front Mol Biosci 2021; 8:673315. [PMID: 33996916 PMCID: PMC8116748 DOI: 10.3389/fmolb.2021.673315] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/07/2021] [Indexed: 12/25/2022] Open
Abstract
Glycogen is a highly-branched polysaccharide that is widely distributed across the three life domains. It has versatile functions in physiological activities such as energy reserve, osmotic regulation, blood glucose homeostasis, and pH maintenance. Recent research also confirms that glycogen plays important roles in longevity and cognition. Intrinsically, glycogen function is determined by its structure that has been intensively studied for many years. The recent association of glycogen α-particle fragility with diabetic conditions further strengthens the importance of glycogen structure in its function. By using improved glycogen extraction procedures and a series of advanced analytical techniques, the fine molecular structure of glycogen particles in human beings and several model organisms such as Escherichia coli, Caenorhabditis elegans, Mus musculus, and Rat rattus have been characterized. However, there are still many unknowns about the assembly mechanisms of glycogen particles, the dynamic changes of glycogen structures, and the composition of glycogen associated proteins (glycogen proteome). In this review, we explored the recent progresses in glycogen studies with a focus on the structure of glycogen particles, which may not only provide insights into glycogen functions, but also facilitate the discovery of novel drug targets for the treatment of diabetes mellitus.
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Affiliation(s)
- Qing-Hua Liu
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China.,Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Jia-Wei Tang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Peng-Bo Wen
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Meng-Meng Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Xiao Zhang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Liang Wang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China.,Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, China
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Muscle Glycogen Metabolism and High-Intensity Exercise Performance: A Narrative Review. Sports Med 2021; 51:1855-1874. [PMID: 33900579 DOI: 10.1007/s40279-021-01475-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
Muscle glycogen is the main substrate during high-intensity exercise and large reductions can occur after relatively short durations. Moreover, muscle glycogen is stored heterogeneously and similarly displays a heterogeneous and fiber-type specific depletion pattern with utilization in both fast- and slow-twitch fibers during high-intensity exercise, with a higher degradation rate in the former. Thus, depletion of individual fast- and slow-twitch fibers has been demonstrated despite muscle glycogen at the whole-muscle level only being moderately lowered. In addition, muscle glycogen is stored in specific subcellular compartments, which have been demonstrated to be important for muscle function and should be considered as well as global muscle glycogen availability. In the present review, we discuss the importance of glycogen metabolism for single and intermittent bouts of high-intensity exercise and outline possible underlying mechanisms for a relationship between muscle glycogen and fatigue during these types of exercise. Traditionally this relationship has been attributed to a decreased ATP resynthesis rate due to inadequate substrate availability at the whole-muscle level, but emerging evidence points to a direct coupling between muscle glycogen and steps in the excitation-contraction coupling including altered muscle excitability and calcium kinetics.
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Matsui T. Exhaustive endurance exercise activates brain glycogen breakdown and lactate production more than insulin-induced hypoglycemia. Am J Physiol Regul Integr Comp Physiol 2021; 320:R500-R507. [PMID: 33533310 DOI: 10.1152/ajpregu.00119.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 01/29/2021] [Indexed: 11/22/2022]
Abstract
Brain glycogen localized in astrocytes produces lactate via cAMP signaling, which regulates memory functions and endurance capacity. Exhaustive endurance exercise with hypoglycemia decreases brain glycogen, although the mechanism underlying this phenomenon remains unclear. Since insulin-induced hypoglycemia decreases brain glycogen, this study tested the hypothesis that hypoglycemia mediates exercise-induced brain glycogen decrease. To test the hypothesis, the effects of insulin- and exhaustive exercise-induced hypoglycemia on brain glycogen levels were compared using the microwave irradiation method in adult Wistar rats. The insulin challenge and exhaustive exercise induced similar levels of severe hypoglycemia. Glycogen in the hypothalamus and cerebellum decreased similarly with the insulin challenge and exhaustive exercise; however, glycogen in the cortex, hippocampus, and brainstem of the exercise group were lower compared with the insulin group. Brain lactate and cAMP levels in the hypothalamus and cerebellum increased similarly with the insulin challenge and exhaustive exercise, but those in the cortex, hippocampus, and brainstem of the exercise group were higher compared with the insulin group. Blood glucose correlated positively with brain glycogen, but the slope of regression lines was greater in the exercise group compared with the insulin group in the cortex, hippocampus, and brainstem, but not the hypothalamus and cerebellum. These findings support the hypothesis that hypoglycemia mediates the exercise-induced reduction in brain glycogen, at least in the hypothalamus and cerebellum. However, glycogen reduction during exhaustive endurance exercise in the cortex, hippocampus, and brainstem is not due to hypoglycemia alone, implicating the role of exercise-specific neuronal activity in brain glycogen decrease.
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Affiliation(s)
- Takashi Matsui
- Exercise Biochemistry Division, Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
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Briski KP, Ibrahim MMH, Mahmood ASMH, Alshamrani AA. Norepinephrine Regulation of Ventromedial Hypothalamic Nucleus Astrocyte Glycogen Metabolism. Int J Mol Sci 2021; 22:ijms22020759. [PMID: 33451134 PMCID: PMC7828624 DOI: 10.3390/ijms22020759] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 12/15/2022] Open
Abstract
The catecholamine norepinephrine (NE) links hindbrain metabolic-sensory neurons with key glucostatic control structures in the brain, including the ventromedial hypothalamic nucleus (VMN). In the brain, the glycogen reserve is maintained within the astrocyte cell compartment as an alternative energy source to blood-derived glucose. VMN astrocytes are direct targets for metabolic stimulus-driven noradrenergic signaling due to their adrenergic receptor expression (AR). The current review discusses recent affirmative evidence that neuro-metabolic stability in the VMN may be shaped by NE influence on astrocyte glycogen metabolism and glycogen-derived substrate fuel supply. Noradrenergic modulation of estrogen receptor (ER) control of VMN glycogen phosphorylase (GP) isoform expression supports the interaction of catecholamine and estradiol signals in shaping the physiological stimulus-specific control of astrocyte glycogen mobilization. Sex-dimorphic NE control of glycogen synthase and GP brain versus muscle type proteins may be due, in part, to the dissimilar noradrenergic governance of astrocyte AR and ER variant profiles in males versus females. Forthcoming advances in the understanding of the molecular mechanistic framework for catecholamine stimulus integration with other regulatory inputs to VMN astrocytes will undoubtedly reveal useful new molecular targets in each sex for glycogen mediated defense of neuronal metabolic equilibrium during neuro-glucopenia.
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11
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Khan T, Sullivan MA, Gunter JH, Kryza T, Lyons N, He Y, Hooper JD. Revisiting Glycogen in Cancer: A Conspicuous and Targetable Enabler of Malignant Transformation. Front Oncol 2020; 10:592455. [PMID: 33224887 PMCID: PMC7667517 DOI: 10.3389/fonc.2020.592455] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023] Open
Abstract
Once thought to be exclusively a storage hub for glucose, glycogen is now known to be essential in a range of physiological processes and pathological conditions. Glycogen lies at the nexus of diverse processes that promote malignancy, including proliferation, migration, invasion, and chemoresistance of cancer cells. It is also implicated in processes associated with the tumor microenvironment such as immune cell effector function and crosstalk with cancer-associated fibroblasts to promote metastasis. The enzymes of glycogen metabolism are dysregulated in a wide variety of malignancies, including cancers of the kidney, ovary, lung, bladder, liver, blood, and breast. Understanding and targeting glycogen metabolism in cancer presents a promising but under-explored therapeutic avenue. In this review, we summarize the current literature on the role of glycogen in cancer progression and discuss its potential as a therapeutic target for cancer treatment.
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Affiliation(s)
- Tashbib Khan
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Mitchell A. Sullivan
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Jennifer H. Gunter
- Faculty of Health, Australian Prostate Cancer Research Centre-Queensland, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD, Australia
| | - Thomas Kryza
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Nicholas Lyons
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Yaowu He
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
| | - John D. Hooper
- Mater Research Institute—The University of Queensland, Translational Research Institute, Woolloongabba, QLD, Australia
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12
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Dynamic Variations in Brain Glycogen are Involved in Modulating Isoflurane Anesthesia in Mice. Neurosci Bull 2020; 36:1513-1523. [PMID: 33048310 PMCID: PMC7719152 DOI: 10.1007/s12264-020-00587-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 05/20/2020] [Indexed: 12/15/2022] Open
Abstract
General anesthesia severely affects the metabolites in the brain. Glycogen, principally stored in astrocytes and providing the short-term delivery of substrates to neurons, has been implicated as an affected molecule. However, whether glycogen plays a pivotal role in modulating anesthesia–arousal remains unclear. Here, we demonstrated that isoflurane-anesthetized mice exhibited dynamic changes in the glycogen levels in various brain regions. Glycogen synthase (GS) and glycogen phosphorylase (GP), key enzymes of glycogen metabolism, showed increased activity after isoflurane exposure. Upon blocking glycogenolysis with 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), a GP antagonist, we found a prolonged time of emergence from anesthesia and an enhanced δ frequency in the EEG (electroencephalogram). In addition, augmented expression of glycogenolysis genes in glycogen phosphorylase, brain (Pygb) knock-in (PygbH11/H11) mice resulted in delayed induction of anesthesia, a shortened emergence time, and a lower ratio of EEG-δ. Our findings revealed a role of brain glycogen in regulating anesthesia–arousal, providing a potential target for modulating anesthesia.
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13
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Martin K, Meeusen R, Thompson KG, Keegan R, Rattray B. Mental Fatigue Impairs Endurance Performance: A Physiological Explanation. Sports Med 2019; 48:2041-2051. [PMID: 29923147 DOI: 10.1007/s40279-018-0946-9] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mental fatigue reflects a change in psychobiological state, caused by prolonged periods of demanding cognitive activity. It has been well documented that mental fatigue impairs cognitive performance; however, more recently, it has been demonstrated that endurance performance is also impaired by mental fatigue. The mechanism behind the detrimental effect of mental fatigue on endurance performance is poorly understood. Variables traditionally believed to limit endurance performance, such as heart rate, lactate accumulation and neuromuscular function, are unaffected by mental fatigue. Rather, it has been suggested that the negative impact of mental fatigue on endurance performance is primarily mediated by the greater perception of effort experienced by mentally fatigued participants. Pageaux et al. (Eur J Appl Physiol 114(5):1095-1105, 2014) first proposed that prolonged performance of a demanding cognitive task increases cerebral adenosine accumulation and that this accumulation may lead to the higher perception of effort experienced during subsequent endurance performance. This theoretical review looks at evidence to support and extend this hypothesis.
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Affiliation(s)
- Kristy Martin
- University of Canberra Research Institute for Sport and Exercise, Canberra, ACT, Australia.
| | - Romain Meeusen
- Vrije Universiteit Brussel Human Performance Research Group, Brussels, Belgium
| | - Kevin G Thompson
- University of Canberra Research Institute for Sport and Exercise, Canberra, ACT, Australia
- New South Wales Institute of Sport, Sydney, NSW, Australia
| | - Richard Keegan
- University of Canberra Research Institute for Sport and Exercise, Canberra, ACT, Australia
| | - Ben Rattray
- University of Canberra Research Institute for Sport and Exercise, Canberra, ACT, Australia
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Mental fatigue impairs time trial performance in sub-elite under 23 cyclists. PLoS One 2019; 14:e0218405. [PMID: 31206523 PMCID: PMC6576783 DOI: 10.1371/journal.pone.0218405] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/31/2019] [Indexed: 01/06/2023] Open
Abstract
PURPOSE This study investigates the effect of a mentally demanding response inhibitory task on time trial performance in sub-elite under 23 cyclists. METHODS Ten under 23 road cyclists completed two separate testing sessions during which they performed two different cognitive tasks before completing a 30-min time trial on the cycle ergometer. In the experimental condition, 30 min of a standard cognitive task (Stroop task) was used to elicit mental fatigue; in the control condition, a non-demanding activity was carried out. Subjective workload and mood were measured before and after the treatments, and motivation was recorded before the time-trial. During the time trial, power, cadence, heart rate, and rate of perceived exertion were assessed. Blood lactate concentrations and heart rate variability (using the root mean square of the successive differences) were measured before and after the time trial. RESULTS The Stroop task was rated more mentally (P < 0.001) and temporally (P < 0.001) demanding, effortful (P < 0.001), and frustrating (P = 0.001) than the control task; fatigue (P = 0.002) and vigor (P = 0.018) after the cognitive tasks were respectively higher and lower than in the control task. Mean power output (P = 0.007) and cadence (P = 0.043) were negatively affected by the Stroop task, while heart rate (P = 0.349), rating of perceived exertion (P = 0.710), blood lactate concentration (P = 0.850), and root mean square of the successive differences (P = 0.355) did not differ between the two conditions. CONCLUSION A mentally demanding activity reduced the subsequent physical performance in sub-elite under 23 cyclists. Thus, avoiding cognitive efforts before training and races could improve performance of high-level athletes.
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15
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Matsui T, Liu YF, Soya M, Shima T, Soya H. Tyrosine as a Mechanistic-Based Biomarker for Brain Glycogen Decrease and Supercompensation With Endurance Exercise in Rats: A Metabolomics Study of Plasma. Front Neurosci 2019; 13:200. [PMID: 30941004 PMCID: PMC6433992 DOI: 10.3389/fnins.2019.00200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/20/2019] [Indexed: 01/02/2023] Open
Abstract
Brain glycogen, localized in astrocytes, produces lactate as an energy source and/or a signal factor to serve neuronal functions involved in memory formation and exercise endurance. In rodents, 4 weeks of chronic moderate exercise-enhancing endurance and cognition increases brain glycogen in the hippocampus and cortex, which is an adaption of brain metabolism achieved through exercise. Although this brain adaptation is likely induced due to the accumulation of acute endurance exercise–induced brain glycogen supercompensation, its molecular mechanisms and biomarkers are unidentified. Since noradrenaline synthesized from blood-borne tyrosine activates not only glycogenolysis but also glycogenesis in astrocytes, we hypothesized that blood tyrosine is a mechanistic-based biomarker of acute exercise–induced brain glycogen supercompensation. To test this hypothesis, we used a rat model of endurance exercise, a microwave irradiation for accurate detection of glycogen in the brain (the cortex, hippocampus, and hypothalamus), and capillary electrophoresis mass spectrometry–based metabolomics to observe the comprehensive metabolic profile of the blood. Endurance exercise induced fatigue factors such as a decrease in blood glucose, an increase in blood lactate, and the depletion of muscle glycogen, but those parameters recovered to basal levels within 6 h after exercise. Brain glycogen decreased during endurance exercise and showed supercompensation within 6 h after exercise. Metabolomics detected 186 metabolites in the plasma, and 110 metabolites changed significantly during and following exhaustive exercise. Brain glycogen levels correlated negatively with plasma glycogenic amino acids (serine, proline, threonine, glutamate, methionine, tyrosine, and tryptophan) (r < −0.9). This is the first study to produce a broad picture of plasma metabolite changes due to endurance exercise–induced brain glycogen supercompensation. Our findings suggest that plasma glycogenic amino acids are sensitive indicators of brain glycogen levels in endurance exercise. In particular, plasma tyrosine as a precursor of brain noradrenaline might be a valuable mechanistic-based biomarker to predict brain glycogen dynamics in endurance exercise.
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Affiliation(s)
- Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan.,Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Japan
| | - Yu-Fan Liu
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Mariko Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan.,Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Japan
| | - Takeru Shima
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan
| | - Hideaki Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan.,Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Japan
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16
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Glycogenolysis in Cerebral Cortex During Sensory Stimulation, Acute Hypoglycemia, and Exercise: Impact on Astrocytic Energetics, Aerobic Glycolysis, and Astrocyte-Neuron Interactions. ADVANCES IN NEUROBIOLOGY 2019; 23:209-267. [DOI: 10.1007/978-3-030-27480-1_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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Hasan Mahmood ASM, Uddin MM, Ibrahim MMH, Mandal SK, Alhamami HN, Briski KP. Sex differences in forebrain estrogen receptor regulation of hypoglycemic patterns of counter-regulatory hormone secretion and ventromedial hypothalamic nucleus glucoregulatory neurotransmitter and astrocyte glycogen metabolic enzyme expression. Neuropeptides 2018; 72:65-74. [PMID: 30396594 PMCID: PMC6293983 DOI: 10.1016/j.npep.2018.10.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 12/13/2022]
Abstract
The female ventromedial hypothalamic nucleus (VMN) is a focal substrate for estradiol (E) regulation of energy balance, feeding, and body weight, but how E shapes VMN gluco-regulatory signaling in each sex is unclear. This study investigated the hypothesis that estrogen receptor-alpha (ERα) and/or -beta (ERβ) control VMN signals that inhibit [γ-aminobutyric acid] or stimulate [nitric oxide, steroidogenic factor-1 (SF-1)] counter-regulation in a sex-dependent manner. VMN nitrergic neurons monitor astrocyte fuel provision; here, we examined how these ER regulate astrocyte glycogen metabolic enzyme, monocarboxylate transporter, and adrenoreceptor protein responses to insulin-induced hypoglycemia (IIH) in each sex. Testes-intact male and E-replaced ovariectomized female rats were pretreated by intracerebroventricular ERα antagonist (MPP) or ERβ antagonist (PHTPP) administration before IIH. Data implicate both ER in hypoglycemic inhibition of neuronal nitric oxide synthase protein in each sex and up-regulation of glutamate decarboxylase65/67 and SF-1 expression in females. ERα and -β enhance astrocyte AMPK and glycogen synthase expression and inhibit glycogen phosphorylase in hypoglycemic females, while ERβ suppresses the same proteins in males. Differential VMN astrocyte protein responses to IIH may partially reflect ERα and -β augmentation of ERβ and down-regulation of alpha1, alpha2, and beta1 adrenoreceptor proteins in females, versus ERβ repression of GPER and alpha2 adrenoreceptor profiles in males. MPP or PHTPP pretreatment blunted counter-regulatory hormone secretion in hypoglycemic males only, suggesting that in males one or more VMN neurotransmitters exhibiting sensitivity to forebrain ER may passively regulate this endocrine outflow, whereas female forebrain ERα and -β are apparently uninvolved in these contra-regulatory responses.
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Affiliation(s)
- A S M Hasan Mahmood
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA
| | - M M Uddin
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA
| | - M M H Ibrahim
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA
| | - S K Mandal
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA
| | - H N Alhamami
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA
| | - K P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA 71201, USA.
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18
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Dakic T, Jevdjovic T, Lakic I, Djurasevic SF, Djordjevic J, Vujovic P. Food For Thought: Short-Term Fasting Upregulates Glucose Transporters in Neurons and Endothelial Cells, But Not in Astrocytes. Neurochem Res 2018; 44:388-399. [PMID: 30460639 DOI: 10.1007/s11064-018-2685-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/30/2018] [Accepted: 11/15/2018] [Indexed: 12/22/2022]
Abstract
Our group previously reported that 6-h fasting increased both insulin II mRNA expression and insulin level in rat hypothalamus. Given that insulin effects on central glucose metabolism are insufficiently understood, we wanted to examine if the centrally produced insulin affects expression and/or regional distribution of glucose transporters, and glycogen stores in the hypothalamus during short-term fasting. In addition to determining the amount of total and activated insulin receptor, glucose transporters, and glycogen, we also studied distribution of insulin receptors and glucose transporters within the hypothalamus. We found that short-term fasting did not affect the astrocytic 45 kDa GLUT1 isoform, but it significantly increased the amount of endothelial 55 kDa GLUT1, and neuronal GLUT3 in the membrane fractions of hypothalamic proteins. The level of GLUT2 whose presence was detected in neurons, ependymocytes and tanycytes was also elevated. Unlike hepatic glycogen which was decreased, hypothalamic glycogen content was not changed after 6-h fasting. Our findings suggest that neurons may be given a priority over astrocytes in terms of glucose supply even during the initial phase of metabolic response to fasting. Namely, increase in glucose influx into the brain extracellular fluid and neurons by increasing the translocation of GLUT1, and GLUT3 in the cell membrane may represent the first line of defense in times of scarcity. The absence of co-localization of these membrane transporters with the activated insulin receptor suggests this process takes place in an insulin-independent manner.
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Affiliation(s)
- Tamara Dakic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia.
| | - Tanja Jevdjovic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Iva Lakic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Sinisa F Djurasevic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Jelena Djordjevic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Predrag Vujovic
- Department for Comparative Physiology and Ecophysiology, Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
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19
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Glace BW, Kremenic IJ, McHugh MP. Effect of carbohydrate beverage ingestion on central versus peripheral fatigue: a placebo-controlled, randomized trial in cyclists. Appl Physiol Nutr Metab 2018; 44:139-147. [PMID: 30058344 DOI: 10.1139/apnm-2017-0777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We investigated whether carbohydrate ingestion delays fatigue in endurance-trained cyclists via peripheral or central mechanisms. Ten men (35 ± 9 years of age) and 10 women (42 ± 7 years of age) were assigned, in a double-blind, crossover design, to a sports drink (CHO) or to a placebo (PL). The following strength measures were made 3 times (before exercise, after a time trial (TT), and after a ride to exhaustion): (i) maximal voluntary contraction (MVC); (ii) MVC with superimposed femoral nerve magnetic stimulation to measure central activation ratio (CAR); and (iii) femoral nerve stimulation in a 3-s pulse train on relaxed muscle. The subjects cycled for 2 h at approximately 65% of peak oxygen consumption, with five 1-min sprints interspersed, followed by a 3-km TT. After strength testing, the cyclists remounted their bikes, performed a brief warm-up, and pedaled at approximately 85% peak oxygen consumption until unable to maintain workload. Changes in metabolic and strength measurements were analyzed with repeated-measures ANOVA. From before exercise to after the TT, MVC declined in men (17%) and women (18%) (p = 0.004), with no effect of beverage (p > 0.193); CAR decreased in both sexes with PL (p = 0.009), and the decline was attenuated by CHO in men only (time × treatment, p = 0.022); and there was no evidence of peripheral fatigue in either sex with either beverage (p > 0.122). Men rode faster in the TT with CHO (p = 0.005) but did not improve performance in the ride to exhaustion (p = 0.080). In women, CHO did not improve performance in the TT (p = 0.173) or in the ride to exhaustion (p = 0.930). We concluded that carbohydrate ingestion preserved central activation and performance in men, but not in women, during long-duration cycling.
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Affiliation(s)
- Beth W Glace
- Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA.,Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA
| | - Ian J Kremenic
- Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA.,Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA
| | - Malachy P McHugh
- Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA.,Nicholas Institute of Sports Medicine and Athletic Trauma, Lenox Hill Hospital, New York, NY 10065, USA
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20
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Hyper-hippocampal glycogen induced by glycogen loading with exhaustive exercise. Sci Rep 2018; 8:1285. [PMID: 29352196 PMCID: PMC5775355 DOI: 10.1038/s41598-018-19445-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/28/2017] [Indexed: 12/29/2022] Open
Abstract
Glycogen loading (GL), a well-known type of sports conditioning, in combination with exercise and a high carbohydrate diet (HCD) for 1 week enhances individual endurance capacity through muscle glycogen supercompensation. This exercise-diet combination is necessary for successful GL. Glycogen in the brain contributes to hippocampus-related memory functions and endurance capacity. Although the effect of HCD on the brain remains unknown, brain supercompensation occurs following exhaustive exercise (EE), a component of GL. We thus employed a rat model of GL and examined whether GL increases glycogen levels in the brain as well as in muscle, and found that GL increased glycogen levels in the hippocampus and hypothalamus, as well as in muscle. We further explored the essential components of GL (exercise and/or diet conditions) to establish a minimal model of GL focusing on the brain. Exercise, rather than a HCD, was found to be crucial for GL-induced hyper-glycogen in muscle, the hippocampus and the hypothalamus. Moreover, EE was essential for hyper-glycogen only in the hippocampus even without HCD. Here we propose the EE component of GL without HCD as a condition that enhances brain glycogen stores especially in the hippocampus, implicating a physiological strategy to enhance hippocampal functions.
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21
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Bain AR, Ainslie PN, Barak OF, Hoiland RL, Drvis I, Mijacika T, Bailey DM, Santoro A, DeMasi DK, Dujic Z, MacLeod DB. Hypercapnia is essential to reduce the cerebral oxidative metabolism during extreme apnea in humans. J Cereb Blood Flow Metab 2017; 37:3231-3242. [PMID: 28071964 PMCID: PMC5584699 DOI: 10.1177/0271678x16686093] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The cerebral metabolic rate of oxygen (CMRO2) is reduced during apnea that yields profound hypoxia and hypercapnia. In this study, to dissociate the impact of hypoxia and hypercapnia on the reduction in CMRO2, 11 breath-hold competitors completed three apneas under: (a) normal conditions (NM), yielding severe hypercapnia and hypoxemia, (b) with prior hyperventilation (HV), yielding severe hypoxemia only, and (c) with prior 100% oxygen breathing (HX), yielding the greatest level of hypercapnia, but in the absence of hypoxemia. The CMRO2 was calculated from the product of cerebral blood flow (ultrasound) and the radial artery-jugular venous oxygen content difference (cannulation). Secondary measures included net-cerebral glucose/lactate exchange and nonoxidative metabolism. Reductions in CMRO2 were largest in the HX condition (-44 ± 15%, p < 0.05), with the most severe hypercapnia (PaCO2 = 58 ± 5 mmHg) but maintained oxygen saturation. The CMRO2 was reduced by 24 ± 27% in NM ( p = 0.05), but unchanged in the HV apnea where hypercapnia was absent. A net-cerebral lactate release was observed at the end of apnea in the HV and NM condition, but not in the HX apnea (main effect p < 0.05). These novel data support hypercapnia/pH as a key mechanism mediating reductions in CMRO2 during apnea, and show that severe hypoxemia stimulates lactate release from the brain.
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Affiliation(s)
- Anthony R Bain
- 1 Centre for Heart Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Philip N Ainslie
- 1 Centre for Heart Lung and Vascular Health, University of British Columbia, Kelowna, BC, Canada
| | - Otto F Barak
- 2 School of Medicine, University of Split, Split, Croatia
| | | | - Ivan Drvis
- 4 School of Kinesiology, University of Zagreb, Zagreb, Croatia
| | - Tanja Mijacika
- 2 School of Medicine, University of Split, Split, Croatia
| | - Damian M Bailey
- 5 Faculty of Life Sciences and Education, University of South Wales, Glamorgan, UK
| | | | | | - Zeljko Dujic
- 2 School of Medicine, University of Split, Split, Croatia
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22
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Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity. Proc Natl Acad Sci U S A 2017; 114:6358-6363. [PMID: 28515312 DOI: 10.1073/pnas.1702739114] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.
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23
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Shima T, Matsui T, Jesmin S, Okamoto M, Soya M, Inoue K, Liu YF, Torres-Aleman I, McEwen BS, Soya H. Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes. Diabetologia 2017; 60:597-606. [PMID: 27928614 DOI: 10.1007/s00125-016-4164-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/03/2016] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by hippocampal glycometabolic dysfunction. If so, such dysfunction should also be ameliorated with moderate exercise by normalising hippocampal glycometabolism, since 4 weeks of moderate exercise enhances memory function and local hippocampal glycogen levels in normal animals. METHODS The hippocampal glycometabolism in OLETF rats (model of human type 2 diabetes) was assessed and, subsequently, the effects of exercise on memory function and hippocampal glycometabolism were investigated. RESULTS OLETF rats, which have memory dysfunction, exhibited higher levels of glycogen in the hippocampus than did control rats, and breakdown of hippocampal glycogen with a single bout of exercise remained unimpaired. However, OLETF rats expressed lower levels of hippocampal monocarboxylate transporter 2 (MCT2, a transporter for lactate to neurons). Four weeks of moderate exercise improved spatial memory accompanied by further increase in hippocampal glycogen levels and restoration of MCT2 expression independent of neurotrophic factor and clinical symptoms in OLETF rats. CONCLUSIONS/INTERPRETATION Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4 weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.
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Affiliation(s)
- Takeru Shima
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan
- Cajal Institute, CSIC, Madrid, Spain
| | - Subrina Jesmin
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Masahiro Okamoto
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Mariko Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Koshiro Inoue
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | - Yu-Fan Liu
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
| | | | - Bruce S McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
| | - Hideaki Soya
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan.
- Department of Sports Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Ibaraki, Japan.
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24
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Strengthened Corticosubcortical Functional Connectivity during Muscle Fatigue. Neural Plast 2016; 2016:1726848. [PMID: 27830093 PMCID: PMC5086541 DOI: 10.1155/2016/1726848] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 08/23/2016] [Accepted: 09/25/2016] [Indexed: 01/27/2023] Open
Abstract
The present study examined functional connectivity (FC) between functional MRI (fMRI) signals of the primary motor cortex (M1) and each of the three subcortical neural structures, cerebellum (CB), basal ganglia (BG), and thalamus (TL), during muscle fatigue using the quantile regression technique. Understanding activation relation between the subcortical structures and the M1 during prolonged motor performance should help delineate how central motor control network modulates acute perturbations at peripheral sensorimotor system such as muscle fatigue. Ten healthy subjects participated in the study and completed a 20-minute intermittent handgrip motor task at 50% of their maximal voluntary contraction (MVC) level. Quantile regression analyses were carried out to compare the FC between the contralateral (left) M1 and CB, BG, and TL in the minimal (beginning 100 s) versus significant (ending 100 s) fatigue stages. Widespread, statistically significant increases in FC were found in bilateral BG, CB, and TL with the left M1 during significant versus minimal fatigue stages. Our results imply that these subcortical nuclei are critical components in the motor control network and actively involved in modulating voluntary muscle fatigue, possibly, by working together with the M1 to strengthen the descending central command to prolong the motor performance.
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Proia P, Di Liegro CM, Schiera G, Fricano A, Di Liegro I. Lactate as a Metabolite and a Regulator in the Central Nervous System. Int J Mol Sci 2016; 17:E1450. [PMID: 27598136 PMCID: PMC5037729 DOI: 10.3390/ijms17091450] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/22/2016] [Accepted: 08/25/2016] [Indexed: 12/21/2022] Open
Abstract
More than two hundred years after its discovery, lactate still remains an intriguing molecule. Considered for a long time as a waste product of metabolism and the culprit behind muscular fatigue, it was then recognized as an important fuel for many cells. In particular, in the nervous system, it has been proposed that lactate, released by astrocytes in response to neuronal activation, is taken up by neurons, oxidized to pyruvate and used for synthesizing acetyl-CoA to be used for the tricarboxylic acid cycle. More recently, in addition to this metabolic role, the discovery of a specific receptor prompted a reconsideration of its role, and lactate is now seen as a sort of hormone, even involved in processes as complex as memory formation and neuroprotection. As a matter of fact, exercise offers many benefits for our organisms, and seems to delay brain aging and neurodegeneration. Now, exercise induces the production and release of lactate into the blood which can reach the liver, the heart, and also the brain. Can lactate be a beneficial molecule produced during exercise, and offer neuroprotection? In this review, we summarize what we have known on lactate, discussing the roles that have been attributed to this molecule over time.
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Affiliation(s)
- Patrizia Proia
- Department of Psychological, Pedagogical and Educational Sciences, Sport and Exercise Sciences Research Unit, University of Palermo, Palermo I-90128, Italy.
| | - Carlo Maria Di Liegro
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo (UNIPA), Palermo I-90128, Italy.
| | - Gabriella Schiera
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo (UNIPA), Palermo I-90128, Italy.
| | - Anna Fricano
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo (UNIPA), Palermo I-90128, Italy.
| | - Italia Di Liegro
- Department of Experimental Biomedicine and Clinical Neurosciences (BIONEC), University of Palermo, Palermo I-90127, Italy.
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Leclair E, Liggins RT, Peckett AJ, Teich T, Coy DH, Vranic M, Riddell MC. Glucagon responses to exercise-induced hypoglycaemia are improved by somatostatin receptor type 2 antagonism in a rat model of diabetes. Diabetologia 2016; 59:1724-31. [PMID: 27075449 DOI: 10.1007/s00125-016-3953-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/18/2016] [Indexed: 12/18/2022]
Abstract
AIMS/HYPOTHESIS Regular exercise is at the cornerstone of care in type 1 diabetes. However, relative hyperinsulinaemia and a blunted glucagon response to exercise promote hypoglycaemia. Recently, a selective antagonist of somatostatin receptor 2, PRL-2903, was shown to improve glucagon counterregulation to hypoglycaemia in resting streptozotocin-induced diabetic rats. The aim of this study was to test the efficacy of PRL-2903 in enhancing glucagon counterregulation during repeated hyperinsulinaemic exercise. METHODS Diabetic rats performed daily exercise for 1 week and were then exposed to saline (154 mmol/l NaCl) or PRL-2903, 10 mg/kg, before hyperinsulinaemic exercise on two separate occasions spaced 1 day apart. In the following week, animals crossed over to the alternate treatment for a third hyperinsulinaemic exercise protocol. RESULTS Liver glycogen content was lower in diabetic rats compared with control rats, despite daily insulin therapy (p < 0.05). Glucagon levels failed to increase during exercise with saline but increased three-to-six fold with PRL-2903 (all p < 0.05). Glucose concentrations tended to be higher during exercise and early recovery with PRL-2903 on both days of treatment; this difference did not achieve statistical significance (p > 0.05). CONCLUSIONS/INTERPRETATION PRL-2903 improves glucagon counterregulation during exercise. However, liver glycogen stores or other factors limit the prevention of exercise-induced hypoglycaemia in rats with streptozotocin-induced diabetes.
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Affiliation(s)
- Erwan Leclair
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | | | - Ashley J Peckett
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | - Trevor Teich
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada
| | - David H Coy
- Department of Medicine, Peptide Research Labs, Tulane University Medical Center, New Orleans, LA, USA
| | - Mladen Vranic
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON, Canada
| | - Michael C Riddell
- School of Kinesiology and Health Science, York University, Toronto, ON, M3J 1P3, Canada.
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Lucas SJE, Helge JW, Schütz UHW, Goldman RF, Cotter JD. Moving in extreme environments: extreme loading; carriage versus distance. EXTREME PHYSIOLOGY & MEDICINE 2016; 5:6. [PMID: 27110357 PMCID: PMC4840901 DOI: 10.1186/s13728-016-0047-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 04/01/2016] [Indexed: 12/17/2022]
Abstract
This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may be at least as problematic, and are therefore included as a reference, e.g. when considering exposure, dangers and (mal)adaptations. As per the other reviews in this series, we describe the nature of the stress and the associated consequences; illustrate relevant regulations, including why and how they are set; present the pros and cons for self versus prescribed acute and chronic exposure; describe humans' (mal)adaptations; and finally suggest future directions for practice and research. In summary, we describe adaptation patterns that are often U or J shaped and that over time minimal or no load carriage decreases the global load carrying capacity and eventually leads to severe adverse effects and manifest disease under minimal absolute but high relative loads. We advocate that further understanding of load carrying capacity and the inherent mechanisms leading to adverse effects may advantageously be studied in this perspective. With improved access to insightful and portable technologies, there are some exciting possibilities to explore these questions in this context.
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Affiliation(s)
- Samuel J. E. Lucas
- />School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT UK
- />Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Jørn W. Helge
- />Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Uwe H. W. Schütz
- />Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
- />Orthopaedic Consulting Office at the Green Tower and Medical Pain Centre Lake Constance–Upper Swabia, Ravensburg, Germany
| | | | - James D. Cotter
- />School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
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Yunoki T, Matsuura R, Yamanaka R, Afroundeh R, Lian CS, Shirakawa K, Ohtsuka Y, Yano T. Relationship between motor corticospinal excitability and ventilatory response during intense exercise. Eur J Appl Physiol 2016; 116:1117-26. [PMID: 27055665 DOI: 10.1007/s00421-016-3374-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 03/28/2016] [Indexed: 11/26/2022]
Abstract
PURPOSE Effort sense has been suggested to be involved in the hyperventilatory response during intense exercise (IE). However, the mechanism by which effort sense induces an increase in ventilation during IE has not been fully elucidated. The aim of this study was to determine the relationship between effort-mediated ventilatory response and corticospinal excitability of lower limb muscle during IE. METHODS Eight subjects performed 3 min of cycling exercise at 75-85 % of maximum workload twice (IE1st and IE2nd). IE2nd was performed after 60 min of resting recovery following 45 min of submaximal cycling exercise at the workload corresponding to ventilatory threshold. Vastus lateralis muscle response to transcranial magnetic stimulation of the motor cortex (motor evoked potentials, MEPs), effort sense of legs (ESL, Borg 0-10 scale), and ventilatory response were measured during the two IEs. RESULTS The slope of ventilation (l/min) against CO2 output (l/min) during IE2nd (28.0 ± 5.6) was significantly greater than that (25.1 ± 5.5) during IE1st. Mean ESL during IE was significantly higher in IE2nd (5.25 ± 0.89) than in IE1st (4.67 ± 0.62). Mean MEP (normalized to maximal M-wave) during IE was significantly lower in IE2nd (66 ± 22 %) than in IE1st (77 ± 24 %). The difference in mean ESL between the two IEs was significantly (p < 0.05, r = -0.82) correlated with the difference in mean MEP between the two IEs. CONCLUSIONS The findings suggest that effort-mediated hyperventilatory response to IE may be associated with a decrease in corticospinal excitability of exercising muscle.
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Affiliation(s)
- Takahiro Yunoki
- Department of Human Development Sciences, Faculty of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan.
| | - Ryouta Matsuura
- Department of Health and Physical Education, Joetsu University of Education, Joetsu, Japan
| | - Ryo Yamanaka
- Japan Institute of Sports Sciences, Tokyo, Japan
| | - Roghayyeh Afroundeh
- Department of Physical Education and Sports Science, Faculty of Education and Psychology, University of Mohaghegh Ardabilli, Ardabil, Iran
| | - Chang-Shun Lian
- Department of Human Development Sciences, Faculty of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan
| | - Kazuki Shirakawa
- Department of Human Development Sciences, Faculty of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan
| | - Yoshinori Ohtsuka
- Department of Human Development Sciences, Faculty of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan
| | - Tokuo Yano
- Department of Human Development Sciences, Faculty of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan
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Abstract
The common pattern of play in 'team sports' is 'stop and go', i.e. where players perform repeated bouts of brief high-intensity exercise punctuated by lower intensity activity. Sprints are generally 2-4 s long and recovery between sprints is of variable length. Energy production during brief sprints is derived from the degradation of intra-muscular phosphocreatine and glycogen (anaerobic metabolism). Prolonged periods of multiple sprints drain muscle glycogen stores, leading to a decrease in power output and a reduction in general work rate during training and competition. The impact of dietary carbohydrate interventions on team sport performance have been typically assessed using intermittent variable-speed shuttle running over a distance of 20 m. This method has evolved to include specific work to rest ratios and skills specific to team sports such as soccer, rugby and basketball. Increasing liver and muscle carbohydrate stores before sports helps delay the onset of fatigue during prolonged intermittent variable-speed running. Carbohydrate intake during exercise, typically ingested as carbohydrate-electrolyte solutions, is also associated with improved performance. The mechanisms responsible are likely to be the availability of carbohydrate as a substrate for central and peripheral functions. Variable-speed running in hot environments is limited by the degree of hyperthermia before muscle glycogen availability becomes a significant contributor to the onset of fatigue. Finally, ingesting carbohydrate immediately after training and competition will rapidly recover liver and muscle glycogen stores.
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Affiliation(s)
- Clyde Williams
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, England, LE11 3TU, UK.
| | - Ian Rollo
- Gatorade Sports Science Institute, Leicester, UK
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Abstract
During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (<25 % energy), high-fat (>60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen. As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise). Furthermore, a 2- to 3-week exposure to minimal carbohydrate (<20 g/day) intake achieves adaptation to high blood ketone concentrations. However, the failure to detect clear performance benefits during endurance/ultra-endurance protocols, combined with evidence of impaired performance of high-intensity exercise via a down-regulation of carbohydrate metabolism led this author to dismiss the use of such fat-adaptation strategies by competitive athletes in conventional sports. Recent re-emergence of interest in LCHF diets, coupled with anecdotes of improved performance by sportspeople who follow them, has created a need to re-examine the potential benefits of this eating style. Unfortunately, the absence of new data prevents a different conclusion from being made. Notwithstanding the outcomes of future research, there is a need for better recognition of current sports nutrition guidelines that promote an individualized and periodized approach to fuel availability during training, allowing the athlete to prepare for competition performance with metabolic flexibility and optimal utilization of all muscle substrates. Nevertheless, there may be a few scenarios where LCHF diets are of benefit, or at least are not detrimental, for sports performance.
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Affiliation(s)
- Louise M Burke
- Sports Nutrition, Australian Institute of Sport, Canberra, ACT, Australia.
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia.
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31
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Wagner G, Herbsleb M, de la Cruz F, Schumann A, Brünner F, Schachtzabel C, Gussew A, Puta C, Smesny S, Gabriel HW, Reichenbach JR, Bär KJ. Hippocampal structure, metabolism, and inflammatory response after a 6-week intense aerobic exercise in healthy young adults: a controlled trial. J Cereb Blood Flow Metab 2015; 35:1570-8. [PMID: 26082010 PMCID: PMC4640322 DOI: 10.1038/jcbfm.2015.125] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/02/2015] [Accepted: 05/12/2015] [Indexed: 12/12/2022]
Abstract
Interventional studies suggest that changes in physical fitness affect brain function and structure. We studied the influence of high intensity physical exercise on hippocampal volume and metabolism in 17 young healthy male adults during a 6-week exercise program compared with matched controls. We further aimed to relate these changes to hypothesized changes in exercised-induced brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α). We show profound improvement of physical fitness in most subjects and a positive correlation between the degree of fitness improvement and increased BDNF levels. We unexpectedly observed an average volume decrease of about 2%, which was restricted to right hippocampal subfields CA2/3, subiculum, and dentate gyrus and which correlated with fitness improvement and increased BDNF levels negatively. This result indicates that mainly those subjects who did not benefit from the exercise program show decreased hippocampal volume, reduced BDNF levels, and increased TNF-α concentrations. While spectroscopy results do not indicate any neuronal loss (unchanged N-acetylaspartate levels) decreased glutamate-glutamine levels were observed in the right anterior hippocampus in the exercise group only. Responder characteristics need to be studied in more detail. Our results point to an important role of the inflammatory response after exercise on changes in hippocampal structure.
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Affiliation(s)
- Gerd Wagner
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Marco Herbsleb
- Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University, Jena, Germany
| | - Feliberto de la Cruz
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Andy Schumann
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Franziska Brünner
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Claudia Schachtzabel
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
| | - Alexander Gussew
- Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University, Jena, Germany
| | - Christian Puta
- Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University, Jena, Germany
| | - Stefan Smesny
- Department of Psychiatry and Psychotherapy, University Hospital, Jena, Germany
| | - Holger W Gabriel
- Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University, Jena, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital-Friedrich Schiller University, Jena, Germany
| | - Karl-Jürgen Bär
- Psychiatric Brain and Body Research Group Jena, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany
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Christie ST, Schrater P. Cognitive cost as dynamic allocation of energetic resources. Front Neurosci 2015; 9:289. [PMID: 26379482 PMCID: PMC4547044 DOI: 10.3389/fnins.2015.00289] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/30/2015] [Indexed: 11/13/2022] Open
Abstract
While it is widely recognized that thinking is somehow costly, involving cognitive effort and producing mental fatigue, these costs have alternatively been assumed to exist, treated as the brain's assessment of lost opportunities, or suggested to be metabolic but with implausible biological bases. We present a model of cognitive cost based on the novel idea that the brain senses and plans for longer-term allocation of metabolic resources by purposively conserving brain activity. We identify several distinct ways the brain might control its metabolic output, and show how a control-theoretic model that models decision-making with an energy budget can explain cognitive effort avoidance in terms of an optimal allocation of limited energetic resources. The model accounts for both subject responsiveness to reward and the detrimental effects of hypoglycemia on cognitive function. A critical component of the model is using astrocytic glycogen as a plausible basis for limited energetic reserves. Glycogen acts as an energy buffer that can temporarily support high neural activity beyond the rate supported by blood glucose supply. The published dynamics of glycogen depletion and repletion are consonant with a broad array of phenomena associated with cognitive cost. Our model thus subsumes both the “cost/benefit” and “limited resource” models of cognitive cost while retaining valuable contributions of each. We discuss how the rational control of metabolic resources could underpin the control of attention, working memory, cognitive look ahead, and model-free vs. model-based policy learning.
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Affiliation(s)
| | - Paul Schrater
- Cognitive Science, University of Minnesota Minneapolis, MN, USA ; Departments of Psychology and Computer Science, University of Minnesota Minneapolis, MN, USA
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Matsui T, Soya S, Kawanaka K, Soya H. Brain Glycogen Decreases During Intense Exercise Without Hypoglycemia: The Possible Involvement of Serotonin. Neurochem Res 2015; 40:1333-40. [PMID: 26037553 DOI: 10.1007/s11064-015-1594-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 04/21/2015] [Accepted: 04/28/2015] [Indexed: 11/25/2022]
Abstract
Brain glycogen stored in astrocytes, a source of lactate as a neuronal energy source, decreases during prolonged exercise with hypoglycemia. However, brain glycogen dynamics during exercise without hypoglycemia remain unknown. Since intense exercise increases brain noradrenaline and serotonin as known inducers for brain glycogenolysis, we hypothesized that brain glycogen decreases with intense exercise not accompanied by hypoglycemia. To test this hypothesis, we employed a well-established acute intense exercise model of swimming in rats. Rats swam for fourteen 20 s bouts with a weight equal to 8 % of their body mass and were sacrificed using high-power (10 kW) microwave irradiation to inactivate brain enzymes for accurate detection of brain glycogen and monoamines. Intense exercise did not alter blood glucose, but did increase blood lactate levels. Immediately after exercise, brain glycogen decreased and brain lactate increased in the hippocampus, cerebellum, cortex, and brainstem. Simultaneously, serotonin turnover in the hippocampus and brainstem mutually increased and were associated with decreased brain glycogen. Intense swimming exercise that does not induce hypoglycemia decreases brain glycogen associated with increased brain lactate, implying an importance of glycogen in brain energetics during intense exercise even without hypoglycemia. Activated serotonergic regulation is a possible underlying mechanism for intense exercise-induced glycogenolysis at least in the hippocampus and brainstem.
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Affiliation(s)
- Takashi Matsui
- Laboratory of Exercise Biochemistry and Neuroendocrinology, Institute for Health and Sport Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8574, Japan
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Rattray B, Argus C, Martin K, Northey J, Driller M. Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance? Front Physiol 2015; 6:79. [PMID: 25852568 PMCID: PMC4362407 DOI: 10.3389/fphys.2015.00079] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/27/2015] [Indexed: 11/23/2022] Open
Abstract
Key PointsCentral fatigue is accepted as a contributor to overall athletic performance, yet little research directly investigates post-exercise recovery strategies targeting the brain Current post-exercise recovery strategies likely impact on the brain through a range of mechanisms, but improvements to these strategies is needed Research is required to optimize post-exercise recovery with a focus on the brain
Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimizing recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilized recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimizing brain fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.
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Affiliation(s)
- Ben Rattray
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Christos Argus
- University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Kristy Martin
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Joseph Northey
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra Canberra, ACT, Australia ; University of Canberra Research Institute for Sport and Exercise, University of Canberra Canberra, ACT, Australia
| | - Matthew Driller
- Department of Sport and Leisure Studies, The University of Waikato Hamilton, New Zealand
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35
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Khowaja A, Choi IY, Seaquist ER, Öz G. In vivo Magnetic Resonance Spectroscopy of cerebral glycogen metabolism in animals and humans. Metab Brain Dis 2015; 30:255-61. [PMID: 24676563 PMCID: PMC4392006 DOI: 10.1007/s11011-014-9530-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/12/2014] [Indexed: 01/31/2023]
Abstract
Glycogen serves as an important energy reservoir in the human body. Despite the abundance of glycogen in the liver and skeletal muscles, its concentration in the brain is relatively low, hence its significance has been questioned. A major challenge in studying brain glycogen metabolism has been the lack of availability of non-invasive techniques for quantification of brain glycogen in vivo. Invasive methods for brain glycogen quantification such as post mortem extraction following high energy microwave irradiation are not applicable in the human brain. With the advent of (13)C Magnetic Resonance Spectroscopy (MRS), it has been possible to measure brain glycogen concentrations and turnover in physiological conditions, as well as under the influence of stressors such as hypoglycemia and visual stimulation. This review presents an overview of the principles of the (13)C MRS methodology and its applications in both animals and humans to further our understanding of glycogen metabolism under normal physiological and pathophysiological conditions such as hypoglycemia unawareness.
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Affiliation(s)
- Ameer Khowaja
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, 420 Delaware Street, SE, Minneapolis, MN 55455, USA
| | - In-Young Choi
- Hoglund Brain Imaging Center, Department of Neurology, Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Elizabeth R. Seaquist
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Minnesota, 420 Delaware Street, SE, Minneapolis, MN 55455, USA
| | - Gülin Öz
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN 55455, USA
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Li LO, Grevengoed TJ, Paul DS, Ilkayeva O, Koves TR, Pascual F, Newgard CB, Muoio DM, Coleman RA. Compartmentalized acyl-CoA metabolism in skeletal muscle regulates systemic glucose homeostasis. Diabetes 2015; 64:23-35. [PMID: 25071025 PMCID: PMC4274800 DOI: 10.2337/db13-1070] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The impaired capacity of skeletal muscle to switch between the oxidation of fatty acid (FA) and glucose is linked to disordered metabolic homeostasis. To understand how muscle FA oxidation affects systemic glucose, we studied mice with a skeletal muscle-specific deficiency of long-chain acyl-CoA synthetase (ACSL)1. ACSL1 deficiency caused a 91% loss of ACSL-specific activity and a 60-85% decrease in muscle FA oxidation. Acsl1(M-/-) mice were more insulin sensitive, and, during an overnight fast, their respiratory exchange ratio was higher, indicating greater glucose use. During endurance exercise, Acsl1(M-/-) mice ran only 48% as far as controls. At the time that Acsl1(M-/-) mice were exhausted but control mice continued to run, liver and muscle glycogen and triacylglycerol stores were similar in both genotypes; however, plasma glucose concentrations in Acsl1(M-/-) mice were ∼40 mg/dL, whereas glucose concentrations in controls were ∼90 mg/dL. Excess use of glucose and the likely use of amino acids for fuel within muscle depleted glucose reserves and diminished substrate availability for hepatic gluconeogenesis. Surprisingly, the content of muscle acyl-CoA at exhaustion was markedly elevated, indicating that acyl-CoAs synthesized by other ACSL isoforms were not available for β-oxidation. This compartmentalization of acyl-CoAs resulted in both an excessive glucose requirement and severely compromised systemic glucose homeostasis.
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Affiliation(s)
- Lei O Li
- Department of Nutrition, University of North Carolina, Chapel Hill, NC
| | | | - David S Paul
- Department of Nutrition, University of North Carolina, Chapel Hill, NC
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, and Departments of Medicine and Pharmacology and Cancer Biology, Duke University, Durham, NC
| | - Timothy R Koves
- Sarah W. Stedman Nutrition and Metabolism Center, and Departments of Medicine and Pharmacology and Cancer Biology, Duke University, Durham, NC
| | - Florencia Pascual
- Department of Nutrition, University of North Carolina, Chapel Hill, NC
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, and Departments of Medicine and Pharmacology and Cancer Biology, Duke University, Durham, NC
| | - Deborah M Muoio
- Sarah W. Stedman Nutrition and Metabolism Center, and Departments of Medicine and Pharmacology and Cancer Biology, Duke University, Durham, NC
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Abstract
Accumulating evidence suggests that diet and lifestyle can play an important role in delaying the onset or halting the progression of age-related health disorders and can improve cognitive function. Exercise has been promoted as a possible prevention for neurodegenerative diseases. Exercise will have a positive influence on cognition and it increases the brain-derived neurotrophic factor, an essential neurotrophin. Several dietary components have been identified as having effects on cognitive abilities. In particular, polyphenols have been reported to exert their neuroprotective actions through the potential to protect neurons against injury induced by neurotoxins, an ability to suppress neuroinflammation, and the potential to promote memory, learning, and cognitive function. Dietary factors can affect multiple brain processes by regulating neurotransmitter pathways, synaptic transmission, membrane fluidity, and signal-transduction pathways. Flavonols are part of the flavonoid family that is found in various fruits, cocoa, wine, tea and beans. Although the antioxidant effects of flavonols are well established in vitro, there is general agreement that flavonols have more complex actions in vivo. Several cross-sectional and longitudinal studies have shown that a higher intake of flavonoids from food may be associated with a better cognitive evolution. Whether this reflects a causal association remains to be elucidated. Several studies have tried to 'manipulate' the brain in order to postpone central fatigue. Most studies have clearly shown that in normal environmental circumstances these interventions are not easy to perform. There is accumulating evidence that rinsing the mouth with a carbohydrate solution will improve endurance performance. There is a need for additional well controlled studies to explore the possible impact of diet and nutrition on brain functioning.
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Rozand V, Pageaux B, Marcora SM, Papaxanthis C, Lepers R. Does mental exertion alter maximal muscle activation? Front Hum Neurosci 2014; 8:755. [PMID: 25309404 PMCID: PMC4176059 DOI: 10.3389/fnhum.2014.00755] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/08/2014] [Indexed: 11/23/2022] Open
Abstract
Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 min each: (i) high mental exertion (incongruent Stroop task), (ii) moderate mental exertion (congruent Stroop task), (iii) low mental exertion (watching a movie). In each condition, mental exertion was combined with 10 intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 min). Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.
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Affiliation(s)
- Vianney Rozand
- Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France
| | - Benjamin Pageaux
- Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France ; Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway Chatham Maritime, UK
| | - Samuele M Marcora
- Endurance Research Group, School of Sport and Exercise Sciences, University of Kent at Medway Chatham Maritime, UK
| | - Charalambos Papaxanthis
- Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France
| | - Romuald Lepers
- Institut National de la Santé et de la Recherche Médicale U1093, Faculty of Sport Sciences, University of Burgundy Dijon, France
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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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Masterjohn C, Park Y, Lee J, Noh SK, Koo SI, Bruno RS. Dietary fructose feeding increases adipose methylglyoxal accumulation in rats in association with low expression and activity of glyoxalase-2. Nutrients 2013; 5:3311-28. [PMID: 23966111 PMCID: PMC3775256 DOI: 10.3390/nu5083311] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 07/05/2013] [Accepted: 08/12/2013] [Indexed: 11/29/2022] Open
Abstract
Methylglyoxal is a precursor to advanced glycation endproducts that may contribute to diabetes and its cardiovascular-related complications. Methylglyoxal is successively catabolized to d-lactate by glyoxalase-1 and glyoxalase-2. The objective of this study was to determine whether dietary fructose and green tea extract (GTE) differentially regulate methylglyoxal accumulation in liver and adipose, mediated by tissue-specific differences in the glyoxalase system. We fed six week old male Sprague-Dawley rats a low-fructose diet (10% w/w) or a high-fructose diet (60% w/w) containing no GTE or GTE at 0.5% or 1.0% for nine weeks. Fructose-fed rats had higher (P < 0.05) adipose methylglyoxal, but GTE had no effect. Plasma and hepatic methylglyoxal were unaffected by fructose and GTE. Fructose and GTE also had no effect on the expression or activity of glyoxalase-1 and glyoxalase-2 at liver or adipose. Regardless of diet, adipose glyoxalase-2 activity was 10.8-times lower (P < 0.05) than adipose glyoxalase-1 activity and 5.9-times lower than liver glyoxalase-2 activity. Adipose glyoxalase-2 activity was also inversely related to adipose methylglyoxal (r = −0.61; P < 0.05). These findings suggest that fructose-mediated adipose methylglyoxal accumulation is independent of GTE supplementation and that its preferential accumulation in adipose compared to liver is due to low constitutive expression of glyoxalase-2.
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Affiliation(s)
- Christopher Masterjohn
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (C.M.); (Y.P.); (J.L.); (S.I.K.)
- Department of Comparative Biosciences, University of Illinois, Urbana, IL 61801, USA
| | - Youngki Park
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (C.M.); (Y.P.); (J.L.); (S.I.K.)
| | - Jiyoung Lee
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (C.M.); (Y.P.); (J.L.); (S.I.K.)
| | - Sang K. Noh
- Department of Food and Nutrition, Changwon National University, Changwon 641-773, Korea; E-Mail:
| | - Sung I. Koo
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (C.M.); (Y.P.); (J.L.); (S.I.K.)
| | - Richard S. Bruno
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA; E-Mails: (C.M.); (Y.P.); (J.L.); (S.I.K.)
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-614-292-5522; Fax: +1-614-292-4339
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Glace BW, Kremenic IJ, McHugh MP. Sex differences in central and peripheral mechanisms of fatigue in cyclists. Eur J Appl Physiol 2012; 113:1091-8. [DOI: 10.1007/s00421-012-2516-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 09/27/2012] [Indexed: 02/03/2023]
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Matsui T, Ishikawa T, Ito H, Okamoto M, Inoue K, Lee MC, Fujikawa T, Ichitani Y, Kawanaka K, Soya H. Brain glycogen supercompensation following exhaustive exercise. J Physiol 2011; 590:607-16. [PMID: 22063629 DOI: 10.1113/jphysiol.2011.217919] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Brain glycogen localized in astrocytes, a critical energy source for neurons, decreases during prolonged exhaustive exercise with hypoglycaemia. However, it is uncertain whether exhaustive exercise induces glycogen supercompensation in the brain as in skeletal muscle. To explore this question, we exercised adult male rats to exhaustion at moderate intensity (20 m min(-1)) by treadmill, and quantified glycogen levels in several brain loci and skeletal muscles using a high-power (10 kW) microwave irradiation method as a gold standard. Skeletal muscle glycogen was depleted by 82-90% with exhaustive exercise, and supercompensated by 43-46% at 24 h after exercise. Brain glycogen levels decreased by 50-64% with exhaustive exercise, and supercompensated by 29-63% (whole brain 46%, cortex 60%, hippocampus 33%, hypothalamus 29%, cerebellum 63% and brainstem 49%) at 6 h after exercise. The brain glycogen supercompensation rates after exercise positively correlated with their decrease rates during exercise. We also observed that cortical and hippocampal glycogen supercompensation were sustained until 24 h after exercise (long-lasting supercompensation), and their basal glycogen levels increased with 4 weeks of exercise training (60 min day(-1) at 20 m min(-1)). These results support the hypothesis that, like the effect in skeletal muscles, glycogen supercompensation also occurs in the brain following exhaustive exercise, and the extent of supercompensation is dependent on that of glycogen decrease during exercise across brain regions. However, supercompensation in the brain preceded that of skeletal muscles. Further, the long-lasting supercompensation of the cortex and hippocampus is probably a prerequisite for their training adaptation (increased basal levels), probably to meet the increased energy demands of the brain in exercising animals.
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Affiliation(s)
- Takashi Matsui
- Laboratory of Exercise Biochemistry & Neuroendocrinology, Institute for Health and Sports Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8574, Ibaraki, Japan
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