1
|
Wiseman RW, Brown CM, Beck TW, Brault JJ, Reinoso TR, Shi Y, Chase PB. Creatine Kinase Equilibration and ΔG ATP over an Extended Range of Physiological Conditions: Implications for Cellular Energetics, Signaling, and Muscle Performance. Int J Mol Sci 2023; 24:13244. [PMID: 37686064 PMCID: PMC10487889 DOI: 10.3390/ijms241713244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
In this report, we establish a straightforward method for estimating the equilibrium constant for the creatine kinase reaction (CK Keq″) over wide but physiologically and experimentally relevant ranges of pH, Mg2+ and temperature. Our empirical formula for CK Keq″ is based on experimental measurements. It can be used to estimate [ADP] when [ADP] is below the resolution of experimental measurements, a typical situation because [ADP] is on the order of micromolar concentrations in living cells and may be much lower in many in vitro experiments. Accurate prediction of [ADP] is essential for in vivo studies of cellular energetics and metabolism and for in vitro studies of ATP-dependent enzyme function under near-physiological conditions. With [ADP], we were able to obtain improved estimates of ΔGATP, necessitating the reinvestigation of previously reported ADP- and ΔGATP-dependent processes. Application to actomyosin force generation in muscle provides support for the hypothesis that, when [Pi] varies and pH is not altered, the maximum Ca2+-activated isometric force depends on ΔGATP in both living and permeabilized muscle preparations. Further analysis of the pH studies introduces a novel hypothesis around the role of submicromolar ADP in force generation.
Collapse
Affiliation(s)
- Robert Woodbury Wiseman
- Departments of Physiology and Radiology, Michigan State University, East Lansing, MI 48824, USA;
| | - Caleb Micah Brown
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Thomas Wesley Beck
- Department of Radiology, University of Washington, Seattle, WA 98195, USA
| | - Jeffrey John Brault
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA;
| | - Tyler Robert Reinoso
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Yun Shi
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Prescott Bryant Chase
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| |
Collapse
|
2
|
Tomalka A, Heim M, Klotz A, Rode C, Siebert T. Ultrastructural and kinetic evidence support that thick filaments slide through the Z-disc. J R Soc Interface 2022; 19:20220642. [PMID: 36475390 PMCID: PMC9727675 DOI: 10.1098/rsif.2022.0642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
How myofilaments operate at short mammalian skeletal muscle lengths is unknown. A common assumption is that thick (myosin-containing) filaments get compressed at the Z-disc. We provide ultrastructural evidence of sarcomeres contracting down to 0.44 µm-approximately a quarter of thick filament resting length-in long-lasting contractions while apparently keeping a regular, parallel thick filament arrangement. Sarcomeres produced force at such extremely short lengths. Furthermore, sarcomeres adopted a bimodal length distribution with both modes below lengths where sarcomeres are expected to generate force in classic force-length measurements. Mammalian fibres did not restore resting length but remained short after deactivation, as previously reported for amphibian fibres, and showed increased forces during passive re-elongation. These findings are incompatible with viscoelastic thick filament compression but agree with predictions of a model incorporating thick filament sliding through the Z-disc. This more coherent picture of mechanical mammalian skeletal fibre functioning opens new perspectives on muscle physiology.
Collapse
Affiliation(s)
- André Tomalka
- Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Maximilian Heim
- Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Annika Klotz
- Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Christian Rode
- Institute of Sport Science, Department of Biomechanics, University of Rostock, Rostock, Germany
| | - Tobias Siebert
- Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany,Stuttgart Center for Simulation Science, University of Stuttgart, Stuttgart, Germany
| |
Collapse
|
3
|
Skeletal Muscle Biochemical Origin of Exercise Intensity Domains and their Relation to Whole-Body V̇O2 Kinetics. Biosci Rep 2022; 42:231600. [PMID: 35880531 PMCID: PMC9366749 DOI: 10.1042/bsr20220798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/16/2022] [Accepted: 06/29/2022] [Indexed: 11/17/2022] Open
Abstract
This article presents the biochemical intra-skeletal-muscle basis of exercise intensity domains: moderate (M), heavy (H), very heavy (VH) and severe (S). Threshold origins are mediated by a "Pi double-threshold" mechanism of muscle fatigue, which assumes: (1) additional ATP usage, underlying muscle V̇O2 and metabolite slow components, is initiated when inorganic phosphate (Pi) exceeds a critical value (Picrit); (2) exercise is terminated because of fatigue, when Pi reaches a peak value (Pipeak); (3) the Pi increase and additional ATP usage increase mutually stimulate each other forming a positive feedback. M/H and H/VH borders are defined by Pi on-kinetics in relation to Picrit and Pipeak. The values of the ATP usage activity, proportional to power output (PO), for the M/H, H/VH and VH/S borders are lowest in untrained muscle and highest in well-trained muscle. The metabolic range between the M/H and H/VH border (or "H space") decreases with muscle training, while the difference between the H/VH and VH/S border (or "VH space") is only weakly dependent on training status. The absolute magnitude of the muscle V̇O2 slow-component, absent in M exercise, rises gradually with PO to a maximal value in H exercise, and then decreases with PO in VH and S exercise. Simulations of untrained, physically-active and well-trained muscle demonstrate that the muscle M/H border need not be identical to the whole-body M/H border determined from pulmonary V̇O2 on-kinetics and blood lactate, while suggesting that the biochemical origins of the H/VH border reside within skeletal muscle and correspond to whole-body critical power.
Collapse
|
4
|
Isaacs JT, Brennen WN, Christensen SB, Denmeade SR. Mipsagargin: The Beginning-Not the End-of Thapsigargin Prodrug-Based Cancer Therapeutics. Molecules 2021; 26:7469. [PMID: 34946547 PMCID: PMC8707208 DOI: 10.3390/molecules26247469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 12/02/2022] Open
Abstract
Søren Brøgger Christensen isolated and characterized the cell-penetrant sesquiterpene lactone Thapsigargin (TG) from the fruit Thapsia garganica. In the late 1980s/early 1990s, TG was supplied to multiple independent and collaborative groups. Using this TG, studies documented with a large variety of mammalian cell types that TG rapidly (i.e., within seconds to a minute) penetrates cells, resulting in an essentially irreversible binding and inhibiting (IC50~10 nM) of SERCA 2b calcium uptake pumps. If exposure to 50-100 nM TG is sustained for >24-48 h, prostate cancer cells undergo apoptotic death. TG-induced death requires changes in the cytoplasmic Ca2+, initiating a calmodulin/calcineurin/calpain-dependent signaling cascade that involves BAD-dependent opening of the mitochondrial permeability transition pore (MPTP); this releases cytochrome C into the cytoplasm, activating caspases and nucleases. Chemically unmodified TG has no therapeutic index and is poorly water soluble. A TG analog, in which the 8-acyl groups is replaced with the 12-aminododecanoyl group, afforded 12-ADT, retaining an EC50 for killing of <100 nM. Conjugation of 12-ADT to a series of 5-8 amino acid peptides was engineered so that they are efficiently hydrolyzed by only one of a series of proteases [e.g., KLK3 (also known as Prostate Specific Antigen); KLK2 (also known as hK2); Fibroblast Activation Protein Protease (FAP); or Folh1 (also known as Prostate Specific Membrane Antigen)]. The obtained conjugates have increased water solubility for systemic delivery in the blood and prevent cell penetrance and, thus, killing until the TG-prodrug is hydrolyzed by the targeting protease in the vicinity of the cancer cells. We summarize the preclinical validation of each of these TG-prodrugs with special attention to the PSMA TG-prodrug, Mipsagargin, which is in phase II clinical testing.
Collapse
Affiliation(s)
- John T. Isaacs
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (W.N.B.); (S.R.D.)
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - William Nathaniel Brennen
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (W.N.B.); (S.R.D.)
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | | | - Samuel R. Denmeade
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (W.N.B.); (S.R.D.)
- Department of Pharmacology and Molecular Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| |
Collapse
|
5
|
Kalakoutis M, Di Giulio I, Douiri A, Ochala J, Harridge SDR, Woledge RC. Methodological considerations in measuring specific force in human single skinned muscle fibres. Acta Physiol (Oxf) 2021; 233:e13719. [PMID: 34286921 DOI: 10.1111/apha.13719] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 02/02/2023]
Abstract
Chemically skinned fibres allow the study of human muscle contractile function in vitro. A particularly important parameter is specific force (SF), that is, maximal isometric force divided by cross-sectional area, representing contractile quality. Although SF varies substantially between studies, the magnitude and cause of this variability remains puzzling. Here, we aimed to summarize and explore the cause of variability in SF between studies. A systematic search was conducted in Medline, Embase and Web of Science databases in June 2020, yielding 137 data sets from 61 publications which studied healthy, young adults. Five-fold differences in mean SF data were observed. Adjustments to the reported data for key methodological differences allowed between-study comparisons to be made. However, adjustment for fibre shape, swelling and sarcomere length failed to significantly reduce SF variance (I2 = 96%). Interestingly, grouping papers based on shared authorship did reveal consistency within research groups. In addition, lower SF was found to be associated with higher phosphocreatine concentrations in the fibre activating solution and with Triton X-100 being used as a skinning agent. Although the analysis showed variance across the literature, the ratio of SF in single fibres containing myosin heavy chain isoforms IIA or I was found to be consistent across research groups. In conclusion, whilst the skinned fibre technique is reliable for studying in vitro force generation of single fibres, the composition of the solution used to activate fibres, which differs between research groups, is likely to heavily influence SF values.
Collapse
Affiliation(s)
- Michaeljohn Kalakoutis
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Irene Di Giulio
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Abdel Douiri
- School of Population Health and Environmental Sciences King’s College London London UK
| | - Julien Ochala
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Stephen D. R. Harridge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| | - Roger C. Woledge
- Centre for Human and Applied Physiological Sciences Faculty of Life Sciences & Medicine King’s College London London UK
| |
Collapse
|
6
|
Kataoka R, Vasenina E, Hammert WB, Ibrahim AH, Dankel SJ, Buckner SL. Is there Evidence for the Suggestion that Fatigue Accumulates Following Resistance Exercise? Sports Med 2021; 52:25-36. [PMID: 34613589 DOI: 10.1007/s40279-021-01572-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2021] [Indexed: 12/28/2022]
Abstract
It has been suggested that improper post-exercise recovery or improper sequence of training may result in an 'accumulation' of fatigue. Despite this suggestion, there is a lack of clarity regarding which physiological mechanisms may be proposed to contribute to fatigue accumulation. The present paper explores the time course of the changes in various fatigue-related measures in order to understand how they may accumulate or lessen over time following an exercise bout or in the context of an exercise program. Regarding peripheral fatigue, the depletion of energy substrates and accumulation of metabolic byproducts has been demonstrated to occur following an acute bout of resistance training; however, peripheral accumulation and depletion appear unlikely candidates to accumulate over time. A number of mechanisms may contribute to the development of central fatigue, postulating the need for prolonged periods of recovery; however, a time course is difficult to determine and is dependent on which measurement is examined. In addition, it has not been demonstrated that central fatigue measures accumulate over time. A potential candidate that may be interpreted as accumulated fatigue is muscle damage, which shares similar characteristics (i.e., prolonged strength loss). Due to the delayed appearance of muscle damage, it may be interpreted as accumulated fatigue. Overall, evidence for the presence of fatigue accumulation with resistance training is equivocal, making it difficult to draw the conclusion that fatigue accumulates. Considerable work remains as to whether fatigue can accumulate over time. Future studies are warranted to elucidate potential mechanisms underlying the concept of fatigue accumulation.
Collapse
Affiliation(s)
- Ryo Kataoka
- USF Muscle Lab, Exercise Science Program, University of South Florida, 4202 E. Fowler Ave. PED 214, Tampa, FL, 33620-8600, USA
| | - Ecaterina Vasenina
- USF Muscle Lab, Exercise Science Program, University of South Florida, 4202 E. Fowler Ave. PED 214, Tampa, FL, 33620-8600, USA
| | - William B Hammert
- USF Muscle Lab, Exercise Science Program, University of South Florida, 4202 E. Fowler Ave. PED 214, Tampa, FL, 33620-8600, USA
| | - Adam H Ibrahim
- USF Muscle Lab, Exercise Science Program, University of South Florida, 4202 E. Fowler Ave. PED 214, Tampa, FL, 33620-8600, USA
| | - Scott J Dankel
- Exercise Physiology Laboratory, Department of Health and Exercise Science, Rowan University, Glassboro, NJ, USA
| | - Samuel L Buckner
- USF Muscle Lab, Exercise Science Program, University of South Florida, 4202 E. Fowler Ave. PED 214, Tampa, FL, 33620-8600, USA.
| |
Collapse
|
7
|
Honerlagen H, Reyer H, Oster M, Ponsuksili S, Trakooljul N, Kuhla B, Reinsch N, Wimmers K. Identification of Genomic Regions Influencing N-Metabolism and N-Excretion in Lactating Holstein- Friesians. Front Genet 2021; 12:699550. [PMID: 34335696 PMCID: PMC8318802 DOI: 10.3389/fgene.2021.699550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/18/2021] [Indexed: 12/03/2022] Open
Abstract
Excreted nitrogen (N) of dairy cows contribute to environmental eutrophication. The main N-excretory metabolite of dairy cows is urea, which is synthesized as a result of N-metabolization in the liver and is excreted via milk and urine. Genetic variation in milk urea (MU) has been postulated but the complex physiology behind the trait as well as the tremendous diversity of processes regulating the N-metabolism impede the consistent determination of causal regions in the bovine genome. In order to map the genetic determinants affecting N-excretion, MU and eight other N-excretory metabolites in milk and urine were assessed in a genome-wide association study. Therefore phenotypes of 371 Holstein- Friesians were obtained in a trial on a dairy farm under near commercial conditions. Genotype data comprised SNP information of the Bovine 50K MD Genome chip (45,613 SNPs). Significantly associated genomic regions for MU concentration revealed GJA1 (BTA 9), RXFP1, and FRY1 (both BTA 12) as putative candidates. For milk urea yield (MUY) a promising QTL on BTA 17 including SH3D19 emerged, whereas RCAN2, CLIC5, ENPP4, and ENPP5 (BTA 23) are suggested to influence urinary urea concentration. Minor N-fractions in milk (MN) may be regulated by ELF2 and SLC7A11 (BTA 17), whilst ITPR2 and MYBPC1 (BTA 5), STIM2 (BTA 6), SGCD (BTA 7), SLC6A2 (BTA 18), TMCC2 and MFSD4A (BTA 16) are suggested to have an impact on various non-urea-N (NUN) fractions excreted via urine. Our results highlight genomic regions and candidate genes for N-excretory metabolites and provide a deeper insight into the predisposed component to regulate the N-metabolism in dairy cows.
Collapse
Affiliation(s)
- Hanne Honerlagen
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Henry Reyer
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Michael Oster
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Siriluck Ponsuksili
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Nares Trakooljul
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Björn Kuhla
- Metabolism Efficiency Unit, Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Norbert Reinsch
- Livestock Genetics and Breeding Unit, Institute of Genetics and Biometry, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Klaus Wimmers
- Genomics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.,Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
| |
Collapse
|
8
|
Martin-Rincon M, Gelabert-Rebato M, Perez-Valera M, Galvan-Alvarez V, Morales-Alamo D, Dorado C, Boushel R, Hallen J, Calbet JAL. Functional reserve and sex differences during exercise to exhaustion revealed by post-exercise ischaemia and repeated supramaximal exercise. J Physiol 2021; 599:3853-3878. [PMID: 34159610 DOI: 10.1113/jp281293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/17/2021] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Females have lower fatigability than males during single limb isometric and dynamic contractions, but whether sex-differences exist during high-intensity whole-body exercise remains unknown. This study shows that males and females respond similarly to repeated supramaximal whole-body exercise, and that at task failure a large functional reserve remains in both sexes. Using post-exercise ischaemia with repeated exercise, we have shown that this functional reserve depends on the glycolytic component of substrate-level phosphorylation and is almost identical in both sexes. Metaboreflex activation during post-exercise ischaemia and the O2 debt per kg of active lean mass are also similar in males and females after supramaximal exercise. Females have a greater capacity to extract oxygen during repeated supramaximal exercise and reach lower P ETC O 2 , experiencing a larger drop in brain oxygenation than males, without apparent negative repercussion on performance. Females had no faster recovery of performance after accounting for sex differences in lean mass. ABSTRACT The purpose of this study was to ascertain what mechanisms explain sex differences at task failure and to determine whether males and females have a functional reserve at exhaustion. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation were determined in 18 males and 18 females (21-36 years old) in two sessions consisting of three bouts of constant-power exercise at 120% of V ̇ O 2 max until exhaustion interspaced by 20 s recovery periods. In one of the two sessions, the circulation of both legs was occluded instantaneously (300 mmHg) during the recovery periods. Females had a higher muscle O2 extraction during fatiguing supramaximal exercise than males. Metaboreflex activation, and lean mass-adjusted O2 deficit and debt were similar in males and females. Compared to males, females reached lower P ETC O 2 and brain oxygenation during supramaximal exercise, without apparent negative consequences on performance. After the occlusions, males and females were able to restart exercising at 120% of V ̇ O 2 max , revealing a similar functional reserve, which depends on glycolytic component of substrate-level phosphorylation and its rate of utilization. After ischaemia, muscle O2 extraction was increased, and muscle V ̇ O 2 was similarly reduced in males and females. The physiological response to repeated supramaximal exercise to exhaustion is remarkably similar in males and females when differences in lean mass are considered. Both sexes fatigue with a large functional reserve, which depends on the glycolytic energy supply, yet females have higher oxygen extraction capacity, but reduced P ETC O 2 and brain oxygenation.
Collapse
Affiliation(s)
- Marcos Martin-Rincon
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Miriam Gelabert-Rebato
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Mario Perez-Valera
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Victor Galvan-Alvarez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - David Morales-Alamo
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Cecilia Dorado
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Robert Boushel
- School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jostein Hallen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Jose A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.,School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| |
Collapse
|
9
|
Rannou F, Nybo L, Andersen JE, Nordsborg NB. Muscle Contractile Characteristics During Exhaustive Dynamic Exercise and Recovery. Front Physiol 2021; 12:660099. [PMID: 34276393 PMCID: PMC8283014 DOI: 10.3389/fphys.2021.660099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/01/2021] [Indexed: 11/13/2022] Open
Abstract
Our aim was to provide an in vivo assessment of human muscle twitch characteristics during and following an exhaustive dynamic exercise to explore temporal alterations of the rate of force development (RFD) and relaxation (RFR). Eleven healthy participants (mean age ± SD: 24 ± 3 years) completed a dynamic knee-extensor exercise in randomized order at three different intensities, eliciting exhaustion after ∼9 min (56 ± 10 W), ∼6 min (60 ± 10 W), and ∼4 min (63 ± 10 W), in addition to a low-intensity (28 ± 5 W) bout. In a novel setup, an electrical doublet stimulation of m. vastus lateralis was applied during exercise (every 30 s) and recovery for frequent evaluation of key contractile properties (maximal force, RFD, RFR, and electromechanical delay) in addition to M-wave characteristics. RFD and RFR remained stable throughout the low-intensity trial but declined in all exhaustive trials to reach a similar level of ∼40% of pre-exercise values at task failure but with the exponential decay augmented by intensity. Following exhaustion, there was a fast initial recovery of RFD and RFR to ∼80% of pre-exercise values within 1 min, followed by a longer suppression at this level. The M-wave characteristics remained unchanged during all trials. In conclusion, this is the first study to quantify the intensity-dependent alterations of RFD and RFR during and after exhaustive dynamic exercise in humans. A hypothesized reduction and fast reversion of RFD was confirmed, and a surprising compromised RFR is reported. The present unique experimental approach allows for novel insight to exercise-induced alterations in human muscle contractile properties which is relevant in health and disease.
Collapse
Affiliation(s)
- Fabrice Rannou
- Department of Sport Medicine and Functional Explorations-ASMS, CRNH, CHU Clermont-Ferrand, Clermont-Ferrand, France.,Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Janni Enghave Andersen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nikolai B Nordsborg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
10
|
Biochemical analysis of serum mineral and vitamin levels in benign essential blepharospasm. JOURNAL OF SURGERY AND MEDICINE 2021. [DOI: 10.28982/josam.924395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
11
|
Tomalka A, Weidner S, Hahn D, Seiberl W, Siebert T. Power Amplification Increases With Contraction Velocity During Stretch-Shortening Cycles of Skinned Muscle Fibers. Front Physiol 2021; 12:644981. [PMID: 33868012 PMCID: PMC8044407 DOI: 10.3389/fphys.2021.644981] [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: 12/22/2020] [Accepted: 03/08/2021] [Indexed: 01/25/2023] Open
Abstract
Muscle force, work, and power output during concentric contractions (active muscle shortening) are increased immediately following an eccentric contraction (active muscle lengthening). This increase in performance is known as the stretch-shortening cycle (SSC)-effect. Recent findings demonstrate that the SSC-effect is present in the sarcomere itself. More recently, it has been suggested that cross-bridge (XB) kinetics and non-cross-bridge (non-XB) structures (e.g., titin and nebulin) contribute to the SSC-effect. As XBs and non-XB structures are characterized by a velocity dependence, we investigated the impact of stretch-shortening velocity on the SSC-effect. Accordingly, we performed in vitro isovelocity ramp experiments with varying ramp velocities (30, 60, and 85% of maximum contraction velocity for both stretch and shortening) and constant stretch-shortening magnitudes (17% of the optimum sarcomere length) using single skinned fibers of rat soleus muscles. The different contributions of XB and non-XB structures to force production were identified using the XB-inhibitor Blebbistatin. We show that (i) the SSC-effect is velocity-dependent-since the power output increases with increasing SSC-velocity. (ii) The energy recovery (ratio of elastic energy storage and release in the SSC) is higher in the Blebbistatin condition compared with the control condition. The stored and released energy in the Blebbistatin condition can be explained by the viscoelastic properties of the non-XB structure titin. Consequently, our experimental findings suggest that the energy stored in titin during the eccentric phase contributes to the SSC-effect in a velocity-dependent manner.
Collapse
Affiliation(s)
- André Tomalka
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Sven Weidner
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Daniel Hahn
- Human Movement Science, Faculty of Sports Science, Ruhr University Bochum, Bochum, Germany
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Wolfgang Seiberl
- Human Movement Science, Bundeswehr University Munich, Neubiberg, Germany
| | - Tobias Siebert
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
- Stuttgart Center for Simulation Science, University of Stuttgart, Stuttgart, Germany
| |
Collapse
|
12
|
Hinks A, MacDougall KB, Mashouri P, Smith IC. Can a chloride channel blocker mitigate muscle fatigue? J Physiol 2021; 599:2145-2147. [DOI: 10.1113/jp281424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Avery Hinks
- Neuromechanical Performance Research Lab, Department of Human Health and Nutritional Science University of Guelph Guelph ON Canada
| | - Keenan B. MacDougall
- Human Performance Lab, Faculty of Kinesiology University of Calgary Calgary AB Canada
| | - Parastoo Mashouri
- Neuromechanical Performance Research Lab, Department of Human Health and Nutritional Science University of Guelph Guelph ON Canada
| | - Ian C. Smith
- Human Performance Lab, Faculty of Kinesiology University of Calgary Calgary AB Canada
| |
Collapse
|
13
|
Ferreira JJ, Pequera G, Launikonis BS, Ríos E, Brum G. A chloride channel blocker prevents the suppression by inorganic phosphate of the cytosolic calcium signals that control muscle contraction. J Physiol 2020; 599:157-170. [PMID: 32991741 DOI: 10.1113/jp279917] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/25/2020] [Indexed: 12/20/2022] Open
Abstract
KEY POINTS Accumulation of inorganic phosphate (Pi ) may contribute to muscle fatigue by precipitating calcium salts inside the sarcoplasmic reticulum (SR). Neither direct demonstration of this process nor definition of the entry pathway of Pi into SR are fully established. We showed that Pi promoted Ca2+ release at concentrations below 10 mm and decreased it at higher concentrations. This decrease correlated well with that of [Ca2+ ]SR . Pre-treatment of permeabilized myofibres with 2 mm Cl- channel blocker 9-anthracenecarboxylic acid (9AC) inhibited both effects of Pi . The biphasic dependence of Ca2+ release on [Pi ] is explained by a direct effect of Pi acting on the SR Ca2+ release channel, combined with the intra-SR precipitation of Ca2+ salts. The effects of 9AC demonstrate that Pi enters the SR via a Cl- pathway of an as-yet-undefined molecular nature. ABSTRACT Fatiguing exercise causes hydrolysis of phosphocreatine, increasing the intracellular concentration of inorganic phosphate (Pi ). Pi diffuses into the sarcoplasmic reticulum (SR) where it is believed to form insoluble Ca2+ salts, thus contributing to the impairment of Ca2+ release. Information on the Pi entrance pathway is still lacking. In amphibian muscles endowed with isoform 3 of the RyR channel, Ca2+ spark frequency is correlated with the Ca2+ load of the SR and can be used to monitor this variable. We studied the effects of Pi on Ca2+ sparks in permeabilized fibres of the frog. Relative event frequency (f/fref ) rose with increasing [Pi ], reaching 2.54 ± 1.6 at 5 mm, and then decreased monotonically, reaching 0.09 ± 0.03 at [Pi ] = 80 mm. Measurement of [Ca2+ ]SR confirmed a decrease correlated with spark frequency at high [Pi ]. A large [Ca2+ ]SR surge was observed upon Pi removal. Anion channels are a putative path for Pi into the SR. We tested the effect of the chloride channel blocker 9-anthracenecarboxylic acid (9AC) on Pi entrance. 9AC (400 µm) applied to the cytoplasm produced a non-significant increase in spark frequency and reduced the Pi effects on this parameter. Fibre treatment with 2 mm 9AC in the presence of high cytoplasmic Mg2+ suppressed the effects of Pi on [Ca2+ ]SR and spark frequency up to 55 mm [Pi ]. These results suggest that chloride channels (or transporters) provide the main pathway of inorganic phosphate into the SR and confirm that Pi impairs Ca2+ release by accumulating and precipitating with Ca2+ inside the SR, thus contributing to myogenic fatigue.
Collapse
Affiliation(s)
- Juan J Ferreira
- Laboratorio de Biofísica del Músculo, Departamento de Biofísica, Facultad de Medicina, Montevideo, Uruguay
| | - Germán Pequera
- Laboratorio de Biofísica del Músculo, Departamento de Biofísica, Facultad de Medicina, Montevideo, Uruguay
| | - Bradley S Launikonis
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Eduardo Ríos
- Section of Cellular Signaling, Department of Physiology and Biophysics, Rush University, Chicago, IL, USA
| | - Gustavo Brum
- Laboratorio de Biofísica del Músculo, Departamento de Biofísica, Facultad de Medicina, Montevideo, Uruguay
| |
Collapse
|
14
|
Serna J, Bergwitz C. Importance of Dietary Phosphorus for Bone Metabolism and Healthy Aging. Nutrients 2020; 12:E3001. [PMID: 33007883 PMCID: PMC7599912 DOI: 10.3390/nu12103001] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 12/13/2022] Open
Abstract
Inorganic phosphate (Pi) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP synthesis. Pi is the main source of dietary phosphorus. Reduced bioavailability of Pi or excessive losses in the urine causes rickets and osteomalacia. While critical for health in normal amounts, dietary phosphorus is plentiful in the Western diet and is often added to foods as a preservative. This abundance of phosphorus may reduce longevity due to metabolic changes and tissue calcifications. In this review, we examine how dietary phosphorus is absorbed in the gut, current knowledge about Pi sensing, and endocrine regulation of Pi levels. Moreover, we also examine the roles of Pi in different tissues, the consequences of low and high dietary phosphorus in these tissues, and the implications for healthy aging.
Collapse
Affiliation(s)
- Juan Serna
- Yale College, Yale University, New Haven, CT 06511, USA;
| | - Clemens Bergwitz
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06519, USA
| |
Collapse
|
15
|
Tomalka A, Weidner S, Hahn D, Seiberl W, Siebert T. Cross-Bridges and Sarcomeric Non-cross-bridge Structures Contribute to Increased Work in Stretch-Shortening Cycles. Front Physiol 2020; 11:921. [PMID: 32848862 PMCID: PMC7399218 DOI: 10.3389/fphys.2020.00921] [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: 04/06/2020] [Accepted: 07/09/2020] [Indexed: 11/13/2022] Open
Abstract
Stretch-shortening cycles (SSCs) refer to the muscle action when an active muscle stretch is immediately followed by active muscle shortening. This combination of eccentric and concentric contractions is the most important type of daily muscle action and plays a significant role in natural locomotion such as walking, running or jumping. SSCs are used in human and animal movements especially when a high movement speed or economy is required. A key feature of SSCs is the increase in muscular force and work during the concentric phase of a SSC by more than 50% compared with concentric muscle actions without prior stretch (SSC-effect). This improved muscle capability is related to various mechanisms, including pre-activation, stretch-reflex responses and elastic recoil from serial elastic tissues. Moreover, it is assumed that a significant contribution to enhanced muscle capability lies in the sarcomeres itself. Thus, we investigated the force output and work produced by single skinned fibers of rat soleus muscles during and after ramp contractions at a constant velocity. Shortening, lengthening, and SSCs were performed under physiological boundary conditions with 85% of the maximum shortening velocity and stretch-shortening magnitudes of 18% of the optimum muscle length. The different contributions of cross-bridge (XB) and non-cross-bridge (non-XB) structures to the total muscle force were identified by using Blebbistatin. The experiments revealed three main results: (i) partial detachment of XBs during the eccentric phase of a SSC, (ii) significantly enhanced forces and mechanical work during the concentric phase of SSCs compared with shortening contractions with and without XB-inhibition, and (iii) no residual force depression after SSCs. The results obtained by administering Blebbistatin propose a titin-actin interaction that depends on XB-binding or active XB-based force production. The findings of this study further suggest that enhanced forces generated during the active lengthening phase of SSCs persist during the subsequent shortening phase, thereby contributing to enhanced work. Accordingly, our data support the hypothesis that sarcomeric mechanisms related to residual force enhancement also contribute to the SSC-effect. The preload of the titin molecule, acting as molecular spring, might be part of that mechanism by increasing the mechanical efficiency of work during physiological SSCs.
Collapse
Affiliation(s)
- André Tomalka
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Sven Weidner
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Daniel Hahn
- Human Movement Science, Faculty of Sports Science, Ruhr University Bochum, Bochum, Germany.,School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Wolfgang Seiberl
- Human Movement Science, Bundeswehr University Munich, Munich, Germany
| | - Tobias Siebert
- Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| |
Collapse
|
16
|
Age-related neuromuscular fatigue and recovery after cycling: Measurements in isometric and dynamic modes. Exp Gerontol 2020; 133:110877. [DOI: 10.1016/j.exger.2020.110877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/08/2020] [Accepted: 02/10/2020] [Indexed: 01/02/2023]
|
17
|
Serefoglu Cabuk K, Tunc U, Ozturk Karabulut G, Fazil K, Karaagac Gunaydin Z, Asik Nacaroglu S, Taskapili M. Serum calcium, magnesium, phosphorus, and vitamin D in benign essential blepharospasm. Graefes Arch Clin Exp Ophthalmol 2020; 258:1293-1297. [PMID: 32236706 DOI: 10.1007/s00417-020-04650-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/03/2020] [Accepted: 03/13/2020] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study aims to compare serum calcium, magnesium, phosphorus, and 25-hydroxy (OH)-vitamin D levels in patients with benign essential blepharospasm (BEB) and healthy subjects and to determine their association with disease severity and frequency. METHODS This is a prospective study conducted in a tertiary care hospital. Fifty patients (female, 39; male, 11) with BEB and 22 healthy subjects (female, 15; male, 7) included in the study. Serum calcium, magnesium, phosphorus, and vitamin D levels of BEB and healthy groups were measured. Blepharospasm severity and frequency were assessed using scales ranging from 0 to 4 by following the Jankovic Rating Scale (JRS). RESULTS Though there was no significant difference regarding magnesium, phosphorus, and 25(OH)-vitamin D levels between the two groups, serum calcium levels of the BEB group were significantly lower than the control group (9.5 ± 0.4 and 9.9 ± 0.4 mg/dl, respectively; P = 0.002), although in the normal range (9-10.5 mg/dl). In the BEB group, the mean Jankovic severity and frequency scores were 3.29 ± 0.54 and 3.59 ± 0.61, respectively. There was a moderate negative correlation between serum 25(OH)-vitamin D levels and Jankovic severity score (r = - 0.332; P = 0.022). CONCLUSION Serum calcium levels of the BEB group were significantly lower than the healthy group. Serum vitamin D levels showed a moderate negative correlation with disease severity. The role of calcium and vitamin D in the evolution of the BEB need further investigation at the cellular and anatomical levels.
Collapse
Affiliation(s)
- Kubra Serefoglu Cabuk
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey.
| | - Ugur Tunc
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| | - Gamze Ozturk Karabulut
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| | - Korhan Fazil
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| | - Zehra Karaagac Gunaydin
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| | - Senay Asik Nacaroglu
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| | - Muhittin Taskapili
- University of Health Sciences, Beyoglu Eye Training and Research Hospital, Bereketzade Mahallesi, Bereketzade Camii Sokak, NO:2, Pbx: 34420 Beyoğlu, Istanbul, Turkey
| |
Collapse
|
18
|
Muangkram Y, Honda M, Amano A, Himeno Y, Noma A. Exploring the role of fatigue-related metabolite activity during high-intensity exercise using a simplified whole-body mathematical model. INFORMATICS IN MEDICINE UNLOCKED 2020. [DOI: 10.1016/j.imu.2020.100355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
|
19
|
Allen DG. Human muscle performance. J Physiol 2019; 598:613-614. [PMID: 31834947 DOI: 10.1113/jp279364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 12/11/2019] [Indexed: 11/08/2022] Open
Affiliation(s)
- David G Allen
- School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia
| |
Collapse
|
20
|
Mohamed AA. Can Proprioceptive Training Reduce Muscle Fatigue in Patients With Motor Neuron Diseases? A New Direction of Treatment. Front Physiol 2019; 10:1243. [PMID: 31632290 PMCID: PMC6779805 DOI: 10.3389/fphys.2019.01243] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Muscle fatigue is a serious problem in patients with motor neuron diseases (MNDs). It commonly disturbs both daily life activity and rehabilitation tolerance. A particular concern should be taken when MNDs occur in older ages. Older patients with MNDs usually have a worse clinical presentation and a lower survival rate. This could increase the occurrence of muscle fatigue. Muscle fatigue occurs due to a dysfunction in either motor or sensory systems. Current exercise interventions performed to decrease the occurrence of muscle fatigue focused only on treating motor causes of muscle fatigue. It has been demonstrated that these interventions have a high debate in their effectiveness on decreasing the occurrence of muscle fatigue. Also, these exercise interventions ignored training the affected sensory part of muscle fatigue, however, the important role of the sensory system in driving the motor system. Thus, this review aimed to develop a novel exercise intervention by using proprioceptive training as an intervention to decrease the occurrence of muscle fatigue in patients with MNDs particularly, older ones. The physiological effects of proprioceptive training to decrease the occurrence of muscle fatigue could include two effects. The first effect includes the ability of the proprioceptive training to increase the sensitivity of muscle spindles as an attempt to normalize the firing rate of α-motoneurons, which their abnormalities have major roles in the occurrence of muscle fatigue. The second effect includes its ability to correct the abnormal movement-compensations, which develop due to the biomechanical constraints imposed on patients with MNDs.
Collapse
Affiliation(s)
- Ayman A. Mohamed
- Department of Physiotherapy and Rehabilitation, School of Health Sciences, Istanbul Gelisim University, Istanbul, Turkey
| |
Collapse
|
21
|
Straight CR, Bell KM, Slosberg JN, Miller MS, Swank DM. A myosin-based mechanism for stretch activation and its possible role revealed by varying phosphate concentration in fast and slow mouse skeletal muscle fibers. Am J Physiol Cell Physiol 2019; 317:C1143-C1152. [PMID: 31532715 DOI: 10.1152/ajpcell.00206.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stretch activation (SA) is a delayed increase in force following a rapid muscle length increase. SA is best known for its role in asynchronous insect flight muscle, where it has replaced calcium's typical role of modulating muscle force levels during a contraction cycle. SA also occurs in mammalian skeletal muscle but has previously been thought to be too low in magnitude, relative to calcium-activated (CA) force, to be a significant contributor to force generation during locomotion. To test this supposition, we compared SA and CA force at different Pi concentrations (0-16 mM) in skinned mouse soleus (slow-twitch) and extensor digitorum longus (EDL; fast-twitch) muscle fibers. CA isometric force decreased similarly in both muscles with increasing Pi, as expected. SA force decreased with Pi in EDL (40%), leaving the SA to CA force ratio relatively constant across Pi concentrations (17-25%). In contrast, SA force increased in soleus (42%), causing a quadrupling of the SA to CA force ratio, from 11% at 0 mM Pi to 43% at 16 mM Pi, showing that SA is a significant force modulator in slow-twitch mammalian fibers. This modulation would be most prominent during prolonged muscle use, which increases Pi concentration and impairs calcium cycling. Based upon our previous Drosophila myosin isoform studies and this work, we propose that in slow-twitch fibers a rapid stretch in the presence of Pi reverses myosin's power stroke, enabling quick rebinding to actin and enhanced force production, while in fast-twitch fibers, stretch and Pi cause myosin to detach from actin.
Collapse
Affiliation(s)
- Chad R Straight
- Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
| | - Kaylyn M Bell
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York
| | - Jared N Slosberg
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Mark S Miller
- Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
| | - Douglas M Swank
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York.,Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| |
Collapse
|
22
|
P i-induced muscle fatigue leads to near-hyperbolic power-duration dependence. Eur J Appl Physiol 2019; 119:2201-2213. [PMID: 31399839 DOI: 10.1007/s00421-019-04204-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/01/2019] [Indexed: 12/20/2022]
Abstract
PURPOSE Consequences of combining three ideas proposed previously by other authors: (1) that there exists a critical power (CP), above which no steady state in [Formula: see text]O2 (oxygen consumption) and metabolites can be achieved in voluntary constant-power exercise; (2) that muscle fatigue is related to decreased exercise efficiency (increased [Formula: see text]O2/power output ratio); and (3) that Pi (inorganic phosphate) is the main fatigue-related metabolite are investigated. METHODS A previously-developed computer model of the skeletal muscle bioenergetic system is used. It was assumed in computer simulations that skeletal muscle work terminates when cytosolic Pi (inorganic phosphate) exceeds a certain critical level. RESULTS Simulated changes in muscle [Formula: see text]O2, cytosolic ADP, pH, PCr and Pi as a function of time at various ATP usage activities (corresponding to power outputs) agreed well with experimental data. Computer simulations resulted in a fourth previously-published idea: (4) that the power-duration relationship describing the dependence of power output (PO) on the time to exhaustion of voluntary constant-power exercise at a given PO has a (near-)hyperbolic shape. CONCLUSIONS Pi is a major factor contributing to muscle fatigue, as such an assumption leads to a (near-)hyperbolic shape of the power-duration relationship, at least for exercise duration of ~ 1-10 min. Thus, a potential mechanism underlying the power-duration relationship shape is offered that was absent in the literature. Other factors/mechanisms, such as cytosol acidification, glycogen stores depletion and central fatigue can contribute to this relationship, especially in longer exercises.
Collapse
|
23
|
Fernandez-Sanz C, De la Fuente S, Sheu SS. Mitochondrial Ca 2+ concentrations in live cells: quantification methods and discrepancies. FEBS Lett 2019; 593:1528-1541. [PMID: 31058316 DOI: 10.1002/1873-3468.13427] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 12/11/2022]
Abstract
Intracellular Ca2+ signaling controls numerous cellular functions. Mitochondria respond to cytosolic Ca2+ changes by adapting mitochondrial functions and, in some cell types, shaping the spatiotemporal properties of the cytosolic Ca2+ signal. Numerous methods have been developed to specifically and quantitatively measure the mitochondrial-free Ca2+ concentrations ([Ca2+ ]m ), but there are still significant discrepancies in the calculated absolute values of [Ca2+ ]m in stimulated live cells. These discrepancies may be due to the distinct properties of the methods used to measure [Ca2+ ]m , the calcium-free/bound ratio, and the cell-type and stimulus-dependent Ca2+ dynamics. Critical processes happening in the mitochondria, such as ATP generation, ROS homeostasis, and mitochondrial permeability transition opening, depend directly on the [Ca2+ ]m values. Thus, precise determination of absolute [Ca2+ ]m values is imperative for understanding Ca2+ signaling. This review summarizes the reported calibrated [Ca2+ ]m values in many cell types and discusses the discrepancies among these values. Areas for future research are also proposed.
Collapse
Affiliation(s)
- Celia Fernandez-Sanz
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sergio De la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| |
Collapse
|
24
|
Sundberg CW, Fitts RH. Bioenergetic basis of skeletal muscle fatigue. CURRENT OPINION IN PHYSIOLOGY 2019; 10:118-127. [PMID: 31342000 DOI: 10.1016/j.cophys.2019.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Energetic demand from high-intensity exercise can easily exceed ATP synthesis rates of mitochondria leading to a reliance on anaerobic metabolism. The reliance on anaerobic metabolism results in the accumulation of intracellular metabolites, namely inorganic phosphate (Pi) and hydrogen (H+), that are closely associated with exercise-induced reductions in power. Cellular and molecular studies have revealed several steps where these metabolites impair contractile function demonstrating a causal role in fatigue. Elevated Pi or H+ directly inhibits force and power of the cross-bridge and decreases myofibrillar Ca2+ sensitivity, whereas Pi also inhibits Ca2+ release from the sarcoplasmic reticulum (SR). When both metabolites are elevated, they act synergistically to cause marked reductions in power, indicating that fatigue during high-intensity exercise has a bioenergetic basis.
Collapse
Affiliation(s)
- Christopher W Sundberg
- Department of Biological Sciences, Marquette University, Milwaukee, WI.,Department of Physical Therapy, Marquette University, Milwaukee, WI
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, WI
| |
Collapse
|
25
|
Krüger RL, Aboodarda SJ, Jaimes LM, MacIntosh BR, Samozino P, Millet GY. Fatigue and recovery measured with dynamic properties versus isometric force: effects of exercise intensity. ACTA ACUST UNITED AC 2019; 222:jeb.197483. [PMID: 30890621 DOI: 10.1242/jeb.197483] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/13/2019] [Indexed: 11/20/2022]
Abstract
Although fatigue can be defined as an exercise-related decrease in maximal power or isometric force, most studies have assessed only isometric force. The main purpose of this experiment was to compare dynamic measures of fatigue [maximal torque (T max), maximal velocity (V max) and maximal power (P max)] with measures associated with maximal isometric force [isometric maximal voluntary contraction (IMVC) and maximal rate of force development (MRFD)] 10 s after different fatiguing exercises and during the recovery period (1-8 min after). Ten young men completed six experimental sessions (3 fatiguing exercises×2 types of fatigue measurements). The fatiguing exercises were: 30 s all-out intensity (AI), 10 min at severe intensity (SI) and 90 min at moderate intensity (MI). Relative P max decreased more than IMVC after AI exercise (P=0.005) while the opposite was found after SI (P=0.005) and MI tasks (P<0.001). There was no difference between the decrease in IMVC and T max after the AI exercise, but IMVC decreased more than T max immediately following and during the recovery from the SI (P=0.042) and MI exercises (P<0.001). Depression of MRFD was greater than V max after all fatiguing exercises and during recovery (all P<0.05). Despite the general definition of fatigue, isometric assessment of fatigue is not interchangeable with dynamic assessment following dynamic exercises with large muscle mass of different intensities, i.e. the results from isometric function cannot be used to estimate dynamic function and vice versa. This implies different physiological mechanisms for the various measures of fatigue.
Collapse
Affiliation(s)
- Renata L Krüger
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4
| | - Saied Jalal Aboodarda
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4
| | - Libia Marcela Jaimes
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4
| | - Brian R MacIntosh
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4
| | - Pierre Samozino
- Univ Savoie Mont Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, F-73000 Chambéry, France
| | - Guillaume Y Millet
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4
| |
Collapse
|
26
|
Induction of sublingual immunotherapy to cow's milk (raw, pasteurized and sterilized) in Balb/c mice sensitized to beta-lactoglobulin. REVUE FRANCAISE D ALLERGOLOGIE 2019. [DOI: 10.1016/j.reval.2018.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
27
|
Lamb GD, Stephenson DG. Measurement of force and calcium release using mechanically skinned fibers from mammalian skeletal muscle. J Appl Physiol (1985) 2018; 125:1105-1127. [DOI: 10.1152/japplphysiol.00445.2018] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The mechanically skinned (or “peeled”) skeletal muscle fiber technique is a highly versatile procedure that allows controlled examination of each of the steps in the excitation-contraction (EC)-coupling sequence in skeletal muscle fibers, starting with excitation/depolarization of the transverse tubular (T)-system through to Ca2+ release from sarcoplasmic reticulum (SR) and finally force development by the contractile apparatus. It can also show the overall response of the whole EC-coupling sequence together, such as in twitch and tetanic force responses. A major advantage over intact muscle fiber preparations is that it is possible to set and rapidly manipulate the “intracellular” conditions, allowing examination of the effects of key variables (e.g., intracellular pH, ATP levels, redox state, etc.) on each individual step in EC coupling. This Cores of Reproducibility in Physiology (CORP) article describes the rationale, procedures, and experimental details of the various ways in which the mechanically skinned fiber technique is used in our laboratory to examine the physiological mechanisms controlling Ca2+ release and contraction in skeletal muscle fibers and the aberrations and dysfunction occurring with exercise and disease.
Collapse
Affiliation(s)
- Graham D. Lamb
- Department of Physiology, Anatomy, and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - D. George Stephenson
- Department of Physiology, Anatomy, and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| |
Collapse
|
28
|
Sundberg CW, Hunter SK, Trappe SW, Smith CS, Fitts RH. Effects of elevated H + and P i on the contractile mechanics of skeletal muscle fibres from young and old men: implications for muscle fatigue in humans. J Physiol 2018; 596:3993-4015. [PMID: 29806714 PMCID: PMC6117549 DOI: 10.1113/jp276018] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 04/27/2018] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS The mechanisms responsible for the loss in muscle power and increased fatigability with ageing are unresolved. We show that the contractile mechanics of fibres from the vastus lateralis of old men were well-preserved compared to those of young men, but the selective loss of fast myosin heavy chain II muscle was strongly associated with age-related decrements in whole-muscle strength and power. We reveal that the combination of acidosis (H+ ) and inorganic phosphate (Pi ) is an important mediator of muscle fatigue in humans by inhibiting the low- to high-force state of the cross-bridge cycle and peak power, but the depressive effects of these ions on cross-bridge function were similar in fibres from young and old men. These findings suggest that the age-related loss in muscle power is primarily determined by the atrophy of fast fibres, but the age-related increased fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi . ABSTRACT The present study aimed to identify the mechanisms responsible for the loss in muscle power and increased fatigability with ageing by integrating measures of whole-muscle function with single fibre contractile mechanics. After adjusting for the 22% smaller muscle mass in old (73-89 years, n = 6) compared to young men (20-29 years, n = 6), isometric torque and power output of the knee extensors were, respectively, 38% and 53% lower with age. Fatigability was ∼2.7-fold greater with age and strongly associated with reductions in the electrically-evoked contractile properties. To test whether cross-bridge mechanisms could explain age-related decrements in knee extensor function, we exposed myofibres (n = 254) from the vastus lateralis to conditions mimicking quiescent muscle and fatiguing levels of acidosis (H+ ) (pH 6.2) and inorganic phosphate (Pi ) (30 mm). The fatigue-mimicking condition caused marked reductions in force, shortening velocity and power and inhibited the low- to high-force state of the cross-bridge cycle, confirming findings from non-human studies that these ions act synergistically to impair cross-bridge function. Other than severe age-related atrophy of fast fibres (-55%), contractile function and the depressive effects of the fatigue-mimicking condition did not differ in fibres from young and old men. The selective loss of fast myosin heavy chain II muscle was strongly associated with the age-related decrease in isometric torque (r = 0.785) and power (r = 0.861). These data suggest that the age-related loss in muscle strength and power are primarily determined by the atrophy of fast fibres, but the age-related increased fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi .
Collapse
Affiliation(s)
- Christopher W. Sundberg
- Exercise Science ProgramMilwaukeeWIUSA
- Clinical & Translational Rehabilitation Health Sciences ProgramDepartment of Physical TherapyMarquette UniversityMilwaukeeWIUSA
| | - Sandra K. Hunter
- Exercise Science ProgramMilwaukeeWIUSA
- Clinical & Translational Rehabilitation Health Sciences ProgramDepartment of Physical TherapyMarquette UniversityMilwaukeeWIUSA
| | - Scott W. Trappe
- Human Performance LaboratoryBall State UniversityMuncieINUSA
| | | | - Robert H. Fitts
- Department of Biological SciencesMarquette UniversityMilwaukeeWIUSA
| |
Collapse
|
29
|
Glass LD, Cheng AJ, MacIntosh BR. Role of Ca 2+ in changing active force during intermittent submaximal stimulation in intact, single mouse muscle fibers. Pflugers Arch 2018; 470:1243-1254. [PMID: 29671103 PMCID: PMC6060763 DOI: 10.1007/s00424-018-2143-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 12/27/2022]
Abstract
Fatigue of single mouse fibers during repeated high-frequency stimulation results initially from decreased Ca2+ sensitivity while free myoplasmic calcium concentration ([Ca2+]m) increases, followed by decreasing [Ca2+]m. Recovery of active force with low-frequency stimulation is slow and persistent fatigue results from low [Ca2+]m. However, the consequences of intermittent submaximal contractions are not known. The aim of the present study was to investigate the changes in [Ca2+]m and active force during intermittent submaximal contractions and subsequent recovery. Single fibers of mouse flexor digitorum brevis muscles at 32 °C were stimulated with 40 or 50 Hz, for 350 ms every 2 s for 2 min and then every 1 s until < 40% of initial force. Values obtained during the intermittent stimulation were compared with a control force-[Ca2+]m relationship. A "P"-shaped pattern in the force-[Ca2+]m relationship was observed during intermittent stimulation. Early in the intermittent stimulation, [Ca2+]m increased while active force decreased. Subsequent force potentiation was accompanied by increased Ca2+ sensitivity. Later, as active force declined, [Ca2+]m decreased significantly (p < 0.001). This was followed, in the final phase, by a significant decrease in Ca2+ sensitivity determined by [Ca2+]m at half-maximal force (Ca50) (p = 0.001). Low-frequency fatigue persisted during recovery while Ca50 was not significantly different from prefatigue (p > 0.5). In conclusion, the main mechanism of fatigue is due to decreases in both [Ca2+]m and Ca2+ sensitivity following the initial force potentiation. The intermittent submaximal contractions resulted in persistent low-frequency fatigue seen during recovery, which was explained by depressed [Ca2+]m with no change in Ca2+ sensitivity.
Collapse
Affiliation(s)
- Lisa D. Glass
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta T2N 1N4 Canada
| | - Arthur J. Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Brian R. MacIntosh
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta T2N 1N4 Canada
| |
Collapse
|
30
|
Hanya E, Katz A. Increased temperature accelerates glycogen synthesis and delays fatigue in isolated mouse muscle during repeated contractions. Acta Physiol (Oxf) 2018; 223:e13027. [PMID: 29297989 DOI: 10.1111/apha.13027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 01/05/2023]
Abstract
AIM Elevated glycogen content in muscle delays fatigue during exercise. We examined if increasing muscle temperature during recovery from exercise affects glycogen synthesis and muscle performance during a subsequent bout of exercise. METHODS Isolated mouse extensor digitorum longus muscles were stimulated electrically to perform repeated tetanic contractions until force decreased to 40% of initial at 25°C. Thereafter, muscles recovered for 120 minutes at 25°C (control), 120 minutes at 35°C or 60 minutes at 35°C followed by 60 minutes at 25°C. After recovery, muscles were again stimulated to fatigue at 25°C. RESULTS In the control group, the number of contractions in the second run was slightly less than during the first run (92 ± 5%). Following recovery for 120 minutes at 35°C, the number of contractions was similar to the first run (98 ± 6%). Allowing recovery for 120 minutes at 35°C in the presence of the antioxidant N-acetylcysteine also did not alter the number of contractions in the second run (98 ± 3%). However, recovery for 60 minutes at 35°C followed by 60 minutes at 25°C resulted in an increase in the number of contractions during the second run (110 ± 2%, P < .001). Incorporation of [14 C]glucose into glycogen (glycogen synthesis) during recovery was 1.7-fold higher at 35°C vs 25°C (1.44 ± 0.08 μmol (30 min)-1 (g wet muscle)-1 vs 0.84 ± 0.04; P < .001). CONCLUSION These data demonstrate that, under the conditions studied, elevating muscle temperature for 60 minutes following a bout of repeated contractions delays muscle fatigue during a subsequent bout of repeated contractions and this is associated with enhanced glycogen synthesis in isolated muscle.
Collapse
Affiliation(s)
- E. Hanya
- Department of Physical Therapy; School of Health Sciences; Ariel University; Ariel Israel
| | - A. Katz
- Department of Physical Therapy; School of Health Sciences; Ariel University; Ariel Israel
| |
Collapse
|
31
|
Cheng AJ, Place N, Westerblad H. Molecular Basis for Exercise-Induced Fatigue: The Importance of Strictly Controlled Cellular Ca 2+ Handling. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029710. [PMID: 28432118 DOI: 10.1101/cshperspect.a029710] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The contractile function of skeletal muscle declines during intense or prolonged physical exercise, that is, fatigue develops. Skeletal muscle fibers fatigue acutely during highly intense exercise when they have to rely on anaerobic metabolism. Early stages of fatigue involve impaired myofibrillar function, whereas decreased Ca2+ release from the sarcoplasmic reticulum (SR) becomes more important in later stages. SR Ca2+ release can also become reduced with more prolonged, lower intensity exercise, and it is then related to glycogen depletion. Increased reactive oxygen/nitrogen species can cause long-lasting impairments in SR Ca2+ release resulting in a prolonged force depression after exercise. In this article, we discuss molecular and cellular mechanisms of the above fatigue-induced changes, with special focus on multiple mechanisms to decrease SR Ca2+ release to avoid energy depletion and preserve muscle fiber integrity. We also discuss fatigue-related effects of exercise-induced Ca2+ fluxes over the sarcolemma and between the cytoplasm and mitochondria.
Collapse
Affiliation(s)
- Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Nicolas Place
- Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
| |
Collapse
|
32
|
Tomalka A, Rode C, Schumacher J, Siebert T. The active force-length relationship is invisible during extensive eccentric contractions in skinned skeletal muscle fibres. Proc Biol Sci 2018; 284:rspb.2016.2497. [PMID: 28469023 DOI: 10.1098/rspb.2016.2497] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/28/2017] [Indexed: 12/20/2022] Open
Abstract
In contrast to experimentally observed progressive forces in eccentric contractions, cross-bridge and sliding-filament theories of muscle contraction predict that varying myofilament overlap will lead to increases and decreases in active force during eccentric contractions. Non-cross-bridge contributions potentially explain the progressive total forces. However, it is not clear whether underlying abrupt changes in the slope of the nonlinear force-length relationship are visible in long isokinetic stretches, and in which proportion cross-bridges and non-cross-bridges contribute to muscle force. Here, we show that maximally activated single skinned rat muscle fibres behave (almost across the entire working range) like linear springs. The force slope is about three times the maximum isometric force per optimal length. Cross-bridge and non-cross-bridge contributions to the muscle force were investigated using an actomyosin inhibitor. The experiments revealed a nonlinear progressive contribution of non-cross-bridge forces and suggest a nonlinear cross-bridge contribution similar to the active force-length relationship (though with increased optimal length and maximum isometric force). The linear muscle behaviour might significantly reduce the control effort. Moreover, the observed slight increase in slope with initial length is in accordance with current models attributing the non-cross-bridge force to titin.
Collapse
Affiliation(s)
- André Tomalka
- Institute of Sport and Movement Science, University of Stuttgart, Allmandring 28, 70569 Stuttgart, Baden-Württemberg, Germany
| | - Christian Rode
- Department of Motion Science, Friedrich-Schiller-University Jena, 07749 Jena, Thuringia, Germany
| | - Jens Schumacher
- Institute of Mathematics/Stochastics, Friedrich-Schiller-University Jena, 07749 Jena, Thuringia, Germany
| | - Tobias Siebert
- Institute of Sport and Movement Science, University of Stuttgart, Allmandring 28, 70569 Stuttgart, Baden-Württemberg, Germany
| |
Collapse
|
33
|
Matvienko TY, Zavodovskyi DA, Nozdrenko DN, Mishchenko IV, Motuziuk OP, Bogutska KI, Sklyarov YP, Prylutskyy YI. [MUSCLE FATIGUE: FACTORS OF DEVELOPMENT AND WAYS OF CORRECTION]. FIZIOLOHICHNYI ZHURNAL (KIEV, UKRAINE : 1994) 2017; 63:95-104. [PMID: 29975834 DOI: 10.15407/fz63.01.095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The data regarding the analysis of the physiological and biochemical mechanisms of muscle fatigue and ways to prevent it are summarized. The effect of the most common endogenous and exogenous antioxidants in the biochemical processes in muscle fatigue was analyzed. It is shown that biocompatible, non-toxic water-soluble C(60) fullerenes, which possess powerful antioxidative properties, promise great prospects in the correction of skeletal muscle fatigue caused by the destructive action of free radicals.
Collapse
|
34
|
Keir DA, Copithorne DB, Hodgson MD, Pogliaghi S, Rice CL, Kowalchuk JM. The slow component of pulmonary O2 uptake accompanies peripheral muscle fatigue during high-intensity exercise. J Appl Physiol (1985) 2016; 121:493-502. [DOI: 10.1152/japplphysiol.00249.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/21/2016] [Indexed: 11/22/2022] Open
Abstract
During constant-power output (PO) exercise above lactate threshold (LT), pulmonary O2 uptake (V̇o2p) features a developing slow component (V̇o2pSC). This progressive increase in O2 cost of exercise is suggested to be related to the effects of muscle fatigue development. We hypothesized that peripheral muscle fatigue as assessed by contractile impairment would be associated with the V̇o2pSC. Eleven healthy men were recruited to perform four constant-PO tests at an intensity corresponding to ∼Δ60 (very heavy, VH) where Δ is 60% of the difference between LT and peak V̇o2p. The VH exercise was completed for each of 3, 8, 13, and 18 min (i.e., VH3, VH8, VH13, VH18) with each preceded by 3 min of cycling at 20 W. Peripheral muscle fatigue was assessed via pre- vs. postexercise measurements of quadriceps torque in response to brief trains of electrical stimulation delivered at low (10 Hz) and high (50 Hz) frequencies. During exercise, breath-by-breath V̇o2p was measured by mass spectrometry and volume turbine. The magnitude of V̇o2pSC increased ( P < 0.05) from 224 ± 81 ml/min at VH3 to 520 ± 119, 625 ± 134, and 678 ± 156 ml/min at VH8, VH13, and VH18, respectively. The ratio of the low-to-high frequency (10/50 Hz) response was reduced ( P < 0.05) at VH3 (−12 ± 9%) and further reduced ( P < 0.05) at VH8 (−25 ± 11%), VH13 (−42 ± 19%), and VH18 (−46 ± 16%), mirroring the temporal pattern of V̇o2pSC development. The reduction in 10/50 Hz ratio was correlated ( P < 0.001, r2 = 0.69) with V̇o2pSC amplitude. The temporal and quantitative association of decrements in muscle torque production and V̇o2pSC suggest a common physiological mechanism between skeletal muscle fatigue and loss of muscle efficiency.
Collapse
Affiliation(s)
- Daniel A. Keir
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - David B. Copithorne
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - Michael D. Hodgson
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
| | - Silvia Pogliaghi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Italy
| | - Charles L. Rice
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, Canada; and
| | - John M. Kowalchuk
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
35
|
Germinario E, Bondì M, Cencetti F, Donati C, Nocella M, Colombini B, Betto R, Bruni P, Bagni MA, Danieli-Betto D. S1P3 receptor influences key physiological properties of fast-twitch extensor digitorum longus muscle. J Appl Physiol (1985) 2016; 120:1288-300. [DOI: 10.1152/japplphysiol.00345.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 12/23/2015] [Indexed: 12/15/2022] Open
Abstract
To examine the role of sphingosine 1-phosphate (S1P) receptor 3 (S1P3) in modulating muscle properties, we utilized transgenic mice depleted of the receptor. Morphological analyses of extensor digitorum longus (EDL) muscle did not show evident differences between wild-type and S1P3-null mice. The body weight of 3-mo-old S1P3-null mice and the mean cross-sectional area of transgenic EDL muscle fibers were similar to those of wild-type. S1P3 deficiency enhanced the expression level of S1P1 and S1P2 receptors mRNA in S1P3-null EDL muscle. The contractile properties of S1P3-null EDL diverge from those of wild-type, largely more fatigable and less able to recover. The absence of S1P3 appears responsible for a lower availability of calcium during fatigue. S1P supplementation, expected to stimulate residual S1P receptors and signaling, reduced fatigue development of S1P3-null muscle. Moreover, in the absence of S1P3, denervated EDL atrophies less than wild-type. The analysis of atrophy-related proteins in S1P3-null EDL evidences high levels of the endogenous regulator of mitochondria biogenesis peroxisome proliferative-activated receptor-γ coactivator 1α (PGC-1α); preserving mitochondria could protect the muscle from disuse atrophy. In conclusion, the absence of S1P3 makes the muscle more sensitive to fatigue and slows down atrophy development after denervation, indicating that S1P3 is involved in the modulation of key physiological properties of the fast-twitch EDL muscle.
Collapse
Affiliation(s)
- Elena Germinario
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- IIM, Interuniversity Institute of Myology, Italy
| | - Michela Bondì
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Francesca Cencetti
- IIM, Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy
| | - Chiara Donati
- IIM, Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy
| | - Marta Nocella
- IIM, Interuniversity Institute of Myology, Italy
- Department of Experimental and Clinical Medicine, University of Firenze, Florence, Italy
| | - Barbara Colombini
- IIM, Interuniversity Institute of Myology, Italy
- Department of Experimental and Clinical Medicine, University of Firenze, Florence, Italy
| | - Romeo Betto
- IIM, Interuniversity Institute of Myology, Italy
- CNR-Institute for Neuroscience, CNR, Padova, Italy
| | - Paola Bruni
- IIM, Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy
| | - Maria Angela Bagni
- IIM, Interuniversity Institute of Myology, Italy
- Department of Experimental and Clinical Medicine, University of Firenze, Florence, Italy
| | - Daniela Danieli-Betto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- IIM, Interuniversity Institute of Myology, Italy
| |
Collapse
|
36
|
Ca2+-dependent regulations and signaling in skeletal muscle: from electro-mechanical coupling to adaptation. Int J Mol Sci 2015; 16:1066-95. [PMID: 25569087 PMCID: PMC4307291 DOI: 10.3390/ijms16011066] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/22/2014] [Indexed: 01/07/2023] Open
Abstract
Calcium (Ca2+) plays a pivotal role in almost all cellular processes and ensures the functionality of an organism. In skeletal muscle fibers, Ca(2+) is critically involved in the innervation of skeletal muscle fibers that results in the exertion of an action potential along the muscle fiber membrane, the prerequisite for skeletal muscle contraction. Furthermore and among others, Ca(2+) regulates also intracellular processes, such as myosin-actin cross bridging, protein synthesis, protein degradation and fiber type shifting by the control of Ca(2+)-sensitive proteases and transcription factors, as well as mitochondrial adaptations, plasticity and respiration. These data highlight the overwhelming significance of Ca(2+) ions for the integrity of skeletal muscle tissue. In this review, we address the major functions of Ca(2+) ions in adult muscle but also highlight recent findings of critical Ca(2+)-dependent mechanisms essential for skeletal muscle-regulation and maintenance.
Collapse
|
37
|
A new mechanokinetic model for muscle contraction, where force and movement are triggered by phosphate release. J Muscle Res Cell Motil 2014; 35:295-306. [PMID: 25319769 DOI: 10.1007/s10974-014-9391-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 09/26/2014] [Indexed: 10/24/2022]
Abstract
The atomic structure of myosin-S1 suggests that its working stroke, which generates tension and shortening in muscle, is triggered by the release of inorganic phosphate from the active site. This mechanism is the basis of a new mechanokinetic model for contractility, using the biochemical actomyosin ATPase cycle, strain-dependent kinetics and dimeric myosins on buckling rods. In this model, phosphate-dependent aspects of contractility arise from a rapid reversible release of phosphate from the initial bound state (A.M.ADP.Pi), which triggers the stroke. Added phosphate drives bound myosin towards this initial state, and the transient tension response to a phosphate jump reflects the rate at which it detaches from actin. Predictions for the tensile and energetic properties of striated muscle as a function of phosphate level, including the tension responses to length steps and Pi-jumps, are compared with experimental data from rabbit psoas fibres at 10 °C. The phosphate sensitivity of isometric tension is maximal when the actin affinity of M.ADP.Pi is near unity. Hence variations in actin affinity modulate the phosphate dependence of isometric tension, and may explain why phosphate sensitivity is temperature-dependent or absent in different muscles.
Collapse
|
38
|
In vivo calcium regulation in diabetic skeletal muscle. Cell Calcium 2014; 56:381-9. [PMID: 25224503 DOI: 10.1016/j.ceca.2014.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 07/23/2014] [Accepted: 08/09/2014] [Indexed: 01/30/2023]
Abstract
In skeletal muscle, dysfunctional contractile activity has been linked to impaired intracellular Ca(2+) concentration ([Ca(2+)]i) regulation. Muscle force production is impaired and fatigability and muscle fragility deteriorate with diabetes. Use of a novel in vivo model permits investigation of [Ca(2+)]i homeostasis in diabetic skeletal muscle. Within this in vivo environment we have shown that diabetes perturbs the Ca(2+) regulatory system such that resting [Ca(2+)]i homeostasis following muscle contractions is compromised and elevations of [Ca(2+)]i are exacerbated. This review considers the impact of diabetes on the capacity of skeletal muscle to regulate [Ca(2+)]i, following muscle contractions and, in particular, the relationship between muscle fatigue and elevated [Ca(2+)]i in a highly ecologically relevant circulation-intact environment. Importantly, the role of mitochondria in calcium sequestration and the possibility that diabetes impacts this process is explored. Given the profound microcirculatory dysfunction in diabetes this preparation offers the unique opportunity to study the interrelationships among microvascular function, blood-myocyte oxygen flux and [Ca(2+)]i as they relate to enhanced muscle fatigability and exercise intolerance.
Collapse
|
39
|
Nielsen J, Cheng AJ, Ørtenblad N, Westerblad H. Subcellular distribution of glycogen and decreased tetanic Ca2+ in fatigued single intact mouse muscle fibres. J Physiol 2014; 592:2003-12. [PMID: 24591577 DOI: 10.1113/jphysiol.2014.271528] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In skeletal muscle fibres, glycogen has been shown to be stored at different subcellular locations: (i) between the myofibrils (intermyofibrillar); (ii) within the myofibrils (intramyofibrillar); and (iii) subsarcolemmal. Of these, intramyofibrillar glycogen has been implied as a critical regulator of sarcoplasmic reticulum Ca(2+) release. The aim of the present study was to test directly how the decrease in cytoplasmic free Ca(2+) ([Ca(2+)]i) during repeated tetanic contractions relates to the subcellular glycogen distribution. Single fibres of mouse flexor digitorum brevis muscles were fatigued with 70 Hz, 350 ms tetani given at 2 s (high-intensity fatigue, HIF) or 10 s (low-intensity fatigue, LIF) intervals, while force and [Ca(2+)]i were measured. Stimulation continued until force decreased to 30% of its initial value. Fibres were then prepared for analyses of subcellular glycogen distribution by transmission electron microscopy. At fatigue, tetanic [Ca(2+)]i was reduced to 70 ± 4% and 54 ± 4% of the initial in HIF (P < 0.01, n = 9) and LIF (P < 0.01, n = 5) fibres, respectively. At fatigue, the mean inter- and intramyofibrillar glycogen content was 60-75% lower than in rested control fibres (P < 0.05), whereas subsarcolemmal glycogen was similar to control. Individual fibres showed a good correlation between the fatigue-induced decrease in tetanic [Ca(2+)]i and the reduction in intermyofibrillar (P = 0.051) and intramyofibrillar (P = 0.0008) glycogen. In conclusion, the fatigue-induced decrease in tetanic [Ca(2+)]i, and hence force, is accompanied by major reductions in inter- and intramyofibrillar glycogen. The stronger correlation between decreased tetanic [Ca(2+)]i and reduced intramyofibrillar glycogen implies that sarcoplasmic reticulum Ca(2+) release critically depends on energy supply from the intramyofibrillar glycogen pool.
Collapse
|
40
|
Calderón JC, Bolaños P, Caputo C. The excitation-contraction coupling mechanism in skeletal muscle. Biophys Rev 2014; 6:133-160. [PMID: 28509964 PMCID: PMC5425715 DOI: 10.1007/s12551-013-0135-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 12/06/2013] [Indexed: 12/27/2022] Open
Abstract
First coined by Alexander Sandow in 1952, the term excitation-contraction coupling (ECC) describes the rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres and Ca2+ release from the SR, which leads to contraction. The sequence of events in twitch skeletal muscle involves: (1) initiation and propagation of an action potential along the plasma membrane, (2) spread of the potential throughout the transverse tubule system (T-tubule system), (3) dihydropyridine receptors (DHPR)-mediated detection of changes in membrane potential, (4) allosteric interaction between DHPR and sarcoplasmic reticulum (SR) ryanodine receptors (RyR), (5) release of Ca2+ from the SR and transient increase of Ca2+ concentration in the myoplasm, (6) activation of the myoplasmic Ca2+ buffering system and the contractile apparatus, followed by (7) Ca2+ disappearance from the myoplasm mediated mainly by its reuptake by the SR through the SR Ca2+ adenosine triphosphatase (SERCA), and under several conditions movement to the mitochondria and extrusion by the Na+/Ca2+ exchanger (NCX). In this text, we review the basics of ECC in skeletal muscle and the techniques used to study it. Moreover, we highlight some recent advances and point out gaps in knowledge on particular issues related to ECC such as (1) DHPR-RyR molecular interaction, (2) differences regarding fibre types, (3) its alteration during muscle fatigue, (4) the role of mitochondria and store-operated Ca2+ entry in the general ECC sequence, (5) contractile potentiators, and (6) Ca2+ sparks.
Collapse
Affiliation(s)
- Juan C Calderón
- Physiology and Biochemistry Research Group-Physis, Department of Physiology and Biochemistry, Faculty of Medicine, University of Antioquia UdeA, Calle 70 No 52-21, Medellín, Colombia.
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela.
- Departamento de Fisiología y Bioquímica, Grupo de Investigación en Fisiología y Bioquímica-Physis, Facultad de Medicina, Universidad de Antioquia, Calle 70 No 52-21, Medellín, Colombia.
| | - Pura Bolaños
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Carlo Caputo
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| |
Collapse
|
41
|
Soares AB, Ticianeli JG, Soares LBM, Amaro G. On the effect of the injection of potassium phosphate in vivo inducing the precipitation of serum calcium with inorganic phosphate. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2013; 5:239-247. [PMID: 24379908 PMCID: PMC3867701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 11/30/2013] [Indexed: 06/03/2023]
Abstract
High concentrations of inorganic phosphate (Pi) resulted from the hydrolysis of ATP is strongly associated to the weakness of the contractile mechanism of muscles due to its attractiveness to calcium. The majority of the experiments to study such effect are conducted in vitro. This work investigates the effects of different concentrations of Pi, induced by the injection of potassium phosphate in live animals, in the precipitation with serum calcium and the generation of calcium phosphate composites. The experiments were also designed to find out the ideal amount of potassium phosphate to induce an effective reaction. Potassium phosphate was injected in Wistar rats, randomly separated and distributed into seven groups. Group I was injected with 0.5 ml of saline solution (control) and groups II through VII were injected with 0.5, 1.5, 2.5, 5.0, 7.5 and 10.0 mg/kg of potassium phosphate, respectively. Blood collected from the inferior vena cava was submitted to biochemical analyses to measure the concentrations of calcium, Pi, urea and creatinine. The results showed that Pi, induced by the injection of potassium phosphate in live animals, causes precipitation with serum calcium, with statistically significant differences between the control and the treatment groups for doses up to 5.0 mg/kg. No statistically significant differences were found between the different doses and the concentration of urea and creatinine in the plasma. We conclude that potassium phosphate can be used to induce serum calcium precipitation in-vivo, with minor effects on other physiological variables, and the ideal dose to do so is 5.0 mg/kg.
Collapse
Affiliation(s)
- Alcimar B Soares
- Laboratory of Biomedical Engineering, Federal University of UberlândiaUberlândia, MG, Brazil
| | - José G Ticianeli
- Laboratory of Biomedical Engineering, Federal University of UberlândiaUberlândia, MG, Brazil
| | - Letícia B M Soares
- Nephrology Service, General Hospital, Federal University of UberlândiaUberlândia, MG, Brazil
| | - George Amaro
- Brazilian Agricultural Research CompanyBoa Vista, RR, Brazil
| |
Collapse
|
42
|
Abstract
Skeletal muscle fatigue is defined as the fall of force or power in response to contractile activity. Both the mechanisms of fatigue and the modes used to elicit it vary tremendously. Conceptual and technological advances allow the examination of fatigue from the level of the single molecule to the intact organism. Evaluation of muscle fatigue in a wide range of disease states builds on our understanding of basic function by revealing the sources of dysfunction in response to disease.
Collapse
Affiliation(s)
- Jane A Kent-Braun
- Department of Kinesiology, University of Massachusetts-Amherst, Amherst, Massachusetts, USA.
| | | | | |
Collapse
|
43
|
Cully TR, Launikonis BS. Store-operated Ca²⁺ entry is not required for store refilling in skeletal muscle. Clin Exp Pharmacol Physiol 2013; 40:338-44. [PMID: 23517302 DOI: 10.1111/1440-1681.12078] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 02/27/2013] [Accepted: 03/03/2013] [Indexed: 11/28/2022]
Abstract
The present review describes store-operated Ca²⁺ entry (SOCE) in skeletal muscle. Fundamental discoveries in the field of skeletal muscle SOCE are described and the techniques that were used to make these. The advantages and limitations in these techniques are discussed to provide a means of questioning and determining the physiological role(s) of SOCE in skeletal muscle. It is concluded that SOCE has little or no role in the filling of the sarcoplasmic reticulum with Ca²⁺ at rest or during a single contracture. It is likely that SOCE is activated during fatigue, although direct measurements of SOCE are lacking and the physiological significance remains uncertain.
Collapse
Affiliation(s)
- Tanya R Cully
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia
| | | |
Collapse
|
44
|
Eshima H, Tanaka Y, Sonobe T, Inagaki T, Nakajima T, Poole DC, Kano Y. In vivo imaging of intracellular Ca2+ after muscle contractions and direct Ca2+ injection in rat skeletal muscle in diabetes. Am J Physiol Regul Integr Comp Physiol 2013; 305:R610-8. [PMID: 23883681 DOI: 10.1152/ajpregu.00023.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of muscle contractions on the profile of postcontraction resting intracellular Ca2+ ([Ca2+]i) accumulation in Type 1 diabetes are unclear. We tested the hypothesis that, following repeated bouts of muscle contractions, the rise in resting [Ca2+]i evident in healthy rats would be increased in diabetic rats and that these changes would be associated with a decreased cytoplasmic Ca2+ -buffering capacity. Adult male Wistar rats were divided randomly into diabetic (DIA; streptozotocin, ip) and healthy control (CONT) groups. Four weeks later, animals were anesthetized and spinotrapezius muscle contractions (10 sets of 50 contractions) were elicited by electrical stimulation (100 Hz). Ca2+ imaging was achieved using Fura-2 AM in the spinotrapezius muscle in vivo (i.e., circulation intact). The ratio (340/380 nm) was determined from fluorescence images following each set of contractions for estimation of [Ca2+]i. Also, muscle Ca2+ buffering was studied in individual myocytes microinjected with 2 mM Ca2+ solution. After muscle contractions, resting [Ca2+]i in DIA increased earlier and more rapidly than in CONT (P < 0.05 vs. precontraction). Peak [Ca2+]i in response to the Ca2+ injection was significantly higher in CONT (25.8 ± 6.0% above baseline) than DIA (10.2 ± 1.1% above baseline). Subsequently, CONT [Ca(2+)]i decreased rapidly (<15 s) to plateau 9-10% above baseline, whereas DIA remained elevated throughout the 60-s measurement window. No differences in SERCA1 and SERCA2 (Ca2+ uptake) protein levels were evident between CONT and DIA, whereas ryanodine receptor (Ca2+ release) protein level and mitochondrial oxidative enzyme activity (succinate dehydrogenase) were decreased in DIA (P < 0.05). In conclusion, diabetes impairs resting [Ca2+]i homeostasis following muscle contractions. Markedly different responses to Ca2+ injection in DIA vs. CONT suggest fundamentally deranged Ca2+ handling.
Collapse
Affiliation(s)
- Hiroaki Eshima
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
45
|
Cairns SP. Holistic approaches to understanding mechanisms of fatigue in high-intensity sport. FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR 2013. [DOI: 10.1080/21641846.2013.765086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
46
|
da Silva LA, Tromm CB, Bom KF, Mariano I, Pozzi B, da Rosa GL, Tuon T, da Luz G, Vuolo F, Petronilho F, Cassiano W, De Souza CT, Pinho RA. Effects of taurine supplementation following eccentric exercise in young adults. Appl Physiol Nutr Metab 2013; 39:101-4. [PMID: 24383513 DOI: 10.1139/apnm-2012-0229] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of the present study was to investigate the effects of taurine supplementation on muscle performance, oxidative stress, and inflammation response after eccentric exercise (EE) in males. Twenty-one participants (mean age, 21 ± 6 years; weight, 78.2 ± 5 kg; height, 176 ± 7 cm) were selected and randomly divided into two groups: placebo (n = 10) and taurine (n = 11). Fourteen days after starting supplementation, subjects performed EE (3 sets until exhaustion, with EE of the elbow flexors on the Scott bench, 80% 1 repetition maximum (RM)). Blood samples were collected and muscle performance was measured on days 1, 14, 16, 18, and 21 after starting the supplements. Then, performance, muscle damage, oxidative stress, and inflammatory markers were analyzed. The taurine supplementation resulted in increased strength levels and thiol total content and decreased muscle soreness, lactate dehydrogenase level, creatine kinase activity, and oxidative damage (xylenol and protein carbonyl). Antioxidant enzymes (superoxide dismutase, catalase, and gluthatione peroxidase) and inflammatory markers (tumor necrosis factor, interleukin-1β (IL-1β), and interleukin-10 (IL-10)) were not altered during the recovery period compared with the placebo group. The results suggest that taurine supplementation represents an important factor in improving performance and decreasing muscle damage and oxidative stress but does not decrease the inflammatory response after EE.
Collapse
Affiliation(s)
- Luciano A da Silva
- a Exercise Biochemistry and Physiology Laboratory, Postgraduate Program in Health Sciences, Health Sciences Unit, Universidade do Extremo Sul Catarinense, 88806-000, Criciúma, SC, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Wada M, Kuratani M, Kanzaki K. Calcium kinetics of sarcoplasmic reticulum and muscle fatigue. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2013. [DOI: 10.7600/jpfsm.2.169] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
48
|
Allen DG, Trajanovska S. The multiple roles of phosphate in muscle fatigue. Front Physiol 2012; 3:463. [PMID: 23248600 PMCID: PMC3518787 DOI: 10.3389/fphys.2012.00463] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/22/2012] [Indexed: 01/23/2023] Open
Abstract
Muscle fatigue is the decline in performance of muscles observed during periods of intense activity. ATP consumption exceeds production during intense activity and there are multiple changes in intracellular metabolites which may contribute to the changes in crossbridge activity. It is also well-established that a reduction in activation, either through action potential changes or reduction in Ca(2+) release from the sarcoplasmic reticulum (SR), makes an additional contribution to fatigue. In this review we focus on the role of intracellular inorganic phosphate (P(i)) whose concentration can increase rapidly from around 5-30 mM during intense fatigue. Studies from skinned muscle fibers show that these changes substantially impair myofibrillar performance although the effects are strongly temperature dependent. Increased P(i) can also cause reduced Ca(2+) release from the SR and may therefore contribute to the reduced activation. In a recent study, we have measured both P(i) and Ca(2+) release in a blood-perfused mammalian preparation and the results from this preparation allows us to test the extent to which the combined effects of P(i) and Ca(2+) changes may contribute to fatigue.
Collapse
Affiliation(s)
- David G Allen
- School of Medical Sciences, Bosch Institute and Sydney School of Medicine, University of Sydney Sydney, NSW, Australia
| | | |
Collapse
|
49
|
Mitochondrial free [Ca(2+)] dynamics measured with a novel low-Ca(2+) affinity aequorin probe. Biochem J 2012; 445:371-6. [PMID: 22671130 DOI: 10.1042/bj20120423] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mitochondria have a very large capacity to accumulate Ca(2+) during cell stimulation driven by the mitochondrial membrane potential. Under these conditions, [Ca(2+)](M) (mitochondrial [Ca(2+)]) may well reach millimolar levels in a few seconds. Measuring the dynamics of [Ca(2+)](M) during prolonged stimulation has been previously precluded by the high Ca(2+) affinity of the probes available. We have now developed a mitochondrially targeted double-mutated form of the photoprotein aequorin which is able to measure [Ca(2+)] in the millimolar range for long periods of time without problems derived from aequorin consumption. We show in the present study that addition of Ca(2+) to permeabilized HeLa cells triggers an increase in [Ca(2+)](M) up to an steady state of approximately 2-3 mM in the absence of phosphate and 0.5-1 mM in the presence of phosphate, suggesting buffering or precipitation of calcium phosphate when the free [Ca(2+)] reaches 0.5-1 mM. Mitochondrial pH acidification partially re-dissolved these complexes. These millimolar [Ca(2+)](M) levels were stable for long periods of time provided the mitochondrial membrane potential was not collapsed. Silencing of the mitochondrial Ca(2+) uniporter largely reduced the rate of [Ca(2+)](M) increase, but the final steady-state [Ca(2+)](M) reached was similar. In intact cells, the new probe allows monitoring of agonist-induced increases of [Ca(2+)](M) without problems derived from aequorin consumption.
Collapse
|
50
|
Kano Y, Sonobe T, Inagaki T, Sudo M, Poole DC. Mechanisms of exercise-induced muscle damage and fatigue: Intracellular calcium accumulation. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2012. [DOI: 10.7600/jpfsm.1.505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|