1
|
Xu H, Czyżowska A, Van Remmen H, Brown JL. Modulation of sarcopenia phenotypes by glutathione peroxidase 4 overexpression in mice. J Physiol 2023; 601:5277-5293. [PMID: 37878529 PMCID: PMC10871152 DOI: 10.1113/jp285259] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/15/2023] [Indexed: 10/27/2023] Open
Abstract
Our laboratory previously showed lipid hydroperoxides and oxylipin levels are elevated in response to loss of skeletal muscle innervation and are associated with muscle pathologies. To elucidate the pathological impact of lipid hydroperoxides, we overexpressed glutathione peroxidase 4 (GPx4), an enzyme that targets reduction of lipid hydroperoxides in membranes, in adult CuZn superoxide dismutase knockout (Sod1KO) mice that show accelerated muscle atrophy associated with loss of innervation. The gastrocnemius muscle from Sod1KO mice shows reduced mitochondrial respiration and elevated oxidative stress (F2 -isoprostanes and hydroperoxides) compared to wild-type (WT) mice. Overexpression of GPx4 improved mitochondrial respiration and reduced hydroperoxide generation in Sod1KO mice, but did not attenuate the muscle loss that occurs in Sod1KO mice. In contrast, contractile force generation is reduced in EDL muscle in Sod1KO mice relative to WT mice, and overexpression of GPx4 restored force generation to WT levels in Sod1KO mice. GPx4 overexpression also prevented loss of muscle contractility at the single fibre level in fast-twitch fibres from Sod1KO mice. Muscle fibres from Sod1KO mice were less sensitive to both depolarization and calcium at the single fibre level and exhibited a reduced activation by S-glutathionylation. GPx4 overexpression in Sod1KO mice rescued the deficits in both membrane excitability and calcium sensitivity of fast-twitch muscle fibres. Overexpression of GPx4 also restored the sarco/endoplasmic reticulum Ca2+ -ATPase activity in Sod1KO gastrocnemius muscles. These data suggest that GPx4 plays an important role in preserving excitation-contraction coupling function and Ca2+ homeostasis, and in maintaining muscle and mitochondrial function in oxidative stress-induced sarcopenia. KEY POINTS: Knockout of CuZn superoxide dismutase (Sod1KO) induces elevated oxidative stress with accelerated muscle atrophy and weakness. Glutathione peroxidase 4 (GPx4) plays a fundamental role in the reduction of lipid hydroperoxides in membranes, and overexpression of GPx4 improves mitochondrial respiration and reduces hydroperoxide generation in Sod1KO mice. Muscle contractile function deficits in Sod1KO mice are alleviated by the overexpression of GPx4. GPx4 overexpression in Sod1KO mice rescues the impaired muscle membrane excitability of fast-twitch muscle fibres and improves their calcium sensitivity. Sarco/endoplasmic reticulum Ca2+ -ATPase activity in Sod1KO muscles is decreased, and it is restored by the overexpression of GPx4. Our results confirm that GPx4 plays an important role in preserving excitation-contraction coupling function and Ca2+ homeostasis, and maintaining muscle and mitochondrial function in oxidative stress-induced sarcopenia.
Collapse
Affiliation(s)
- Hongyang Xu
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Agnieszka Czyżowska
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Oklahoma City VA Medical Center, Oklahoma City, OK, USA
| | - Jacob L Brown
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Oklahoma City VA Medical Center, Oklahoma City, OK, USA
| |
Collapse
|
2
|
Ahn B, Ranjit R, Kneis P, Xu H, Piekarz KM, Freeman WM, Kinter M, Richardson A, Ran Q, Brooks SV, Van Remmen H. Scavenging mitochondrial hydrogen peroxide by peroxiredoxin 3 overexpression attenuates contractile dysfunction and muscle atrophy in a murine model of accelerated sarcopenia. Aging Cell 2022; 21:e13569. [PMID: 35199907 PMCID: PMC8920438 DOI: 10.1111/acel.13569] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 01/21/2022] [Accepted: 02/01/2022] [Indexed: 01/14/2023] Open
Abstract
Age-related muscle atrophy and weakness, or sarcopenia, are significant contributors to compromised health and quality of life in the elderly. While the mechanisms driving this pathology are not fully defined, reactive oxygen species, neuromuscular junction (NMJ) disruption, and loss of innervation are important risk factors. The goal of this study is to determine the impact of mitochondrial hydrogen peroxide on neurogenic atrophy and contractile dysfunction. Mice with muscle-specific overexpression of the mitochondrial H2 O2 scavenger peroxiredoxin3 (mPRDX3) were crossed to Sod1KO mice, an established mouse model of sarcopenia, to determine whether reduced mitochondrial H2 O2 can prevent or delay the redox-dependent sarcopenia. Basal rates of H2 O2 generation were elevated in isolated muscle mitochondria from Sod1KO, but normalized by mPRDX3 overexpression. The mPRDX3 overexpression prevented the declines in maximum mitochondrial oxygen consumption rate and calcium retention capacity in Sod1KO. Muscle atrophy in Sod1KO was mitigated by ~20% by mPRDX3 overexpression, which was associated with an increase in myofiber cross-sectional area. With direct muscle stimulation, maximum isometric specific force was reduced by ~20% in Sod1KO mice, and mPRDX3 overexpression preserved specific force at wild-type levels. The force deficit with nerve stimulation was exacerbated in Sod1KO compared to direct muscle stimulation, suggesting NMJ disruption in Sod1KO. Notably, this defect was not resolved by overexpression of mPRDX3. Our findings demonstrate that muscle-specific PRDX3 overexpression reduces mitochondrial H2 O2 generation, improves mitochondrial function, and mitigates loss of muscle quantity and quality, despite persisting NMJ impairment in a murine model of redox-dependent sarcopenia.
Collapse
Affiliation(s)
- Bumsoo Ahn
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Department of Internal MedicineWake Forest School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Rojina Ranjit
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Parker Kneis
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Hongyang Xu
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Katarzyna M. Piekarz
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Center for NeuroscienceUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA
| | - Willard M. Freeman
- Genes and Human Disease Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Michael Kinter
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA
| | - Arlan Richardson
- Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA,Department of BiochemistryOUHSCOklahoma CityOklahomaUSA,Oklahoma City VA Medical CenterOklahoma CityOklahomaUSA
| | - Qitao Ran
- Department of Cell Systems & AnatomyUT Health San AntonioSan AntonioTexasUSA
| | - Susan V. Brooks
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborMichiganUSA
| | - Holly Van Remmen
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Center for NeuroscienceUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA,Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA,Oklahoma City VA Medical CenterOklahoma CityOklahomaUSA,Department of PhysiologyOUHSCOklahoma CityOklahomaUSA
| |
Collapse
|
3
|
Ahn B, Ranjit R, Premkumar P, Pharaoh G, Piekarz KM, Matsuzaki S, Claflin DR, Riddle K, Judge J, Bhaskaran S, Satara Natarajan K, Barboza E, Wronowski B, Kinter M, Humphries KM, Griffin TM, Freeman WM, Richardson A, Brooks SV, Van Remmen H. Mitochondrial oxidative stress impairs contractile function but paradoxically increases muscle mass via fibre branching. J Cachexia Sarcopenia Muscle 2019; 10:411-428. [PMID: 30706998 PMCID: PMC6463475 DOI: 10.1002/jcsm.12375] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Excess reactive oxygen species (ROS) and muscle weakness occur in parallel in multiple pathological conditions. However, the causative role of skeletal muscle mitochondrial ROS (mtROS) on neuromuscular junction (NMJ) morphology and function and muscle weakness has not been directly investigated. METHODS We generated mice lacking skeletal muscle-specific manganese-superoxide dismutase (mSod2KO) to increase mtROS using a cre-Lox approach driven by human skeletal actin. We determined primary functional parameters of skeletal muscle mitochondrial function (respiration, ROS, and calcium retention capacity) using permeabilized muscle fibres and isolated muscle mitochondria. We assessed contractile properties of isolated skeletal muscle using in situ and in vitro preparations and whole lumbrical muscles to elucidate the mechanisms of contractile dysfunction. RESULTS The mSod2KO mice, contrary to our prediction, exhibit a 10-15% increase in muscle mass associated with an ~50% increase in central nuclei and ~35% increase in branched fibres (P < 0.05). Despite the increase in muscle mass of gastrocnemius and quadriceps, in situ sciatic nerve-stimulated isometric maximum-specific force (N/cm2 ), force per cross-sectional area, is impaired by ~60% and associated with increased NMJ fragmentation and size by ~40% (P < 0.05). Intrinsic alterations of components of the contractile machinery show elevated markers of oxidative stress, for example, lipid peroxidation is increased by ~100%, oxidized glutathione is elevated by ~50%, and oxidative modifications of myofibrillar proteins are increased by ~30% (P < 0.05). We also find an approximate 20% decrease in the intracellular calcium transient that is associated with specific force deficit. Excess superoxide generation from the mitochondrial complexes causes a deficiency of succinate dehydrogenase and reduced complex-II-mediated respiration and adenosine triphosphate generation rates leading to severe exercise intolerance (~10 min vs. ~2 h in wild type, P < 0.05). CONCLUSIONS Increased skeletal muscle mtROS is sufficient to elicit NMJ disruption and contractile abnormalities, but not muscle atrophy, suggesting new roles for mitochondrial oxidative stress in maintenance of muscle mass through increased fibre branching.
Collapse
Affiliation(s)
- Bumsoo Ahn
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Rojina Ranjit
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Pavithra Premkumar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Gavin Pharaoh
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Katarzyna M Piekarz
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Satoshi Matsuzaki
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Dennis R Claflin
- Department of Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, USA
| | - Kaitlyn Riddle
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Jennifer Judge
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
| | - Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | | | - Erika Barboza
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Benjamin Wronowski
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Michael Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Kenneth M Humphries
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Timothy M Griffin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Willard M Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Arlan Richardson
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| |
Collapse
|
4
|
Kissane RWP, Egginton S, Askew GN. Regional variation in the mechanical properties and fibre-type composition of the rat extensor digitorum longus muscle. Exp Physiol 2017; 103:111-124. [DOI: 10.1113/ep086483] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 10/23/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Roger W. P. Kissane
- School of Biomedical Sciences; Faculty of Biological Sciences, University of Leeds; Leeds UK
| | - Stuart Egginton
- School of Biomedical Sciences; Faculty of Biological Sciences, University of Leeds; Leeds UK
| | - Graham N. Askew
- School of Biomedical Sciences; Faculty of Biological Sciences, University of Leeds; Leeds UK
| |
Collapse
|
5
|
Bowen TS, Eisenkolb S, Drobner J, Fischer T, Werner S, Linke A, Mangner N, Schuler G, Adams V. High-intensity interval training prevents oxidant-mediated diaphragm muscle weakness in hypertensive mice. FASEB J 2016; 31:60-71. [PMID: 27650398 DOI: 10.1096/fj.201600672r] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/07/2016] [Indexed: 01/07/2023]
Abstract
Hypertension is a key risk factor for heart failure, with the latter characterized by diaphragm muscle weakness that is mediated in part by increased oxidative stress. In the present study, we used a deoxycorticosterone acetate (DOCA)-salt mouse model to determine whether hypertension could independently induce diaphragm dysfunction and further investigated the effects of high-intensity interval training (HIIT). Sham-treated (n = 11), DOCA-salt-treated (n = 11), and DOCA-salt+HIIT-treated (n = 15) mice were studied over 4 wk. Diaphragm contractile function, protein expression, enzyme activity, and fiber cross-sectional area and type were subsequently determined. Elevated blood pressure confirmed hypertension in DOCA-salt mice independent of HIIT (P < 0.05). Diaphragm forces were impaired by ∼15-20% in DOCA-salt vs. sham-treated mice (P < 0.05), but this effect was prevented after HIIT. Myosin heavy chain (MyHC) protein expression tended to decrease (∼30%; P = 0.06) in DOCA-salt vs. sham- and DOCA-salt+HIIT mice, whereas oxidative stress increased (P < 0.05). Enzyme activity of NADPH oxidase was higher, but superoxide dismutase was lower, with MyHC oxidation elevated by ∼50%. HIIT further prevented direct oxidant-mediated diaphragm contractile dysfunction (P < 0.05) after a 30 min exposure to H2O-2 (1 mM). Our data suggest that hypertension induces diaphragm contractile dysfunction via an oxidant-mediated mechanism that is prevented by HIIT.-Bowen, T. S., Eisenkolb, S., Drobner, J., Fischer, T., Werner, S., Linke, A., Mangner, N., Schuler, G., Adams, V. High-intensity interval training prevents oxidant-mediated diaphragm muscle weakness in hypertensive mice.
Collapse
Affiliation(s)
- T Scott Bowen
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Sophia Eisenkolb
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Juliane Drobner
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Tina Fischer
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Sarah Werner
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Axel Linke
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Norman Mangner
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Gerhard Schuler
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| | - Volker Adams
- Department of Internal Medicine and Cardiology, Leipzig University Heart Center, Leipzig, Germany
| |
Collapse
|
6
|
Smith IC, Vigna C, Levy AS, Denniss SG, Rush JWE, Tupling AR. The effects of buthionine sulfoximine treatment on diaphragm contractility and SERCA pump function in adult and middle aged rats. Physiol Rep 2015; 3:3/9/e12547. [PMID: 26371231 PMCID: PMC4600388 DOI: 10.14814/phy2.12547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This study examined the effects of 10 days of buthionine sulfoximine (BSO) treatment on in vitro contractility and sarcoplasmic reticulum calcium pump (SERCA) expression and function in adult (AD; 6–8 months old) and middle aged (MA; 14–17 months old) rat diaphragm in both the basal state and following fatiguing stimulation. BSO treatment reduced the cellular concentrations of free glutathione (GSH) by >95% and oxidized glutathione (GSSG) by >80% in both age cohorts. GSH content in AD Control diaphragm was 32% higher (P < 0.01) than in MA Control, with no differences in GSSG. The ratio of GSH:GSSG, an indicator of cellular oxidative state, was 34.6 ± 7.4 in MA Control, 52.5 ± 10.1 in AD Control, 10.6 ± 1.7 in MA BSO, and 9.5 ± 1.1 in AD BSO (BSO vs. Control, P < 0.05). Several findings suggest that the effects of BSO treatment are age dependent. AD BSO diaphragm had 26% higher twitch and 28% higher tetanic force (both P < 0.05) than AD Controls, whereas no significant difference existed between the two MA groups. In contrast to our previous work on BSO-treated AD rats, BSO treatment did not influence maximal SERCA ATPase activity in MA rat diaphragm, nor did SERCA2a expression increase in BSO-treated MA diaphragm. Biotinylated iodoacetamide binding to SERCA1a, a specific marker of free cysteine residues, was reduced by 35% (P < 0.05) in AD Control diaphragm following fatiguing stimulation, but was not reduced in any other group. Collectively, these results suggest an important role for redox regulation in both contractility and SERCA function which is influenced by aging.
Collapse
Affiliation(s)
- Ian C Smith
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Chris Vigna
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Andrew S Levy
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Steven G Denniss
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - James W E Rush
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
7
|
Baltusnikas J, Kilikevicius A, Venckunas T, Fokin A, Lionikas A, Ratkevicius A. Regenerated soleus muscle shows reduced creatine kinase efflux after contractile activity in vitro. Appl Physiol Nutr Metab 2015; 40:129-33. [PMID: 25565131 DOI: 10.1139/apnm-2014-0274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regenerated skeletal muscles show less muscle damage after strenuous muscle exercise. The aim of the studies was to investigate if the regeneration is associated with reduced muscle creatine kinase (CK) efflux immediately after the exercise. Cryolesion was applied to the soleus muscle of 3-month-old C57BL/6J male mice. Then total CK efflux was assessed in vitro in the regenerated muscles without exercise or after 100 eccentric contractions. The same measurements were performed in the control muscles, which were not exposed to cryolesion. Regenerated muscles generated weaker (P < 0.05) twitches, but stronger (P < 0.05) 150-Hz and 300-Hz tetani with prolonged (P < 0.01) contraction times compared with the control muscles. There was no difference between regenerated and control muscles in the total CK efflux without exercise, but only control muscles showed an increase (P < 0.001) in the CK efflux after the exercise. Our results suggest that muscle regeneration is associated with modulation of contractile properties and improvement in muscle resistance to damage after eccentric exercise.
Collapse
Affiliation(s)
- Juozas Baltusnikas
- a Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221 Kaunas, Lithuania
| | | | | | | | | | | |
Collapse
|
8
|
Pereyra-Venegas J, Segura-Alegría B, Guadarrama-Olmos JC, Mariscal-Tovar S, Quiróz-González S, Jiménez-Estrada I. Effects provoked by chronic undernourishment on the fibre type composition and contractility of fast muscles in male and female developing rats. J Anim Physiol Anim Nutr (Berl) 2014; 99:974-86. [DOI: 10.1111/jpn.12274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 10/27/2014] [Indexed: 11/26/2022]
Affiliation(s)
- J. Pereyra-Venegas
- Departamento de Biología; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla de Baz Estado de México México
- Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México City México
| | - B. Segura-Alegría
- Departamento de Biología; Facultad de Estudios Superiores Iztacala; Universidad Nacional Autónoma de México; Tlalnepantla de Baz Estado de México México
| | - J. C. Guadarrama-Olmos
- Departamento de Fisiología, Biofísica y Neurociencias; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco; Del. Gustavo A. Madero. México City México
| | - S. Mariscal-Tovar
- Departamento de Fisiología, Biofísica y Neurociencias; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco; Del. Gustavo A. Madero. México City México
| | - S. Quiróz-González
- Departamento de Acupuntura y Rehabilitación; Universidad Estatal del Valle de Ecatepec; Valle de Anáhuac Ecatepec Estado de México México
| | - I. Jiménez-Estrada
- Departamento de Fisiología, Biofísica y Neurociencias; Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional; San Pedro Zacatenco; Del. Gustavo A. Madero. México City México
| |
Collapse
|
9
|
Larkin LM, Hanes MC, Kayupov E, Claflin DR, Faulkner JA, Brooks SV. Weakness of whole muscles in mice deficient in Cu, Zn superoxide dismutase is not explained by defects at the level of the contractile apparatus. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1173-1181. [PMID: 22696118 PMCID: PMC3705120 DOI: 10.1007/s11357-012-9441-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 05/21/2012] [Indexed: 06/01/2023]
Abstract
Mice deficient in Cu,Zn superoxide dismutase (Sod1 (-/-) mice) demonstrate elevated oxidative stress associated with rapid age-related declines in muscle mass and force. The decline in mass for muscles of Sod1 (-/-) mice is explained by a loss of muscle fibers, but the mechanism underlying the weakness is not clear. We hypothesized that the reduced maximum isometric force (F o) normalized by cross-sectional area (specific F o) for whole muscles of Sod1 (-/-) compared with wild-type (WT) mice is due to decreased specific F o of individual fibers. Force generation was measured for permeabilized fibers from muscles of Sod1 (-/-) and WT mice at 8 and 20 months of age. WT mice were also studied at 28 months to determine whether any deficits observed for fibers from Sod1 (-/-) mice were similar to those observed in old WT mice. No effects of genotype were observed for F o or specific F o at either 8 or 20 months, and no age-associated decrease in specific F o was observed for fibers from Sod1 (-/-) mice, whereas specific F o for fibers of WT mice decreased by 20 % by 28 months. Oxidative stress has also been associated with decreased maximum velocity of shortening (V max), and we found a 10 % lower V max for fibers from Sod1 (-/-) compared with WT mice at 20 months. We conclude that the low specific F o of muscles of Sod1 (-/-) mice is not explained by damage to contractile proteins. Moreover, the properties of fibers of Sod1 (-/-) mice do not recapitulate those observed with aging in WT animals.
Collapse
Affiliation(s)
- Lisa M. Larkin
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Michael C. Hanes
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Erdan Kayupov
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Dennis R. Claflin
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
- />Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI 48109 USA
| | - John A. Faulkner
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Susan V. Brooks
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| |
Collapse
|
10
|
Shortt CM, O'Halloran KD. Hydrogen peroxide alters sternohyoid muscle function. Oral Dis 2013; 20:162-70. [PMID: 23445083 DOI: 10.1111/odi.12084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/07/2013] [Accepted: 02/07/2013] [Indexed: 11/30/2022]
Abstract
Upper airway (UA) dilator muscles are critical for the maintenance of airway patency. Injury or fatigue to this group of muscles, as observed in patients with obstructive sleep apnoea (OSA) and animal models of OSA, may leave the UA susceptible to collapse. Although the mechanisms underlying respiratory muscle dysfunction are not completely understood, there is strong evidence suggesting a link between increased production of reactive oxygen species and altered muscle function. The aim of this study was to examine the effects of H2O2 on rat sternohyoid muscle function in vitro. Sternohyoid contractile and endurance properties were examined at 35 °C under control or hypoxic conditions. Studies were conducted in the presence of varying concentrations of H2O2 (0, 0.01, 0.1 and 1 mM). Muscle function was also examined in the presence of antioxidants [desferoxamine (DFX), catalase] and the reducing agent dithiothreitol (DTT). H2O2 decreased muscle endurance in a concentration-dependent manner. This was partially reversed by catalase, DFX and DTT. Our results suggest that oxidants may contribute to UA respiratory muscle dysfunction with implications for the control of UA patency in vivo.
Collapse
Affiliation(s)
- C M Shortt
- UCD School of Medicine and Medical Science, Health Sciences, University College Dublin, Dublin, Ireland
| | | |
Collapse
|
11
|
Gilliam LAA, St Clair DK. Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress. Antioxid Redox Signal 2011; 15:2543-63. [PMID: 21457105 PMCID: PMC3176345 DOI: 10.1089/ars.2011.3965] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
SIGNIFICANCE Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity. RECENT ADVANCES Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction. CRITICAL ISSUES These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress. FUTURE DIRECTIONS Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.
Collapse
|
12
|
Cacciani N, Paoli A, Reggiani C, Patruno M. Hypoxia: the third wheel between nerve and muscle. Neurol Res 2008; 30:149-54. [PMID: 18397606 DOI: 10.1179/174313208x281226] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Skeletal muscles not only obey carefully all motor commands received via motor nerves from nervous system, but also are ready to modify their structure and function to be more suited to the tasks assigned by nervous system. Thus, nervous system appears as the major modulator of the muscle structure and function. Other factors, however, may interfere with the nerve-muscle partnership and among them, hypoxia plays a pivotal role because skeletal muscles exhibit a great variability of the oxygen fluxes and because hypoxia per se has a powerful influence on muscle fibers. The adaptation of skeletal muscles to nerve-induced activity is particularly evident with low frequency tonic patterns and examples are given by chronic low frequency stimulation and by endurance training. Adaptation includes fiber type transitions towards a slow-oxidative phenotype, increased mitochondrial density and increased capillary/fiber ratio. Hypoxia can trigger some of such changes and this has suggested that low oxygen tension at fiber level might be a mediator, possibly based on HIF and VEGF, of the muscle adaptation to increased contractile activity. Chronic hypoxia can, however, induce opposite modifications, such as a fiber type transition from slow-oxidative to fast-glycolytic and mitochondrial loss. In such conditions, the increased contractile activity can antagonize hypoxia effects. Thus, hypoxia can play a double role in the nerve-muscle relationship, either reinforcing the nerve influence or antagonizing it. This short review aims to re-examine the ambiguous relationships between nerve-induced contractile activity and hypoxic conditions and to suggest possible interpretations of the double role played by hypoxia.
Collapse
Affiliation(s)
- N Cacciani
- Department of Anatomy and Physiology, University of Padova, Padova, Italy
| | | | | | | |
Collapse
|
13
|
Oba T, Maeno Y, Nagao M, Sakuma N, Murayama T. Cellular redox state protects acetaldehyde-induced alteration in cardiomyocyte function by modifying Ca2+ release from sarcoplasmic reticulum. Am J Physiol Heart Circ Physiol 2008; 294:H121-33. [DOI: 10.1152/ajpheart.00520.2007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies indicate that low concentrations of acetaldehyde may function as the primary factor in alcoholic cardiomyopathy by disrupting Ca2+ handling or disturbing cardiac excitation-contraction coupling. By producing reactive oxygen species, acetaldehyde shifts the intracellular redox potential from a reduced state to an oxidized state. We examined whether the redox state modulates acetaldehyde-induced Ca2+ handling by measuring Ca2+ transient using a confocal imaging system and single ryanodine receptor type 2 (RyR2) channel activity using the planar lipid bilayer method. Ca2+ transient was recorded in isolated rat ventricular myocytes with incorporated fluo 3. Intracellular reduced glutathione level was estimated using the monochlorobimane fluorometric method. Acetaldehyde at 1 and 10 μM increased Ca2+ transient amplitude and its relative area in intact myocytes, but acetaldehyde at 100 μM decreased Ca2+ transient area significantly. Acetaldehyde showed a minor effect on Ca2+ transient in myocytes in which intracellular reduced glutathione content had been decreased against challenge of diethylmaleate to a level comparable to that induced by exposure to ∼50 μM acetaldehyde. Channel activity of the RyR2 with slightly reduced cytoplasmic redox potential from near resting state (−213 mV) or without redox fixation was augmented by all concentrations of acetaldehyde (1–100 μM) used here. However, acetaldehyde failed to activate the RyR2 channel, when the cytoplasmic redox potential was kept with a reduced (−230 mV) or markedly oxidized (−180 mV) state. This result was similar to effects of acetaldehyde on Ca2+ transient in diethylmaleate-treated myocytes, probably being in oxidized redox potential. The present results suggest that acetaldehyde acts as an RyR2 activator to disturb cardiac muscle function, and redox potential protects the heart from acetaldehyde-induced alterations in myocytes.
Collapse
|
14
|
Abstract
Repeated, intense use of muscles leads to a decline in performance known as muscle fatigue. Many muscle properties change during fatigue including the action potential, extracellular and intracellular ions, and many intracellular metabolites. A range of mechanisms have been identified that contribute to the decline of performance. The traditional explanation, accumulation of intracellular lactate and hydrogen ions causing impaired function of the contractile proteins, is probably of limited importance in mammals. Alternative explanations that will be considered are the effects of ionic changes on the action potential, failure of SR Ca2+release by various mechanisms, and the effects of reactive oxygen species. Many different activities lead to fatigue, and an important challenge is to identify the various mechanisms that contribute under different circumstances. Most of the mechanistic studies of fatigue are on isolated animal tissues, and another major challenge is to use the knowledge generated in these studies to identify the mechanisms of fatigue in intact animals and particularly in human diseases.
Collapse
|
15
|
Tupling AR, Vigna C, Ford RJ, Tsuchiya SC, Graham DA, Denniss SG, Rush JWE. Effects of buthionine sulfoximine treatment on diaphragm contractility and SR Ca2+ pump function in rats. J Appl Physiol (1985) 2007; 103:1921-8. [PMID: 17717121 DOI: 10.1152/japplphysiol.00529.2007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to examine the effects of glutathione (GSH) depletion and cellular oxidation on rat diaphragm contractility and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) function in vitro under basal conditions and following fatiguing stimulation. Buthionine sulfoximine (BSO) treatment (n = 10) for 10 days (20 mM in drinking water) reduced (P < 0.05) diaphragm GSH content (nmol/mg protein) and the ratio of GSH to glutathione disulfide (GSH/GSSG) by 91% and 71%, respectively, compared with controls (CTL) (n = 10). Western blotting showed that Hsp70 expression in diaphragm was not increased (P > 0.05) with BSO treatment. As hypothesized, basal peak twitch force (g/mm(2)) was increased (P < 0.05), and fatigability in response to repetitive stimulation (350-ms trains at 100 Hz once every 1 s for 5 min) was also increased (P < 0.05) in BSO compared with CTL. Both Ca(2+) uptake and maximal SERCA activity (mumol.g protein(-1).min(-1)) measured in diaphragm homogenates that were prepared at rest were increased (P < 0.05) with BSO treatment, an effect that could be partly explained by a twofold increase (P < 0.05) in SERCA2a expression with BSO. In response to the 5-min stimulation protocol, both Ca(2+) uptake and maximal SERCA activity were increased (P < 0.05) in CTL but not (P > 0.05) in BSO diaphragm. We conclude that 1) cellular redox state is more optimal for contractile function and fatigability is increased in rat diaphragm following BSO treatment, 2) SERCA2a expression is modulated by redox signaling, and 3) regulation of SERCA function in working diaphragm is altered following BSO treatment.
Collapse
Affiliation(s)
- A R Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
| | | | | | | | | | | | | |
Collapse
|
16
|
Edwards JN, Macdonald WA, van der Poel C, Stephenson DG. O2(*-) production at 37 degrees C plays a critical role in depressing tetanic force of isolated rat and mouse skeletal muscle. Am J Physiol Cell Physiol 2007; 293:C650-60. [PMID: 17459949 DOI: 10.1152/ajpcell.00037.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To find out whether the decrease in muscle performance of isolated mammalian skeletal muscle associated with the increase in temperature toward physiological levels is related to the increase in muscle superoxide (O(2)(*-)) production, O(2)(*-) released extracellularly by intact isolated rat and mouse extensor digitorum longus (EDL) muscles was measured at 22, 32, and 37 degrees C in Krebs-Ringer solution, and tetanic force was measured in both preparations at 22 and 37 degrees C under the same conditions. The rate of O(2)(*-) production increased marginally when the temperature was increased from 22 to 32 degrees C, but increased fivefold when the temperature was increased from 22 to 37 degrees C in both rat and mouse preparations. This increase was accompanied by a marked decrease in tetanic force after 30 min incubation at 37 degrees C in both rat and mouse EDL muscles. Tetanic force remained largely depressed after return to 22 degrees C for up to 120 min. The specific maximum Ca(2+)-activated force measured in mechanically skinned fibers after the temperature treatment was markedly depressed in mouse fibers but was not significantly depressed in rat muscle fibers. The resting membrane and intracellular action potentials were, however, significantly affected by the temperature treatment in the rat fibers. The effects of the temperature treatment on tetanic force, maximum Ca(2+)-activated force, and membrane potential were largely prevented by 1 mM Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl), a membrane-permeable superoxide dismutase mimetic, indicating that the increased O(2)(*-) production at physiological temperatures is largely responsible for the observed depression in tetanic force at 37 degrees C by affecting the contractile apparatus and plasma membrane.
Collapse
|
17
|
Lynch GS. Novel therapies for sarcopenia: ameliorating age-related changes in skeletal muscle. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.12.1.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
18
|
Kristensen M, Hansen T. Statistical analyses of repeated measures in physiological research: a tutorial. ADVANCES IN PHYSIOLOGY EDUCATION 2004; 28:2-14. [PMID: 14973047 DOI: 10.1152/advan.00042.2003] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Experimental designs involving repeated measurements on experimental units are widely used in physiological research. Often, relatively many consecutive observations on each experimental unit are involved and the data may be quite nonlinear. Yet evidently, one of the most commonly used statistical methods for dealing with such data sets in physiological research is the repeated-measurements ANOVA model. The problem herewith is that it is not well suited for data sets with many consecutive measurements; it does not deal with nonlinear features of the data, and the interpretability of the model may be low. The use of inappropriate statistical models increases the likelihood of drawing wrong conclusions. The aim of this article is to illustrate, for a reasonably typical repeated-measurements data set, how fundamental assumptions of the repeated-measurements ANOVA model are inappropriate and how researchers may benefit from adopting different modeling approaches using a variety of different kinds of models. We emphasize intuitive ideas rather than mathematical rigor. We illustrate how such models represent alternatives that 1) can have much higher interpretability, 2) are more likely to meet underlying assumptions, 3) provide better fitted models, and 4) are readily implemented in widely distributed software products.
Collapse
Affiliation(s)
- Michael Kristensen
- August Krogh Institute, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
| | | |
Collapse
|
19
|
Medved I, Brown MJ, Bjorksten AR, McKenna MJ. Effects of intravenous N-acetylcysteine infusion on time to fatigue and potassium regulation during prolonged cycling exercise. J Appl Physiol (1985) 2004; 96:211-7. [PMID: 12959960 DOI: 10.1152/japplphysiol.00458.2003] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The production of reactive oxygen species in skeletal muscle is linked with muscle fatigue. This study investigated whether the antioxidant compound N-acetylcysteine (NAC) augments time to fatigue during prolonged, submaximal cycling exercise. Seven men completed a double-blind, crossover study, receiving NAC or placebo before and during cycling exercise, comprising 45 min at 70% of peak oxygen consumption (Vo2 peak) and then to fatigue at 90% Vo2 peak. NAC was intravenously infused at 125 mg.kg-1.h-1 for 15 min and then 25 mg.kg-1.h-1 for 20 min before and throughout exercise, which was continued until fatigue. Arterialized venous blood was analyzed for NAC concentration, hematology, and plasma electrolytes. NAC induced no serious adverse reactions and did not affect hematology, acid-base status, or plasma electrolytes. Time to fatigue was reproducible in preliminary trials (coefficient of variation 7.4 +/- 1.2%) and was not augmented by NAC (NAC 14.6 +/- 4.5 min; control 12.8 +/- 5.4 min). However, time to fatigue during NAC trials was correlated with Vo2 peak (r = 0.78; P < 0.05), suggesting that NAC effects on performance may be dependent on training status. The rise in plasma K+ concentration at fatigue was attenuated by NAC (P < 0.05). The ratio of rise in K+ concentration to work and the percentage change in time to fatigue tended to be inversely related (r = -0.71; P < 0.07). Further research is required to clarify a possible training status-dependent effect of NAC on muscle performance and K+ regulation.
Collapse
Affiliation(s)
- Ivan Medved
- Muscle, Ions and Exercise Group, School of Human Movement, Recreation and Performance, Centre for Tehabilitation, Exercise and Sport Science, Victoria University of Technology, Melbourne 8001, Victoria, Australia
| | | | | | | |
Collapse
|
20
|
Plant DR, Gregorevic P, Warmington SA, Williams DA, Lynch GS. Endurance training adaptations modulate the redox-force relationship of rat isolated slow-twitch skeletal muscles. Clin Exp Pharmacol Physiol 2003; 30:77-81. [PMID: 12542458 DOI: 10.1046/j.1440-1681.2002.03794.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. Studies have shown that, in isolated skeletal muscles, maximum isometric force production (Po) is dependent on muscle redox state. Endurance training increases the anti-oxidant capacity of skeletal muscles, a factor that could impact on the force-producing capacity following exogenous exposure to an oxidant. We tested the hypothesis that 12 weeks treadmill training would increase anti-oxidant capacity in rat skeletal muscles and alter their response to exogenous oxidant exposure. 2. At the conclusion of the 12 week endurance-training programme, soleus (slow-twitch) muscles from trained rats had greater citrate synthase (CS) and catalase (CAT) activity compared with soleus muscles from untrained rats (P < 0.05). In contrast, CAT activity of extensor digitorum longus (EDL; fast-twitch) muscles from trained rats was not different to EDL muscles of untrained rats. The CS activity was lower in EDL muscles from trained compared with untrained rats (P < 0.05). 3. Equilibration with exogenous hydrogen peroxide (H2O2, 5 mmol/L) increased the Po of soleus muscles from untrained rats for the duration of treatment (30 min), whereas the Po of EDL muscles was affected biphasically, with a small increase initially (after 5 min), followed by a more marked decrease in Po (after 30 min). The H2O2-induced increase in Po of soleus muscles from trained rats was less than that in untrained rats (P < 0.05), but no differences were observed in the Po of EDL muscles following training. 4. The results indicate that 12 weeks endurance running training conferred adaptations in soleus but not EDL muscles. These adaptations were associated with an attenuation of the oxidant-induced increase in Po of soleus muscles from trained compared with untrained rats. We conclude that endurance training-adapted soleus muscles have a slightly altered redox-force relationship.
Collapse
MESH Headings
- Adaptation, Physiological
- Animals
- Antioxidants/metabolism
- Body Weight
- Catalase/metabolism
- Citrate (si)-Synthase/metabolism
- Hydrogen Peroxide/metabolism
- Muscle Contraction/physiology
- Muscle Fibers, Fast-Twitch/enzymology
- Muscle Fibers, Fast-Twitch/metabolism
- Muscle Fibers, Fast-Twitch/physiology
- Muscle Fibers, Slow-Twitch/enzymology
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle Fibers, Slow-Twitch/physiology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiology
- Oxidants/metabolism
- Oxidation-Reduction
- Physical Conditioning, Animal/physiology
- Physical Exertion/physiology
- Rats
Collapse
Affiliation(s)
- David R Plant
- Department of Physiology, The University of Melbourne, Victoria, Australia
| | | | | | | | | |
Collapse
|
21
|
Ryall JG, Gregorevic P, Plant DR, Sillence MN, Lynch GS. Beta 2-agonist fenoterol has greater effects on contractile function of rat skeletal muscles than clenbuterol. Am J Physiol Regul Integr Comp Physiol 2002; 283:R1386-94. [PMID: 12388476 DOI: 10.1152/ajpregu.00324.2002] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Potential treatments for skeletal muscle wasting and weakness ideally possess both anabolic and ergogenic properties. Although the beta(2)-adrenoceptor agonist clenbuterol has well-characterized effects on skeletal muscle, less is known about the therapeutic potential of the related beta(2)-adrenoceptor agonist fenoterol. We administered an equimolar dose of either clenbuterol or fenoterol to rats for 4 wk to compare their effects on skeletal muscle and tested the hypothesis that fenoterol would produce more powerful anabolic and ergogenic effects. Clenbuterol treatment increased fiber cross-sectional area (CSA) by 6% and maximal isometric force (P(o)) by 20% in extensor digitorum longus (EDL) muscles, whereas fiber CSA in soleus muscles decreased by 3% and P(o) was unchanged, compared with untreated controls. In the EDL muscles, fenoterol treatment increased fiber CSA by 20% and increased P(o) by 12% above values achieved after clenbuterol treatment. Soleus muscles of fenoterol-treated rats exhibited a 13% increase in fiber CSA and a 17% increase in P(o) above that of clenbuterol-treated rats. These data indicate that fenoterol has greater effects on the functional properties of rat skeletal muscles than clenbuterol.
Collapse
Affiliation(s)
- James G Ryall
- Department of Physiology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | | | | | | | | |
Collapse
|
22
|
Gregorevic P, Williams DA, Lynch GS. Hyperbaric oxygen increases the contractile function of regenerating rat slow muscles. Med Sci Sports Exerc 2002; 34:630-6. [PMID: 11932571 DOI: 10.1097/00005768-200204000-00011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED Human trials of hyperbaric oxygen (HBO) treatment of sports-related muscle injuries are equivocal. Although most human skeletal muscles are composed of mixed muscle fiber types, it is unclear whether HBO affects fiber types differently. PURPOSE We tested the hypothesis that HBO can enhance the functional properties of regenerating rat soleus muscles that are composed predominantly of slow fibers. METHODS After intramuscular injection of bupivacaine hydrochloride to induce the degeneration of all fibers within the soleus muscle, treated rats received daily HBO treatment at 3 atmospheres absolute. RESULTS In untreated rats, injured muscles demonstrated a reduced force-producing capacity (control soleus vs injured soleus, 220.3 +/- 2.5 vs 157.6 +/- 3.3 kN.m(-2) at 25 d postinjury, respectively, P < 0.05) and contained smaller regenerating muscle fibers than uninjured soleus muscles (fiber cross sectional area in control soleus vs injured soleus, 2289 +/- 164 vs 1154 +/- 92 microm 2 at 25 d postinjury, respectively, P < 0.05). The regenerating soleus muscles of HBO-treated rats demonstrated a greater force-producing capacity as a percentage of contralateral control muscles than the regenerating muscles from untreated rats at 14 d postinjury (regenerating HBO-soleus peak tension and untreated soleus peak tension, 42.9 +/- 1.9 and 35.8 +/- 3.9% of contralateral control muscles, respectively, P < 0.05), but no effect of treatment was observed at 25 d postinjury. CONCLUSION HBO enhanced the contractile properties of regenerating rat soleus muscles after myotoxic injury, but this improvement was not sustained for the duration of the regenerative process. The data indicate that the outcome of HBO treatment of a muscle injury may be influenced by the fiber type composition of the injured muscle.
Collapse
Affiliation(s)
- Paul Gregorevic
- Department of Physiology, The University of Melbourne, Victoria, Australia 3010
| | | | | |
Collapse
|
23
|
GREGOREVIC PAUL, WILLIAMS DAVIDA, LYNCH GORDONS. Hyperbaric oxygen increases the contractile function of regenerating rat slow muscles. Med Sci Sports Exerc 2002. [DOI: 10.1249/00005768-200204000-00011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
24
|
Plant DR, Lynch GS, Williams DA. Hydrogen peroxide increases depolarization-induced contraction of mechanically skinned slow twitch fibres from rat skeletal muscles. J Physiol 2002; 539:883-91. [PMID: 11897857 PMCID: PMC2290173 DOI: 10.1113/jphysiol.2001.013369] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The effect of exogenous hydrogen peroxide (H(2)O(2)) on excitation-contraction (E-C) coupling and sarcoplasmic reticulum (SR) function was compared in mechanically skinned slow twitch fibres (prepared from the soleus muscles) and fast twitch fibres (prepared from the extensor digitorum longus; EDL muscles) of adult rats. Equilibration (5 min) with 1 mM H(2)O(2) diminished the ability of the Ca(2+)-depleted SR to reload Ca(2+) in both slow (P < 0.01) and fast twitch fibres (P < 0.05) compared to control. Under conditions when all Ca(2+) uptake was prevented, 1 mM H(2)O(2) increased SR Ca(2+) "leak" in fast twitch fibres by 24 +/- 5 % (P < 0.05), but leak was not altered in slow twitch fibres. Treatment with 1 mM H(2)O(2) also increased the peak force of low [caffeine] contracture by approximately 45% in both fibre types compared to control (P < 0.01), which could be partly reversed following treatment with 10 mM dithiothreitol (DTT). The changes in SR function caused by 1 mM H(2)O(2) were associated with an approximately 65% increase in the peak height of depolarization-induced contractile response (DICR) in slow twitch fibres, compared to control (no H(2)O(2); P < 0.05). In contrast, peak contractile force of fast twitch fibres was not altered by 1 mM H(2)O(2) treatment. Equilibration with 5 mM H(2)O(2) induced a spontaneous force response in both slow and fast twitch fibres, which could be partly reversed by 2 min treatment with 10 mM DTT. Peak DICR was also increased approximately 40% by 5 mM H(2)O(2) in slow twitch fibres compared to control (no H(2)O(2); P < 0.05). Our results indicate that exogenous H(2)O(2) increases depolarization-induced contraction of mechanically skinned slow but not fast twitch fibres. The increase in depolarization-induced contraction in slow twitch fibres might be mediated by an increased SR Ca(2+) release during contraction and/or an increase in Ca(2+) sensitivity.
Collapse
Affiliation(s)
- David R Plant
- Department of Physiology, University of Melbourne, Victoria 3010, Australia
| | | | | |
Collapse
|
25
|
Annotated Patent Selections. Expert Opin Ther Pat 2002. [DOI: 10.1517/13543776.12.1.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
26
|
Plant DR, Lynch GS, Williams DA. Hydrogen peroxide modulates Ca2+-activation of single permeabilized fibres from fast- and slow-twitch skeletal muscles of rats. J Muscle Res Cell Motil 2001; 21:747-52. [PMID: 11392556 DOI: 10.1023/a:1010344008224] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We examined the effects of redox modulation on single membrane-permeabilized fibre segments from the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles of adult rats to determine whether the contractile apparatus was the redox target responsible for the increased contractility of muscles exposed to low concentrations of H2O2. The effects of H2O2 on maximum Ca2+-activated force were dose-dependent with 30 min exposure to 5 mM H2O2 causing a progressive decrease by 22+/-3 and 13+/-2% in soleus and EDL permeabilized muscle fibres, respectively. Lower concentrations of exogenous H2O2 (100 microM and 1 mM) had no effect on maximum Ca2+-activated force. Subsequent exposure to the reductant dithiothreitol (DTT, 10 mM, 10 min) fully reversed the H2O2-induced depression of force in EDL, but not in soleus muscle fibres. Incubation with DTT alone for 10 min did not alter Ca2+-activated force in either soleus or EDL muscle fibres. The sensitivity of the contractile filaments to Ca2+ (pCa50) was not altered by exposure to any concentration of exogenous H2O2. However, all concentrations of H2O2 diminished the Hill coefficient in permeabilized fibres from the EDL muscle, indicating that the cooperativity of Ca2+ binding to troponin is altered. H2O2 (5 mM) did not affect rigor force, which indicates that the number of crossbridges participating in contraction was not reduced. In conclusion, H2O2 may reduce the maximum Ca2+ activated force production in skinned muscle fibres by decreasing the force per crossbridge.
Collapse
Affiliation(s)
- D R Plant
- Department of Physiology, The University of Melbourne, Victoria, Australia
| | | | | |
Collapse
|