1
|
Kano R, Tabuchi A, Tanaka Y, Shirakawa H, Hoshino D, Poole DC, Kano Y. In vivo cytosolic H 2O 2 changes and Ca 2+ homeostasis in mouse skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2024; 326:R43-R52. [PMID: 37899753 DOI: 10.1152/ajpregu.00152.2023] [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: 06/22/2023] [Revised: 09/21/2023] [Accepted: 10/20/2023] [Indexed: 10/31/2023]
Abstract
Hydrogen peroxide (H2O2) and calcium ions (Ca2+) are functional regulators of skeletal muscle contraction and metabolism. Although H2O2 is one of the activators of the type-1 ryanodine receptor (RyR1) in the Ca2+ release channel, the interdependence between H2O2 and Ca2+ dynamics remains unclear. This study tested the following hypotheses using an in vivo model of mouse tibialis anterior (TA) skeletal muscle. 1) Under resting conditions, elevated cytosolic H2O2 concentration ([H2O2]cyto) leads to a concentration-dependent increase in cytosolic Ca2+ concentration ([Ca2+]cyto) through its effect on RyR1; and 2) in hypoxia (cardiac arrest) and muscle contractions (electrical stimulation), increased [H2O2]cyto induces Ca2+ accumulation. Cytosolic H2O2 (HyPer7) and Ca2+ (Fura-2) dynamics were resolved by TA bioimaging in young C57BL/6J male mice under four conditions: 1) elevated exogenous H2O2; 2) cardiac arrest; 3) twitch (1 Hz, 60 s) contractions; and 4) tetanic (30 s) contractions. Exogenous H2O2 (0.1-100 mM) induced a concentration-dependent increase in [H2O2]cyto (+55% at 0.1 mM; +280% at 100 mM) and an increase in [Ca2+]cyto (+3% at 1.0 mM; +8% at 10 mM). This increase in [Ca2+]cyto was inhibited by pharmacological inhibition of RyR1 by dantrolene. Cardiac arrest-induced hypoxia increased [H2O2]cyto (+33%) and [Ca2+]cyto (+20%) 50 min postcardiac arrest. Compared with the exogenous 1.0 mM H2O2 condition, [H2O2]cyto after tetanic muscle contractions rose less than one-tenth as much, whereas [Ca2+]cyto was 4.7-fold higher. In conclusion, substantial increases in [H2O2]cyto levels evoke only modest Ca2+ accumulation via their effect on the sarcoplasmic reticulum RyR1. On the other hand, contrary to hypoxia secondary to cardiac arrest, increases in [H2O2]cyto from muscle contractions are small, indicating that H2O2 generation is unlikely to be a primary factor driving the significant Ca2+ accumulation after, especially tetanic, muscle contractions.NEW & NOTEWORTHY We developed an in vivo mouse myocyte H2O2 imaging model during exogenous H2O2 loading, ischemic hypoxia induced by cardiac arrest, and muscle contractions. In this study, the interrelationship between cytosolic H2O2 levels and Ca2+ homeostasis during muscle contraction and hypoxic conditions was revealed. These results contribute to the elucidation of the mechanisms of muscle fatigue and exercise adaptation.
Collapse
Affiliation(s)
- Ryotaro Kano
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Research Fellowship for Young Scientists, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Ayaka Tabuchi
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Yoshinori Tanaka
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Hideki Shirakawa
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Daisuke Hoshino
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Japan
| | - David C Poole
- Departments of Anatomy and Physiology and Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - Yutaka Kano
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Japan
| |
Collapse
|
2
|
Watanabe D, Aibara C, Wada M. Treatment with EUK-134 improves sarcoplasmic reticulum Ca2+ release but not myofibrillar Ca2+ sensitivity after fatiguing contraction of rat fast-twitch muscle. Am J Physiol Regul Integr Comp Physiol 2019; 316:R543-R551. [DOI: 10.1152/ajpregu.00387.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Skeletal muscles undergoing vigorous activity can enter a state of prolonged low-frequency force depression (PLFFD). This study was conducted to examine whether antioxidant treatment is capable of accelerating the recovery from PLFFD, with a focus on the function of the sarcoplasmic reticulum (SR) and myofibril. One hour before fatiguing stimulation (FS) was administered, rats received an intraperitoneal injection of Eukarion (EUK-134), which mimics the activities of superoxide dismutase and catalase. Intact muscles of the hindlimbs were electrically stimulated via the sciatic nerve until the force was reduced to ~50% of the initial force (FS). Thirty minutes after cessation of FS, the superficial regions of gastrocnemius muscles were dissected and used for biochemical and skinned-fiber analyses. Whole muscle analyses revealed that antioxidant alleviated the FS-induced decrease in the reduced glutathione content. Skinned-fiber analyses showed that the antioxidant did not affect the FS-induced decrease in the ratio of force at 1 Hz to that at 50 Hz. However, the antioxidant partially inhibited the FS-mediated decrease in the ratio of depolarization-induced force to the maximum Ca2+-activated force. Furthermore, the antioxidant completely suppressed the FS-induced increase in myofibrillar Ca2+ sensitivity. These results suggest that antioxidant treatment is ineffective in facilitating the restoration of PLFFD, probably due to its negative effect on myofibrillar Ca2+ sensitivity, which supersedes its positive effect on SR Ca2+ release.
Collapse
Affiliation(s)
- Daiki Watanabe
- Department of Engineering Science, University of Electro-Communication, Tokyo, Japan
| | - Chihiro Aibara
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Masanobu Wada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| |
Collapse
|
3
|
Wiedenmann T, Dietrich N, Fleming T, Altamura S, Deelman LE, Henning RH, Muckenthaler MU, Nawroth PP, Hammes HP, Wagner AH, Hecker M. Modulation of glutathione peroxidase activity by age-dependent carbonylation in glomeruli of diabetic mice. J Diabetes Complications 2018; 32:130-138. [PMID: 29223856 DOI: 10.1016/j.jdiacomp.2017.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/09/2017] [Accepted: 11/18/2017] [Indexed: 12/29/2022]
Abstract
AIMS Low levels of reactive oxygen species and resulting oxidative protein modifications may play a beneficial role in cellular function under stress conditions. Here we studied the influence of age-dependent protein carbonylation on expression and activity of the anti-oxidative selenoenzyme glutathione peroxidase (GPx) in insulin-deficient Ins2Akita mice and type 2 diabetic obese db/db mice in context of diabetic nephropathy. METHODS Protein carbonylation, GPx expression and activity were examined in kidney tissue and lysates by common histological and protein biochemical methods. RESULTS In kidneys of Ins2Akita mice, carbonylated proteins, GPx-1 and GPx-4 expression were mainly detected in podocytes and mesangial cells. GPx activity was increased in kidney cortex homogenates of these mice. Remarkably, young animals did not show a concomitant increase in GPx expression but enhanced GPx carbonylation. No carbonylation-dependent modification of GPx activity was detected in db/db mice. In cultured podocytes hyperglycemia induced an increase in GPx expression but had no effect on activity or carbonylation. In kidney tissue sections of type 1 or type 2 diabetes patients, GPx-1 and GPx-4 expression but not overall protein carbonylation was significantly decreased. CONCLUSIONS These results indicate the existence of a threshold for beneficial carbonylation-dependent redox signaling during the progression of diabetic nephropathy.
Collapse
Affiliation(s)
- Tanja Wiedenmann
- Department of Cardiovascular Physiology, Heidelberg University, Germany
| | | | - Thomas Fleming
- Department of Internal Medicine I and Clinical Chemistry, Heidelberg University Hospital, Germany
| | - Sandro Altamura
- Department of Pediatric Hematology, Oncology and Immunology, Heidelberg University, Germany
| | - Leo E Deelman
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Rob H Henning
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Martina U Muckenthaler
- Department of Pediatric Hematology, Oncology and Immunology, Heidelberg University, Germany
| | - Peter P Nawroth
- Department of Internal Medicine I and Clinical Chemistry, Heidelberg University Hospital, Germany; German Center for Diabetes Research (DZD); Joint Heidelberg-IDC Translational Diabetes Program, Helmholtz-Zentrum, München, Germany
| | | | - Andreas H Wagner
- Department of Cardiovascular Physiology, Heidelberg University, Germany.
| | - Markus Hecker
- Department of Cardiovascular Physiology, Heidelberg University, Germany
| |
Collapse
|
4
|
Vázquez P, Tirado-Cortés A, Álvarez R, Ronjat M, Amaya A, Ortega A. Reversible oxidation of vicinal-thiols motif in sarcoplasmic reticulum calcium regulatory proteins is involved in muscle fatigue mechanism. Cell Calcium 2016; 60:245-55. [PMID: 27422341 DOI: 10.1016/j.ceca.2016.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 11/16/2022]
Abstract
The mechanism underlying fatigue in skeletal muscle (SM) related to the redox-potential hypothesis, ranges from a direct effect of oxygen reactive species, to a number of other free radical intermediates targeting specific amino acids in the Ca(2+)-regulatory proteins of the sarcoplasmic reticulum (SR). In the present study, we investigate the selective oxidation/reduction of the protein motif Cys-(Xn=2-6)-Cys, known as a vicinal thiol group (VTG), present in the SR Ca(2+)-ATPase (SERCA) and in the Ca(2+)-channel ryanodine receptor (RyR) which are modified during muscle fatigue in SM. Selective oxidation of VTG with phenyl arsine oxide (PAO) increases fatigue in rat isolated SM and fatigue is prevented when muscle is previously incubated with a VTG selective reducing agent, 2,3-dimercaptopropanol (British anti-Lewisite (BAL)). In isolated SR membranes, PAO [<0.1mM] modifies SERCA conformation and inhibits ATPase activity but does not affect Ca(2+)-release. However, PAO at [>0.1mM] inhibits SERCA and RyR activities in a reversible manner by selectively reducing them. Interestingly, as observed by differential scanning calorimetry, the conformation of SERCA from fatigued muscle changed in a similar manner as when SERCA VTG where oxidized. The addition of BAL to fatigued muscle restored the structural conformation and activity of SERCA with full recovery of muscle force production after fatigue. We conclude that VTG reversible oxidation of SR Ca(2+) regulatory proteins are involved in muscle contraction/relaxation and are a molecular mechanism to be considered for muscle fatigue.
Collapse
Affiliation(s)
- Pável Vázquez
- Department of Biochemistry and Molecular Biology, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico; Department of Toxicology and Pharmacology, Faculty of Chemistry, Universidad Autónoma del Estado de México, Mexico; Grenoble Institut des Neurosciences, Université Joseph Fourier, LabEx Ion Channel Science and Therapeutics, France
| | - Aldo Tirado-Cortés
- Department of Biochemistry and Molecular Biology, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Rocío Álvarez
- Department of Biochemistry and Molecular Biology, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Michel Ronjat
- Grenoble Institut des Neurosciences, Université Joseph Fourier, LabEx Ion Channel Science and Therapeutics, France
| | - Araceli Amaya
- Department of Toxicology and Pharmacology, Faculty of Chemistry, Universidad Autónoma del Estado de México, Mexico
| | - Alicia Ortega
- Department of Biochemistry and Molecular Biology, School of Medicine, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico; Department of Biochemistry, National Institute of Perinatology, Mexico.
| |
Collapse
|
5
|
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
|
6
|
Aoi W, Naito Y, Yoshikawa T. Role of oxidative stress in impaired insulin signaling associated with exercise-induced muscle damage. Free Radic Biol Med 2013; 65:1265-1272. [PMID: 24075894 DOI: 10.1016/j.freeradbiomed.2013.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 09/18/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
Abstract
Skeletal muscle is a major tissue that utilizes blood glucose. A single bout of exercise improves glucose uptake in skeletal muscle through insulin-dependent and insulin-independent signal transduction mechanisms. However, glucose utilization is decreased in muscle damage induced by acute, unaccustomed, or eccentric exercise. The decrease in glucose utilization is caused by decreased insulin-stimulated glucose uptake in damaged muscles with inhibition of the membrane translocation of glucose transporter 4 through phosphatidyl 3-kinase/Akt signaling. In addition to inflammatory cytokines, reactive oxygen species including 4-hydroxy-2-nonenal and peroxynitrate can induce degradation or inactivation of signaling proteins through posttranslational modification, thereby resulting in a disturbance in insulin signal transduction. In contrast, treatment with factors that attenuate oxidative stress in damaged muscle suppresses the impairment of insulin sensitivity. Muscle-damaging exercise may thus lead to decreased endurance capacity and muscle fatigue in exercise, and it may decrease the efficiency of exercise therapy for metabolic improvement.
Collapse
Affiliation(s)
- Wataru Aoi
- Laboratory of Health Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.
| | - Yuji Naito
- Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Toshikazu Yoshikawa
- Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| |
Collapse
|
7
|
Frohnert BI, Bernlohr DA. Protein carbonylation, mitochondrial dysfunction, and insulin resistance. Adv Nutr 2013; 4:157-63. [PMID: 23493532 PMCID: PMC3649096 DOI: 10.3945/an.112.003319] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Oxidative stress has been identified as a common mechanism for cellular damage and dysfunction in a wide variety of disease states. Current understanding of the metabolic changes associated with obesity and the development of insulin resistance has focused on the role of oxidative stress and its interaction with inflammatory processes at both the tissue and organismal level. Obesity-related oxidative stress is an important contributing factor in the development of insulin resistance in the adipocyte as well as the myocyte. Moreover, oxidative stress has been linked to mitochondrial dysfunction, and this is thought to play a role in the metabolic defects associated with oxidative stress. Of the various effects of oxidative stress, protein carbonylation has been identified as a potential mechanism underlying mitochondrial dysfunction. As such, this review focuses on the relationship between protein carbonylation and mitochondrial biology and addresses those features that point to either the causal or casual relationship of lipid peroxidation-induced protein carbonylation as a determining factor in mitochondrial dysfunction.
Collapse
|
8
|
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]
|
9
|
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]
|
10
|
Haramizu S, Ota N, Hase T, Murase T. Aging-associated changes in physical performance and energy metabolism in the senescence-accelerated mouse. J Gerontol A Biol Sci Med Sci 2011; 66:646-55. [PMID: 21415262 DOI: 10.1093/gerona/glr037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of the study was to clarify the aging-associated changes in physical performance and energy metabolism in senescence-accelerated prone mouse (SAMP1). The endurance of aged SAMP1 was significantly lower by 28% than the age-matched senescence-resistant mouse (SAMR1). Oxygen consumption and fat oxidation in aged SAMP1 were lower by 19% and 22%, respectively. Peroxisome proliferator-activated receptor-γ coactivator-1β and medium-chain acyl coenzyme A dehydrogenase messenger RNA expression was significantly lower in aged SAMP1. Aged SAMP1 exhibited higher plasma glucose, insulin, leptin, and lower adiponectin concentrations. Aged SAMP1 also had higher malondialdehyde levels in plasma and tissues and lower peroxisome proliferator-activated receptor-γ messenger RNA and protein levels in adipose tissue. These results indicate that physical performance and energy expenditure decrease earlier with aging in SAMP1, accompanied by decreased fatty acid catabolism in muscle and liver and increased inflammation and oxidative stress in adipose tissue. SAMP1 could thus be a useful accelerated functional depression model for studying physical performance and energy metabolism.
Collapse
Affiliation(s)
- Satoshi Haramizu
- Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan
| | | | | | | |
Collapse
|
11
|
Abstract
Relatively low levels of reactive oxygen species (ROS) produced inside resting skeletal muscles play important functions in cell signaling. When ROS production increases to levels beyond the buffering capacity of muscle antioxidant systems, a state of oxidative stress develops, which leads to skeletal muscle contractile dysfunction. A clear association between oxidative stress and depressed skeletal muscle performance has been described in several acute and chronic conditions, such as systemic inflammation and chronic obstructive lung diseases. The observation that the levels of oxidant-derived posttranslational protein modifications, including protein carbonylation, are elevated inside skeletal muscle fibers when oxidative stress develops suggest that these modifications play important roles in regulating muscle function. This proposal is supported by recent studies that unveiled that several myofilament (myosin heavy chain and actin), mitochondrial (aconitase, creatine kinase), and cytosolic (enolase, aldolase and glyceraldehyde 3-phosphate dehydrogenase and carbonic anhydrase III) proteins are carbonylated inside skeletal muscle fibers in many animal models of muscle dysfunction, and in humans with impaired skeletal muscle contractility. However, the functional importance of carbonylation in determining the function of muscle-specific proteins and the precise contribution of carbonylation-induced dysfunction of these proteins to overall muscle contractile deficit in various pathologies remain to be determined.
Collapse
Affiliation(s)
- Esther Barreiro
- Pulmonology Department, IMIM-Hospital del Mar, Catalonia, Spain
| | | |
Collapse
|
12
|
Mishima T, Kuratani M, Kanzaki K, Yamada T, Matsunaga S, Wada M. No relationship between enzyme activity and structure of nucleotide binding site in sarcoplasmic reticulum Ca(2+)-ATPase from short-term stimulated rat muscle. Acta Physiol (Oxf) 2009; 196:401-9. [PMID: 19302261 DOI: 10.1111/j.1748-1716.2009.01986.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM We examined whether structural alterations to the adenine nucleotide binding site (ANBS) within sarcoplasmic (endo) reticulum Ca(2+)-ATPase (SERCA) would account for contraction-induced changes in the catalytic activity of the enzyme as assessed in vitro. METHODS Repetitive contractions were induced in rat gastrocnemius by electrical nerve stimulation. Measurements of sarcoplasmic reticulum properties were performed on control and stimulated muscles immediately after or at 30 min after the cessation of 5-min stimulation. In order to examine the properties at the ANBS, the binding capacity of SERCA to fluorescence isothiocyanate (FITC), a competitive inhibitor at the ANBS, was analysed in microsomes. RESULTS Short-term electrical stimulation evoked a 23.9% and 32.6% decrease (P < 0.05) in SERCA activity and in the FITC binding capacity, respectively, in the superficial region of the muscle. Whereas SERCA activity reverted to normal levels during 30-min recovery, a restoration of the FITC binding capacity did not occur. CONCLUSION The discordant changes between the enzyme activity and the FITC binding suggest that, at least during recovery after exercise, changes in SERCA activity may not correlate closely with structural alterations to the ANBS within the enzyme.
Collapse
Affiliation(s)
- T Mishima
- Department of Pre-School Education, Hachinohe Junior College, Aomori, Japan
| | | | | | | | | | | |
Collapse
|
13
|
Álvarez R, Vázquez P, Pérez F, Jiménez A, Tirado A, Irles C, González-Serratos H, Ortega A. Regulation of fast skeletal muscle activity by SERCA1 vicinal-cysteines. J Muscle Res Cell Motil 2008; 30:5-16. [DOI: 10.1007/s10974-008-9156-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 11/25/2008] [Indexed: 11/25/2022]
|