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Chatel B, Ducreux S, Harhous Z, Bendridi N, Varlet I, Ogier AC, Bernard M, Gondin J, Rieusset J, Westerblad H, Bendahan D, Gineste C. Impaired aerobic capacity and premature fatigue preceding muscle weakness in the skeletal muscle Tfam-knockout mouse model. Dis Model Mech 2021; 14:272176. [PMID: 34378772 PMCID: PMC8461820 DOI: 10.1242/dmm.048981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/30/2021] [Indexed: 11/20/2022] Open
Abstract
Mitochondrial diseases are genetic disorders that lead to impaired mitochondrial function, resulting in exercise intolerance and muscle weakness. In patients, muscle fatigue due to defects in mitochondrial oxidative capacities commonly precedes muscle weakness. In mice, deletion of the fast-twitch skeletal muscle-specific Tfam gene (Tfam KO) leads to a deficit in respiratory chain activity, severe muscle weakness and early death. Here, we performed a time-course study of mitochondrial and muscular dysfunctions in 11- and 14-week-old Tfam KO mice, i.e. before and when mice are about to enter the terminal stage, respectively. Although force in the unfatigued state was reduced in Tfam KO mice compared to control littermates (wild type) only at 14 weeks, during repeated submaximal contractions fatigue was faster at both ages. During fatiguing stimulation, total phosphocreatine breakdown was larger in Tfam KO muscle than in wild-type muscle at both ages, whereas phosphocreatine consumption was faster only at 14 weeks. In conclusion, the Tfam KO mouse model represents a reliable model of lethal mitochondrial myopathy in which impaired mitochondrial energy production and premature fatigue occur before muscle weakness and early death. Summary: A time-course study of mitochondrial and muscular dysfunctions in a mouse model of mitochondrial myopathy reveals that decreased resistance to fatigue together with decreased oxidative capacities arise ahead of muscle weakness.
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Affiliation(s)
- Benjamin Chatel
- Aix-Marseille Université, CRMBM UMR CNRS 7339, 13385 Marseille, France.,CellMade, 73370 Le-Bourget-du-Lac, France
| | - Sylvie Ducreux
- CarMeN Laboratory, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite et F-69500 Bron, France
| | - Zeina Harhous
- CarMeN Laboratory, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite et F-69500 Bron, France
| | - Nadia Bendridi
- CarMeN Laboratory, INSERM, INRA, INSA Lyon, Université Claude Bernard Lyon 1, 69600 Oullins, France
| | - Isabelle Varlet
- Aix-Marseille Université, CRMBM UMR CNRS 7339, 13385 Marseille, France
| | - Augustin C Ogier
- Aix-Marseille Université, Université de Toulon, CNRS, LIS, 13397 Marseille, France
| | - Monique Bernard
- Aix-Marseille Université, CRMBM UMR CNRS 7339, 13385 Marseille, France
| | - Julien Gondin
- Institut NeuroMyoGène, UMR CNRS 5310 - INSERM U1217, Université Claude Bernard Lyon 1, F-69008 Lyon, France
| | - Jennifer Rieusset
- CarMeN Laboratory, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite et F-69500 Bron, France
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - David Bendahan
- Aix-Marseille Université, CRMBM UMR CNRS 7339, 13385 Marseille, France
| | - Charlotte Gineste
- Aix-Marseille Université, CRMBM UMR CNRS 7339, 13385 Marseille, France
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Korzeniewski B. Mechanisms of the effect of oxidative phosphorylation deficiencies on the skeletal muscle bioenergetic system in patients with mitochondrial myopathies. J Appl Physiol (1985) 2021; 131:768-777. [PMID: 34197225 DOI: 10.1152/japplphysiol.00196.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Simulations carried out using a previously developed model of the skeletal muscle bioenergetic system, involving the "inorganic phosphate (Pi) double-threshold" mechanism of muscle fatigue, lead to the conclusion that a decrease in the oxidative phosphorylation (OXPHOS) activity, caused by mutations in mitochondrial or nuclear DNA, is the main mechanism underlying the changes in the kinetic properties of the system in mitochondrial myopathies (MM). These changes generally involve the very-heavy-exercise-like behavior and exercise termination because of fatigue at low work intensities. In particular, a sufficiently large (at a given work intensity) decrease in OXPHOS activity leads to slowing of the primary phase II of the oxygen uptake (V̇o2) on-kinetics, decrease in maximal V̇o2 (V̇o2max), appearance of the slow component of the V̇o2 on-kinetics, exercise intolerance, and lactic acidosis at relatively low power outputs encountered in experimental studies in patients with MM. Thus, the "Pi double-threshold" mechanism of muscle fatigue is able to account, at least semiquantitatively, for various kinetic effects of inborn OXPHOS deficiencies of the skeletal muscle bioenergetic system. Exercise can be potentially lengthened and V̇o2max elevated in patients with MM through an increase in peak Pi (Pipeak), at which exercise is terminated because of fatigue. Generally, a mechanism underlying the kinetic effects of OXPHOS deficiencies on the skeletal muscle bioenergetic system in MM is proposed that was absent in the literature.NEW & NOTEWORTHY A mechanism of the OXPHOS deficiencies-induced changes of the skeletal muscle bioenergetic system in patients with mitochondrial myopathies (MM), namely, appearance of the slow component of the V̇o2 on-kinetics at relatively low work intensities, slowed primary phase II of the V̇o2 on-kinetics, lowered V̇o2max, and lactic acidosis is proposed. It involves a decrease in OXPHOS activity acting through the "Pi double-threshold" mechanism of muscle fatigue comprising initiation of the additional ATP usage and termination of exercise.
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Santos-Díaz A, Noseworthy MD. Phosphorus magnetic resonance spectroscopy and imaging (31P-MRS/MRSI) as a window to brain and muscle metabolism: A review of the methods. Biomed Signal Process Control 2020. [DOI: 10.1016/j.bspc.2020.101967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Meyerspeer M, Boesch C, Cameron D, Dezortová M, Forbes SC, Heerschap A, Jeneson JA, Kan HE, Kent J, Layec G, Prompers JJ, Reyngoudt H, Sleigh A, Valkovič L, Kemp GJ. 31 P magnetic resonance spectroscopy in skeletal muscle: Experts' consensus recommendations. NMR IN BIOMEDICINE 2020; 34:e4246. [PMID: 32037688 PMCID: PMC8243949 DOI: 10.1002/nbm.4246] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/01/2019] [Accepted: 12/02/2019] [Indexed: 05/07/2023]
Abstract
Skeletal muscle phosphorus-31 31 P MRS is the oldest MRS methodology to be applied to in vivo metabolic research. The technical requirements of 31 P MRS in skeletal muscle depend on the research question, and to assess those questions requires understanding both the relevant muscle physiology, and how 31 P MRS methods can probe it. Here we consider basic signal-acquisition parameters related to radio frequency excitation, TR, TE, spectral resolution, shim and localisation. We make specific recommendations for studies of resting and exercising muscle, including magnetisation transfer, and for data processing. We summarise the metabolic information that can be quantitatively assessed with 31 P MRS, either measured directly or derived by calculations that depend on particular metabolic models, and we give advice on potential problems of interpretation. We give expected values and tolerable ranges for some measured quantities, and minimum requirements for reporting acquisition parameters and experimental results in publications. Reliable examination depends on a reproducible setup, standardised preconditioning of the subject, and careful control of potential difficulties, and we summarise some important considerations and potential confounders. Our recommendations include the quantification and standardisation of contraction intensity, and how best to account for heterogeneous muscle recruitment. We highlight some pitfalls in the assessment of mitochondrial function by analysis of phosphocreatine (PCr) recovery kinetics. Finally, we outline how complementary techniques (near-infrared spectroscopy, arterial spin labelling, BOLD and various other MRI and 1 H MRS measurements) can help in the physiological/metabolic interpretation of 31 P MRS studies by providing information about blood flow and oxygen delivery/utilisation. Our recommendations will assist in achieving the fullest possible reliable picture of muscle physiology and pathophysiology.
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Affiliation(s)
- Martin Meyerspeer
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
- High Field MR CenterMedical University of ViennaViennaAustria
| | - Chris Boesch
- DBMR and DIPRUniversity and InselspitalBernSwitzerland
| | - Donnie Cameron
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- C. J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CentreLeidenthe Netherlands
| | - Monika Dezortová
- MR‐Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental MedicinePragueCzech Republic
| | - Sean C. Forbes
- Department of Physical TherapyUniversity of FloridaGainesvilleFloridaUSA
| | - Arend Heerschap
- Department of Radiology and Nuclear MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - Jeroen A.L. Jeneson
- Department of RadiologyAmsterdam University Medical Center|site AMCAmsterdamthe Netherlands
- Cognitive Neuroscience CenterUniversity Medical Center GroningenGroningenthe Netherlands
- Center for Child Development and Exercise, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Hermien E. Kan
- C. J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CentreLeidenthe Netherlands
- Duchenne CenterThe Netherlands
| | - Jane Kent
- Department of KinesiologyUniversity of Massachusetts AmherstMAUSA
| | - Gwenaël Layec
- Department of KinesiologyUniversity of Massachusetts AmherstMAUSA
- Institute for Applied Life SciencesUniversity of MassachusettsAmherstMAUSA
| | | | - Harmen Reyngoudt
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of Myology AIM‐CEAParisFrance
| | - Alison Sleigh
- Wolfson Brain Imaging CentreUniversity of CambridgeCambridgeUK
- Wellcome Trust‐MRC Institute of Metabolic ScienceUniversity of CambridgeCambridgeUK
- NIHR/Wellcome Trust Clinical Research FacilityCambridge University Hospitals NHS Foundation TrustCambridgeUK
| | - Ladislav Valkovič
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), RDM Cardiovascular Medicine, BHF Centre of Research ExcellenceUniversity of OxfordOxfordUK
- Department of Imaging MethodsInstitute of Measurement Science, Slovak Academy of SciencesBratislavaSlovakia
| | - Graham J. Kemp
- Department of Musculoskeletal Biology and Liverpool Magnetic Resonance Imaging Centre (LiMRIC)University of LiverpoolLiverpoolUK
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Unexplained exertional intolerance associated with impaired systemic oxygen extraction. Eur J Appl Physiol 2019; 119:2375-2389. [PMID: 31493035 DOI: 10.1007/s00421-019-04222-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 08/28/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE The clinical investigation of exertional intolerance generally focuses on cardiopulmonary diseases, while peripheral factors are often overlooked. We hypothesize that a subset of patients exists whose predominant exercise limitation is due to abnormal systemic oxygen extraction (SOE). METHODS We reviewed invasive cardiopulmonary exercise test (iCPET) results of 313 consecutive patients presenting with unexplained exertional intolerance. An exercise limit due to poor SOE was defined as peak exercise (Ca-vO2)/[Hb] ≤ 0.8 and VO2max < 80% predicted in the absence of a cardiac or pulmonary mechanical limit. Those with peak (Ca-vO2)/[Hb] > 0.8, VO2max ≥ 80%, and no cardiac or pulmonary limit were considered otherwise normal. The otherwise normal group was divided into hyperventilators (HV) and normals (NL). Hyperventilation was defined as peak PaCO2 < [1.5 × HCO3 + 6]. RESULTS Prevalence of impaired SOE as the sole cause of exertional intolerance was 12.5% (32/257). At peak exercise, poor SOE and HV had less acidemic arterial blood compared to NL (pHa = 7.39 ± 0.05 vs. 7.38 ± 0.05 vs. 7.32 ± 0.02, p < 0.001), which was explained by relative hypocapnia (PaCO2 = 29.9 ± 5.4 mmHg vs. 31.6 ± 5.4 vs. 37.5 ± 3.4, p < 0.001). For a subset of poor SOE, this relative alkalemia, also seen in mixed venous blood, was associated with a normal PvO2 nadir (28 ± 2 mmHg vs. 26 ± 4, p = 0.627) but increased SvO2 at peak exercise (44.1 ± 5.2% vs. 31.4 ± 7.0, p < 0.001). CONCLUSIONS We identified a cohort of patients whose exercise limitation is due only to systemic oxygen extraction, due to either an intrinsic abnormality of skeletal muscle mitochondrion, limb muscle microcirculatory dysregulation, or hyperventilation and left shift the oxyhemoglobin dissociation curve.
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Cordeiro AV, Silva VRR, Pauli JR, da Silva ASR, Cintra DE, Moura LP, Ropelle ER. The role of sphingosine-1-phosphate in skeletal muscle: Physiology, mechanisms, and clinical perspectives. J Cell Physiol 2018; 234:10047-10059. [PMID: 30523638 DOI: 10.1002/jcp.27870] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/15/2018] [Indexed: 12/21/2022]
Abstract
Sphingolipids were discovered more than a century ago and were simply considered as a class of cell membrane lipids for a long time. However, after the discovery of several intracellular functions and their role in the control of many physiological and pathophysiological conditions, these molecules have gained much attention. For instance, the sphingosine-1-phosphate (S1P) is a circulating bioactive sphingolipid capable of triggering strong intracellular reactions through the family of S1P receptors (S1PRs) spread in several cell types and tissues. Recently, the role of S1P in the control of skeletal muscle metabolism, atrophy, regeneration, and metabolic disorders has been widely investigated. In this review, we summarized the knowledge of S1P and its effects in skeletal muscle metabolism, highlighting the role of S1P/S1PRs axis in skeletal muscle regeneration, fatigue, ceramide accumulation, and insulin resistance. Finally, we discussed the physical exercise role in S1P/S1PRs signaling in skeletal muscle cells, and how this nonpharmacological strategy may be prospective for future investigations due to its ability to increase S1P levels.
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Affiliation(s)
- André V Cordeiro
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Vagner R R Silva
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - José R Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,School of Applied Sciences, Center of Research in Sport Sciences (CEPECE), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Adelino S R da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, USP, Ribeirão Preto, São Paulo, Brazil.,School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Dennys E Cintra
- Laboratory of Nutritional Genomics (LabGeN), School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil
| | - Leandro P Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,School of Applied Sciences, Center of Research in Sport Sciences (CEPECE), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo R Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,School of Applied Sciences, Center of Research in Sport Sciences (CEPECE), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.,Department of Internal Medicine, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Mitochondrial dysfunction in myotonic dystrophy type 1. Neuromuscul Disord 2017; 28:144-149. [PMID: 29289451 DOI: 10.1016/j.nmd.2017.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 11/20/2022]
Abstract
The pathophysiological mechanism linking the nucleotide expansion in the DMPK gene to the clinical manifestations of myotonic dystrophy type 1 (DM1) is still unclear. In vitro studies demonstrate DMPK involvement in the redox homeostasis of cells and the mitochondrial dysfunction in DM1, but in vivo investigations of oxidative metabolism in skeletal muscle have provided ambiguous results and have never been performed in the brain. Twenty-five DM1 patients (14M, 39 ± 11years) underwent brain proton MR spectroscopy (1H-MRS), and sixteen cases (9M, 40 ± 13 years old) also calf muscle phosphorus MRS (31P-MRS). Findings were compared to those of sex- and age-matched controls. Eight DM1 patients showed pathological increase of brain lactate and, compared to those without, had larger lateral ventricles (p < 0.01), smaller gray matter volumes (p < 0.05) and higher white matter lesion load (p < 0.05). A reduction of phosphocreatine/inorganic phosphate (p < 0.001) at rest and, at first minute of exercise, a lower [phosphocreatine] (p = 0.003) and greater [ADP] (p = 0.004) were found in DM1 patients compared to controls. The post-exercise indices of muscle oxidative metabolism were all impaired in DM1, including the increase of time constant of phosphocreatine resynthesis (TC PCr, p = 0.038) and the reduction of the maximum rate of mitochondrial ATP synthesis (p = 0.033). TC PCr values correlated with the myotonic area score (ρ = 0.74, p = 0.01) indicating higher impairment of muscle oxidative metabolism in clinically more affected patients. Our findings provide clear in vivo evidence of multisystem impairment of oxidative metabolism in DM1 patients, providing a rationale for targeted treatment enhancing energy metabolism.
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Valkovič L, Chmelík M, Krššák M. In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism. Anal Biochem 2017; 529:193-215. [PMID: 28119063 PMCID: PMC5478074 DOI: 10.1016/j.ab.2017.01.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 01/18/2023]
Abstract
In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.
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Affiliation(s)
- Ladislav Valkovič
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Oxford, United Kingdom; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia.
| | - Marek Chmelík
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Institute for Clinical Molecular MRI in Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria
| | - Martin Krššák
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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Fouré A, Wegrzyk J, Le Fur Y, Mattei JP, Boudinet H, Vilmen C, Bendahan D, Gondin J. Impaired mitochondrial function and reduced energy cost as a result of muscle damage. Med Sci Sports Exerc 2016; 47:1135-44. [PMID: 25371171 DOI: 10.1249/mss.0000000000000523] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE Although it has been largely acknowledged that isometric neuromuscular electrostimulation (NMES) exercise induces larger muscle damage than voluntary contractions, the corresponding effects on muscle energetics remain to be determined. Voluntary exercise-induced muscle damage (EIMD) has been reported to have minor slight effects on muscle metabolic response to subsequent dynamic exercise, but the magnitude of muscle energetics alterations for NMES EIMD has never been documented. METHODS ³¹P magnetic resonance spectroscopy measurements were performed in 13 young healthy males during a standardized rest-exercise-recovery protocol before (D0) and 2 d (D2) and 4 d (D4) after NMES EIMD on knee extensor muscles. Changes in kinetics of phosphorylated metabolite concentrations (i.e., phosphocreatine [PCr], inorganic phosphate [Pi], and adenosine triphosphate [ATP]) and pH were assessed to investigate aerobic and anaerobic rates of ATP production and energy cost of contraction (Ec). RESULTS Resting [Pi]/[PCr] ratio increased at D2 (+39%) and D4 (+29%), mainly owing to the increased [Pi] (+43% and +32%, respectively), whereas a significant decrease in resting pH was determined (-0.04 pH unit and -0.03 pH unit, respectively). PCr recovery rate decreased at D2 (-21%) and D4 (-23%) in conjunction with a significantly decreased total rate of ATP production at D4 (-18%) mainly owing to an altered aerobic ATP production (-19%). Paradoxically, Ec was decreased at D4 (-21%). CONCLUSION Overall, NMES EIMD led to intramuscular acidosis in resting muscle and mitochondrial impairment in exercising muscle. Alterations of noncontractile processes and/or adaptive mechanisms to muscle damage might account for the decreased Ec during the dynamic exercise.
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Affiliation(s)
- Alexandre Fouré
- 1Aix-Marseille University, Centre National de la Recherche Scientifique (CNRS), Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Unité Mixte de Recherche 7339, Marseille, FRANCE; 2Assistance Publique des Hôpitaux de Marseille (APHM), Sainte Marguerite Hospital, Department of Rheumatology, Marseille, FRANCE; and 3APHM, La Timone Hospital, Centre d'Exploration Métabolique par Résonance Magnétique (CEMEREM), Imaging Center, Marseille, FRANCE
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Rodan LH, Wells GD, Banks L, Thompson S, Schneiderman JE, Tein I. L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes) Syndrome. PLoS One 2015; 10:e0127066. [PMID: 25993630 PMCID: PMC4439047 DOI: 10.1371/journal.pone.0127066] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 04/10/2015] [Indexed: 11/23/2022] Open
Abstract
Objective To study the effects of L-arginine (L-Arg) on total body aerobic capacity and muscle metabolism as assessed by 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes) syndrome. Methods We performed a case control study in 3 MELAS siblings (m.3243A>G tRNAleu(UUR) in MTTL1 gene) with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO2peak) using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine. Results At baseline (no L-Arg), MELAS had lower serum Arg (p = 0.001). On 31P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr) (p = 0.05), decreased ATP (p = 0.018), and decreased intracellular Mg2+ (p = 0.0002) when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1) increase in mean % maximum work at anaerobic threshold (AT) (2) increase in % maximum heart rate at AT (3) small increase in VO2peak. On 31P-MRS the following mean trends were noted: (1) A blunted decrease in pH after exercise (less acidosis) (2) increase in Pi/PCr ratio (ADP) suggesting increased work capacity (3) a faster half time of PCr recovery (marker of mitochondrial activity) following 5 minutes of moderate intensity exercise (4) increase in torque. Significance These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study. Classification of Evidence Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects. Trial Registration ClinicalTrials.gov NCT01603446.
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Affiliation(s)
- Lance H. Rodan
- Division of Neurology, Dept. of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada, M5G 1X8
| | - Greg D. Wells
- Physiology and Experimental Medicine Program, Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada, M5G 1X8
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ont., Canada, M5G 1X8
| | - Laura Banks
- Physiology and Experimental Medicine Program, Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada, M5G 1X8
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ont., Canada, M5G 1X8
| | - Sara Thompson
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ont., Canada, M5G 1X8
| | - Jane E. Schneiderman
- Physiology and Experimental Medicine Program, Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada, M5G 1X8
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ont., Canada, M5G 1X8
| | - Ingrid Tein
- Division of Neurology, Dept. of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada, M5G 1X8
- Dept. of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ont., Canada, M5G 1X8
- * E-mail:
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Kemp GJ, Ahmad RE, Nicolay K, Prompers JJ. Quantification of skeletal muscle mitochondrial function by 31P magnetic resonance spectroscopy techniques: a quantitative review. Acta Physiol (Oxf) 2015; 213:107-44. [PMID: 24773619 DOI: 10.1111/apha.12307] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 12/30/2013] [Accepted: 04/23/2014] [Indexed: 12/16/2022]
Abstract
Magnetic resonance spectroscopy (MRS) can give information about cellular metabolism in vivo which is difficult to obtain in other ways. In skeletal muscle, non-invasive (31) P MRS measurements of the post-exercise recovery kinetics of pH, [PCr], [Pi] and [ADP] contain valuable information about muscle mitochondrial function and cellular pH homeostasis in vivo, but quantitative interpretation depends on understanding the underlying physiology. Here, by giving examples of the analysis of (31) P MRS recovery data, by some simple computational simulation, and by extensively comparing data from published studies using both (31) P MRS and invasive direct measurements of muscle O2 consumption in a common analytical framework, we consider what can be learnt quantitatively about mitochondrial metabolism in skeletal muscle using MRS-based methodology. We explore some technical and conceptual limitations of current methods, and point out some aspects of the physiology which are still incompletely understood.
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Affiliation(s)
- G. J. Kemp
- Department of Musculoskeletal Biology, and Magnetic Resonance and Image Analysis Research Centre; University of Liverpool; Liverpool UK
| | - R. E. Ahmad
- Department of Musculoskeletal Biology, and Magnetic Resonance and Image Analysis Research Centre; University of Liverpool; Liverpool UK
| | - K. Nicolay
- Biomedical NMR; Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven the Netherlands
| | - J. J. Prompers
- Biomedical NMR; Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven the Netherlands
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Heier CR, Guerron AD, Korotcov A, Lin S, Gordish-Dressman H, Fricke S, Sze RW, Hoffman EP, Wang P, Nagaraju K. Non-invasive MRI and spectroscopy of mdx mice reveal temporal changes in dystrophic muscle imaging and in energy deficits. PLoS One 2014; 9:e112477. [PMID: 25390038 PMCID: PMC4229202 DOI: 10.1371/journal.pone.0112477] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/04/2014] [Indexed: 01/16/2023] Open
Abstract
In Duchenne muscular dystrophy (DMD), a genetic disruption of dystrophin protein expression results in repeated muscle injury and chronic inflammation. Magnetic resonance imaging shows promise as a surrogate outcome measure in both DMD and rehabilitation medicine that is capable of predicting clinical benefit years in advance of functional outcome measures. The mdx mouse reproduces the dystrophin deficiency that causes DMD and is routinely used for preclinical drug testing. There is a need to develop sensitive, non-invasive outcome measures in the mdx model that can be readily translatable to human clinical trials. Here we report the use of magnetic resonance imaging and spectroscopy techniques for the non-invasive monitoring of muscle damage in mdx mice. Using these techniques, we studied dystrophic mdx muscle in mice from 6 to 12 weeks of age, examining both the peak disease phase and natural recovery phase of the mdx disease course. T2 and fat-suppressed imaging revealed significant levels of tissue with elevated signal intensity in mdx hindlimb muscles at all ages; spectroscopy revealed a significant deficiency of energy metabolites in 6-week-old mdx mice. As the mdx mice progressed from the peak disease stage to the recovery stage of disease, each of these phenotypes was either eliminated or reduced, and the cross-sectional area of the mdx muscle was significantly increased when compared to that of wild-type mice. Histology indicates that hyper-intense MRI foci correspond to areas of dystrophic lesions containing inflammation as well as regenerating, degenerating and hypertrophied myofibers. Statistical sample size calculations provide several robust measures with the ability to detect intervention effects using small numbers of animals. These data establish a framework for further imaging or preclinical studies, and they support the development of MRI as a sensitive, non-invasive outcome measure for muscular dystrophy.
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Affiliation(s)
- Christopher R. Heier
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D.C., United States of America
| | - Alfredo D. Guerron
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D.C., United States of America
| | - Alexandru Korotcov
- Department of Radiology, Howard University College of Medicine, Washington, D.C., United States of America
| | - Stephen Lin
- Department of Radiology, Howard University College of Medicine, Washington, D.C., United States of America
| | - Heather Gordish-Dressman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D.C., United States of America
- Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
| | - Stanley Fricke
- Department of Diagnostic Imaging and Radiology, Children's National Medical Center, Washington, D.C., United States of America
| | - Raymond W. Sze
- Department of Radiology, Children's National Medical Center, Washington, D.C., United States of America
| | - Eric P. Hoffman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D.C., United States of America
- Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
| | - Paul Wang
- Department of Radiology, Howard University College of Medicine, Washington, D.C., United States of America
- Department of Electrical Engineering, Fu Jen Catholic University, Taipei, Taiwan
| | - Kanneboyina Nagaraju
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, D.C., United States of America
- Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America
- * E-mail:
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Prompers JJ, Wessels B, Kemp GJ, Nicolay K. MITOCHONDRIA: investigation of in vivo muscle mitochondrial function by 31P magnetic resonance spectroscopy. Int J Biochem Cell Biol 2014; 50:67-72. [PMID: 24569118 DOI: 10.1016/j.biocel.2014.02.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/06/2014] [Accepted: 02/16/2014] [Indexed: 01/06/2023]
Abstract
The most important function of mitochondria is the production of energy in the form of ATP. The socio-economic impact of human diseases that affect skeletal muscle mitochondrial function is growing, and improving their clinical management critically depends on the development of non-invasive assays to assess mitochondrial function and monitor the effects of interventions. 31P magnetic resonance spectroscopy provides two approaches that have been used to assess in vivo ATP synthesis in skeletal muscle: measuring Pi→ATP exchange flux using saturation transfer in resting muscle, and measuring phosphocreatine recovery kinetics after exercise. However, Pi→ATP exchange does not represent net mitochondrial ATP synthesis flux and has no simple relationship with mitochondrial function. Post-exercise phosphocreatine recovery kinetics, on the other hand, yield reliable measures of muscle mitochondrial capacity in vivo, whose ability to define the site of functional defects is enhanced by combination with other non-invasive techniques.
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Affiliation(s)
- Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
| | - Bart Wessels
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Graham J Kemp
- Department of Musculoskeletal Biology and Magnetic Resonance & Image Analysis Research Centre, University of Liverpool, UK
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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14
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Golomb BA, Erickson LC, Scott-Van Zeeland AA, Koperski S, Haas RH, Wallace DC, Naviaux RK, Lincoln AJ, Reiner GE, Hamilton G. Assessing bioenergetic compromise in autism spectrum disorder with 31P magnetic resonance spectroscopy: preliminary report. J Child Neurol 2014; 29:187-93. [PMID: 24141271 PMCID: PMC3931549 DOI: 10.1177/0883073813498466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We sought to examine, via Phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) in a case-control design, whether bioenergetic deficits in autism spectrum disorders extend to the brain and muscle. Six cases with autism spectrum disorder with suspected mitochondrial dysfunction (age 6-18 years) and 6 age/sex-matched controls underwent (31)P magnetic resonance spectroscopy. The outcomes of focus were muscle resting phosphocreatine and intracellular pH as well as postexercise phosphocreatine recovery time constant and frontal brain phosphocreatine. Intracellular muscle pH was lower in each autism spectrum disorder case than their matched control (6/6, P = .03; P = .0048, paired t test). Muscle phosphocreatine (5/6), brain phosphocreatine (3/4), and muscle phosphocreatine recovery time constant (3/3) trends were in the predicted direction (not all participants completed each). This study introduces (31)P magnetic resonance spectroscopy as a noninvasive tool for assessment of mitochondrial function in autism spectrum disorder enabling bioenergetic assessment in brain and provides preliminary evidence suggesting that bioenergetic defects in cases with autism spectrum disorder are present in muscle and may extend to brain.
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Affiliation(s)
- Beatrice A. Golomb
- Department of Family and Preventive Medicine, University of
California, San Diego, La Jolla, CA, USA
| | - Laura C. Erickson
- Department of Family and Preventive Medicine, University of
California, San Diego, La Jolla, CA, USA
- Interdisciplinary Program in Neuroscience, Georgetown
University, Washington, DC, USA
| | | | - Sabrina Koperski
- Department of Family and Preventive Medicine, University of
California, San Diego, La Jolla, CA, USA
| | - Richard H. Haas
- Departments of Neuroscience and Pediatrics, University of
California, San Diego, La Jolla, CA, USA
| | - Douglas C. Wallace
- Department of Pathology and Laboratory Medicine, University of
Pennsylvania, Pittsburg, PA, USA
| | - Robert K. Naviaux
- Departments of Medicine, Pediatrics, and Pathology,
University of California, San Diego, La Jolla, CA, USA
| | - Alan J. Lincoln
- Alliant International University and Center for
Autism Research, Evaluation and Service, San Diego, La Jolla, CA, USA
| | - Gail E. Reiner
- Departments of Neuroscience and Pediatrics, University of
California, San Diego, La Jolla, CA, USA
| | - Gavin Hamilton
- Department of Radiology, University of California,
San Diego, La Jolla, CA, USA
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15
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Phillips AC, Sleigh A, McAllister CJ, Brage S, Carpenter TA, Kemp GJ, Holland AJ. Defective mitochondrial function in vivo in skeletal muscle in adults with Down's syndrome: a 31P-MRS study. PLoS One 2013; 8:e84031. [PMID: 24391872 PMCID: PMC3877137 DOI: 10.1371/journal.pone.0084031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/11/2013] [Indexed: 01/11/2023] Open
Abstract
Down's syndrome (DS) is a developmental disorder associated with intellectual disability (ID). We have previously shown that people with DS engage in very low levels of exercise compared to people with ID not due to DS. Many aspects of the DS phenotype, such as dementia, low activity levels and poor muscle tone, are shared with disorders of mitochondrial origin, and mitochondrial dysfunction has been demonstrated in cultured DS tissue. We undertook a phosphorus magnetic resonance spectroscopy ((31)P-MRS) study in the quadriceps muscle of 14 people with DS and 11 non-DS ID controls to investigate the post-exercise resynthesis kinetics of phosphocreatine (PCr), which relies on mitochondrial respiratory function and yields a measure of muscle mitochondrial function in vivo. We found that the PCr recovery rate constant was significantly decreased in adults with DS compared to non-DS ID controls (1.7 ± 0.1 min(-1) vs 2.1 ± 0.1 min(-1) respectively) who were matched for physical activity levels, indicating that muscle mitochondrial function in vivo is impaired in DS. This is the first study to investigate mitochondrial function in vivo in DS using (31)P-MRS. Our study is consistent with previous in vitro studies, supporting a theory of a global mitochondrial defect in DS.
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Affiliation(s)
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | | | - Soren Brage
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - T. Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Graham J. Kemp
- Department of Musculoskeletal Biology, University of Liverpool, Liverpool, United Kingdom
| | - Anthony J. Holland
- Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
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16
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Nachbauer W, Boesch S, Schneider R, Eigentler A, Wanschitz J, Poewe W, Schocke M. Bioenergetics of the calf muscle in Friedreich ataxia patients measured by 31P-MRS before and after treatment with recombinant human erythropoietin. PLoS One 2013; 8:e69229. [PMID: 23922695 PMCID: PMC3726701 DOI: 10.1371/journal.pone.0069229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 06/06/2013] [Indexed: 12/15/2022] Open
Abstract
Friedreich ataxia (FRDA) is caused by a GAA repeat expansion in the FXN gene leading to reduced expression of the mitochondrial protein frataxin. Recombinant human erythropoietin (rhuEPO) is suggested to increase frataxin levels, alter mitochondrial function and improve clinical scores in FRDA patients. Aim of the present pilot study was to investigate mitochondrial metabolism of skeletal muscle tissue in FRDA patients and examine effects of rhuEPO administration by phosphorus 31 magnetic resonance spectroscopy (31P MRS). Seven genetically confirmed FRDA patients underwent 31P MRS of the calf muscles using a rest-exercise-recovery protocol before and after receiving 3000 IU of rhuEPO for eight weeks. FRDA patients showed more rapid phosphocreatine (PCr) depletion and increased accumulation of inorganic phosphate (Pi) during incremental exercise as compared to controls. After maximal exhaustive exercise prolonged regeneration of PCR and slowed decline in Pi can be seen in FRDA. PCr regeneration as hallmark of mitochondrial ATP production revealed correlation to activity of complex II/III of the respiratory chain and to demographic values. PCr and Pi kinetics were not influenced by rhuEPO administration. Our results confirm mitochondrial dysfunction and exercise intolerance due to impaired oxidative phosphorylation in skeletal muscle tissue of FRDA patients. MRS did not show improved mitochondrial bioenergetics after eight weeks of rhuEPO exposition in skeletal muscle tissue of FRDA patients. Trial Registration EU Clinical Trials Register2008-000040-13
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Affiliation(s)
- Wolfgang Nachbauer
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Sylvia Boesch
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
- * E-mail:
| | - Rainer Schneider
- Department of Biochemistry, Leopold-Franzens-University Innsbruck, Innsbruck, Austria
| | - Andreas Eigentler
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Julia Wanschitz
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Michael Schocke
- Department of Radiology, Medical University Innsbruck, Innsbruck, Austria
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17
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Advanced MR methods at ultra-high field (7 Tesla) for clinical musculoskeletal applications. Eur Radiol 2012; 22:2338-46. [DOI: 10.1007/s00330-012-2508-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/02/2012] [Accepted: 05/04/2012] [Indexed: 12/16/2022]
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18
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Kan HE, Klomp DWJ, Wohlgemuth M, van Loosbroek-Wagemans I, van Engelen BGM, Padberg GW, Heerschap A. Only fat infiltrated muscles in resting lower leg of FSHD patients show disturbed energy metabolism. NMR IN BIOMEDICINE 2010; 23:563-568. [PMID: 20175146 DOI: 10.1002/nbm.1494] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Facioscapulohumeral muscular dystrophy (FSHD) is characterized by asymmetric dysfunctioning of individual muscles. Currently, it is unknown why specific muscles are affected before others and more particularly what pathophysiology is causing this differential progression. The aim of our study was to use a combination of (31)P magnetic resonance spectroscopic imaging (MRSI) and T1-weighted MRI to uncover metabolic differences in fat infiltrated and not fat infiltrated muscles in patients with FSHD. T1-weighted images and 3D (31)P MRSI were obtained from the calf muscles of nine patients with diagnosed FSHD and nine healthy age and sex matched volunteers. Muscles of patients were classified as fat infiltrated (PFM) and non fat-infiltrated (PNM) based on visual assessment of the MR images. Ratios of phosphocreatine (PCr), phosphodiesters (PDE) and inorganic phosphate (Pi) over ATP and tissue pH were compared between PFM and PNM and the same muscles in healthy volunteers. Of all patients, seven showed moderate to severe fatty infiltration in one or more muscles. In these muscles, decreases in PCr/ATP and increases in tissue pH were observed compared to the same muscles in healthy volunteers. Interestingly, these differences were absent in the PNM group. Our data show that differences in metabolite ratios and tissue pH in skeletal muscle between healthy volunteers and patients with FSHD appear to be specific for fat infiltrated muscles. Normal appearing muscles on T1 weighted images of patients showed normal phosphoryl metabolism, which suggests that in FSHD disease progression is truly muscle specific.
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Affiliation(s)
- H E Kan
- Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
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19
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Banerjee B, Sharma U, Balasubramanian K, Kalaivani M, Kalra V, Jagannathan NR. Effect of creatine monohydrate in improving cellular energetics and muscle strength in ambulatory Duchenne muscular dystrophy patients: a randomized, placebo-controlled 31P MRS study. Magn Reson Imaging 2010; 28:698-707. [PMID: 20395096 DOI: 10.1016/j.mri.2010.03.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 02/24/2010] [Accepted: 03/05/2010] [Indexed: 11/18/2022]
Abstract
Randomized, placebo-controlled single blinded study was carried out to evaluate the effect of oral creatine supplementation on cellular energetics, manual muscle test (MMT) score and functional status in steroid-naive, ambulatory boys suffering with Duchenne muscular dystrophy (DMD; n=33). Eighteen patients received creatine monohydrate (Cr; 5 g/day for 8 weeks), while 15 received placebo (500 mg of vitamin C). Phosphorus metabolite ratios were determined from the right calf muscle of patients using phosphorus magnetic resonance spectroscopy ((31)P MRS) both prior to (baseline) and after supplementation of Cr or placebo. In addition, metabolite ratios were determined in normal calf muscle of age and sex matched controls (n=8). Significant differences in several metabolite ratios were observed between controls and DMD patients indicating a lower energy state in these patients. Analysis using analysis of covariance adjusted for age and stature showed that the mean phosphocreatine (PCr)/inorganic phosphate (Pi) ratio in patients treated with Cr (4.7; 95% CI; 3.9-5.6) was significantly higher (P=.03) compared to the placebo group (3.3; 95% CI; 2.5-4.2). The mean percentage increase in PCr/Pi ratio was also more in patients <7 years of age compared to older patients after Cr supplementation indicating variation in therapeutic effect with the age. In the placebo group, significant reduction in PCr/Pi (P=.0009), PCr/t-ATP (P=.05) and an increase in phosphodiester (PDE)/PCr ratios was observed after supplementation. Further, in the placebo group, patients <7 years showed reduction of PCr/t-ATP and Pi/t-ATP compared to older patients (>7 years), after supplementation. These results imply that the significant difference observed in PCr/Pi ratio between the Cr and the placebo groups after supplementation may be attributed to a decrease of PCr in the placebo group and an increase in PCr in the Cr group. Changes in MMT score between the two groups was significant (P=.04); however, no change in functional scale (P=.19) was observed. Parents reported subjective improvement on Cr supplementation versus worsening in placebo (P=.02). Our results indicated that Cr was well tolerated and oral Cr significantly improved the muscle PCr/Pi ratio and preserved the muscle strength in short term. However, this study provides no evidence that creatine will prove beneficial after long-term treatment, or have any positive effect on patient lifespan.
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Affiliation(s)
- Bidisha Banerjee
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
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20
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Trevelyan AJ, Kirby DM, Smulders-Srinivasan TK, Nooteboom M, Acin-Perez R, Enriquez JA, Whittington MA, Lightowlers RN, Turnbull DM. Mitochondrial DNA mutations affect calcium handling in differentiated neurons. ACTA ACUST UNITED AC 2010; 133:787-96. [PMID: 20207702 PMCID: PMC2842518 DOI: 10.1093/brain/awq023] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mutations in the mitochondrial genome are associated with a wide range of neurological symptoms, but many aspects of the basic neuronal pathology are not understood. One candidate mechanism, given the well-established role of mitochondria in calcium buffering, is a deficit in neuronal calcium homoeostasis. We therefore examined calcium responses in the neurons derived from various ‘cybrid’ embryonic stem cell lines carrying different mitochondrial DNA mutations. Brief (∼50 ms), focal glutamatergic stimuli induced a transient rise in intracellular calcium concentration, which was visualized by bulk loading the cells with the calcium dye, Oregon Green BAPTA-1. Calcium entered the neurons through N-methyl-d-aspartic acid and voltage-gated calcium channels, as has been described in many other neuronal classes. Intriguingly, while mitochondrial mutations did not affect the calcium transient in response to single glutamatergic stimuli, they did alter the responses to repeated stimuli, with each successive calcium transient decaying ever more slowly in mitochondrial mutant cell lines. A train of stimuli thus caused intracellular calcium in these cells to be significantly elevated for many tens of seconds. These results suggest that calcium-handling deficits are likely to contribute to the pathological phenotype seen in patients with mitochondrial DNA mutations.
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Affiliation(s)
- Andrew J Trevelyan
- Mitochondrial Research Group, Institute for Ageing and Health Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, England.
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21
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Trattnig S, Friedrich KM, Bogner W, Welsch GH. Advanced musculoskeletal MRI at ultra-high field (7 T). ACTA ACUST UNITED AC 2010. [DOI: 10.2217/iim.09.26] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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van Elderen SG, Doornbos J, van Essen EH, Lemkes HH, Maassen JA, Smit JW, de Roos A. Phosphorus-31 magnetic resonance spectroscopy of skeletal muscle in maternally inherited diabetes and deafness A3243G mitochondrial mutation carriers. J Magn Reson Imaging 2009; 29:127-31. [DOI: 10.1002/jmri.21620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Jeppesen TD, Quistorff B, Wibrand F, Vissing J. 31P-MRS of skeletal muscle is not a sensitive diagnostic test for mitochondrial myopathy. J Neurol 2007; 254:29-37. [PMID: 17278044 DOI: 10.1007/s00415-006-0229-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Accepted: 03/15/2006] [Indexed: 11/25/2022]
Abstract
Clinical phenotypes of persons with mitochondrial DNA (mtDNA) mutations vary considerably. Therefore, diagnosing mitochondrial myopathy (MM) patients can be challenging and warrants diagnostic guidelines. (31)phosphorous magnetic resonance spectroscopy ((31)P-MRS) have been included as a minor diagnostic criterion for MM but the diagnostic strength of this test has not been compared with that of other commonly used diagnostic procedures for MM. To investigate this, we studied seven patients with single, large-scale deletions-, nine with point mutations of mtDNA and 14 healthy subjects, who were investigated for the following: 1) (31)P-MRS of lower arm and leg muscles before and after exercise, 2) resting and peak-exercise induced increases of plasma lactate, 3) muscle morphology and -mitochondrial enzyme activity, 4) maximal oxygen uptake (VO(2max)), 5) venous oxygen desaturation during handgrip exercise and 6) a neurological examination. All MM patients had clinical symptoms of MM, > 2% ragged red fibers in muscle, and impaired oxygen desaturation during handgrip. Fourteen of 16 patients had impaired VO(2max), 10/16 had elevated resting plasma lactate, and 10/11 that were investigated had impaired citrate synthase-corrected complex I activity. Resting PCr/P(i) ratio and leg P(i) recovery were lower in MM patients vs. healthy subjects. PCr and ATP production after exercise were similar in patients and healthy subjects. Although the specificity for MM of some (31)P-MRS variables was as high as 100%, the sensitivity was low (0-63%) and the diagnostic strength of (31)P-MRS was inferior to the other diagnostic tests for MM. Thus, (31)P-MRS should not be a routine test for MM, but may be an important research tool.
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Affiliation(s)
- Tina Dysgaard Jeppesen
- Neuromuscular Research Unit, Section 7611, National University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
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24
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Sharma U, Kumar V, Wadhwa S, Jagannathan NR. In vivo 31P MRS study of skeletal muscle metabolism in patients with postpolio residual paralysis. Magn Reson Imaging 2007; 25:244-9. [PMID: 17275621 DOI: 10.1016/j.mri.2006.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Accepted: 09/12/2006] [Indexed: 11/20/2022]
Abstract
The muscle metabolism of at-rest patients with varying degrees of postpolio residual paralysis (PPRP) was studied and compared with that of controls using in vivo phosphorus magnetic resonance spectroscopy. The phosphocreatine (PCr)/inorganic phosphate (Pi) and PCr/adenosine triphosphate ratios were lower in patients than in controls. Reduction in PCr/Pi suggests abnormalities in oxidative phosphorylation. A significant increase was observed in the phosphomonoester/PCr ratio in patients, indicating the accumulation of intermediary compounds of the glycolytic pathway. Furthermore, the phosphodiester/PCr ratio was also significantly increased in patients. In general, the observed changes in metabolite ratios were found to be related to the degree of residual paralysis, suggesting that metabolic changes are secondary to chronic neurogenic processes. These metabolic alterations appear to be the possible cause of energy deficit and underlying muscle fatigue in PPRP patients. The present results provide an insight into the metabolic impairment and degree of muscle damage in patients with PPRP.
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Affiliation(s)
- Uma Sharma
- Department of NMR, All India Institute of Medical Sciences, New Delhi 110029, India
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25
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Trenell MI, Sue CM, Thompson CH, Kemp GJ. Supplemental oxygen and muscle metabolism in mitochondrial myopathy patients. Eur J Appl Physiol 2007; 99:541-7. [PMID: 17219172 DOI: 10.1007/s00421-006-0372-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2006] [Indexed: 11/29/2022]
Abstract
Patients with mitochondrial myopathy (MM) have a reduced capacity to perform exercise due to a reduced oxidative capacity. We undertook this study to determine whether skeletal muscle metabolism could be improved with oxygen therapy in patients with MM. Six patients with MM and six controls, matched for age, gender and physical activity, underwent (31)P-magnetic resonance spectroscopy ((31)P-MRS) examination. (31)P-MR spectra were collected at rest and in series during exercise and recovery whilst breathing normoxic (0.21 O(2)) or hyperoxic (1.0 O(2)) air. At rest, MM showed an elevated [ADP] (18 +/- 3 micromol/l) and pH (7.03 +/- 0.01) in comparison to the control group (12 +/- 1 micromol/l, 7.01 +/- 0.01) (P < 0.05) consistent with mitochondrial dysfunction. Oxygen supplementation did not change resting metabolites in either MM or the control group (P > 0.05). Inferred maximal ATP synthesis rate improved by 33% with oxygen in MM (21 +/- 3 vs. 28 +/- 5 mmol/(l min), P < 0.05) but only improved by 5% in controls (40 +/- 3 vs. 42 +/- 3 mmol/(l min), P > 0.05). We conclude that oxygen therapy is associated with significant improvements in muscle metabolism in patients with MM. These data suggest that patients with MM could benefit from therapies which improve the provision of oxygen.
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Affiliation(s)
- Michael I Trenell
- Department of Neurogenetics, Kolling Institute for Medical Research, Sydney, Australia.
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26
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Chance B, Im J, Nioka S, Kushmerick M. Skeletal muscle energetics with PNMR: personal views and historic perspectives. NMR IN BIOMEDICINE 2006; 19:904-26. [PMID: 17075955 DOI: 10.1002/nbm.1109] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This article reviews historical and current NMR approaches to describing in vivo bioenergetics of skeletal muscles in normal and diseased populations. It draws upon the first author's more than 70 years of personal experience in enzyme kinetics and the last author's physiological approaches. The development of in vivo PNMR jointly with researchers around the world is described. It is explained how non-invasive PNMR has advanced human exercise biochemistry, physiology and pathology. Further, after a brief explanation of bioenergetics with PNMR on creatine kinase, anerobic glycolysis and mitochondrial oxidative phosphorylation, some basic and controversial subjects are focused upon, and the authors' view of the subjects are offered, with questions and answers. Some of the research has been introduced in exercise physiology. Future directions of NMR on bioenergetics, as a part of system biological approaches, are indicated.
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Affiliation(s)
- Britton Chance
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
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Slade JM, Towse TF, Delano MC, Wiseman RW, Meyer RA. A gated 31P NMR method for the estimation of phosphocreatine recovery time and contractile ATP cost in human muscle. NMR IN BIOMEDICINE 2006; 19:573-80. [PMID: 16642462 DOI: 10.1002/nbm.1037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Muscle phosphocreatine (PCr) recovery time constant (an index of muscle aerobic capacity) and contractile ATP cost were estimated from a gated (31)P NMR protocol which does not require intense, repetitive exercise. Subjects performed 2-s duration, maximum voluntary isometric ankle dorsiflexion contractions at 30-s intervals for 8 min (total 15 contractions), while single-shot (31)P spectra (51.7 MHz, TR 3 s) were acquired from the anterior compartment muscle. Spectra from the sixth through 15th contractions were retrospectively sorted, yielding 10 spectra (each 10 averages) gated to times before and after contraction. There was no significant decrease in muscle pH, allowing the calculation of contractile ATP cost directly from the percentage change in PCr during contraction cycles [8.86 +/- 0.82% (SE, n = 11) of PCr at rest], corresponding to an ATP cost of 1.69 +/- 0.16 mM/s (range 0.99-2.49 mM/s), assuming an 8.2 mM ATP concentration. The time constant for PCr recovery (tau 41.8 +/- 4.2 s, range 22.0-60.8 s) was calculated from tau = -Deltat/ln[D/(D + Q)], where Q is the percentage change in PCr due to contraction, D is the additional steady-state percentage drop in PCr from rest and Deltat is the interval between contractions. In the same subjects, the monoexponential PCr recovery time constant after more intense, repetitive isometric ankle dorsiflexion exercise (30 s at 0.5 Hz, 50% duty cycle) was similar to (36.2 +/- 3.5 s, range 16.5-58.8 s) and well correlated with (r = 0.82) the gated result. In contrast to the gated protocol, muscle pH decreased from 7.01 +/- 0.01 to 6.78 +/- 0.04 during recovery after the repetitive protocol. Hence the gated protocol allows the estimation of muscle ATP cost and PCr recovery without intense exercise or muscle acidification.
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Affiliation(s)
- Jill M Slade
- Department of Osteopathic Manipulative Medicine, Michigan State University, East Lansing, 48824, USA
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Hanisch F, Müller T, Muser A, Deschauer M, Zierz S. Lactate increase and oxygen desaturation in mitochondrial disorders – Evaluation of two diagnostic screening protocols. J Neurol 2006; 253:417-23. [PMID: 16619117 DOI: 10.1007/s00415-006-0987-0] [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] [Received: 04/23/2005] [Revised: 07/04/2005] [Accepted: 07/13/2005] [Indexed: 10/24/2022]
Abstract
BACKGROUND Mitochondrial disorders are characterized by an accumulation of lactate and an insufficient oxygen extraction from blood during exercise. Therefore, both parameters (lactate and oxygen saturation) can be used as screening tests in mitochondrial disorders. However, conflicting results regarding sensitivities and specifities of both tests have been reported. METHOD We examined 27 patients with genetically defined mitochondrial disorders (single deletions n = 15, multiple deletions n = 5, A3243G mutation n = 7), patients with other neuromuscular disorders, and healthy controls. In the first test subjects performed intermittent isometric handgrip exercise (0.5 Hz) at 80% (3 minutes) and 30% (3 and 15 minutes) of maximal contraction force (MCF). Oxygen saturation and partial pressure in cubital venous blood from the exercising arm were measured. In the second test subjects underwent cycle ergometry at 30 W for 15 minutes. Venous lactate at rest, during and 15 minutes postexercise was determined. RESULT Both tests showed specificities of 92-96%. Sensitivities for changes of venous oxygen partial pressure and oxygen saturation ranged from 21-26% at 80% MCF for 3 minutes to 47-58% at 30% MCF for 15 minutes. Sensitivities for venous resting, peak, and post-exercise lactate was 33%, 58%, and 67%, respectively. The degree of deoxygenation, however,was independent of the intensity and duration of the applied forces. Oxygen desaturation and lactate increase in patients with mitochondrial disorders were not different in patients with and without clinical symptoms of myopathy. There were significant correlations between the heteroplasmy and both the degree of oxygen desaturation and lactate increase in patients with single deletions. In patients who performed both protocols (n = 16) a combination of both tests increased sensitivity up to 87%. CONCLUSION Oxygen desaturation in forearm exercise tests and lactate increase in cycle ergometry tests show a high specifity but only moderate sensitivity. Combination of the two screening test clearly increases the sensitivity.
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Affiliation(s)
- Frank Hanisch
- Klinik und Poliklinik für Neurologie, Martin-Luther-Universität, Halle-Wittenberg, Ernst-Grube Str. 40, 06097, Halle/Saale, Germany.
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Trenell MI, Sue CM, Kemp GJ, Sachinwalla T, Thompson CH. Aerobic exercise and muscle metabolism in patients with mitochondrial myopathy. Muscle Nerve 2006; 33:524-31. [PMID: 16372322 DOI: 10.1002/mus.20484] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Exercise therapy improves mitochondrial function in patients with mitochondrial myopathy (MM). We undertook this study to determine the metabolic abnormalities that are improved by exercise therapy. This study identified metabolic pathology using (31)P-magnetic resonance spectroscopy and magnetic resonance imaging (MRI) in a group of patients with MM compared to a control group matched for age, gender, and physical activity. We also observed the effect of exercise therapy for 12 weeks on muscle metabolism and physical function in the MM group. During muscle activity, there was impaired responsiveness of the mitochondria to changes in cytosolic adenosine diphosphate concentration, increased dependence on anaerobic energy pathways, and an adaptive increase in proton efflux in patients with MM. Following exercise therapy, mitochondrial function and muscle mass improved without any change in proton efflux rate. These metabolic findings were accompanied by improvements in functional ability. We conclude that there are significant metabolic differences between patients with MM and a control population, independent of age, gender, and physical activity. Exercise therapy can assist in improving mitochondrial function in MM patients.
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Affiliation(s)
- Michael I Trenell
- School of Molecular and Microbial Bioscience, University of Sydney, Sydney, Australia
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30
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Saft C, Zange J, Andrich J, Müller K, Lindenberg K, Landwehrmeyer B, Vorgerd M, Kraus PH, Przuntek H, Schöls L. Mitochondrial impairment in patients and asymptomatic mutation carriers of Huntington's disease. Mov Disord 2005; 20:674-9. [PMID: 15704211 DOI: 10.1002/mds.20373] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disorder caused by a CAG repeat expansion in the IT-15 gene; however, it remains unknown how the mutation leads to selective neurodegeneration. Several lines of evidence suggest impaired mitochondrial function as a component of the neurodegenerative process in HD. We assessed energy metabolism in the skeletal muscle of 15 HD patients and 12 asymptomatic mutation carriers in vivo using 31P magnetic resonance spectroscopy. Phosphocreatine recovery after exercise is a direct measure of ATP synthesis and was slowed significantly in HD patients and mutation carriers in comparison to age- and gender-matched healthy controls. We found that oxidative function is impaired to a similar extent in manifest HD patients and asymptomatic mutation carriers. Our findings suggest that mitochondrial dysfunction is an early and persistent component of the pathophysiology of HD.
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Affiliation(s)
- Carsten Saft
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, Germany
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31
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Kornblum C, Schröder R, Müller K, Vorgerd M, Eggers J, Bogdanow M, Papassotiropoulos A, Fabian K, Klockgether T, Zange J. Creatine has no beneficial effect on skeletal muscle energy metabolism in patients with single mitochondrial DNA deletions: a placebo-controlled, double-blind 31P-MRS crossover study. Eur J Neurol 2005; 12:300-9. [PMID: 15804248 DOI: 10.1111/j.1468-1331.2004.00970.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of our randomized, double-blind, placebo-controlled crossover study in 15 patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) because of single large-scale mitochondrial (mt) DNA deletions was to determine whether oral creatine (Cr) monohydrate can improve skeletal muscle energy metabolism in vivo. Each treatment phase with Cr in a dosage of 150 mg/kg body weight/day or placebo lasted 6 weeks. The effect of Cr was estimated by phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS), clinical and laboratory tests. (31)P-MRS analysis prior to treatment showed clear evidence of severe mitochondrial dysfunction. However, there were no relevant changes in (31)P-MRS parameters under Cr. In particular, phosphocreatine (PCr)/ATP at rest did not increase, and there was no facilitation of post-exercise PCr recovery. Clinical scores and laboratory tests did not alter significantly under Cr, which was tolerated without major side-effects in all patients. Cr supplementation did not improve skeletal muscle oxidative phosphorylation in our series of patients. However, one explanation for our negative findings may be the short study duration or the limited number of patients included.
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Affiliation(s)
- C Kornblum
- Department of Neurology, University of Bonn, Bonn, Germany.
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32
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Möller HE, Kurlemann G, Pützler M, Wiedermann D, Hilbich T, Fiedler B. Magnetic resonance spectroscopy in patients with MELAS. J Neurol Sci 2004; 229-230:131-9. [PMID: 15760631 DOI: 10.1016/j.jns.2004.11.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Localized magnetic resonance spectroscopy (MRS) yields sensitive metabolic markers to provide insight into the pathophysiology of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) in vivo. Findings in full MELAS syndrome at 1H MRS of the brain typically include severely elevated lactate and reduced N-acetylaspartate, glutamate, myo-inositol, and total creatine concentrations in stroke-like lesions. Similar but less extreme alterations are also common in gray matter (GM) regions that appear normal at magnetic resonance imaging. Phosphorus spectroscopy of peripheral muscle permits investigation of the bioenergetic status. A decline of the phosphorylation potential indicates a low energy reserve at rest. Phosphocreatine resynthesis during post-exercise recovery is delayed pointing to reduced mitochondrial capacity. As MRS is inherently non-invasive, follow-up studies can be performed to assess treatment response quantitatively.
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Affiliation(s)
- Harald E Möller
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1A, 04103 Leipzig, Germany.
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33
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Vaux EC, Taylor DJ, Altmann P, Rajagopalan B, Graham K, Cooper R, Bonomo Y, Styles P. Effects of Carnitine Supplementation on Muscle Metabolism by the Use of Magnetic Resonance Spectroscopy and Near-Infrared Spectroscopy in End-Stage Renal Disease. ACTA ACUST UNITED AC 2004; 97:c41-8. [PMID: 15218329 DOI: 10.1159/000078399] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2003] [Accepted: 12/22/2003] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIM A defect in skeletal muscle mitochondrial metabolism develops in patients with chronic renal failure on haemodialysis. Treatment with carnitine, a compound essential for normal mitochondrial function, has been suggested to have significant benefits in such patients, so we carried out a study to see if carnitine acts by improving muscle bioenergetics and function. METHODS In a phase II randomised double-blind trial, patients with end-stage renal disease received placebo or intravenous L-carnitine (20 mg/kg dry body weight three times weekly after haemodialysis) for 16 weeks (n = 13 in each group). 31P magnetic resonance spectroscopy, 1H magnetic resonance imaging and near-infrared spectroscopy were used to measure muscle bioenergetics and function at baseline and at 16 weeks. RESULTS There were no significant differences between groups at baseline. Mean plasma carnitine rose 10-fold in the carnitine group but was unchanged in the placebo group. L-carnitine had no statistically significant effect on any of the parameters measured. The rate of proton efflux from muscle, as a measure of tissue perfusion, was low in both groups and was not affected by treatment. CONCLUSIONS The study failed to show any significant effect of 16 weeks' L-carnitine supplementation on these objective measures of muscle metabolism and function. Slow proton efflux from muscle provides evidence supporting low blood flow and, therefore, decreased oxygen availability, as an underlying mechanism for muscle mitochondrial dysfunction in this disorder.
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Affiliation(s)
- E C Vaux
- Oxford Kidney Unit, Churchill Hospital, Headington, UK
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Lindholm H, Löfberg M, Somer H, Näveri H, Sovijärvi A. Abnormal blood lactate accumulation after exercise in patients with multiple mitochondrial DNA deletions and minor muscular symptoms. Clin Physiol Funct Imaging 2004; 24:109-15. [PMID: 15056184 DOI: 10.1111/j.1475-097x.2004.00531.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
STUDY OBJECTIVES Muscle is one of the most commonly affected organs in mitochondrial disorders, and the symptoms are often exercise related. The cardiopulmonary exercise test with the determination of lactic acid formation could give supplementary information about the exercise-induced metabolic stress and compensatory mechanisms used in these disorders. The aim of this study was to evaluate the exercise capacity and lactate kinetics related to exercise in subjects with two genetically characterized mitochondrial disorders (multiple mitochondrial DNA deletions with PEO, MELAS) compared with lactate kinetics in subjects with metabolic myopathy (McArdle's disease) and in the healthy controls. DESIGN The subjects were consecutive, co-operative patients of Department of Neurology of Helsinki University Hospital. Molecular genetic analyses were used for group classification of the mitochondrial myopathy. STUDY SUBJECTS The study groups consisted of 11 patients with multiple deletions (PEO) and five patients with a point mutation in the mitochondrial DNA (MELAS), four patients with a muscle phosphorylase enzyme deficiency (McArdle's disease) and 13 healthy controls. The clinical disease of the patients was relatively mild. MEASUREMENTS AND RESULTS A graded exercise test with ventilatory gas analyses and venous blood lactic acid analyses was performed. The main finding was the prolonged accumulation of blood lactate after the exercise in the PEO and MELAS groups compared with the controls. An overcompensation in ventilation was found in the MELAS and PEO group. CONCLUSIONS The blood lactate accumulation after exercise occurs in patients with multiple mitochondrial DNA deletions or MELAS even in patients with only mild exercise intolerance. Cardiopulmonary exercise can be used in the diagnostic process of patients with mitochondrial myopathies.
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Affiliation(s)
- Harri Lindholm
- Laboratory Department, Division of Clinical Physiology, Helsinki University Hospital, Helsinki, Finland.
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35
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Tarnopolsky MA, Simon DK, Roy BD, Chorneyko K, Lowther SA, Johns DR, Sandhu JK, Li Y, Sikorska M. Attenuation of free radical production and paracrystalline inclusions by creatine supplementation in a patient with a novel cytochrome b mutation. Muscle Nerve 2004; 29:537-47. [PMID: 15052619 DOI: 10.1002/mus.20020] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mitochondrial cytopathies are associated with increased free radical generation and paracrystalline inclusions. Paracrystalline inclusions were serendipitously found in a young male athlete with a very high respiratory exchange ratio during steady-state exercise; he also had an unusually low aerobic capacity. Direct sequencing of the mitochondrial DNA (mtDNA) coding regions revealed a novel missense mutation (G15497A) resulting in a glycine-->serine conversion at a highly conserved site in the cytochrome b gene in the subject, his mother, and sister. Cybrids, prepared by fusion of the subject's platelets with either U87MG rho degrees or SH-SY5Y rho degrees cells, generated higher basal levels of reactive oxygen species (ROS), had a lower adenosine triphosphate (ATP) content, and were more sensitive to oxygen and glucose deprivation and peroxynitrite generation compared to control cybrids with wild-type mtDNA. Cell survival was significantly enhanced with 50 mmol/L creatine monohydrate (CM) administration. The subject was also treated with CM (10 g/d) for a period of 5 weeks and a repeat muscle biopsy showed no paracrystalline inclusions. The results suggest that the development of exercise-induced paracrystalline inclusions may be influenced by the G15497A mtDNA mutation, and that CM mitigates against the pathological consequences of this mutation.
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Affiliation(s)
- Mark A Tarnopolsky
- Department of Medicine, McMaster University Medical Center, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.
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Bendahan D, Mattei JP, Ghattas B, Confort-Gouny S, Le Guern ME, Cozzone PJ. Citrulline/malate promotes aerobic energy production in human exercising muscle. Br J Sports Med 2002; 36:282-9. [PMID: 12145119 PMCID: PMC1724533 DOI: 10.1136/bjsm.36.4.282] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Previous studies have shown an antiasthenic effect of citrulline/malate (CM) but the mechanism of action at the muscular level remains unknown. OBJECTIVE To investigate the effects of CM supplementation on muscle energetics. METHODS Eighteen men complaining of fatigue but with no documented disease were included in the study. A rest-exercise (finger flexions)-recovery protocol was performed twice before (D-7 and D0), three times during (D3, D8, D15), and once after (D22) 15 days of oral supplementation with 6 g/day CM. Metabolism of the flexor digitorum superficialis was analysed by (31)P magnetic resonance spectroscopy at 4.7 T. RESULTS Metabolic variables measured twice before CM ingestion showed no differences, indicating good reproducibility of measurements and no learning effect from repeating the exercise protocol. CM ingestion resulted in a significant reduction in the sensation of fatigue, a 34% increase in the rate of oxidative ATP production during exercise, and a 20% increase in the rate of phosphocreatine recovery after exercise, indicating a larger contribution of oxidative ATP synthesis to energy production. Considering subjects individually and variables characterising aerobic function, extrema were measured after either eight or 15 days of treatment, indicating chronological heterogeneity of treatment induced changes. One way analysis of variance confirmed improved aerobic function, which may be the result of an enhanced malate supply activating ATP production from the tricarboxylic acid cycle through anaplerotic reactions. CONCLUSION The changes in muscle metabolism produced by CM treatment indicate that CM may promote aerobic energy production.
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Affiliation(s)
- D Bendahan
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS 6612, Faculté de Médecine de la Timone, 27 Boulevard Jean Moulin, 13005 Marseille, France
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37
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Möller HE, Wiedermann D, Kurlemann G, Hilbich T, Schuierer G. Application of NMR spectroscopy to monitoring MELAS treatment: a case report. Muscle Nerve 2002; 25:593-600. [PMID: 11932978 DOI: 10.1002/mus.10084] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
1H magnetic resonance spectroscopy (MRS) of the brain and (31)P MRS and saturation transfer of resting skeletal muscle were used to investigate intracellular metabolites and fluxes through the creatine kinase (CK) reaction in a patient with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). Acute cortical lesions were characterized by severely elevated lactate levels and reduced concentrations of N-acetylaspartyl compounds, glutamate, and myo-inositol. Similar but less extreme alterations were also observed in gray matter regions that appeared normal on magnetic resonance images. Investigation of the gastrocnemius muscle at rest demonstrated a reduced phosphocreatine level, elevated concentrations of inorganic phosphate and free adenosine 5'-diphosphate, and an abnormally low phosphorylation potential. Besides a moderately increased muscular phosphocreatine concentration, none of the metabolic disturbances detected on MRS improved with oral creatine supplementation. Forward and reverse fluxes through the CK reaction did not significantly change upon creatine treatment. Follow-up MRS investigations may thus provide objective markers of treatment response in vivo without the hazards or inconvenience of biopsy.
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Affiliation(s)
- Harald E Möller
- Institut für Physikalische Chemie, Universität Münster, Münster, Germany.
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38
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Chen JT, Taivassalo T, Argov Z, Arnold DL. Modeling in vivo recovery of intracellular pH in muscle to provide a novel index of proton handling: application to the diagnosis of mitochondrial myopathy. Magn Reson Med 2001; 46:870-8. [PMID: 11675637 DOI: 10.1002/mrm.1271] [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: 11/07/2022]
Abstract
Post-exercise recovery of intracellular pH (pH(i)) assessed using phosphorus magnetic resonance spectroscopy has not been previously evaluated in its entirety due to its complex time-course and missing data points resulting from a transient loss of inorganic phosphate signal. By considering the transition from exercise to recovery as a step function input, pH(i) recovery was modeled based on the creatine-kinase equilibrium, and the entire pH(i) recovery was characterized by calculating the time required for pH(i) recovery (t(pHrec)). Applying this methodology, normal subjects showed a strong linear correlation between phosphocreatine (PCr) half-time and t(pHrec) (r = 0.90, P < 0.001). In mitochondrial myopathy (MM) patients with weakness in the limb examined, 9/10 had faster pH(i) recovery relative to PCr recovery; wide normal ranges from a control group which included deconditioned subjects resulted in 7 of those 10 patients having otherwise normal recovery indices. Therefore, modeling pH(i) recovery allows characterization of the entire pH(i) recovery and detects altered proton handling in MM patients, including those with otherwise normal recovery indices.
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Affiliation(s)
- J T Chen
- Magnetic Resonance Spectroscopy Unit, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
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39
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Löfberg M, Lindholm H, Näveri H, Majander A, Suomalainen A, Paetau A, Sovijärvi A, Härkönen M, Somer H. ATP, phosphocreatine and lactate in exercising muscle in mitochondrial disease and McArdle's disease. Neuromuscul Disord 2001; 11:370-5. [PMID: 11369188 DOI: 10.1016/s0960-8966(00)00205-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We studied exercise-induced changes in the adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels in the skeletal muscle of mitochondrial patients and patients with McArdle's disease. Needle muscle biopsy specimens for biochemical measurement were obtained before and immediately after maximal short-term bicycle exercise test from 12 patients suffering from autosomal dominant and recessive forms of progressive external ophthalmoplegia and multiple deletions of mitochondrial DNA (adPEO, arPEO, respectively), five patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) 3243 A-->G point mutation, and four patients with McArdle's disease. Muscle ATP and PCr levels at rest or after exercise did not differ significantly from those of the controls in any patient group. In patients with mitochondrial disease, muscle lactate tended to be lower at rest and increase more during exercise than in controls, the most remarkable rise being measured in patients with adPEO with generalized muscle symptoms and in patients with MELAS point mutation. In McArdle patients, the muscle lactate level decreased during exercise. No correlation was found between the muscle ATP and PCr levels and the respiratory chain enzyme activity.
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Affiliation(s)
- M Löfberg
- Institute of Neurosciences, Department of Neurology, Helsinki University Hospital, 00029 HUS, Helsinki, Finland.
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40
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Lodi R, Schapira AHV, Manners D, Styles P, Wood NW, Taylor DJ, Warner TT. Abnormal in vivo skeletal muscle energy metabolism in Huntington's disease and dentatorubropallidoluysian atrophy. Ann Neurol 2001. [DOI: 10.1002/1531-8249(200007)48:1<72::aid-ana11>3.0.co;2-i] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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41
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Abstract
Most of the mitochondrial disorders affect the brain and muscle metabolism with variable degrees of impairment. The diagnostic usefulness of the following physiological and imaging methods, which also offer functional information that can be used for follow-up, is critically assessed: lactate levels, exercise testing, phosphorus magnetic resonance spectroscopy (MRS), proton MRS, functional magnetic resonance imaging, positron emission tomography, optical tissue oximetry and single photon emission tomography. Knowledge of the advantages, shortcomings and results of each method in the evaluation of mitochondrial diseases is mandatory before they can be applied to other disorders with suspected oxidative impairment.
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Affiliation(s)
- Z Argov
- Department of Neurology, Hadassah University Hospital, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Abstract
Phosphorus magnetic resonance spectroscopy (P-MRS) has now been used in the investigation of muscle energy metabolism in health and disease for over 15 years. The present review describes the basics of the metabolic observations made by P-MRS including the assumptions and problems associated with the use of this technique. Extramuscular factors, which may affect the P-MRS results, are detailed. The important P-MRS observations in patients with mitochondrial myopathies, including the monitoring of experimental therapies, are emphasized. The findings in other metabolic myopathies (those associated with glycolytic defects or endocrine disturbances) and in the destructive myopathies (the dystrophies and the inflammatory myopathies) are also described. Observations made in normal and abnormal fatigue, fibromyalgia, and malignant hyperthermia are considered. Finally, a summary of the possible diagnostic use of P-MRS in exercise intolerance is provided.
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Affiliation(s)
- Z Argov
- Magnetic Resonance Spectroscopy Unit, Montreal Neurological Institute, Quebec, Canada
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43
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Abstract
Magnetic resonance spectroscopy and imaging of muscle and brain offers new possibilities for noninvasive diagnosis of metabolic myopathies. These functional techniques allow assessment of the pathophysiology of these disorders and also can be used for monitoring disease evolution and response to therapy. In this article, the authors review the magnetic resonance spectroscopy and imaging features of mitochondrial encephalomyopathies, glycolytic disorders, and hypothyroidism.
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Affiliation(s)
- Z Argov
- Associate Professor, Department of Neurology, Hadassah University Hospital, Jerusalem
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44
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Larson-Meyer DE, Newcomer BR, Hunter GR, Hetherington HP, Weinsier RL. 31P MRS measurement of mitochondrial function in skeletal muscle: reliability, force-level sensitivity and relation to whole body maximal oxygen uptake. NMR IN BIOMEDICINE 2000; 13:14-27. [PMID: 10668050 DOI: 10.1002/(sici)1099-1492(200002)13:1<14::aid-nbm605>3.0.co;2-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The reliability, relation to whole-body maximal oxygen uptake (VO(2max)), and force-level sensitivity of (31)P MRS markers of mitochondrial function were studied in 39 normal-weight women. Following 90 s isometric plantar-flexion exercises at 45, 70 and 100% of maximum voluntary contraction, skeletal muscle mitochondrial function was determined from the phosphocreatine recovery time constant (TC(PCr)), the ADP recovery time constant (TC(ADP)), and the rate of change in PCr during the first 14 s of recovery (OxPhos). VO(2max) was measured on a treadmill. Test-retest measurements were obtained in a subset of seven women. Overall, TC(PCr), TC(ADP) and OxPhos were reproducible for all exercises (coefficients of variation = 2.3-19.3%). With increasing force-level, TC(PCr) was prolonged (29.0 +/- 8.2, 31.9 +/- 9.0 and 35.4 +/- 9.5 s), OxPhos was increased (0.159 +/- 0.081, 0.247 +/- 0.090 and 0.310 +/- 0.114), and TC(ADP) was shortened (22.4 +/- 7.9, 21.3 +/- 6.2, and 19.5 +/- 6.7; p < 0.01). All MRS markers of mitochondrial function were correlated with VO(2max) (r = 0.41-0.72; p < 0.05). These results suggest that measurements of TC(PCr), TC(ADP) and OxPhos yield reproducible results that correlate with whole-body VO(2max) and that vary in force-level sensitivity.
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Affiliation(s)
- D E Larson-Meyer
- Department of Nutrition Sciences, Division of Physiology and Metabolism, The University of Alabama at Birmingham, Birmingham, AL 35205, USA.
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Lodi R, Cooper JM, Bradley JL, Manners D, Styles P, Taylor DJ, Schapira AH. Deficit of in vivo mitochondrial ATP production in patients with Friedreich ataxia. Proc Natl Acad Sci U S A 1999; 96:11492-5. [PMID: 10500204 PMCID: PMC18061 DOI: 10.1073/pnas.96.20.11492] [Citation(s) in RCA: 238] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/1998] [Accepted: 07/06/1999] [Indexed: 11/18/2022] Open
Abstract
Friedreich ataxia (FRDA), the most common of the inherited ataxias, is an autosomal recessive degenerative disorder, characterized clinically by onset before the age of 25 of progressive gait and limb ataxia, absence of deep tendon reflexes, extensor plantar responses, and loss of position and vibration sense in the lower limbs. FRDA is caused by a GAA triplet expansion in the first intron of the FRDA gene on chromosome 9q13 in 97% of patients. The FRDA gene encodes a widely expressed 210-aa protein, frataxin, which is located in mitochondria and is severely reduced in FRDA patients. Frataxin function is still unknown but the knockout of the yeast frataxin homologue gene (YFH1) showed a severe defect of mitochondrial respiration and loss of mtDNA associated with elevated intramitochondrial iron. Here we report in vivo evidence of impaired mitochondrial respiration in skeletal muscle of FRDA patients. Using phosphorus magnetic resonance spectroscopy we demonstrated a maximum rate of muscle mitochondrial ATP production (V(max)) below the normal range in all 12 FRDA patients and a strong negative correlation between mitochondrial V(max) and the number of GAA repeats in the smaller allele. Our results show that FRDA is a nuclear-encoded mitochondrial disorder affecting oxidative phosphorylation and give a rationale for treatments aimed to improve mitochondrial function in this condition.
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Affiliation(s)
- R Lodi
- Medical Research Council, Biochemical and Clinical Magnetic Resonance Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom OX1 9DU.
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Vorgerd M, Bolz H, Patzold T, Kubisch C, Malin JP, Mortier W. Phenotypic variability in rippling muscle disease. Neurology 1999; 52:1453-9. [PMID: 10227634 DOI: 10.1212/wnl.52.7.1453] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To characterize the phenotype of hereditary rippling muscle disease (RMD) and to report the results of genetic linkage studies. BACKGROUND RMD is a rare autosomal-dominant inherited muscle disorder. Individuals complain of muscle stiffness, exercise-induced muscle pain, and cramp-like sensations. The characteristic feature of RMD is increased mechanical muscle irritability, which is electrically silent in electromyographic examinations. METHODS Forty-six individuals from two unrelated German kindreds with RMD were examined. Linkage analysis to the RMD locus on chromosome 1q41-q43 was performed. RESULTS In kindred A, 15 individuals from four generations, and in kindred B, four individuals from three generations had clinical features of RMD. The most consistent clinical findings were percussion-induced rapid muscle contractions (PIRCs) and muscle mounding, which were present in all 19 affected individuals. Only 12 individuals exhibited muscle rippling, indicating that rippling is not always present in RMD. Twelve of 19 individuals had muscle-related complaints, primarily exertional cramps and stiffness. The mean age at the onset of complaints was 22 years (range, 5 to 54 years). Seven of 19 individuals showed only mechanical-induced muscle irritability but did not have muscular symptoms. Genetic analysis excluded linkage to the RMD locus on chromosome 1q4 in both kindreds. CONCLUSIONS The phenotype of RMD is variable but generalized PIRCs are the most obvious and reliable clinical feature of RMD. Diagnostic criteria of RMD should include generalized PIRCs in addition to muscle mounding, rippling, and creatine kinase elevation.
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Affiliation(s)
- M Vorgerd
- Department of Neurology, Ruhr-University, Bochum, Germany.
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Lane RJ, Barrett MC, Taylor DJ, Kemp GJ, Lodi R. Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle. Neuromuscul Disord 1998; 8:204-9. [PMID: 9631403 DOI: 10.1016/s0960-8966(98)00021-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It has been shown previously that some patients with chronic fatigue syndrome show an abnormal increase in plasma lactate following a short period of moderate exercise, in the sub-anaerobic threshold exercise test (SATET). This cannot be explained satisfactorily by the effects of 'inactivity' or 'deconditioning', and patients with abnormal lactate responses to exercise (SATET +ve) have been found to have significantly fewer Type 1 muscle fibres in quadriceps biopsies than SATET -ve patients. We performed phosphorus magnetic resonance spectroscopy on forearm muscles of 10 SATET +ve patients, 9 SATET -ve patients and 13 sedentary volunteers. There were no differences in resting spectra between these groups but at the end of exercise, intracellular pH in the SATET +ve patients was significantly lower than in both the SATET -ve cases and controls (P < 0.03), and the SATET +ve patients also showed a significantly lower ATP synthesis rate during recovery (P < 0.01), indicating impaired mitochondrial oxidative phosphorylation. These observations support other evidence which indicates that chronic fatigue syndrome is a heterogeneous disorder, and confirms the view that some chronic fatigue syndrome patients have a peripheral component to their fatigue.
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Affiliation(s)
- R J Lane
- Division of Clinical Neuroscience and Psychological Medicine, Imperial College School of Medicine, Charing Cross Hospital, London, UK.
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Taylor DJ, Amato A, Hands LJ, Kemp GJ, Ramaswami G, Nicolaides A, Radda GK. Changes in energy metabolism of calf muscle in patients with intermittent claudication assessed by 31P magnetic resonance spectroscopy: a phase II open study. Vasc Med 1998; 1:241-5. [PMID: 9552578 DOI: 10.1177/1358863x9600100401] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Energy status and metabolism in skeletal muscle of nine patients with peripheral arterial disease and suffering from intermittent claudication were evaluated using 31phosphorus magnetic resonance spectroscopy (MRS) before and after treatment for 3 months with propionyl-L-carnitine (PLC; 2 g/day p.o.). Maximum walking distance (MWD) was assessed on a standard treadmill (4 km/h, zero incline). For the group as a whole 31P MRS results did not change significantly with PLC. Although MWD increased by a mean of 36%, this change did not reach significance. However, when these variables were assessed with respect to the change in MWD, there were significant differences between those who increased MWD by > 30% (responders, R; n = 5) and those who did not (nonresponders, NR; n = 4). Compared with pretreatment values, during exercise the decrease in muscle pH in R relative to the decrease in phosphocreatine was less after PLC (p = 0.04). After exercise there was a significant inverse correlation between the changes in recovery half-time (t1/2) for phosphocreatine and in MWD (r = -0.91, p = 0.01). With PLC, Vmax increased in R (p = 0.04), but not in NR. For the patient group as a whole, the changes in Vmax and MWD correlated positively (r = 0.90, p = 0.01). This study helps to identify the changes in muscle metabolism that correlate with changes in exercise performance, and may accompany treatment with PLC.
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Affiliation(s)
- D J Taylor
- MRC Biochemical and Clinical Magnetic Resonance Unit, Oxford Radcliffe Hospital Trust, UK
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Radda GK. The study of mitochondrial diseases using magnetic resonance spectroscopy. Biofactors 1998; 7:251-2. [PMID: 9568260 DOI: 10.1002/biof.5520070320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- G K Radda
- Department of Biochemistry, University of Oxford, UK
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Argov Z, De Stefano N, Arnold DL. Muscle high-energy phosphates in central nervous system disorders. The phosphorus MRS experience. ITALIAN JOURNAL OF NEUROLOGICAL SCIENCES 1997; 18:353-7. [PMID: 9494867 DOI: 10.1007/bf02048238] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phosphorus magnetic resonance spectroscopy (MRS) was used to study muscle phosphates metabolism in several brain disorders. Those with primary mitochondrial encephalomyopathies showed the typical pattern of impaired oxidative metabolism at rest and during recovery after exercise. In migraine, Parkinson's disease and alternating hemiplegia muscle MRS observations lend support to a possible mitochondrial dysfunction. Similar observations in multiple sclerosis are probably the result of secondary deconditioning. In post polio syndrome and in some of the hereditary ataxias, elevated intracellular inorganic phosphates may be the result of another, yet unknown, metabolic impairment. Thus, muscle phosphate metabolism may be altered in various central nervous system (CNS) disorders by different metabolic impairments. All these possibilities should be taken into account when evaluating MRS results in brain diseases.
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Affiliation(s)
- Z Argov
- Magnetic Resonance Spectroscopy Unit, Montreal Neurological Institute, Canada
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