1
|
Wang Q, Cui C, Zhang N, Lin W, Chai S, Chow SKH, Wong RMY, Hu Y, Law SW, Cheung WH. Effects of physical exercise on neuromuscular junction degeneration during ageing: A systematic review. J Orthop Translat 2024; 46:91-102. [PMID: 38817243 PMCID: PMC11137388 DOI: 10.1016/j.jot.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/27/2024] [Accepted: 03/31/2024] [Indexed: 06/01/2024] Open
Abstract
The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.
Collapse
Affiliation(s)
- Qianjin Wang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Can Cui
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Ning Zhang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wujian Lin
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Senlin Chai
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Simon Kwoon-Ho Chow
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| | - Ronald Man Yeung Wong
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yong Hu
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Sheung Wai Law
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wing-Hoi Cheung
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| |
Collapse
|
2
|
Krause Neto W, Silva W, Oliveira T, Vilas Boas A, Ciena A, Caperuto ÉC, Gama EF. Ladder-based resistance training with the progression of training load altered the tibial nerve ultrastructure and muscle fiber area without altering the morphology of the postsynaptic compartment. Front Physiol 2024; 15:1371839. [PMID: 38694209 PMCID: PMC11061484 DOI: 10.3389/fphys.2024.1371839] [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: 02/01/2024] [Accepted: 04/02/2024] [Indexed: 05/04/2024] Open
Abstract
Scientific evidence regarding the effect of different ladder-based resistance training (LRT) protocols on the morphology of the neuromuscular system is scarce. Therefore, the present study aimed to compare the morphological response induced by different LRT protocols in the ultrastructure of the tibial nerve and morphology of the motor endplate and muscle fibers of the soleus and plantaris muscles of young adult Wistar rats. Rats were divided into groups: sedentary control (control, n = 9), a predetermined number of climbs and progressive submaximal intensity (fixed, n = 9), high-intensity and high-volume pyramidal system with a predetermined number of climbs (Pyramid, n = 9) and lrt with a high-intensity pyramidal system to exhaustion (failure, n = 9). myelinated fibers and myelin sheath thickness were statistically larger in pyramid, fixed, and failure. myelinated axons were statistically larger in pyramid than in control. schwann cell nuclei were statistically larger in pyramid, fixed, and failure. microtubules and neurofilaments were greater in pyramid than in control. morphological analysis of the postsynaptic component of the plantar and soleus muscles did not indicate any significant difference. for plantaris, the type i myofibers were statistically larger in the pyramid and fixed compared to control. the pyramid, fixed, and failure groups for type ii myofibers had larger csa than control. for soleus, the type i myofibers were statistically larger in the pyramid than in control. pyramid and fixed had larger csa for type ii myofibers than control and failure. the pyramid and fixed groups showed greater mass progression delta than the failure. We concluded that the LRT protocols with greater volume and progression of accumulated mass elicit more significant changes in the ultrastructure of the tibial nerve and muscle hypertrophy without endplate changes.
Collapse
Affiliation(s)
- Walter Krause Neto
- Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Wellington Silva
- Depatment of Physical Education, Laboratory of Human Movement, Universidade São Judas Tadeu, São Paulo, Brazil
| | - Tony Oliveira
- Depatment of Physical Education, Laboratory of Human Movement, Universidade São Judas Tadeu, São Paulo, Brazil
| | - Alan Vilas Boas
- Depatment of Physical Education, Laboratory of Human Movement, Universidade São Judas Tadeu, São Paulo, Brazil
| | - Adriano Ciena
- Department of Physical Education, Laboratory of Morphology and Physical Activity, Universidade Estadual Paulista Júlio de Mesquita Filho, São Paulo, Brazil
| | - Érico Chagas Caperuto
- Depatment of Physical Education, Laboratory of Human Movement, Universidade São Judas Tadeu, São Paulo, Brazil
| | - Eliane Florencio Gama
- Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
| |
Collapse
|
3
|
Tibúrcio FC, Leite APS, Muller KS, Pinto CG, Valentino E, Castro PATDS, Matsumura CY, de Carvalho SF, Matheus SMM. Effects of Nandrolone Decanoate on Skeletal Muscle and Neuromuscular Junction of Sedentary and Exercised Rats. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1940. [PMID: 38003989 PMCID: PMC10673219 DOI: 10.3390/medicina59111940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/03/2023] [Accepted: 10/23/2023] [Indexed: 11/26/2023]
Abstract
Background and Objectives: Nandrolone decanoate (ND) is the most widely used among the anabolic androgenic steroids (AAS), synthetic substances derived from testosterone, to improve muscular and health gains associated with exercises. The AAS leads to physical performance enhancement and presents anti-aging properties, but its abuse is associated with several adverse effects. Supraphysiological doses of AAS with or without physical exercise can cause morphological and functional alterations in neuromuscular interactions. This study aims to investigate the effects of ND supraphysiological doses in neuromuscular interactions, focusing on the soleus muscle and its neuromuscular junctions (NMJs) in rats, associated or not with physical exercise. Materials and Methods: Forty male Sprague Dawley rats were divided into four groups: sedentary and exercised groups, with or without ND at the dose of 10 mg/kg/week. The animals were treated for eight weeks, with intramuscular injections, and the soleus muscle was collected for morphological analyses. Results: The supraphysiological doses of ND in the sedentary group caused muscle degeneration, evidenced by splitting fibers, clusters of small fibers, irregular myofibrils, altered sarcomeres, an increase in collagen deposition and in the number of type I muscle fibers (slow-twitch) and central nuclei, as well as a decrease in fibers with peripheral nuclei. On the other hand, in the ND exercise group, there was an increase in the NMJs diameter with scattering of its acetylcholine receptors, although no major morphological changes were found in the skeletal muscle. Thus, the alterations caused by ND in sedentary rats were partially reversed by physical exercise. Conclusions: The supraphysiological ND exposure in the sedentary rats promoted an increase in muscle oxidative pattern and adverse morphological alterations in skeletal muscle, resulting from damage or post-injury regeneration. In the ND-exercised rats, no major morphological changes were found. Thus, the physical exercise partially reversed the alterations caused by ND in sedentary rats.
Collapse
Affiliation(s)
- Felipe Cantore Tibúrcio
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Ana Paula Silveira Leite
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Kevin Silva Muller
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Carina Guidi Pinto
- Medical School, São Paulo State University (Unesp), Botucatu 18618-687, SP, Brazil; (F.C.T.); (A.P.S.L.); (K.S.M.); (C.G.P.)
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Erick Valentino
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Paula Aiello Tomé de Souza Castro
- Department of Physical Therapy, Center for Biological and Health Sciences, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil;
| | - Cintia Yuri Matsumura
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| | - Shelly Favorito de Carvalho
- Electron Microscopy Center, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil;
| | - Selma Maria Michelin Matheus
- Division of Anatomy, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu 18618-689, SP, Brazil; (C.Y.M.)
| |
Collapse
|
4
|
Qi Z, Wang S, Xuan A, Gu X, Deng J, Huang C, Zhang L, Yin X. MiR-142a-3p: A novel ACh receptor transcriptional regulator in association with peripheral nerve injury. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 30:325-336. [PMID: 36381585 PMCID: PMC9633872 DOI: 10.1016/j.omtn.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 10/12/2022] [Indexed: 12/15/2022]
Abstract
Long-term denervation leads to the disintegration of nicotinic acetylcholine receptor (nAChR) located at the endplate structure, which translates to deficits in functional activation despite nerve repair. Because of a lack of effective measures to protect AChR expression, we explored the effect of alterations in muscular miR-142a-3p on nAChR. In this study, we constructed a model of miR-142a-3p knockdown by transfecting a miR-142a-3p inhibitor short hairpin RNA (shRNA) into C2C12 myotubes, and we injected this miR-142a-3p inhibitor shRNA into the tibialis anterior (TA) muscle in uninjured mice and in denervated mice by transecting the sciatic nerve. Our results showed that miR-142a-3p knockdown led to an increased number and area of AChR clusters in myotubes in vitro and larger neuromuscular endplates in adult mice. Furthermore, miR-142a-3p knockdown delayed the disintegration of motor endplates after denervation. Last, upon miR-142a-3p knockdown in uninjured and denervated mice, we observed an increase in the mRNA levels of five AChR subunits as well as mRNAs of genes implicated in AChR transcription and AChR clustering. Together, these results suggest that miR-142a-3p may be a potential target for therapeutic intervention to prevent motor endplate degradation following peripheral nerve injury.
Collapse
Affiliation(s)
- Zhidan Qi
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China
| | - Shen Wang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China
| | - Ang Xuan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Xinyi Gu
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China
| | - Jin Deng
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China
| | - Chen Huang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China
| | - Lei Zhang
- Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, China,Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xiaofeng Yin
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China,Pizhou People’s Hospital, Jiangsu, China,Corresponding author Xiaofeng Yin, Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing, China.
| |
Collapse
|
5
|
Jang J, Koh JH, Kim Y, Kim HJ, Park S, Chang Y, Jung J, Wolfe RR, Kim IY. Balanced Free Essential Amino Acids and Resistance Exercise Training Synergistically Improve Dexamethasone-Induced Impairments in Muscle Strength, Endurance, and Insulin Sensitivity in Mice. Int J Mol Sci 2022; 23:ijms23179735. [PMID: 36077132 PMCID: PMC9456044 DOI: 10.3390/ijms23179735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Our previous study shows that an essential amino acid (EAA)-enriched diet attenuates dexamethasone (DEX)-induced declines in muscle mass and strength, as well as insulin sensitivity, but does not affect endurance. In the present study, we hypothesized that the beneficial effects will be synergized by adding resistance exercise training (RET) to EAA, and diet-free EAA would improve endurance. To test hypotheses, mice were randomized into the following four groups: control, EAA, RET, and EAA+RET. All mice except the control were subjected to DEX treatment. We evaluated the cumulative rate of myofibrillar protein synthesis (MPS) using 2H2O labeling and mass spectrometry. Neuromuscular junction (NMJ) stability, mitochondrial contents, and molecular signaling were demonstrated in skeletal muscle. Insulin sensitivity and glucose metabolism using 13C6-glucose tracing during oral glucose tolerance tests were analyzed. We found that EAA and RET synergistically improve muscle mass and/or strength, and endurance capacity, as well as insulin sensitivity, and glucose metabolism in DEX-treated muscle. These improvements are accomplished, in part, through improvements in myofibrillar protein synthesis, NMJ, fiber type preservation, and/or mitochondrial biogenesis. In conclusion, free EAA supplementation, particularly when combined with RET, can serve as an effective means that counteracts the adverse effects on muscle of DEX that are found frequently in clinical settings.
Collapse
Affiliation(s)
- Jiwoong Jang
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon 21565, Korea
| | - Jin-Ho Koh
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
| | - Yeongmin Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Hee-Joo Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Sanghee Park
- Department of Internal Medicine, Gil Medical Center, Gachon University, Incheon 21565, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
| | - Yewon Chang
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Jiyeon Jung
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Korea
| | - Robert R. Wolfe
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Il-Young Kim
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
- Correspondence: ; Tel.: +82-32-899-6685
| |
Collapse
|
6
|
Arabzadeh E, Reza Rahimi A, Zargani M, Feyz Simorghi Z, Emami S, Sheikhi S, Zaeri Amirani Z, Yousefi P, Sarshin A, Aghaei F, Feizollahi F. Resistance exercise promotes functional test via sciatic nerve regeneration, and muscle atrophy improvement through GAP-43 regulation in animal model of traumatic nerve injuries. Neurosci Lett 2022; 787:136812. [PMID: 35872241 DOI: 10.1016/j.neulet.2022.136812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/12/2022] [Accepted: 07/19/2022] [Indexed: 11/30/2022]
Abstract
Resistance training improves muscle strength through a combination of neural plasticity and muscle hypertrophy. This study aimed to evaluate the effects of resistance exercise on sciatic nerve regeneration and histology, growth-associated protein 43 (GAP-43) expressions, and soleus muscle atrophy following traumatic nerve injuries in Wistar rats. In the present study, 40 male Wistar rats were randomly assigned into four groups: healthy control (HC) as a sham group was exposed to the surgical procedures without any sciatic nerve compression, lesioned control (LC), resistance training (RT,non-lesioned), and lesioned rats+RT (LRT) (n=10 in each). The RT group performed a resistance-training program 5 days/week for 4 weeks. Sciatic functional index (SFI) score, beam score and Basso, Beattie, and Bresnahan (BBB) score decreased and the hot plate time increased significantly in the LC group compared to the HC (p<0.05) group. However, the LRT group showed a significant increase in the SFI score (p=0.001) and a significant decrease in hot plate time (p=0.0232) compared to the LC group. The LC group also showed neurological morphological damage and muscle atrophy and a decrease in GAP-43 in nerve tissue. In comparison to the LC group, a significant increase in sciatic nerve caliber, diameter, number of muscle fibers, and the expression of GAP-43 (p<0.05) was observed in the LRT group. Doing resistance training even for four weeks seems to affect sciatic nerve lesions and injuries. It can also repair and regenerate nerve tissue by upregulating GAP-43 expression, improving motor behavioral tests, and controlling muscle atrophy.
Collapse
Affiliation(s)
- Ehsan Arabzadeh
- Exercise Physiology Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Ali Reza Rahimi
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Mehdi Zargani
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Zeinab Feyz Simorghi
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Shaghayegh Emami
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Sahar Sheikhi
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Zeinab Zaeri Amirani
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Parisa Yousefi
- Department of Exercise Physiology, Islamic Azad University, Karaj Branch, Karaj, Alborz, Iran
| | - Amir Sarshin
- Clinical Care and Health Promotion Research Center, Karaj branch, Islamic Azad University, Karaj, Iran
| | - Fariba Aghaei
- Clinical Care and Health Promotion Research Center, Karaj branch, Islamic Azad University, Karaj, Iran
| | - Foad Feizollahi
- Clinical Care and Health Promotion Research Center, Karaj branch, Islamic Azad University, Karaj, Iran.
| |
Collapse
|
7
|
Jones EJ, Chiou S, Atherton PJ, Phillips BE, Piasecki M. Ageing and exercise-induced motor unit remodelling. J Physiol 2022; 600:1839-1849. [PMID: 35278221 PMCID: PMC9314090 DOI: 10.1113/jp281726] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/14/2022] [Indexed: 11/08/2022] Open
Abstract
A motor unit (MU) comprises the neuron cell body, its corresponding axon and each of the muscle fibres it innervates. Many studies highlight age-related reductions in the number of MUs, yet the ability of a MU to undergo remodelling and to expand to rescue denervated muscle fibres is also a defining feature of MU plasticity. Remodelling of MUs involves two coordinated processes: (i) axonal sprouting and new branching growth from adjacent surviving neurons, and (ii) the formation of key structures around the neuromuscular junction to resume muscle-nerve communication. These processes rely on neurotrophins and coordinated signalling in muscle-nerve interactions. To date, several neurotrophins have attracted focus in animal models, including brain-derived neurotrophic factor and insulin-like growth factors I and II. Exercise in older age has demonstrated benefits in multiple physiological systems including skeletal muscle, yet evidence suggests this may also extend to peripheral MU remodelling. There is, however, a lack of research in humans due to methodological limitations which are easily surmountable in animal models. To improve mechanistic insight of the effects of exercise on MU remodelling with advancing age, future research should focus on combining methodological approaches to explore the in vivo physiological function of the MU alongside alterations of the localised molecular environment.
Collapse
Affiliation(s)
- Eleanor J. Jones
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC–Versus Arthritis Centre of Excellence for Musculoskeletal Ageing ResearchNottingham NIHR Biomedical Research CentreSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Shin‐Yi Chiou
- School of SportExercise, and Rehabilitation Sciences, MRC‐Versus Arthritis Centre for Musculoskeletal Ageing Research, Centre for Human Brain HealthUniversity of BirminghamBirminghamUK
| | - Philip J. Atherton
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC–Versus Arthritis Centre of Excellence for Musculoskeletal Ageing ResearchNottingham NIHR Biomedical Research CentreSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Bethan E. Phillips
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC–Versus Arthritis Centre of Excellence for Musculoskeletal Ageing ResearchNottingham NIHR Biomedical Research CentreSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Mathew Piasecki
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC–Versus Arthritis Centre of Excellence for Musculoskeletal Ageing ResearchNottingham NIHR Biomedical Research CentreSchool of MedicineUniversity of NottinghamNottinghamUK
| |
Collapse
|
8
|
Jacob CDS, Barbosa GK, Rodrigues MP, Pimentel Neto J, Rocha LC, Ciena AP. Stretching prior to resistance training promotes adaptations on the postsynaptic region in different myofiber types. Eur J Histochem 2022; 66. [PMID: 35164481 PMCID: PMC8875788 DOI: 10.4081/ejh.2022.3356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/01/2022] [Indexed: 11/23/2022] Open
Abstract
The morphology of the neuromuscular junction adapts according to changes in its pattern of use, especially at the postsynaptic region according to the myofibrillar type and physical exercise. This investigation revealed the morphological adaptations of the postsynaptic region after static stretching, resistance training, and their association in adult male Wistar rats. We processed the soleus and plantaris muscles for histochemical (muscle fibers) and postsynaptic region imaging techniques. We observed muscle hypertrophy in both groups submitted to resistance training, even though the cross-section area is larger when there is no previous static stretching. The soleus postsynaptic region revealed higher compactness and fragmentation index in the combined exercise. The resistance training promoted higher adaptations in the postsynaptic area of plantaris; moreover, the previous static stretching decreased this area. In conclusion, the neuromuscular system’s components responded according to the myofiber type even though it is the same physical exercise. Besides, static stretching (isolated or combined) plays a crucial role in neuromuscular adaptations.
Collapse
|
9
|
Bannow LI, Bonaterra GA, Bertoune M, Maus S, Schulz R, Weissmann N, Kraut S, Kinscherf R, Hildebrandt W. Effect of chronic intermittent hypoxia (CIH) on neuromuscular junctions and mitochondria in slow- and fast-twitch skeletal muscles of mice—the role of iNOS. Skelet Muscle 2022; 12:6. [PMID: 35151349 PMCID: PMC8841105 DOI: 10.1186/s13395-022-00288-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/10/2022] [Indexed: 01/17/2023] Open
Abstract
Background Obstructive sleep apnea (OSA) imposes vascular and metabolic risks through chronic intermittent hypoxia (CIH) and impairs skeletal muscle performance. As studies addressing limb muscles are rare, the reasons for the lower exercise capacity are unknown. We hypothesize that CIH-related morphological alterations in neuromuscular junctions (NMJ) and mitochondrial integrity might be the cause of functional disorders in skeletal muscles. Methods Mice were kept under 6 weeks of CIH (alternating 7% and 21% O2 fractions every 30 s, 8 h/day, 5 days/week) compared to normoxia (NOX). Analyses included neuromuscular junctions (NMJ) postsynaptic morphology and integrity, fiber cross-sectional area (CSA) and composition (ATPase), mitochondrial ultrastructure (transmission-electron-microscopy), and relevant transcripts (RT-qPCR). Besides wildtype (WT), we included inducible nitric oxide synthase knockout mice (iNOS−/−) to evaluate whether iNOS is protective or risk-mediating. Results In WT soleus muscle, CIH vs. NOX reduced NMJ size (− 37.0%, p < 0.001) and length (− 25.0%, p < 0.05) together with fiber CSA of type IIa fibers (− 14%, p < 0.05) and increased centronucleated fiber fraction (p < 0.001). Moreover, CIH vs. NOX increased the fraction of damaged mitochondria (1.8-fold, p < 0.001). Compared to WT, iNOS−/− similarly decreased NMJ area and length with NOX (− 55%, p < 0.001 and − 33%, p < 0.05, respectively) or with CIH (− 37%, p < 0.05 and − 29%, p < 0.05), however, prompted no fiber atrophy. Moreover, increased fractions of damaged (2.1-fold, p < 0.001) or swollen (> 6-fold, p < 0.001) mitochondria were observed with iNOS−/− vs. WT under NOX and similarly under CIH. Both, CIH- and iNOS−/− massively upregulated suppressor-of-cytokine-signaling-3 (SOCS3) > 10-fold without changes in IL6 mRNA expression. Furthermore, inflammatory markers like CD68 (macrophages) and IL1β were significantly lower in CIH vs. NOX. None of these morphological alterations with CIH- or iNOS−/− were detected in the gastrocnemius muscle. Notably, iNOS expression was undetectable in WT muscle, unlike the liver, where it was massively decreased with CIH. Conclusion CIH leads to NMJ and mitochondrial damage associated with fiber atrophy/centronucleation selectively in slow-twitch muscle of WT. This effect is largely mimicked by iNOS−/− at NOX (except for atrophy). Both conditions involve massive SOCS3 upregulation likely through denervation without Il6 upregulation but accompanied by a decrease of macrophage density especially next to denervated endplates. In the absence of muscular iNOS expression in WT, this damage may arise from extramuscular, e.g., motoneuronal iNOS deficiency (through CIH or knockout) awaiting functional evaluation. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-022-00288-7.
Collapse
|
10
|
The Neuromuscular Junction: Roles in Aging and Neuromuscular Disease. Int J Mol Sci 2021; 22:ijms22158058. [PMID: 34360831 PMCID: PMC8347593 DOI: 10.3390/ijms22158058] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized synapse that bridges the motor neuron and the skeletal muscle fiber and is crucial for conversion of electrical impulses originating in the motor neuron to action potentials in the muscle fiber. The consideration of contributing factors to skeletal muscle injury, muscular dystrophy and sarcopenia cannot be restricted only to processes intrinsic to the muscle, as data show that these conditions incur denervation-like findings, such as fragmented NMJ morphology and corresponding functional changes in neuromuscular transmission. Primary defects in the NMJ also influence functional loss in motor neuron disease, congenital myasthenic syndromes and myasthenia gravis, resulting in skeletal muscle weakness and heightened fatigue. Such findings underscore the role that the NMJ plays in neuromuscular performance. Regardless of cause or effect, functional denervation is now an accepted consequence of sarcopenia and muscle disease. In this short review, we provide an overview of the pathologic etiology, symptoms, and therapeutic strategies related to the NMJ. In particular, we examine the role of the NMJ as a disease modifier and a potential therapeutic target in neuromuscular injury and disease.
Collapse
|
11
|
Barbosa GK, Jacob CDS, Rodrigues MP, Rocha LC, Pimentel Neto J, Ciena AP. Morphological Changes in the Motor Endplate and in the Belly Muscle Induced by Previous Static Stretching to the Climbing Protocol. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-9. [PMID: 34294184 DOI: 10.1017/s1431927621012253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Static stretching provides benefits to the range of motion, modulates intramuscular connective tissue, and is incorporated into warm-up exercises. In this study, we present the effects in the motor endplate and belly muscle resulting from previous static stretching to climbing training. Twenty-four adult male Wistar rats were divided into four groups (n = 6 each): Sedentary (Sed), Climbing (Clb), Static stretching (Ss), and Static stretching prior to climbing (Ssc). The animals (Clb, Ss, and Ssc groups) were subjected to a training protocol 3×/week for 8 weeks, and the Ssc group was subjected to the Ss and Clb protocols in the same session. Samples from the animals were processed for immunostaining, histochemistry, and light microscopy. The Clb group presented a higher motor endplate; the Ss group presented no changes in the motor endplate; and the Ssc group demonstrated a higher compactness. We concluded that static stretching prior to the climbing protocol maintained the density of the motor endplate and increased the compactness of the neuromuscular junction structure. Also, there was a reduction in the myofibers’ diameter (Type I and IIa), an increase in myofibrillar densities (Type I and IIx, and total), and the reorganization of the myonuclei and the interstitium.
Collapse
Affiliation(s)
- Gabriela K Barbosa
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| | - Carolina Dos S Jacob
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| | - Mariana P Rodrigues
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| | - Lara C Rocha
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| | - Jurandyr Pimentel Neto
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| | - Adriano P Ciena
- Department of Physical Activity, Laboratory of Morphology and Physical Activity - LAMAF, Institute of Biosciences (IB), São Paulo State University - UNESP, Rio Claro13506-900, SP, Brazil
| |
Collapse
|
12
|
Lourenço Í, Krause Neto W, dos Santos Portella Amorim L, Moraes Munhoz Ortiz V, Lopes Geraldo V, Henrique da Silva Ferreira G, Chagas Caperuto É, Florencio Gama E. Muscle hypertrophy and ladder-based resistance training for rodents: A systematic review and meta-analysis. Physiol Rep 2020; 8:e14502. [PMID: 32889774 PMCID: PMC7507488 DOI: 10.14814/phy2.14502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/02/2020] [Accepted: 06/09/2020] [Indexed: 12/20/2022] Open
Abstract
This study aimed to review the effects of ladder-based resistance training (LRT) on muscle hypertrophy and strength in rodents through a systematic review with meta-analysis. We systematically searched PubMed/Medline, SportDiscuss, Scopus, Google Scholar, Science Direct, and Scielo database on May 18, 2020. Thirty-four studies were included measuring total (mCSA) or mean muscle fibers cross-sectional area (fCSA) or maximum load-carrying capacity (MLCC) or muscle mass (MM). About the main results, LRT provides sufficient mechanical stimulation to increase mCSA and fCSA. Meta-analysis showed a significant overall effect on the fCSA (SMD 1.89, 95% CI [1.18, 2.61], p < .00001, I2 = 85%); however, subgroup analysis showed that some muscle types might not be hypertrophied through the LRT. Meta-analysis showed a significant training effect on the MM (SMD 0.92, 95% CI [0.52, 1.32], p < .00001, I2 = 72%). Sub-group analysis revealed that soleus (SMD 1.32, 95% CI [0.11, 2.54], p = .03, I2 = 86%) and FHL (SMD 1.92, 95% CI [1.00, 2.85], p < .0001, I2 = 71%) presented significant training effects, despite moderate heterogeneity levels (I2 = 72%). MLCC increases considerably after a period of LRT, regardless of its duration and the characteristics of the protocols (SMD 12.37, 95% CI [9.36, 15.37], p < .00001, I2 = 90%). Through these results, we reach the following conclusions: (a) LRT is efficient to induce muscle hypertrophy, although this effect varies between different types of skeletal muscles, and; (b) the ability of rodents to carry load increases regardless of the type and duration of the protocol used.
Collapse
Affiliation(s)
- Ítalo Lourenço
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Walter Krause Neto
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Laura dos Santos Portella Amorim
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Vagner Moraes Munhoz Ortiz
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Vitor Lopes Geraldo
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Gabriel Henrique da Silva Ferreira
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| | - Érico Chagas Caperuto
- Department of Physical EducationLaboratory of Human MovimentUniversidade São Judas TadeuSão PauloSPBrazil
| | - Eliane Florencio Gama
- Department of Physical EducationLaboratory of Morphoquantitative Studies and ImmunohistochemistryUniversidade São Judas TadeuSão PauloSPBrazil
| |
Collapse
|
13
|
Lovering RM, Iyer SR, Edwards B, Davies KE. Alterations of neuromuscular junctions in Duchenne muscular dystrophy. Neurosci Lett 2020; 737:135304. [PMID: 32818587 DOI: 10.1016/j.neulet.2020.135304] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/09/2020] [Accepted: 08/11/2020] [Indexed: 12/18/2022]
Abstract
The focus of this review is on Duchenne muscular dystrophy (DMD), which is caused by the absence of the protein dystrophin and is characterized as a neuromuscular disease in which muscle weakness, increased susceptibility to muscle injury, and inadequate repair appear to underlie the pathology. Considerable attention has been dedicated to studying muscle fiber damage, but data show that both human patients and animal models for DMD present with fragmented neuromuscular junction (NMJ) morphology. In addition to pre- and post-synaptic abnormalities, studies indicate increased susceptibility of the NMJ to contraction-induced injury, with corresponding functional changes in neuromuscular transmission and nerve-evoked electromyographic activity. Such findings suggest that alterations in the NMJ of dystrophic muscle may play a role in muscle weakness via impairment of neuromuscular transmission. Further work is needed to fully understand the role of the NMJ in the weakness, susceptibility to injury, and progressive wasting associated with DMD.
Collapse
Affiliation(s)
- Richard M Lovering
- Departments of Orthopaedics and Physiology, University of Maryland School of Medicine, Baltimore, MD, USA; University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Shama R Iyer
- Departments of Orthopaedics and Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Benjamin Edwards
- MDUK Oxford Neuromuscular Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Kay E Davies
- MDUK Oxford Neuromuscular Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| |
Collapse
|
14
|
Rocha LC, Jacob CDS, Barbosa GK, Pimentel Neto J, Krause Neto W, Gama EF, Ciena AP. Remodeling of the skeletal muscle and postsynaptic component after short-term joint immobilization and aquatic training. Histochem Cell Biol 2020; 154:621-628. [PMID: 32797254 DOI: 10.1007/s00418-020-01910-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2020] [Indexed: 12/16/2022]
Abstract
Joint immobilization is commonly used as a conservative treatment for osteoarticular and musculotendinous traumas. However, joint immobilization might elicit degenerative effects on the neuromuscular system and muscle atrophy. For this reason, the choice of strategies that mitigate these effects is essential in the post-immobilization period. Therefore, this study aimed to investigate the impact of aquatic training on the morphology of muscle fibers and motor endplates of the gastrocnemius muscle in the post-immobilization period. Male Wistar rats (90 days old) were divided into groups: Sedentary: no procedure; Immobilization: joint immobilization protocol (10 days); Immobilization/non-training: joint immobilization protocol (10 days) followed by four weeks without exercise intervention; Immobilization/training: joint immobilization protocol (10 days) and post-immobilization aquatic training (4 weeks). After the procedures, we quantified the cross-sectional area (CSA), volume and numerical density of different myofibers types, and total and stained area and perimeter of the motor endplate. We demonstrate the following main results: (a) short-term joint immobilization resulted in myofibers atrophy; however, we verified a small change in the postsynaptic component; (b) the period of inactivity after immobilization caused severe changes in the motor endplate (lower stained area, stained perimeter, total area, and total perimeter) and maintenance of muscle atrophy due to immobilization; (c) the prescription of post-immobilization exercise proved to be effective in restoring muscle morphology and inducing plasticity in the motor endplate. We conclude that short-term joint immobilization (10 days) results in atrophy type I and II myofibers, in addition to a decline in the total perimeter of the motor endplate. Besides, the post-immobilization period appears to be decisive in muscle and postsynaptic remodeling. Thus, aquatic training is effective in stimulating adjustments associated with muscle hypertrophy and plasticity of the motor endplate during the post-immobilization period.
Collapse
Affiliation(s)
- Lara Caetano Rocha
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Avenue 24A, n 1515, Rio Claro, SP, 13506-900, Brazil
| | - Carolina Dos Santos Jacob
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Avenue 24A, n 1515, Rio Claro, SP, 13506-900, Brazil
| | - Gabriela Klein Barbosa
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Avenue 24A, n 1515, Rio Claro, SP, 13506-900, Brazil
| | - Jurandyr Pimentel Neto
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Avenue 24A, n 1515, Rio Claro, SP, 13506-900, Brazil
| | - Walter Krause Neto
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, SP, Brazil
| | - Eliane Florencio Gama
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, SP, Brazil
| | - Adriano Polican Ciena
- Laboratory of Morphology and Physical Activity (LAMAF), Institute of Biosciences, São Paulo State University (UNESP), Avenue 24A, n 1515, Rio Claro, SP, 13506-900, Brazil.
| |
Collapse
|
15
|
Damiani APL, Caldas LC, Melo AB, Contreiro CDE, Estevam WM, Nogueira BV, Ferreira LG, Leopoldo AS, Leopoldo APL. RESISTANCE TRANING PROTOCOLS PROMOTE STRENGTH INCREASE WITHOUT MORPHOLOGICAL CHANGES. REV BRAS MED ESPORTE 2020. [DOI: 10.1590/1517-869220202603209955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Introduction Resistance training (RT) has been related to increased protein synthesis, and in the myocardium it triggers morphological adaptations that result in improved cardiac contractility. In skeletal muscle, RT promotes an improvement in functional capacity and in sarcopenia caused by aging. However, the efficacy of this training method in the cardiac and skeletal systems has not yet been clarified. Objective To investigate the effect of different vertical ladder RT protocols on cardiac and skeletal structure and morphology. Materials and Methods: Wistar rats (n = 28) were randomized into four groups: sedentary (C); RT protocol with 4 to 9 climbs, 3 sessions/week, 120 second interval and intensity of 50% to 100% of the maximum load (ML) with progressive addition of 30 g (RT1); RT protocol with 4 to 5 climbs, 3 sessions/week, 60 second interval and intensity of 50% to 100% of the ML, where a 30 g overload was added in the 5th climb (RT2); RT protocol with 4 to 5 climbs, 5 sessions/week, 60 second interval and intensity of 50% to 100% of the ML; the animals that completed the 4th climb underwent the 5th climb with 100% ML plus 30 g (RT3). RT protocols were performed for 9 weeks with a duration of 30 to 45 minutes/day. The nutritional profile and cardiac/skeletal muscle morphology were evaluated along with the cross sectional area and collagen fraction. Results RT did not promote adaptations in cardiac and musculoskeletal structure and morphology, nor was it able to reduce body weight and body fat deposits. However, RT brought about an increase in absolute and relative strength. Conclusion Vertical ladder RT protocols, regardless of weekly frequency, lead to increased muscle strength without cardiac and skeletal structural adaptations. Level of evidence I, Therapeutic studies - Investigating treatment results.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - André Soares Leopoldo
- Universidade Federal do Espírito Santo, Brazil; Universidade Federal do Espírito Santo, Brazil
| | - Ana Paula Lima Leopoldo
- Universidade Federal do Espírito Santo, Brazil; Universidade Federal do Espírito Santo, Brazil
| |
Collapse
|
16
|
|
17
|
Cunha JE, Barbosa GM, Castro PATDS, Luiz BLF, Silva ACA, Russo TL, Vasilceac FA, Cunha TM, Cunha FQ, Salvini TF. Knee osteoarthritis induces atrophy and neuromuscular junction remodeling in the quadriceps and tibialis anterior muscles of rats. Sci Rep 2019; 9:6366. [PMID: 31019213 PMCID: PMC6482306 DOI: 10.1038/s41598-019-42546-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 04/01/2019] [Indexed: 12/21/2022] Open
Abstract
Knee osteoarthritis (KOA) is associated with muscle weakness, but it is unclear which structures are involved in the muscle changes. This study assessed morphological alterations and the expression of genes and proteins linked to muscular atrophy and neuromuscular junctions (NMJs) in KOA, induced by anterior cruciate ligament transection (ACLT) in rats. Two groups of rats were assessed: control (without intervention) and KOA (ACLT surgery in the right knee). After 8 weeks, quadriceps, tibialis anterior (TA) and gastrocnemius muscles were analyzed (area of muscle fibers, NMJ, gene and protein expression). KOA group showed atrophy in quadriceps (15.7%) and TA (33%), with an increase in atrogin-1 and muscle RING-finger protein-1 (MuRF-1). KOA group showed quadriceps NMJ remodeling (reduction area and perimeter) and decrease in NMJ diameter in TA muscle. The expression of nicotinic acetylcholine receptor (nAChR) γ-nAChR increased and that of α-nAChR and muscle specific tyrosine kinase (MuSK) declined in the quadriceps, with a decrease in ε-nAChR in TA. MuRF-1 protein expression increased in quadriceps and TA, with no changes in neural cell adhesion molecule (NCAM). In conclusion, ACLT-induced KOA promotes NMJ remodeling and atrophy in quadriceps and TA muscles, associated with inflammatory signs and changes in muscle gene and protein expression.
Collapse
Affiliation(s)
| | | | | | | | | | - Thiago Luiz Russo
- Physical Therapy Department, Federal University of São Carlos, São Carlos, SP, Brazil
| | | | - Thiago Mattar Cunha
- Pharmacology Department, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Tania Fátima Salvini
- Physical Therapy Department, Federal University of São Carlos, São Carlos, SP, Brazil.
| |
Collapse
|
18
|
Graber TG, Fandrey KR, Thompson LV. Novel individualized power training protocol preserves physical function in adult and older mice. GeroScience 2019; 41:165-183. [PMID: 31076998 PMCID: PMC6544743 DOI: 10.1007/s11357-019-00069-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/16/2019] [Indexed: 11/27/2022] Open
Abstract
Sarcopenia, the age-related loss of muscle mass and strength, contributes to frailty, functional decline, and reduced quality of life in older adults. Exercise is a recognized therapy for sarcopenia and muscle dysfunction, though not a cure. Muscle power declines at an increased rate compared to force, and force output declines earlier than mass. Thus, there is a need for research of exercise focusing on improving power output and functionality in older adults. Our primary purpose was proof-of-concept that a novel individualized power exercise modality would induce positive adaptations in adult mice, before the exercise program was applied to an aged cohort. We hypothesized that after following our protocol, both adult and older mice would show improved function, though there would be evidence of anabolic resistance in the older mice. Male C57BL/6 mice (12 months of age at study conclusion) were randomized into control (n = 9) and exercise (n = 6) groups. The trained group used progressive resistance (with a weighted harness) and intensity (~ 4-10 rpm) on a custom motorized running wheel. The mice trained similarly to a human workout regimen (4-5 sets/session, 3 sessions/week, for 12 weeks). We determined significant (p < 0.05) positive adaptations post-intervention, including: neuromuscular function (rotarod), strength/endurance (inverted cling grip test), training physiology (force/power output per session), muscle size (soleus mass), and power/velocity of contraction (in vitro physiology). Secondly, we trained a cohort of older male mice (28 months old at conclusion): control (n = 12) and exercised (n = 8). While the older exercised mice did preserve function and gain benefits, they also demonstrated evidence of anabolic resistance.
Collapse
Affiliation(s)
- Ted G. Graber
- Department of Nutrition and Metabolism, Division of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX USA
| | - Katie R. Fandrey
- Program in Physical Therapy, University of Minnesota-Twin Cities, Minneapolis, MN USA
| | - LaDora V. Thompson
- Department of Physical Therapy & Athletic Training, Boston University, Boston, MA USA
| |
Collapse
|
19
|
Lenell C, Newkirk B, Johnson AM. Laryngeal Neuromuscular Response to Short- and Long-Term Vocalization Training in Young Male Rats. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:247-256. [PMID: 30950702 PMCID: PMC6436889 DOI: 10.1044/2018_jslhr-s-18-0316] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 06/09/2023]
Abstract
Purpose Although vocal training is often purported to restore and rebalance laryngeal muscle function, little is known about the direct effects of vocal training on the laryngeal muscles themselves. Consequently, parameters of vocal exercise dose, such as training duration and intensity, have not been well defined. The goal of this study was to use a behavioral animal model to determine the effects of short- and long-term ultrasonic vocalization (USV) training on USV acoustics, thyroarytenoid (TA) muscle neuromuscular junctions (NMJs), and TA muscle fiber size in adult rats. Method Twenty-four young adult male Long-Evans rats were divided into 3 groups (untrained control, 4-week training, and 8-week training). Baseline and posttraining USVs were recorded and acoustically analyzed for fundamental frequency, frequency bandwidth, amplitude, and duration. Presynaptic and postsynaptic NMJ morphological features and muscle fiber size were measured in the TA. Results USV training had no effect on USV acoustics. Eight weeks of USV training, however, resulted in a lower NMJ motor endplate dispersion ratio, consistent with previous findings. USV training did not affect fiber size within the TA muscle. Conclusions This study demonstrated that 8 weeks of USV training can induce peripheral neural adaptations in the NMJ of the TA muscle in young rats. The observed adaptations suggest that vocal training is consistent with endurance-type exercise, but the adaptations occur on a longer time scale than similar adaptations in the limb muscles.
Collapse
Affiliation(s)
- Charles Lenell
- Department of Communicative Sciences and Disorders, New York University, New York
| | - Bethany Newkirk
- Paragon Rehabilitation, Creasy Springs Health Campus, Lafayette, IN
| | - Aaron M. Johnson
- Department of Communicative Sciences and Disorders, New York University, New York
- NYU Voice Center, Department of Otolaryngology–Head and Neck Surgery, New York University School of Medicine, New York
| |
Collapse
|
20
|
Choi YJ, Hee Kim Y, Bae GE, Yu JH, Yoon SZ, Kang HW, Lee KS, Kim JH, Lee YS. Relationship between the muscle relaxation effect and body muscle mass measured using bioelectrical impedance analysis: A nonrandomized controlled trial. J Int Med Res 2019; 47:1521-1532. [PMID: 30719949 PMCID: PMC6460603 DOI: 10.1177/0300060518822197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Objective The dose of neuromuscular blocking drugs is commonly based on body weight, but using muscle mass might be more effective. This study investigated the relationship between the effect of neuromuscular blocking drugs and muscle mass measured using bioelectrical impedance analysis. Methods Patients who were scheduled for elective surgery using a muscle relaxant were screened for inclusion in this study. Under intravenous anaesthesia, 12 mg or 9 mg of rocuronium was administered to males and females, respectively; and the maximal relaxation effect of T1 was measured using a TOF-Watch-SX® acceleromyograph. Results This study enrolled 40 patients; 20 males and 20 females. For both sexes, the maximal relaxation effect of T1 did not correlate with the body weight-based dose of neuromuscular blocking drugs (males, r2 = 0.12; females, r2 = 0.26). Instead, it correlated with the dose based on bioelectrical impedance analysis-measured muscle mass when injected with the same dose of rocuronium (males, r2 = 0.78, female, r2 = 0.82). Conclusions This study showed that the muscle relaxation effect of rocuronium was correlated with muscle mass and did not correlate with body weight when using the same dose. Therefore, a muscle mass-based dose of neuromuscular blocking drugs is recommended.
Collapse
Affiliation(s)
- Yoon-Ji Choi
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Yun Hee Kim
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Go Eun Bae
- 2 Maypure Clinic, Uijeongbu, Republic of Korea
| | - Joon Ho Yu
- 3 Department of Anaesthesiology and Pain Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Seung Zhoo Yoon
- 3 Department of Anaesthesiology and Pain Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Hee Won Kang
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Kuen Su Lee
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Jae-Hwan Kim
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - Yoon-Sook Lee
- 1 Department of Anaesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| |
Collapse
|
21
|
Ahtiainen JP, Lensu S, Ruotsalainen I, Schumann M, Ihalainen JK, Fachada V, Mendias CL, Brook MS, Smith K, Atherton PJ, Koch LG, Britton SL, Kainulainen H. Physiological adaptations to resistance training in rats selectively bred for low and high response to aerobic exercise training. Exp Physiol 2018; 103:1513-1523. [PMID: 30184287 DOI: 10.1113/ep087144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/03/2018] [Indexed: 01/28/2023]
Abstract
NEW FINDINGS What is the central question of this study? Can phenotypic traits associated with low response to one mode of training be extrapolated to other exercise-inducible phenotypes? The present study investigated whether rats that are low responders to endurance training are also low responders to resistance training. What is the main finding and its importance? After resistance training, rats that are high responders to aerobic exercise training improved more in maximal strength compared with low-responder rats. However, the greater gain in strength in high-responder rats was not accompanied by muscle hypertrophy, suggesting that the responses observed could be mainly neural in origin. ABSTRACT The purpose of this study was to determine whether rats selectively bred for low and high response to aerobic exercise training co-segregate for differences in muscle adaptations to ladder-climbing resistance training. Five high-responder (HRT) and five low-responder (LRT) rats completed the resistance training, while six HRT and six LRT rats served as sedentary control animals. Before and after the 6 week intervention, body composition was determined by dual energy X-ray absorptiometry. Before tissue harvesting, the right triceps surae muscles were loaded by electrical stimulation. Muscle fibre cross-sectional areas, nuclei per cell, phosphorylation status of selected signalling proteins of mTOR and Smad pathways, and muscle protein, DNA and RNA concentrations were determined for the right gastrocnemius muscle. The daily protein synthesis rate was determined by the deuterium oxide method from the left quadriceps femoris muscle. Tissue weights of fore- and hindlimb muscles were measured. In response to resistance training, maximal carrying capacity was greater in HRT (∼3.3 times body mass) than LRT (∼2.5 times body mass), indicating greater improvements of strength in HRT. However, muscle hypertrophy that could be related to greater strength gains in HRT was not observed. Furthermore, noteworthy changes within the experimental groups or differences between groups were not observed in the present measures. The lack of hypertrophic muscular adaptations despite considerable increases in muscular strength suggest that adaptations to the present ladder-climbing training in HRT and LRT rats were largely induced by neural adaptations.
Collapse
Affiliation(s)
- Juha P Ahtiainen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Sanna Lensu
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | | | - Moritz Schumann
- German Sport University, Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine, Cologne, Germany
| | - Johanna K Ihalainen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Vasco Fachada
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | | | - Matthew S Brook
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - Kenneth Smith
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - Philip J Atherton
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - Lauren G Koch
- Department of Physiology and Pharmacology, The University of Toledo, College of Medicine and Life Sciences, Toledo, OH, USA
| | - Steven L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Heikki Kainulainen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
22
|
Abstract
Age-dependent declines in muscle function are observed across species. The loss of mobility resulting from the decline in muscle function represents an important health issue and a key determinant of quality of life for the elderly. It is believed that changes in the structure and function of the neuromuscular junction are important contributors to the observed declines in motor function with increased age. Numerous studies indicate that the aging muscle is an important contributor to the deterioration of the neuromuscular junction but the cellular and molecular mechanisms driving the degeneration of the synapse remain incompletely described. Importantly, growing data from both animal models and humans indicate that exercise can rejuvenate the neuromuscular junction and improve motor function. In this review we will focus on the role of muscle-derived neurotrophin signaling in the rejuvenation of the aged neuromuscular junction in response to exercise.
Collapse
Affiliation(s)
- Tabita Kreko-Pierce
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA.,Barshoph Institute of Longevity and Aging Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA
| | - Benjamin A Eaton
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA.,Barshoph Institute of Longevity and Aging Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA
| |
Collapse
|
23
|
Krause Neto W, Silva WDA, Ciena AP, de Souza RR, Anaruma CA, Gama EF. Aging Induces Changes in the Somatic Nerve and Postsynaptic Component without Any Alterations in Skeletal Muscles Morphology and Capacity to Carry Load of Wistar Rats. Front Neurosci 2017; 11:688. [PMID: 29326543 PMCID: PMC5741656 DOI: 10.3389/fnins.2017.00688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/22/2017] [Indexed: 01/09/2023] Open
Abstract
The present study aimed to analyze the morphology of the peripheral nerve, postsynaptic compartment, skeletal muscles and weight-bearing capacity of Wistar rats at specific ages. Twenty rats were divided into groups: 10 months-old (ADULT) and 24 months-old (OLD). After euthanasia, we prepared and analyzed the tibial nerve using transmission electron microscopy and the soleus and plantaris muscles for cytofluorescence and histochemistry. For the comparison of the results between groups we used dependent and independent Student's t-test with level of significance set at p ≤ 0.05. For the tibial nerve, the OLD group presented the following alterations compared to the ADULT group: larger area and diameter of both myelinated fibers and axons, smaller area occupied by myelinated and unmyelinated axons, lower numerical density of myelinated fibers, and fewer myelinated fibers with normal morphology. Both aged soleus and plantaris end-plate showed greater total perimeter, stained perimeter, total area and stained area compared to ADULT group (p < 0.05). Yet, aged soleus end-plate presented greater dispersion than ADULT samples (p < 0.05). For the morphology of soleus and plantaris muscles, density of the interstitial volume was greater in the OLD group (p < 0.05). No statistical difference was found between groups in the weight-bearing tests. The results of the present study demonstrated that the aging process induces changes in the peripheral nerve and postsynaptic compartment without any change in skeletal muscles and ability to carry load in Wistar rats.
Collapse
Affiliation(s)
- Walter Krause Neto
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Wellington de Assis Silva
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Adriano P Ciena
- Laboratory of Morphology and Physical Activity, Department of Physical Education, São Paulo State University, Rio Claro, Brazil
| | - Romeu R de Souza
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Carlos A Anaruma
- Laboratory of Morphology and Physical Activity, Department of Physical Education, São Paulo State University, Rio Claro, Brazil
| | - Eliane F Gama
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| |
Collapse
|
24
|
Hulla R, Gatchel RJ, Liegey-Dougall A. Biopsychosocial Measures Related to Chronic Low Back Pain Postural Control in Older Adults. Healthcare (Basel) 2017; 5:E74. [PMID: 29036904 PMCID: PMC5746708 DOI: 10.3390/healthcare5040074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 09/27/2017] [Accepted: 10/09/2017] [Indexed: 11/17/2022] Open
Abstract
This study examined the biopsychosocial measures related to postural control in the growing population of older adults (i.e., 60 years and older). The sample of the study consisted of 129 older adults (M = 74.45, SD = 6.95), with 34 males and 95 females; 36 were classified with chronic low-back pain (CLBP), and 93 without chronic low-back pain (NCLBP). Physical and psychosocial constructs were analyzed as predictors for postural control measures. Additionally, gender and classification of low-back pain were examined as moderators for all physical and psychosocial measures. Results demonstrated that physical and psychosocial measures were able to significantly predict composite, visual, and vestibular balance measures, but not somatosensory or preference balance measures. The chair-stand test, modified sit-and-reach test, sleep disturbance, and balance efficacy were all identified as individually significant predictors. Gender and CLBP did not moderate the utility of any predictor variables. Results of the current study re-confirm the importance of utilizing the biopsychosocial approach for future research examining postural control in older adults.
Collapse
Affiliation(s)
- Ryan Hulla
- Department of Psychology, University of Texas at Arlington, Arlington, TX 76019, USA.
| | - Robert J Gatchel
- Department of Psychology, University of Texas at Arlington, Arlington, TX 76019, USA.
| | - Angela Liegey-Dougall
- Department of Psychology, University of Texas at Arlington, Arlington, TX 76019, USA.
| |
Collapse
|
25
|
|
26
|
Malanotte JA, Kakihata CMM, Karvat J, Brancalhão RMC, Ribeiro LDFC, Bertolini GRF. Jumping in aquatic environment after sciatic nerve compression: nociceptive evaluation and morphological characteristics of the soleus muscle of Wistar rats. EINSTEIN-SAO PAULO 2017; 15:77-84. [PMID: 28444094 PMCID: PMC5433312 DOI: 10.1590/s1679-45082017ao3613] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/28/2017] [Indexed: 11/21/2022] Open
Abstract
Objective To evaluate the effect of jumping in aquatic environment on nociception and in the soleus muscle of trained and not trained Wistar rats, in the treatment of compressive neuropathy of the sciatic nerve. Methods Twenty-five Wistar rats were distributed into five groups: Control, Lesion, Trained + Lesion, Lesion + Exercise, and Trained + Lesion + Exercise. The training was jumping exercise in water environment for 20 days prior to injury, and treatment after the injury. Nociception was evaluated in two occasions, before injury and seven after injury. On the last day of the experiment, the right soleus muscles were collected, processed and analyzed as to morphology and morphometry. Results In the assessment of nociception in the injury site, the Control Group had higher average than the rest, and the Lesion Group was larger than the Trained + Lesion and Lesion + Exercise Groups. The Control Group showed higher nociceptive threshold in paw, compared to the others. In the morphometric analysis, in relation to Control Group, all the injured groups showed decreased muscle fiber area, and in the Lesion Group was lower than in the Lesion + Exercise Group and Trained + Lesion Group. Considering the diameter of the muscle fiber, the Control Group had a higher average than the Trained + Lesion Group and the Trained + Lesion + Exercise Group; and the Lesion Group showed an average lower than the Trained + Lesion and Lesion + Exercise Groups. Conclusion Resistance exercise produced increased nociception. When performed prior or after nerve damage, it proved effective in avoiding hypotrophy. The combination of the two protocols led to decrease in diameter and area of the muscle fiber.
Collapse
Affiliation(s)
| | | | - Jhenifer Karvat
- Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brazil
| | | | | | | |
Collapse
|
27
|
Krause Neto W, de Assis Silva W, Ciena AP, Anaruma CA, Gama EF. Divergent effects of resistance training and anabolic steroid on the postsynaptic region of different skeletal muscles of aged rats. Exp Gerontol 2017; 98:80-90. [PMID: 28811140 DOI: 10.1016/j.exger.2017.08.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 02/01/2023]
Abstract
This study aimed to analyze the effects of resistance training associated with testosterone administration in the neuromuscular junction (NMJ) postsynaptic region of different skeletal muscle types of aged rats. Wistar rats were divided into: SEI - 20-months-old control, SEF - 24-months-old control, T - 20-months-old with testosterone, S - 20-months-old resistance trained and ST - 20-months-old with resistance training associated with testosterone propionate. All groups were submitted to familiarization and maximum load carrying testing (MLCT). The MLCT was applied before and after the resistance training (RT) period. RT (6-8×/session with progressive loads of 50 to 100%, 3×/week and 120s interval) was performed in ladder climbing for 15weeks. The administration of testosterone propionate was performed 2×/week (10mg/kg/body weight). After euthanize, soleus and plantaris muscles were removed and prepared for histochemistry and cytofluorescence. T, S and ST significantly increased their maximum carrying load capacity compared to SEI and SEF (p<0.05). For soleus postsynaptic region, ST had lower total and stained area than SEF (p<0.05). For plantaris, the postsynaptic component of T was statistically larger than SEI (p<0.05). For soleus histochemistry, T, S and ST groups showed the same magnitude of type I myofibers hypertrophy, thus statistically different from SEI and SEF (p<0.05). The cross-sectional area of the type IIa myofibers of the ST was larger than SEF (p<0.05). The volume density of type I myofibers show to be lower in ST than SEI (p<0.05). As for type IIa myofibers, ST increased Vv [type IIa] compared to SEI and SEF (p<0.05). For plantaris, T significantly hypertrophied type I myofibers compared to SEI and SEF (p<0.05). S and ST demonstrated significant increases of type I myofibers compared to SEI and SEF (p<0.05). As for type IIx myofibers, both S and ST showed myofibers larger than SEI (p<0.05). However, only the ST had significant difference compared to SEF (p<0.05). In conclusion, both therapies, alone or combined, have little effect on the morphology of the NMJ postsynaptic region of distinct muscles. Moreover, the three therapies are potentially stimulating for strength gains and muscle hypertrophy.
Collapse
Affiliation(s)
- Walter Krause Neto
- Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry, São Judas Tadeu University, São Paulo, SP, Brazil.
| | - Wellington de Assis Silva
- Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry, São Judas Tadeu University, São Paulo, SP, Brazil
| | - Adriano Polican Ciena
- Department of Physical Education, Laboratory of Morphology and Physical Activity, São Paulo State University "Júlio de Mesquita Filho", Rio Claro, SP, Brazil
| | - Carlos Alberto Anaruma
- Department of Physical Education, Laboratory of Morphology and Physical Activity, São Paulo State University "Júlio de Mesquita Filho", Rio Claro, SP, Brazil
| | - Eliane Florencio Gama
- Department of Physical Education, Laboratory of Morphoquantitative Studies and Immunohistochemistry, São Judas Tadeu University, São Paulo, SP, Brazil
| |
Collapse
|
28
|
Castro PATDS, Faccioni LC, Boer PA, Carvalho RF, Matheus SMM, Dal-Pai-Silva M. Neuromuscular junctions (NMJs): ultrastructural analysis and nicotinic acetylcholine receptor (nAChR) subunit mRNA expression in offspring subjected to protein restriction throughout pregnancy. Int J Exp Pathol 2017; 98:109-116. [PMID: 28543723 DOI: 10.1111/iep.12229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 02/17/2017] [Indexed: 11/29/2022] Open
Abstract
Protein restriction during gestation can alter the skeletal muscle phenotype of offspring; however, little is known with regard to whether this also affects the neuromuscular junction (NMJ), as muscle phenotype maintenance depends upon NMJ functional integrity. This study aimed to evaluate the effects of a low protein (6%) intake by dams throughout gestation on male offspring NMJ morphology and nicotinic acetylcholine receptor (nAChR) α1, γ and ε subunit expression in the soleus (SOL) and extensor digitorum longus (EDL) muscles. Four groups of male Wistar offspring rats were studied. The offspring of dams fed low-protein (6% protein, LP) and normal protein (17% protein, NP) diets were evaluated at 30 and 120 days of age, and the SOL and EDL muscles were collected for analysis. Morphological studies using transmission electron microscopy revealed that only SOL NMJs were affected in 30-day-old offspring in the LP group compared with the NP group. SOL NMJs exhibited fewer synaptic folds, the postsynaptic membranes were smooth and myelin figures were also frequently observed in the terminal axons. With regard to the expression of mRNAs encoding nAChR subunits, only 30-day-old LP offspring EDL muscles exhibited reduced α, γ and ε subunit expression compared with the NP group. In conclusion, our results demonstrate that a low-protein diet (6%) imposed throughout pregnancy impairs the expression of mRNAs encoding the nAChR α, γ and ε subunits in EDL NMJs and promotes morphological changes in SOL NMJs of 30-day-old offspring, indicating specific differences among muscle types following long-term maternal protein restriction.
Collapse
Affiliation(s)
| | | | - Patrícia Aline Boer
- Department of Internal Medicine, State University of Campinas, Campinas, São Paulo, Brazil
| | | | | | - Maeli Dal-Pai-Silva
- Department of Morphology, UNESP Institute of Biosciences, Botucatu, São Paulo, Brazil
| |
Collapse
|
29
|
Carbone PO, Krause Neto W, Gama EF, Silva WDA, Nobre TL, Caperuto EC, Mascaro MB, Souza RRD. MORPHOLOGICAL ADJUSTMENTS OF THE RADIAL NERVE ARE INTENSITY-DEPENDENT. REV BRAS MED ESPORTE 2017. [DOI: 10.1590/1517-869220172301157903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
ABSTRACT Introduction: Peripheral nerve adaptation is critical for strength gains. However, information about intensity effects on nerve morphology is scarce. Objective: To compare the effects of different intensities of resistance training on radial nerve structures. Methods: Rats were divided into three groups: control (GC), training with 50% (GF1) and training 75% (GF2) of the animal’s body weight. The morphological analysis of the nerve was done by light and transmission electron microscopy. One-way ANOVA and the Tukey’s post hoc test were applied and the significance level was set at p≤0.05. Results: Training groups had an increase of strength compared to GC (p≤0.05). All measured nerve components (mean area and diameter of myelin fibers and axons, mean area and thickness of the myelin sheath, and of neurofilaments and microtubules) were higher in GF2 compared to the other (p≤0.05). Conclusion: Results demonstrated greater morphological changes on radial nerve after heavier loads. This can be important for rehabilitation therapies, training, and progression.
Collapse
|
30
|
Kakihata CMM, Malanotte JA, Karvat J, Brancalhão RMC, de Fátima Chasko Ribeiro L, Bertolini GRF. The morphological and functional effects of exercise in the aquatic environment, performed before and/or after sciatic nerve compression in Wistar rats. J Exerc Rehabil 2016; 12:393-400. [PMID: 27807516 PMCID: PMC5091053 DOI: 10.12965/jer.1632670.335] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/27/2016] [Indexed: 12/30/2022] Open
Abstract
The aim of this study was to evaluate the effects of exercise in the aquatic environment, performed before and/or after sciatic nerve compression in Wistar rats on morphological and functional parameters. Twenty-five Wistar rats were divided into the following groups: control (C), lesion (L), trained+lesion (TL), lesion+exercise (LE), and training+lesion+exercise (TLE), who underwent right sciatic nerve compression on day 21 of the experiment. The TL and TLE groups were submitted to a jumping exercise in a water environment for 20 days prior to injury and the LE and TLE groups after injury. The functional analysis was carried out using the sciatic functional index (SFI). On the last day of the experiment, the right sciatic nerves were collected, processed and analysed according to morphology and morphometry. The C group showed higher SFI in relation to the other groups. In the morphometric analysis, in comparison to C, all groups showed a decrease in the diameter of the injured nerve fibre, the myelin sheath and an increase in the percentage of connective tissue. There was a decrease in axon diameter in L, TL, and LE groups and a decrease in the density of nerve fibres in the TL and LE groups. The exercise did not affect functional recovery. However, the exercise prior to the injury improved morphology of the nervous tissue, and when performed pre- and postinjury, there was also an improvement in nerve regeneration, but this was not the case with exercise performed after the injury demonstrating worse results.
Collapse
Affiliation(s)
| | | | - Jhenifer Karvat
- Universidade Estadual do Oeste do Paraná, Cascavel, Brazil; Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | | | | | | |
Collapse
|
31
|
Brett CN, Roberts SJ. Possible abnormal response to rocuronium in a patient taking multiple fitness supplements. Anaesth Intensive Care 2016; 44:640-1. [PMID: 27608352 DOI: 10.1177/0310057x1604400520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- C N Brett
- Specialist Anaesthetist, Department of Anaesthesia, Christchurch Hospital, Christchurch, New Zealand
| | - S J Roberts
- Anaesthesia Registrar, Anaesthesia, Christchurch Public Hospitals, Christchurch, Canterbury DHB, New Zealand
| |
Collapse
|
32
|
Rogers RS, Nishimune H. The role of laminins in the organization and function of neuromuscular junctions. Matrix Biol 2016; 57-58:86-105. [PMID: 27614294 DOI: 10.1016/j.matbio.2016.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/10/2016] [Accepted: 08/17/2016] [Indexed: 01/11/2023]
Abstract
The synapse between motor neurons and skeletal muscle is known as the neuromuscular junction (NMJ). Proper alignment of presynaptic and post-synaptic structures of motor neurons and muscle fibers, respectively, is essential for efficient motor control of skeletal muscles. The synaptic cleft between these two cells is filled with basal lamina. Laminins are heterotrimer extracellular matrix molecules that are key members of the basal lamina. Laminin α4, α5, and β2 chains specifically localize to NMJs, and these laminin isoforms play a critical role in maintenance of NMJs and organization of synaptic vesicle release sites known as active zones. These individual laminin chains exert their role in organizing NMJs by binding to their receptors including integrins, dystroglycan, and voltage-gated calcium channels (VGCCs). Disruption of these laminins or the laminin-receptor interaction occurs in neuromuscular diseases including Pierson syndrome and Lambert-Eaton myasthenic syndrome (LEMS). Interventions to maintain proper level of laminins and their receptor interactions may be insightful in treating neuromuscular diseases and aging related degeneration of NMJs.
Collapse
Affiliation(s)
- Robert S Rogers
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
| |
Collapse
|
33
|
Deschenes MR, Kressin KA, Garratt RN, Leathrum CM, Shaffrey EC. Effects of exercise training on neuromuscular junction morphology and pre- to post-synaptic coupling in young and aged rats. Neuroscience 2016; 316:167-77. [PMID: 26711679 PMCID: PMC4724510 DOI: 10.1016/j.neuroscience.2015.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/13/2015] [Accepted: 12/02/2015] [Indexed: 11/17/2022]
Abstract
The objective of this study was to determine whether pre- to post-synaptic coupling of the neuromuscular junction (NMJ) could be maintained in the face of significant morphological remodeling brought about by exercise training, and whether aging altered this capacity. Eighteen young adult (8 mo) and eighteen aged (24 mo) Fischer 344 rats were randomly assigned to either endurance trained (treadmill running) or untrained control conditions resulting in four groups (N=9/group). After the 10-week intervention rats were euthanized and hindlimb muscles were surgically removed, quickly frozen at approximate resting length and stored at -85°C. The plantaris and EDL muscles were selected for study as they have different functions (ankle extensor and ankle flexor, respectively) but both are similarly and overwhelmingly comprised of fast-twitch myofibers. NMJs were stained with immunofluorescent procedures and images were collected with confocal microscopy. Each variable of interest was analyzed with a 2-way ANOVA with main effects of age and endurance training; in all cases significance was set at P⩽0.05. Results showed that no main effects of aging were detected in NMJs of either the plantaris or the EDL. Similarly, endurance training failed to alter any synaptic parameters of EDL muscles. The same exercise stimulus in the plantaris however, resulted in significant pre- and post-synaptic remodeling, but without altering pre- to post-synaptic coupling of the NMJs. Myofiber profiles of the same plantaris and EDL muscles were also analyzed. Unlike NMJs, myofibers displayed significant age-related atrophy in both the plantaris and EDL muscles. Overall, these results confirm that despite significant training-induced reconfiguration of NMJs, pre- to post-synaptic coupling remains intact underscoring the importance of maintaining proper apposition of neurotransmitter release and binding sites so that effective nerve to muscle communication is assured.
Collapse
Affiliation(s)
- M R Deschenes
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA; Program in Neuroscience, College of William & Mary, Williamsburg, VA 23187-8795, USA.
| | - K A Kressin
- Program in Neuroscience, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - R N Garratt
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - C M Leathrum
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - E C Shaffrey
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
| |
Collapse
|
34
|
Krause Neto W, Ciena AP, Anaruma CA, de Souza RR, Gama EF. Effects of exercise on neuromuscular junction components across age: systematic review of animal experimental studies. BMC Res Notes 2015; 8:713. [PMID: 26601719 PMCID: PMC4658757 DOI: 10.1186/s13104-015-1644-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND During almost one-third of our life, maturation of the nervous system promotes strength and muscle mass increase. However, as age advances, the nervous system begins to suffer a slow and continue reduction of its functions. Neuromuscular junction (NMJ) is one of the structures of which change due to aging process. Physical training leads to significant adjustments in NMJs of young and aged animals. Nevertheless, studies that aimed to investigate this effect have, in many cases, methodological variables that may have some influence on the result. Thus, this study aimed to carry out a systematic review about the effects of exercise training on the NMJ compartments of young, adult and aged animals. RESULTS We searched PubMed, Google Scholar, Science Direct, Scielo and Lilacs databases for animal experimental studies that studied exercise effects on the NMJs components across age. After inclusion and exclusion criteria, we included nine articles in systematic review and two for meta-analysis (young/adult NMJ). CONCLUSIONS We identified that exercise training cause NMJ hypertrophy on young animals and NMJ compression on aged ones. However, many methodological issues such as age, skeletal muscle and fibers type, and type of exercise and training protocol might influence the results. Graphical abstract: Flow gram is actually to be show at results section as Fig 1.
Collapse
Affiliation(s)
- Walter Krause Neto
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
| | - Adriano Polican Ciena
- Laboratory of Histology and Electron Microscopy, Physical Education Department, "Julio de Mesquita Filho" São Paulo State University, Rio Claro, SP, Brazil.
| | - Carlos Alberto Anaruma
- Laboratory of Histology and Electron Microscopy, Physical Education Department, "Julio de Mesquita Filho" São Paulo State University, Rio Claro, SP, Brazil.
| | - Romeu Rodrigues de Souza
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
| | - Eliane Florencio Gama
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
| |
Collapse
|
35
|
Goebel RT, Kleinöder H, Yue Z, Gosh R, Mester J. Effect of Segment-Body Vibration on Strength Parameters. SPORTS MEDICINE-OPEN 2015; 1:14. [PMID: 26258006 PMCID: PMC4526247 DOI: 10.1186/s40798-015-0022-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 05/21/2015] [Indexed: 12/19/2022]
Abstract
Background In this study, we examine the biomechanical advantage of combining localized vibrations to hamstring muscles involved in a traditional resistance training routine. Methods Thirty-six male and female participants with at least 2 years of experience in resistance training were recruited from the German Sport University Cologne. The participants were randomized into two training groups: vibration training group (VG) and traditional training group (TTG). Both groups underwent a 4-week training phase, where each participant worked out at 70 % of the individual 1 repeat maximum (RM—maximum load capacity of a muscle for one lift to fatigue) (4 sets with 12 repetitions each). For participants in the VG group, local vibration was additionally applied directly to hamstring muscles during exercise. A 2-week examination phase preceded the pretests. After the pretests, the subjects underwent a prescribed training for 4 weeks. At the conclusion of the training, a 2-week detraining was imposed and then the study concluded with posttests and retest. Results The measured parameters were maximum isometric force of the hamstrings and maximum range of motion and muscle tension at maximum knee angle. The study revealed a significant increase in maximum isometric force in both training groups (VG = 21 %, TTG = 14 %). However, VG groups showed an increase in their range of motion by approximately 2 %. Moreover, the muscle tension at maximum knee angle increased less in VG (approximately 35 %) compared to TG (approximately 46 %). Conclusions We conclude that segment-body vibrations applied in resistance training can offer an effective tool to increase maximum isometric force, compared to traditional training. The cause for these findings can be attributed to the additional local vibration stimulus.
Collapse
Affiliation(s)
| | - Heinz Kleinöder
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| | - Zengyuan Yue
- The German Research Center, Center of Elite Sport, German Sport University Cologne, Cologne, Germany
| | - Ranajay Gosh
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA USA
| | - Joachim Mester
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Cologne, Germany
| |
Collapse
|
36
|
Hicks MR, Cao TV, Standley PR. Biomechanical strain vehicles for fibroblast-directed skeletal myoblast differentiation and myotube functionality in a novel coculture. Am J Physiol Cell Physiol 2014; 307:C671-83. [PMID: 25122874 DOI: 10.1152/ajpcell.00335.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Skeletal muscle functionality is governed by multiple stimuli, including cytokines and biomechanical strain. Fibroblasts embedded within muscle connective tissue respond to biomechanical strain by secreting cytokines that induce myoblast differentiation and, we hypothesize, regulate myotube function. A coculture was established to allow cross talk between fibroblasts in Bioflex wells and myoblasts on nondeformable coverslips situated above Bioflex wells. Cyclic short-duration strain (CSDS) modeling repetitive stress/injury, acyclic long-duration strain (ALDS) modeling manipulative therapy, and combined strain paradigms (CSDS + ALDS) were applied to fibroblasts. Nonstrained myoblasts in uniculture and coculture served as controls. After fibroblasts had induced myoblast differentiation, myotube contraction was assessed by perfusion of ACh (10(-11)-10(-3) M). CSDS-treated fibroblasts increased myotube contractile sensitivity vs. uniculture (P < 0.05). As contraction is dependent on ACh binding, expression and clustering of nicotinic ACh receptors (nAChRs) were measured. CSDS-treated fibroblasts increased nAChR expression (P < 0.05), which correlated with myotube contraction. ALDS-treated fibroblasts did not significantly affect contraction or nAChR expression. Agrin-treated myotubes were then used to design a computer algorithm to identify α-bungarotoxin-stained nAChR clusters. ALDS-treated fibroblasts increased nAChR clustering (P < 0.05), while CSDS-treated fibroblasts disrupted cluster formation. CSDS-treated fibroblasts produced nAChRs preferentially located in nonclustered regions (P < 0.05). Strain-activated fibroblasts mediate myotube differentiation with multiple functional phenotypes. Similar to muscle injury, CSDS-treated fibroblasts disrupted nAChR clusters and hypersensitized myotube contraction, while ALDS-treated fibroblasts aggregated nAChRs in large clusters, which may have important clinical implications. Cellular strategies aimed at improving muscle functionality, such as through biomechanical strain vehicles that activate fibroblasts to stabilize postsynaptic nAChRs on nearby skeletal muscle, may serve as novel targets in neuromuscular disorders.
Collapse
Affiliation(s)
- Michael R Hicks
- The University of Arizona College of Medicine-Phoenix, Phoenix, Arizona; and School of Life Sciences, Arizona State University, Tempe, Arizona
| | - Thanh V Cao
- The University of Arizona College of Medicine-Phoenix, Phoenix, Arizona; and
| | - Paul R Standley
- The University of Arizona College of Medicine-Phoenix, Phoenix, Arizona; and
| |
Collapse
|
37
|
Deschenes MR, Sherman EG, Roby MA, Glass EK, Harris MB. Effect of resistance training on neuromuscular junctions of young and aged muscles featuring different recruitment patterns. J Neurosci Res 2014; 93:504-13. [PMID: 25287122 DOI: 10.1002/jnr.23495] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/21/2014] [Accepted: 09/10/2014] [Indexed: 11/08/2022]
Abstract
To examine the effects of aging on neuromuscular adaptations to resistance training (i.e., weight lifting), young (9 months of age) and aged (20 months of age) male rats either participated in a 7-week ladder climbing protocol with additional weight attached to their tails or served as controls (n = 10/group). At the conclusion, rats were euthanized and hindlimb muscles were quickly removed and frozen for later analysis. Longitudinal sections of the soleus and plantaris muscles were collected, and pre- and postsynaptic features of neuromuscular junctions (NMJs) were visualized with immunofluorescence staining procedures. Cross-sections of the same muscles were histochemically stained to determine myofiber profiles (fiber type and size). Statistical analysis was by two-way ANOVA (main effects of age and treatment) with significance set at P ≤ 0.05. Results revealed that training-induced remodeling of NMJs was evident only at the postsynaptic endplate region of soleus fast-twitch myofibers. In contrast, aging was associated with pre- and postsynaptic remodeling in fast- and slow-twitch myofibers of the plantaris. Although both the soleus and the plantaris muscles failed to display either training or aging-related alterations in myofiber size, aged plantaris muscles exhibited an increased expression of type I (slow-twitch) myofibers in conjunction with a reduced percentage of type II (fast-twitch) myofibers, suggesting early stages of sarcopenia. These data demonstrate the high degree of specificity of synaptic modifications made in response to exercise and aging and that the sparsely recruited plantaris is more vulnerable to the effects of aging than the more frequently recruited soleus muscle.
Collapse
Affiliation(s)
- Michael R Deschenes
- Department of Kinesiology and Health Sciences, The College of William and Mary, Williamsburg, Virginia; Program in Neuroscience, The College of William and Mary, Williamsburg, Virginia
| | | | | | | | | |
Collapse
|
38
|
Rudolf R, Khan MM, Labeit S, Deschenes MR. Degeneration of neuromuscular junction in age and dystrophy. Front Aging Neurosci 2014; 6:99. [PMID: 24904412 PMCID: PMC4033055 DOI: 10.3389/fnagi.2014.00099] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/08/2014] [Indexed: 12/27/2022] Open
Abstract
Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions (NMJs) serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and post-synaptic origin. Consequently, NMJs are good indicators of motor health on a systemic level. Indeed, upon sarcopenia and dystrophy, NMJs morphologically deteriorate and exhibit altered characteristics of primary signaling molecules, such as nicotinic acetylcholine receptor and agrin. Since a remarkable reversibility of these changes can be observed by exercise, there is significant interest in understanding the molecular mechanisms underlying synaptic deterioration upon aging and dystrophy and how synapses are reset by the aforementioned treatments. Here, we review the literature that describes the phenomena observed at the NMJ in sarcopenic and dystrophic muscle as well as to how these alterations can be reversed and to what extent. In a second part, the current information about molecular machineries underlying these processes is reported.
Collapse
Affiliation(s)
- Rüdiger Rudolf
- Institute of Molecular and Cell Biology, University of Applied Sciences Mannheim , Mannheim , Germany ; Institute of Medical Technology, University of Heidelberg and University of Applied Sciences Mannheim , Mannheim , Germany ; Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , Eggenstein-Leopoldshafen , Germany
| | - Muzamil Majid Khan
- Institute of Molecular and Cell Biology, University of Applied Sciences Mannheim , Mannheim , Germany ; Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , Eggenstein-Leopoldshafen , Germany
| | - Siegfried Labeit
- Institute of Integrative Pathophysiology, University Medical Centre Mannheim , Mannheim , Germany
| | - Michael R Deschenes
- Department of Kinesiology and Health Sciences, The College of William and Mary , Williamsburg, VA , USA
| |
Collapse
|
39
|
Nishimune H, Stanford JA, Mori Y. Role of exercise in maintaining the integrity of the neuromuscular junction. Muscle Nerve 2013; 49:315-24. [PMID: 24122772 DOI: 10.1002/mus.24095] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2013] [Indexed: 01/16/2023]
Abstract
Physical activity plays an important role in preventing chronic disease in adults and the elderly. Exercise has beneficial effects on the nervous system, including at the neuromuscular junction (NMJ). Exercise causes hypertrophy of NMJs and improves recovery from peripheral nerve injuries, whereas decreased physical activity causes degenerative changes in NMJs. Recent studies have begun to elucidate molecular mechanisms underlying the beneficial effects of exercise. These mechanisms involve Bassoon, neuregulin-1, peroxisome proliferator-activated receptor gamma coactivator 1α, insulin-like growth factor-1, glial cell line-derived neurotrophic factor, neurotrophin 4, Homer, and nuclear factor of activated T cells c1. For example, NMJ denervation and active zone decreases have been observed in aged NMJs, but these age-dependent degenerative changes can be ameliorated by exercise. In this review we assess the effects of exercise on the maintenance and regeneration of NMJs and highlight recent insights into the molecular mechanisms underlying these exercise effects.
Collapse
Affiliation(s)
- Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Boulevard, MS 3051, HLSIC Room 2073, Kansas City, Kansas, 66160, USA
| | | | | |
Collapse
|
40
|
Adams GR, Bamman MM. Characterization and regulation of mechanical loading-induced compensatory muscle hypertrophy. Compr Physiol 2013; 2:2829-70. [PMID: 23720267 DOI: 10.1002/cphy.c110066] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In mammalian systems, skeletal muscle exists in a dynamic state that monitors and regulates the physiological investment in muscle size to meet the current level of functional demand. This review attempts to consolidate current knowledge concerning development of the compensatory hypertrophy that occurs in response to a sustained increase in the mechanical loading of skeletal muscle. Topics covered include: defining and measuring compensatory hypertrophy, experimental models, loading stimulus parameters, acute responses to increased loading, hyperplasia, myofiber-type adaptations, the involvement of satellite cells, mRNA translational control, mechanotransduction, and endocrinology. The authors conclude with their impressions of current knowledge gaps in the field that are ripe for future study.
Collapse
Affiliation(s)
- Gregory R Adams
- Department of Physiology and Biophysics, University of California Irvine, Irvine, California, USA.
| | | |
Collapse
|
41
|
Kraemer WJ, Flanagan SD, Volek JS, Nindl BC, Vingren JL, Dunn-Lewis C, Comstock BA, Hooper DR, Szivak TK, Looney DP, Maresh CM, Hymer WC. Resistance exercise induces region-specific adaptations in anterior pituitary gland structure and function in rats. J Appl Physiol (1985) 2013; 115:1641-7. [PMID: 24092688 DOI: 10.1152/japplphysiol.00687.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The anterior pituitary gland (AP) increases growth hormone (GH) secretion in response to resistance exercise (RE), but the nature of AP adaptations to RE is unknown. To that end, we examined the effects of RE on regional AP somatotroph GH release, structure, and relative quantity. Thirty-six Sprague-Dawley rats were assigned to one of four groups: 1) no training or acute exercise (NT-NEX); 2) no training with acute exercise (NT-EX); 3) resistance training without acute exercise (RT-NEX); 4) resistance training with acute exercise (RT-EX). RE incorporated 10, 1 m-weighted ladder climbs at an 85° angle. RT groups trained 3 days/wk for 7 wk, progressively. After death, trunk blood was collected, and each AP was divided into quadrants (ventral-dorsal and left-right). We measured: 1) trunk plasma GH; 2) somatotroph GH release; 3) somatotroph size; 4) somatotroph secretory content; and 5) percent of AP cells identified as somatotrophs. Trunk GH differed by group (NT-NEX, 8.9 ± 2.4 μg/l; RT-NEX, 9.2 ± 3.5 μg/l; NT-EX, 15.6 ± 3.4 μg/l; RT-EX, 23.4 ± 4.6 μg/l). RT-EX demonstrated greater somatotroph GH release than all other groups, predominantly in ventral regions (P < 0.05-0.10). Ventral somatotrophs were larger in NT-EX and RT-NEX compared with RT-EX (P < 0.05-0.10). RT-NEX exhibited significantly greater secretory granule content than all other groups but in the ventral-right region only (P < 0.05-0.10). Our findings indicate reproducible patterns of spatially distinct, functionally different somatotroph subpopulations in the rat pituitary gland. RE training appears to induce dynamic adaptations in somatotroph structure and function.
Collapse
Affiliation(s)
- William J Kraemer
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Effects of endurance and resistance training on calcitonin gene-related Peptide and acetylcholine receptor at slow and fast twitch skeletal muscles and sciatic nerve in male wistar rats. INTERNATIONAL JOURNAL OF PEPTIDES 2012; 2012:962651. [PMID: 22754579 PMCID: PMC3382945 DOI: 10.1155/2012/962651] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 03/10/2012] [Accepted: 04/08/2012] [Indexed: 11/17/2022]
Abstract
The aim of this study was to investigate effects of endurance and resistance training (ET and RT) on CGRP and AChRs at slow and fast twitch muscles and sciatic nerve in rats. Twenty-five male rats were randomly assigned into three groups including sedentary (SED), endurance training (ET), and resistance training (RT). Animals of ET exercised for 12 weeks, five times/week, and 60 min/day at 30 m/min. Animals of RT were housed in metal cage with 2 m high wire-mesh tower, with water bottles set at the top. 48 h after the last session of training protocol, animals were anaesthetized. The right sciatic nerves were removed; then, Soleus (SOL) and Tibialis anterior (TA) muscles were excised and immediately snap frozen in liquid nitrogen. All frozen tissues were stored at -80°C. Results showed that, after both ET and RT, CGRP content as well as AChR content of SOL and TA muscles significantly increased. But there was no significant difference among groups at sciatic nerve' CGRP content. In conclusion, data demonstrate that ET and RT lead to changes of CGRP and AChR content of ST and FT muscles. The changes indicate to the importance of neuromuscular activity.
Collapse
|
43
|
Behan M, Moeser AE, Thomas CF, Russell JA, Wang H, Leverson GE, Connor NP. The effect of tongue exercise on serotonergic input to the hypoglossal nucleus in young and old rats. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2012; 55:919-29. [PMID: 22232395 PMCID: PMC3326185 DOI: 10.1044/1092-4388(2011/11-0091)] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
PURPOSE Breathing and swallowing problems affect elderly people and may be related to age-associated tongue dysfunction. Hypoglossal motoneurons that innervate the tongue receive a robust, excitatory serotonergic (5HT) input and may be affected by aging. We used a rat model of aging and progressive resistance tongue exercise to determine whether age-related alterations in 5HT inputs to the hypoglossal nucleus can be modified. We hypothesized that tongue forces would increase with exercise, 5HT input to the tongue would decrease with age, and tongue exercise would augment 5HT input to the hypoglossal nucleus. METHOD Young (9-10 months), middle-aged (24-25 months), and old (32-33 months) male F344/BN rats received tongue exercise for 8 weeks. Immunoreactivity for 5HT was measured in digital images of sections through the hypoglossal nucleus using ImageJ software. RESULTS Tongue exercise resulted in increased maximum tongue forces at all ages. There was a statistically significant increase in 5HT immunoreactivity in the hypoglossal nucleus in exercised, young rats but only in the caudal third of the nucleus and primarily in the ventral half. CONCLUSION Specificity found in serotonergic input following exercise may reflect the topographic organization of motoneurons in the hypoglossal nucleus and the tongue muscles engaged in the exercise paradigm.
Collapse
|
44
|
Abstract
Potentiation has been reported in power tasks immediately following a strength stimulus; however, only whole-body performance has been assessed. To determine the acute effects of weightlifting on vertical jump joint kinetics, performance was assessed before, during, and after snatch pull exercise in male athletes. Jumping was assessed using 3D motion analysis and inverse dynamics. Jump height was enhanced at the midpoint (5.77%; p = .001) and end (5.90%; p < .001) of the exercise session, indicating a greater power-generating ability. At the midpoint, knee extensor net joint work was increased (p = .05) and associated with increased jump height (r = .57; p = .02). Following exercise, ankle plantar flexor net joint work was increased (p = .02) and associated with increased jump height (r = .67; p = .006). Snatch pull exercise elicited acute enhancements in vertical jump performance. At the midpoint of the exercise session, greater work at the knee joint contributed to enhanced performance. At the end of the exercise session, greater work at the ankle contributed to enhanced performance. Consequently, potentiation is not elicited uniformly across joints during multijoint exercise.
Collapse
|
45
|
Bobinski F, Martins D, Bratti T, Mazzardo-Martins L, Winkelmann-Duarte E, Guglielmo L, Santos A. Neuroprotective and neuroregenerative effects of low-intensity aerobic exercise on sciatic nerve crush injury in mice. Neuroscience 2011; 194:337-48. [DOI: 10.1016/j.neuroscience.2011.07.075] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/28/2011] [Accepted: 07/30/2011] [Indexed: 11/17/2022]
|
46
|
Salanova M, Bortoloso E, Schiffl G, Gutsmann M, Belavy DL, Felsenberg D, Furlan S, Volpe P, Blottner D. Expression and regulation of Homer in human skeletal muscle during neuromuscular junction adaptation to disuse and exercise. FASEB J 2011; 25:4312-25. [PMID: 21885651 DOI: 10.1096/fj.11-186049] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Protein calcium sensors of the Homer family have been proposed to modulate the activity of various ion channels and nuclear factor of activated T cells (NFAT), the transcription factor modulating skeletal muscle differentiation. We monitored Homer expression and subcellular localization in human skeletal muscle biopsies following 60 d of bedrest [Second Berlin Bedrest Study (BBR2-2)]. Soleus (SOL) and vastus lateralis (VL) biopsies were taken at start (pre) and at end (end) of bedrest from healthy male volunteers of a control group without exercise (CTR; n=9), a resistive-only exercise group (RE; n=7), and a combined resistive/vibration exercise group (RVE; n=7). Confocal analysis showed Homer immunoreactivity at the postsynaptic microdomain of the neuromuscular junction (NMJ) at bedrest start. After bedrest, Homer immunoreactivity decreased (CTR), remained unchanged (RE), or increased (RVE) at the NMJ. Homer2 mRNA and protein were differently regulated in a muscle-specific way. Activated NFATc1 translocates from cytoplasm to nucleus; increased amounts of NFATc1-immunopositive slow-type myonuclei were found in RVE myofibers of both muscles. Pulldown assays identified NFATc1 and Homer as molecular partners in skeletal muscle. A direct motor nerve control of Homer2 was confirmed in rat NMJs by in vivo denervation. Homer2 is localized at the NMJ and is part of the calcineurin-NFATc1 signaling pathway. RVE has additional benefit over RE as countermeasure preventing disuse-induced neuromuscular maladaptation during bedrest.
Collapse
Affiliation(s)
- Michele Salanova
- Center of Space Medicine Berlin, Neuromuscular Group, Institute of Anatomy, Charité Universitätsmedizin Berlin, Campus Charité Mitte, Philippstrasse 12, 10115, Berlin, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
McMullen CA, Butterfield TA, Dietrich M, Andreatta RD, Andrade FH, Fry L, Stemple JC. Chronic stimulation-induced changes in the rodent thyroarytenoid muscle. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2011; 54:845-853. [PMID: 21106694 DOI: 10.1044/1092-4388(2010/10-0127)] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PURPOSE Therapies for certain voice disorders purport principles of skeletal muscle rehabilitation to increase muscle mass, strength, and endurance. However, applicability of limb muscle rehabilitation to the laryngeal muscles has not been tested. In this study, the authors examined the feasibility of the rat thyroarytenoid muscle to remodel as a consequence of increased activity instantiated through chronic electrical stimulation. METHOD Twenty adult Sprague-Dawley rats (Rattus norvegicus), assigned to a 1-week or 2-week stimulation group, were implanted with a nerve cuff electrode placed around the right recurrent laryngeal nerve and were fitted with a head connector. All animals were placed under anesthesia twice a day for 1 hr each time. Following the training, rats were killed, and thyroarytenoid muscles were isolated for histology and immunohistochemistry. RESULTS Mean muscle fiber area decreased, neuromuscular junction density increased, mitochondrial content increased qualitatively, and glycogen-positive fibers increased, demonstrating exercise-induced changes similar to those seen in limb muscles after endurance training. CONCLUSION Rat thyroarytenoid muscles are capable of remodeling in response to chronic electrical stimulation.
Collapse
|
48
|
Johnson AM, Connor NP. Effects of electrical stimulation on neuromuscular junction morphology in the aging rat tongue. Muscle Nerve 2011; 43:203-11. [PMID: 21254085 DOI: 10.1002/mus.21819] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alterations in neuromuscular junction (NMJ) structure in cranial muscles may contribute to age-related deficits in critical sensorimotor actions such as swallowing. Neuromuscular electrical stimulation (NMES) is used in swallowing therapy, but it is unclear how NMJ structure is affected or if NMJ morphology is best measured in two or three dimensions. Two- and three-dimensional measurements of NMJ morphology in the genioglossus muscle were compared in rats that had undergone 8 weeks of hypoglossal nerve stimulation vs. untreated controls. The relationship between motor endplate volume and nerve terminal volume had a mean positive slope in 90% of the young adult controls, but it was positive in only 50% of the old controls; 89% of NMES old rats had a positive slope. NMJ measurements were more accurate when measured in three dimensions. In the NMJ, aging and NMES are associated with changes in the pre- and post-synaptic relationship.
Collapse
Affiliation(s)
- Aaron M Johnson
- Department of Surgery, University of Wisconsin-Madison, Madison, WI 53792, USA
| | | |
Collapse
|
49
|
McCullough MJ, Peplinski NG, Kinnell KR, Spitsbergen JM. Glial cell line-derived neurotrophic factor protein content in rat skeletal muscle is altered by increased physical activity in vivo and in vitro. Neuroscience 2010; 174:234-44. [PMID: 21081155 DOI: 10.1016/j.neuroscience.2010.11.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 10/27/2010] [Accepted: 11/10/2010] [Indexed: 01/14/2023]
Abstract
Current evidence suggests that exercise and glial cell line-derived neurotrophic factor (GDNF) independently cause significant morphological changes in the neuromuscular system. The aim of the current study was to determine if increased physical activity regulates GDNF protein content in rat skeletal muscle. Extensor Digitorum Longus (EDL) and Soleus (SOL) hind limb skeletal muscles were analyzed following 2 weeks of involuntary exercise and 4 h of field stimulation or stretch in muscle bath preparations. GDNF protein content was measured via enzyme-linked immunosorbent assay (ELISA). Two weeks of exercise increased GDNF protein content in SOL as compared to sedentary controls (4.4±0.3 pg GDNF/mg tissue and 3.1±0.6 pg GDNF/mg tissue, respectively) and decreased GDNF protein content in EDL as compared to controls (1.0±0.1 pg GDNF/mg tissue and 2.3±0.7 pg GDNF/mg tissue, respectively). GDNF protein content in the EDL decreased following both field stimulation (56%±18% decrease from controls) and stretch (66%±10% decrease from controls). SOL responded to field stimulation with a 38%±7% increase from controls in GDNF protein content, but showed no change following stretch. Pre-treatment with α-bungarotoxin abolished the effects of field stimulation in both muscles and blocked the effect of stretch in EDL. α-bungarotoxin pre-treatment and stretch increased GDNF protein content to 240%±10% of controls in the SOL. Exposure to carbamylcholine decreased GDNF protein content to 51%±28% of controls in the EDL but not SOL. These results suggest that GDNF protein content in skeletal muscle may be controlled by stretch, where it may increase GDNF protein content, and membrane depolarization/acetylcholine (ACh) which acts to decrease GDNF protein content.
Collapse
Affiliation(s)
- M J McCullough
- Western Michigan University, Department of Biological Sciences, 1903 W. Michigan Avenue, Kalamazoo, MI 49008-5410, USA
| | | | | | | |
Collapse
|
50
|
Aboussouan LS. Mechanisms of exercise limitation and pulmonary rehabilitation for patients with neuromuscular disease. Chron Respir Dis 2010; 6:231-49. [PMID: 19858353 DOI: 10.1177/1479972309345927] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Indications for exercise and pulmonary rehabilitation extend to neuromuscular diseases tough these conditions pose particular challenges given the associated skeletal muscle impairment and respiratory muscle dysfunction. These challenges are compounded by the variety of exercise prescriptions (aerobic, muscle strengthening, and respiratory muscle training) and the variety of neuromuscular disorders (muscular, motor neuron, motor nerve root, and neuromuscular transmission disorders). Studies support a level II evidence of effectiveness (i.e., likely to be effective) for a combination of aerobic exercise and strengthening exercises in muscular disorders, and for strengthening exercises in amyotrophic lateral sclerosis. The potential deleterious effects of work overload in the dystrophinopathies have not been confirmed in Becker muscular dystrophy. Adjunctive pharmacologic interventions (e.g., theophylline, steroids, PDE5 inhibitors, creatine), training recommendations (e.g., interval or lower intensity training) and supportive techniques (e.g., noninvasive ventilation, neuromuscular electrical stimulation, and diaphragm pacing) may result in more effective training but require more study before formal recommendations can be made. The exercise prescription should include avoidance of inspiratory muscle training in hypercapnia or low vital capacity, and should match the desired outcome (e.g., extremity training for task-specific performance, exercise training to enhance exercise performance, respiratory muscle training where respiratory muscle involvement contributes to the impairment).
Collapse
Affiliation(s)
- L S Aboussouan
- Cleveland Clinic Foundation, Respiratory Institute, Cleveland, OH 44195, USA.
| |
Collapse
|