Este trabalho foi financiado pela AHA SDG 10SDG2630086 de Zhao X, RO1-AR061385 a Ma J e Grant GO RC2AR05896 para Brotto M.

<ol>
	<li>Winegrad, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+intracellular+calcium+movements+in+excitation-contraction+coupling+in+skeletal+muscle.">Role of intracellular calcium movements in excitation-contraction coupling in skeletal muscle.</a> Fed. 24, 1146-1152 (1965).</li><li>Sandow, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Excitation-contraction+coupling+in+skeletal+muscle.">Excitation-contraction coupling in skeletal muscle.</a> Pharmacol. Rev. 17, 265-320 (1965).</li><li>Thornton, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Store-operated+Ca(2+)+entry+(SOCE)+contributes+to+normal+skeletal+muscle+contractility+in+young+but+not+in+aged+skeletal+muscle.">Store-operated Ca(2+) entry (SOCE) contributes to normal skeletal muscle contractility in young but not in aged skeletal muscle.</a> Aging. 3, 621-634 (2011).</li><li>Zhao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2++overload+and+sarcoplasmic+reticulum+instability+in+tric-a+null+skeletal+muscle.">Ca2+ overload and sarcoplasmic reticulum instability in tric-a null skeletal muscle.</a> J. Biol. Chem. 285, 37370-37376 (2010).</li><li>Brotto, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Defective+maintenance+of+intracellular+Ca2++homeostasis+is+linked+to+increased+muscle+fatigability+in+the+MG29+null+mice.">Defective maintenance of intracellular Ca2+ homeostasis is linked to increased muscle fatigability in the MG29 null mice.</a> Cell Res. 14, 373-378 (2004).</li><li>Florkin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Machina+carnis.+The+Biochemistry+of+Muscular+Contraction+in+its+Historical+Development.">Machina carnis. The Biochemistry of Muscular Contraction in its Historical Development.</a> Med. Hist. 17, 316-317 (1973).</li><li>Galvani, A., Aldini, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=De+viribus+electricitatis+in+motu+musculari+commentarius.">De viribus electricitatis in motu musculari commentarius.</a> ApudSocietatem Typographicam. , (1792).</li><li>Fulton, J. F., Fulton, J. F., Wilson, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Selected Reading in the History of Physiology. , (1930).</li><li>Piccolino, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Luigi+Galvani+and+animal+electricity:+two+centuries+after+the+foundation+of+electrophysiology.">Luigi Galvani and animal electricity: two centuries after the foundation of electrophysiology.</a> Trends Neurosci. 20, 443-448 (1997).</li><li>Hodgkin, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Croonian+Lecture:+Ionic+Movements+and+Electrical+Activity+in+Giant+Nerve+Fibres.">The Croonian Lecture: Ionic Movements and Electrical Activity in Giant Nerve Fibres.</a> Proceedings of the Royal Society of London. Series B, Biological Sciences. 148, 1-37 (1958).</li><li>Hodgkin, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Sherrington Lectures VII the Conduction of the Nervous Impulse. , 71964 (1965).</li><li>Ringer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+further+contribution+regarding+the+influence+of+the+different+constituents+of+the+blood+on+the+contraction+of+the+heart.">A further contribution regarding the influence of the different constituents of the blood on the contraction of the heart.</a> J. Physiol. 4, 29-42.3 .</li><li>Ringer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Further+experiments+regarding+the+influence+of+small+quantities+of+lime,+and+other+salts+on+muscular+tissue.">Further experiments regarding the influence of small quantities of lime, and other salts on muscular tissue.</a> J. Physiol. 7, 291-308 .</li><li>Ringer, S., Buxton, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concerning+the+action+of+calcium,+potassium+and+sodium+salts+upon+the+eel's+heart+and+upon+the+skeletal+muscles+of+the+frog.">Concerning the action of calcium, potassium and sodium salts upon the eel's heart and upon the skeletal muscles of the frog.</a> J. Physiol. 8, 15-19 .</li><li>Ringer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regarding+the+action+of+lime,+potassium+and+sodium+salts+on+skeletal+muscle.">Regarding the action of lime, potassium and sodium salts on skeletal muscle.</a> J. Physiol. 8, 20-24 (1887).</li><li>Campbell, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Intracellular Calcium its Universal Role as Regulator. , (1983).</li><li>Mol, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Cell Cardiol. 16, ll3-ll6 (1984).</li><li>Ridings, J. W., Barry, S. R., Faulkner, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aminophylline+enhances+contractility+of+frog+skeletal+muscle:+an+effect+dependent+on+extracellular+calcium.">Aminophylline enhances contractility of frog skeletal muscle: an effect dependent on extracellular calcium.</a> J. Appl. Physiol. 67, 671-676 (1989).</li><li>Fitts, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cross-bridge+cycle+and+skeletal+muscle+fatigue.">The cross-bridge cycle and skeletal muscle fatigue.</a> J. Appl. Physiol. 104, 551-558 (2008).</li><li>Kolbeck, R. C., Speir, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diaphragm+contactility+as+related+to+cellular+calcium+metabolism:+Influence+of+theophylline+and+fatigue.">Diaphragm contactility as related to cellular calcium metabolism: Influence of theophylline and fatigue.</a> American Review of Respiratory Disease. 139, 495 (1989).</li><li>Kolbeck, R. C., Nosek, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fatigue+of+rapid+and+slow+onset+in+isolated+perfused+rat+and+mouse+diaphragms.">Fatigue of rapid and slow onset in isolated perfused rat and mouse diaphragms.</a> J. Appl. Physiol. 77, 1991-1998 (1994).</li><li>Moore, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diaphragm+atrophy+and+weakness+in+cortisone-treated+rats.">Diaphragm atrophy and weakness in cortisone-treated rats.</a> J. Appl. Physiol. 67, 2420-2426 (1989).</li><li>Lannergren, J., Westerblad, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Force+decline+due+to+fatigue+and+intracellular+acidification+in+isolated+fibres+from+mouse+skeletal+muscle.">Force decline due to fatigue and intracellular acidification in isolated fibres from mouse skeletal muscle.</a> J. Physiol. 434, 307-322 (1991).</li><li>Westerblad, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+gradients+of+intracellular+calcium+in+skeletal+muscle+during+fatigue.">Spatial gradients of intracellular calcium in skeletal muscle during fatigue.</a> Pflugers Arch. 415, 734-740 (1990).</li><li>Zhao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+resistance+to+fatigue+and+altered+calcium+handling+properties+of+sarcalumenin+knockout+mice.">Enhanced resistance to fatigue and altered calcium handling properties of sarcalumenin knockout mice.</a> Physiol. Genomics. 23, 72-78 (2005).</li><li>Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardioprotection+of+ischemia/reperfusion+injury+by+cholesterol-dependent+MG53-mediated+membrane+repair.">Cardioprotection of ischemia/reperfusion injury by cholesterol-dependent MG53-mediated membrane repair.</a> Circ. Res. 107, 76-83 (2010).</li><li>Cai, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MG53+nucleates+assembly+of+cell+membrane+repair+machinery.">MG53 nucleates assembly of cell membrane repair machinery.</a> Nat. Cell Biol. 11, 56-64 (2009).</li><li>Shen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deficiency+of+MIP/MTMR14+phosphatase+induces+a+muscle+disorder+by+disrupting+Ca(2+)+homeostasis.">Deficiency of MIP/MTMR14 phosphatase induces a muscle disorder by disrupting Ca(2+) homeostasis.</a> Nat. Cell Biol. 11, 769-776 (2009).</li><li>Romero-Suarez, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Muscle-specific+inositide+phosphatase+(MIP/MTMR14)+is+reduced+with+age+and+its+loss+accelerates+skeletal+muscle+aging+process+by+altering+calcium+homeostasis.">Muscle-specific inositide phosphatase (MIP/MTMR14) is reduced with age and its loss accelerates skeletal muscle aging process by altering calcium homeostasis.</a> Aging (Albany NY). 2, 504-513 (2010).</li><li>Yazawa, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TRIC+channels+are+essential+for+Ca2++handling+in+intracellular+stores.">TRIC channels are essential for Ca2+ handling in intracellular stores.</a> Nature. 448, 78-82 (2007).</li><li>Brotto, M. A., Nosek, T. M., Kolbeck, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+ageing+on+the+fatigability+of+isolated+mouse+skeletal+muscles+from+mature+and+aged+mice.">Influence of ageing on the fatigability of isolated mouse skeletal muscles from mature and aged mice.</a> Exp. Physiol. 87, 77-82 (2002).</li><li>Zhao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compromised+store-operated+Ca2++entry+in+aged+skeletal+muscle.">Compromised store-operated Ca2+ entry in aged skeletal muscle.</a> Aging Cell. 7, 561-568 (2008).</li><li>Pan, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dysfunction+of+store-operated+calcium+channel+in+muscle+cells+lacking+mg29.">Dysfunction of store-operated calcium channel in muscle cells lacking mg29.</a> Nat. Cell Biol. 4, 379-383 (2002).</li><li>Zhao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Azumolene+inhibits+a+component+of+store-operated+calcium+entry+coupled+to+the+skeletal+muscle+ryanodine+receptor.">Azumolene inhibits a component of store-operated calcium entry coupled to the skeletal muscle ryanodine receptor.</a> J. Biol. Chem. 281, 33477-33486 (2006).</li><li>Renaud, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+force+development+by+Na+,+K+,+Na++K++pump+and+KATP+channel+during+muscular+activity.">Modulation of force development by Na+, K+, Na+ K+ pump and KATP channel during muscular activity.</a> Can. J. Appl. Physiol. 27, 296-315 (2002).</li><li>Brotto, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+and+biochemical+modifications+in+skeletal+muscles+from+malarial+mice.">Functional and biochemical modifications in skeletal muscles from malarial mice.</a> Exp. Physiol. 90, 417-425 (2005).</li><li>Brotto, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+and+fatigue-induced+modification+of+function+and+proteins+in+intact+and+skinned+murine+diaphragm+muscle.">Hypoxia and fatigue-induced modification of function and proteins in intact and skinned murine diaphragm muscle.</a> Pflugers Arch. 440, 727-734 (2000).</li><li>Smith, M. A., Reid, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Redox+modulation+of+contractile+function+in+respiratory+and+limb+skeletal+muscle.">Redox modulation of contractile function in respiratory and limb skeletal muscle.</a> Respir Physiol Neurobiol. 151, 229-241 (2006).</li><li>Bagni, M. A., Cecchi, G., Colomo, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myofilament+spacing+and+force+generation+in+intact+frog+muscle+fibres.">Myofilament spacing and force generation in intact frog muscle fibres.</a> J. Physiol. 430, 61-75 (1990).</li></ol>

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Medição da força contráctil e fatigabilidade é importante para a avaliação global da função do músculo esquelético. O principal objetivo deste ensaio é identificar alterações na força muscular e propriedades fatigantes sob certas condições patológicas, como sarcopenia e fadiga muscular, e para testar o efeito de drogas / reagentes sobre a contratilidade muscular. Desde que a força muscular está intimamente relacionada com o Ca 2 + intracelular lançamento, extracelular Ca 2 + e ...

Os músculos esqueléticos anexar a ossos do esqueleto e gerar forças contrácteis sob o controlo do sistema nervoso central. Acoplamento excitação-contração (ECC) refere-se ao processo de conversão de um estímulo eléctrico a uma resposta mecânica. Ca 2 + de sinalização é um componente essencial da função contráctil do músculo esquelético. Eficaz a mobilização de Ca 2 + do retículo sarcoplasmático (RS) é um componente importante para ECC em células musculares 1, 2, e mudanças no Ca 2 + intracelular de sinalização estão subjacentes à disfunção contráctil correspondente numa série de doenças musculares 3-5. Avaliação adequada da contratilidade muscular é essencial e complementar ao Ca 2 + de imagem e outros ensaios para obter insights sobre a função do músculo esquelético, não apenas no nível de contração, mas também ao nível cinética. Força e velocidade também pode ser obtido a informar a propriedade importante deforça muscular e do estado do processo de ECC em diferentes condições fisiológicas e fisiopatológicas. Este campo fecundo de pesquisa tem uma história muito rica e muitas teorias de contração muscular apareceu mais de dois milênios 6. Pesquisa muscular moderna provavelmente começa em 1674-1682 com a observação microscópica de cross-estrias e miofibrilas nas fibras musculares por Leeuwenhoek 6. Quase um século depois, Luigi Galvani observou que os contratos musculares sapo vigorosamente quando seu nervo é tocado com bisturi durante uma descarga de centelha de uma máquina elétrica distante 7-9. Contracção pode também ser produzida através da ligação do nervo para o músculo da perna por meio de um condutor metálico. Os detalhes do mecanismo de sinalização elétrica complexa defendidas por Galvani foram eventualmente formulado por Hodgkin, Huxley e Katz em sua famosa equação 10, 11, que se tornou a base de eletrofisiologia. As observações notáveis ​​de Ringer sobre os efeitos do Ca 2 + extracelular sobre a contractilidade do coração e músculos esqueléticos rã 12-15 representam o primeiro passo importante no reconhecimento de Ca 2 + como um regulador chave da contractilidade do músculo 16, 17. A partir da década de 1980 até os dias atuais uma explosão de descobertas no campo da contratilidade muscular foi realizado devido à introdução de contratilidade muscular e protocolos fatigabilidade em murinos músculos esqueléticos 18. Jones e Edwards foram os primeiros a sugerir que a fadiga de baixa freqüência intermitente (induzida pelo exercício diminuição da força) 19 foi associado a alterações no maquinário ECC e não o aparato contrátil. No final dos anos 1980 e início de 1990, Kolkeck et al 20, Kolbeck e Nosek 21, e Reid 22 foram usar o músculo diafragma de modelos de roedores para estudar os efeitos da teofilinas, cortiosterone, e radicais livres sobre a contratilidade muscular, enquanto Brooks e Faulkner foram os primeiros a informar sobre as medidas de força repetida e medições de potência em fast-e-lento músculos de ratos 22. Além disso, Lannegren, Westerblad, Cordeiro e Westerblad foram os primeiros a ligar diretamente contratilidade ex vivo com Ca 2 + intracelular regulação e começou a questionar o papel da acidose em fadiga muscular 23, 24. Nossos laboratórios têm contribuído significativamente desde o início de 2000 para a compreensão de novos genes com modulador e funções de regulação no músculo ECC com papéis críticos da contratilidade muscular, cansaço e envelhecimento, usando uma combinação de intactas rato estudos de contratilidade muscular, intracelular de Ca 2 monitoramento + em intactas e sem pele fibras musculares e molecular-genéticos manipulações 3-5, 25-29. Aqui nós mostramos o protocolo experimental para medir a contratilidade de murinos sóleo isolados e longus extensor dos dedos (EDL) dos músculos, o que corresponde a uma maior parte slow-oxidativo (tipo I e IIa fibras musculares) e um músculo principalmente fast-glyocolytic (tipo IIb e fibras musculares IIx) com distintas propriedades contrácteis. Neste protocolo, intactas músculo-tendão complexos foram isolados e banhado numa Radnotti PowerLab ADI sistema de câmara fornecido com ou oxigénio puro ou uma mistura de oxigénio (95%) e CO2 (5%). Forças contrácteis foram gerados por estímulos eléctricos a partir de um estimulador Grass e detectado utilizando um transdutor de força que foi integrado com um sistema de PowerLab/400 ADI, o que permite a personalização de rotinas de macro para controlar a aquisição, a recolha, a digitalização e armazenamento de dados. Esta configuração pode medir a força muscular, força muscular, assim como a relação força versus frequência, fadiga muscular, a recuperação da fadiga muscular, velocidade e propriedades cinéticas totais de contração muscular. Além disso, os efeitos de drogas sobre a contração do músculo pode ser monitorado através destas experiências. </p&gt; As vantagens deste método reside na remoção dos componentes neuronais e vasculares de distância a partir do músculo esquelético, o que permite avaliar directamente as propriedades intrínsecas de contrair o músculo. Além disso, os ensaios de contratilidade ex vivo permite que a manipulação do meio extracelular em torno dos músculos isolados, o que permite o uso de manipulações farmacológicas de vários canais de iões e transportadores de permeação, de modo a definir os seus papéis fisiológicos para a função do músculo esquelético. Este sistema ex vivo nos permitiu descobrir recentemente um comportamento distinto alternano em certas preparações de músculo mutantes, que estavam ligados a alteração do Ca 2 + intracelular manipulação propriedades 4. Alternans são definidos como episódios de ruptura flutuação de força contrátil durante a fase de declínio do perfil fatigante. Durante esses eventos forças contráteis aumentar momentaneamente acima de seu nível anterior de força durante estimulação cansativo, talvez porque seja mais Ca 2 + está sendo lançado ou a maquinaria contrátil tornou-se mais sensível ao Ca + 30 2. Tratamento de ciclopiazônico ácido (CPA), um bloqueador reversível da sarcoplasmático-retículo endoplasmático cálcio ATPase (SERCA), cafeína, um agonista de rianodina canal (RYR) e repetiu fatigante estímulos podem induzir a alternância mecânica 4, sugerindo que a alternância estão diretamente relacionados à modulação do processo de acoplamento CE. Demonstração do método de induzir e gravar alternância mecânico in vitro configuração contratilidade serve como um exemplo para mostrar os parâmetros diversificados experimentais que poderiam ser obtidos com este sistema ou similares, com base em interesses de pesquisa individuais. Este método pode ser de interesse para os investigadores que estudam a fisiologia muscular. Configuração similar pode também ser usado para os complexos isolados de outros muscle-tendon/ligament esqueléticoslocalizações anatómicas, assim como para as fibras individuais e as tiras musculares.

<table border="1"><tbody><tr><td> Nome do reagente </td><td> Companhia </td><td> Número de catálogo </td><td> Comentários (opcional) </td></tr><tr><td> 2-APB </td><td> Tocris </td><td> 1224 </td><td> Bloqueador de um certo número de canais de Ca 2 + e de entrada, incluindo TRP, etc SOC </td></tr><tr><td> SKF96365 </td><td> Sigma </td><td> SKF-96365 </td><td> Bloqueador de um certo número de canais de Ca 2 + de entrada incluindo SOC e mediada pelo receptor de entrada de Ca 2 +, etc </td></tr><tr><td> BTP-2 </td><td> Millipore </td><td> 203.890-5mg </td><td> Relativamente específica bloqueador SOC </td></tr><tr><td> CPA </td><td> Sigma </td><td> C1530 </td><td> SERCA bloqueador reversível </td></tr><tr><td> cafeína </td><td> Sigma </td><td> C0750 </td><td> Agonista RYR ação rápida </td></tr><tr><td> Quatro Radnoti Unidade Tissue Organ Sistema Bath </td><td> Radnoti </td><td> 159920 </td><td></td></tr><tr><td> Suporte combinação tecido / Eletrodo Estimular </td><td> Radnoti </td><td> 160151 </td><td> Vertical Tipo Zig Zag com suporte de tecido </td></tr><tr><td> Quad Ponte Amp </td><td> ADInstruments </td><td> FE224 </td><td></td></tr><tr><td> PowerLab/400 </td><td> ADInstruments </td><td></td><td> Este produto não está mais disponível. Escolha outra versão do sistema de aquisição de dados. </td></tr><tr><td> Os transdutores de força (5 mg - 25 g) </td><td> ADInstruments </td><td> MLT0201/RAD </td><td></td></tr><tr><td> Gráfico v4.02 </td><td> ADInstruments </td&gt; <td></td><td> LabChart 7.3 é a versão mais recente do software gráfico. </td></tr><tr><td> S8800 dupla Pulso Digital Estimulador </td><td> TECNOLOGIAS DE GRAMA </td><td></td><td> Este produto não está mais disponível. S88X dupla saída de pulso quadrado Stimulator é um novo estimulador. </td></tr><tr><td> RF Unidade Transformador de isolamento </td><td> TECNOLOGIAS DE GRAMA </td><td> Modelo SIU5 </td><td></td></tr><tr><td></td><td></td><td></td><td></td></tr></tbody></table>

ex vivo assessment of contractility, fatigability and alternans in isolated skeletal muscles

Descrito aqui é um método para medir a contratilidade dos músculos esqueléticos isolados. Parâmetros, tais como a força muscular, a força muscular, a cinética contráteis, fatigabilidade ea recuperação após a fadiga pode ser obtido para avaliar aspectos específicos do acoplamento excitação-contração (ECC) do processo, como a excitabilidade, máquinas contrátil e Ca 2 + capacidade de manipulação. Este método remove o suprimento nervoso e sangue e se concentra sobre o músculo esquelético isolado em si. Rotineiramente usar esse método para identificar os componentes genéticos que alteram a propriedade contrátil do músculo esquelético embora modulação Ca 2 + vias de sinalização. Aqui, nós descrevemos um fenótipo do músculo esquelético recentemente identificado, isto é, a alternância mecânico, como um exemplo de várias informações e rico que pode ser obtida utilizando o ensaio in vitro a contractilidade do músculo. Combinação deste ensaio com ensaios de célula única, as abordagens genéticas e bioquímicasensaios Stry pode fornecer importantes insights sobre os mecanismos de ECC no músculo esquelético.

Watch this Scientific Journal Video about Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles at JoVE.com

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

Nós descrevemos um método para medir diretamente a força muscular, a força muscular, a cinética contráteis e fatigabilidade de músculos esqueléticos isolados em um<em&gt; In vitro</em&gt; Sistema usando estimulação campo. Informações valiosas sobre Ca<sup&gt; 2 +</sup&gt; As propriedades de manuseamento e maquinaria contrátil do músculo pode ser obtida utilizando-se diferentes protocolos de estimulação.

Avaliação ex vivo de Fatigabilidade Contratilidade e Alternans em músculos esqueléticos isolados

 
Described here is a method to measure contractility of isolated skeletal muscles. Parameters such as muscle force, muscle power, contractile kinetics, ...

ex-vivo-assessment-contractility-fatigability-alternans-isolated

Research

JoVE Journal

Biology

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

23.6K visualizações.  UMDNJ-Robert Wood Johnson Medical School. Nós descrevemos um método para medir diretamente a força muscular, a força muscular, a cinética contráteis e fatigabilidade de músculos esqueléticos isolados em um In vitro Sistema usando estimulação campo. Informações valiosas sobre Ca 2 + As propriedades de manuseamento e maquinaria contrátil do músculo pode ser obtida utilizando-se diferentes protocolos de estimulação.

Vídeo: Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

In vivo Micro-circulation Measurement in Skeletal Muscle by Intra-vital Microscopy

BACKGROUND: Regulatory factors and detailed physiology of in vivo microcirculation have remained not fully clarified after many different modalities of imaging had invented. While many macroscopic parameters of blood flow reflect flow velocity, changes in blood flow velocity and red blood cell (RBC) flux does not hold linear relationship in the microscopic observations. There are reports of discrepancy between RBC velocity and RBC flux, RBC flux and plasma flow volume, and of spatial and temporal heterogeneity of flow regulation in the peripheral tissues in microscopic observations, a scientific basis for the requirement of more detailed studies in microcirculatory regulation using intravital microscopy. METHODS: We modified Jeff Lichtman's method of in vivo microscopic observation of mouse sternomastoid muscles. Mice are anesthetized,
ventilated, and injected with PKH26L-fluorescently labeled RBCs for microscopic observation.RESULT &amp; CONCLUSIONS: Fluorescently labeled RBCs are detected and distinguished well by a wide-field microscope. Muscle contraction evoked by electrical stimulation induced increase in RBC flux. Quantification of other parameters including RBC velocity and capillary density were feasible. Mice tolerated well the surgery, injection of stained RBCs, microscopic observation, and electrical stimulation. No muscle or blood vessel damage was observed, suggesting that our method is relatively less invasive and suited for long-term observations.

A new versatile method for observation of microcirculation is presented. It is considered suitable for long-term observation, and for combination with pharmacophysiological or molecular biological interventions.

Medição in vivo Micro-circulação no músculo esquelético por Intra-vital Microscopia

BACKGROUND: Regulatory factors and detailed physiology of in vivo microcirculation have remained not fully clarified after many different modalities of ...

Biologia

DNA Transfection of Mammalian Skeletal Muscles using In Vivo Electroporation

A growing interest in cell biology is to express transgenically modified forms of essential proteins (e.g. fluorescently tagged constructs and/or mutant variants) in order to investigate their endogenous distribution and functional relevance. An interesting approach that has been implemented to fulfill this objective in fully differentiated cells is the in vivo transfection of plasmids by various methods into specific tissues such as liver1, skeletal muscle2,3, and even the brain4. We present here a detailed description of the steps that must be followed in order to efficiently transfect genetic material into fibers of the flexor digitorum brevis (FDB) and interosseus (IO) muscles of adult mice using an in vivo electroporation approach. The experimental parameters have been optimized so as to maximize the number of muscle fibers transfected while minimizing tissue damages that may impair the quality and quantity of the proteins expressed in individual fibers. We have verified that the implementation of the methodology described in this paper results in a high yield of soluble proteins, i.e. EGFP and ECFP3, calpain, FKBP12, &beta;2a-DHPR, etc. ; structural proteins, i.e. minidystrophin and &alpha;-actinin; and membrane proteins, i.e. &alpha;1s-DHPR, RyR1, cardiac Na/Ca2+ exchanger , NaV1.4 Na channel, SERCA1, etc., when applied to FDB, IO and other muscles of mice and rats. The efficient expression of some of these proteins has been verified with biochemical3 and functional evidence5. However, by far the most common confirmatory approach used by us are standard fluorescent microscopy and 2-photon laser scanning microscopy (TPLSM), which permit to identify not only the overall expression, but also the detailed intracellular localization, of fluorescently tagged protein constructs. The method could be equally used to transfect plasmids encoding for the expression of proteins of physiological relevance (as shown here), or for interference RNA (siRNA) aiming to suppress the expression of normally expressed proteins (not tested by us yet). It should be noted that the transfection of FDB and IO muscle fibers is particularly relevant for the investigation of mammalian muscle physiology since fibers enzymatically dissociated from these muscles are currently one of the most suitable models to investigate basic mechanisms of excitability and excitation-contraction coupling under current or voltage clamp conditions2,6-8.

DNA Transfection of Mammalian Skeletal Muscles using In Vivo Electroporation

We describe detailed procedures for the efficient transfection of plasmid DNA into the fibers of foot muscles of live mice using electroporation and the subsequent visualization of protein expression using fluorescence microscopy.

Transfecção de DNA de mamíferos usando músculos esqueléticos In Vivo Eletroporação

 A growing interest in cell biology is to express transgenically modified forms of essential proteins (e.g. fluorescently tagged constructs and/or mutant ...

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

The isolated microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of factors that control vessel diameter, and thus, perfusion resistance1-5. This is a classic experimental preparation that was, in large measure, initially described by Uchida et al.15 several decades ago. This initial description provided the basis for the techniques that was extensively modified and enhanced, primarily in the laboratory of Dr. Brian Duling at the University of Virginia6-8, and we present a current approach in the following pages. This preparation will specifically refer to the gracilis arteriole in a rat as the microvessel of choice, but the basic preparation can readily be applied to vessels isolated from nearly any other tissue or organ across species9-13. Mechanical (i.e., dimensional) changes in the isolated microvessels can easily be evaluated in response to a broad array of physiological (e.g., hypoxia, intravascular pressure, or shear) or pharmacological challenges, and can provide insight into mechanistic elements comprising integrated responses in an intact, although ex vivo, tissue. The significance of this method is that it allows for facile manipulation of the influences on the integrated regulation of microvessel diameter, while also allowing for the control of many of the contributions from other sources, including intravascular pressure (myogenic), autonomic innervation, hemodynamic (e.g., shear stress), endothelial dependent or independent stimuli, hormonal, and parenchymal influences, to provide a partial list. Under appropriate experimental conditions and with appropriate goals, this can serve as an advantage over in vivo or in situ tissue/organ preparations, which do not readily allow for the facile control of broader systemic variables. 
The major limitation of this preparation is essentially the consequence of its strengths. By definition, the behavior of these vessels is being studied under conditions where many of the most significant contributors to the regulation of vascular resistance have been removed, including neural, humoral, metabolic, etc. As such, the investigator is cautioned to avoid over-interpretation and extrapolation of the data that are collected utilizing this preparation. The other significant area of concern with regard to this preparation is that it can be very easy to damage cellular components such as the endothelial lining or the vascular smooth muscle, such that variable source of error can be introduced. It is strongly recommended that the individual investigator utilize appropriate measurements to ensure the quality of the preparation, both at the initiation of the experiment and periodically throughout the course of a protocol.

The ex vivo Isolated Skeletal Microvessel Preparation for Investigation of Vascular Reactivity

An ex vivo preparation is described for isolation of the largest gracilis muscle resistance arterioles for interrogation of both vascular responses to vasoactive stimuli and the assessment of basic structural properties via passive wall mechanics.

O Ex vivo Preparação microvasos isolada esquelético de Investigação da reatividade vascular

The isolated  microvessel preparation is an ex vivo preparation that allows for examination of the different contributions of  factors that control vessel ...

Isometric and Eccentric Force Generation Assessment of Skeletal Muscles Isolated from Murine Models of Muscular Dystrophies

Critical to the evaluation of potential therapeutics for muscular disease are sensitive and reproducible physiological assessments of muscle function. Because many pre-clinical trials rely on mouse models for these diseases, isolated muscle function has become one of the standards for Go/NoGo decisions in moving drug candidates forward into patients. We will demonstrate the preparation of the extensor digitorum longus (EDL) and diaphragm muscles for functional testing, which are the predominant muscles utilized for these studies. The EDL muscle geometry is ideal for isolated muscle preparations, with two easily accessible tendons, and a small size that can be supported by superfusion in a bath. The diaphragm exhibits profound progressive pathology in dystrophic animals, and can serve as a platform for evaluating many potential therapies countering fibrosis, and promoting myofiber stability. Protocols for routine testing, including isometric and eccentric contractions, will be shown. Isometric force provides assessment of strength, and eccentric contractions help to evaluate sarcolemma stability, which is disrupted in many types of muscular dystrophies. Comparisons of the expected results between muscles from wildtype and dystrophic muscles will also be provided. These measures can complement morphological and biochemical measurements of tissue homeostasis, as well as whole animal assessments of muscle function.

Muscle function measurements contribute to the evaluation of potential therapeutics for muscle pathology, as well as to the determination of mechanisms underlying physiology of this tissue. We will demonstrate the preparation of the extensor digitorum longus and diaphragm muscles for functional testing. Protocols for isometric and eccentric contractions will be shown, as well as differences in results between dystrophic muscles, representing a pathological state, and wildtype muscles.

Avaliação Geração isométrica e excêntrica Força dos músculos esqueléticos Isolado de modelos murinos de Distrofias Musculares

Critical to the evaluation of potential  therapeutics for muscular disease are sensitive and reproducible physiological  assessments of muscle function. ...

Assessment of Calcium Sparks in Intact Skeletal Muscle Fibers

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in the striated muscle fibers that appear as highly localized Ca2+ release events mediated by ryanodine receptor (RyR) Ca2+ release channels on the sarcoplasmic reticulum (SR) membrane. Proper assessment of muscle Ca2+ sparks could provide information on the intracellular Ca2+&#160;handling properties of healthy and diseased striated muscles. Although Ca2+ sparks events are commonly seen in resting cardiomyocytes, they are rarely observed in resting skeletal muscle fibers; thus there is a need for methods to generate and analyze sparks in skeletal muscle fibers.
Detailed here is an experimental protocol for measuring Ca2+ sparks in isolated flexor digitorm brevis (FDB) muscle fibers using fluorescent Ca2+ indictors and laser scanning confocal microscopy. In this approach, isolated FDB fibers are exposed to transient hypoosmotic stress followed by a return to isotonic physiological solution. Under these conditions, a robust Ca2+ sparks response is detected adjacent to the sarcolemmal membrane in young healthy FDB muscle fibers. Altered Ca2+ sparks response is detected in dystrophic or aged skeletal muscle fibers. This approach has recently demonstrated that membrane-delimited signaling involving cross-talk between inositol (1,4,5)-triphosphate receptor (IP3R) and RyR contributes to Ca2+ spark activation in skeletal muscle. In summary, our studies using osmotic stress induced Ca2+ sparks showed that this intracellular response reflects a muscle signaling mechanism in physiology and aging/disease states, including mouse models of muscle dystrophy (mdx mice) or amyotrophic lateral sclerosis (ALS model).

Described here is a method to directly measure calcium sparks, the elementary units of Ca2+ release from sarcoplasmic reticulum&#160;in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca2+ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca2+ signaling can be employed to assess muscle function in health and disease.

Avaliação do cálcio Faíscas intactas fibras musculares esqueléticas

Maintaining homeostatic Ca2+ signaling is a fundamental physiological process in living cells. Ca2+ sparks are the elementary units of Ca2+ signaling in ...

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice

Papillary muscle isolated from adult mouse hearts can be used to study cardiac contractility during different physiological/pathological conditions. The contractile characteristics can be evaluated independently of external influences such as vascular tonus or neurohumoral status. It depicts a scientific approach between single cell measurements with isolated cardiac myocytes and in vivo studies like echocardiography. Thus, papillary muscle preparations serve as an excellent model to study cardiac physiology/pathophysiology and can be used for investigations like the modulation by pharmacological agents or the exploration of transgenic animal models. Here, we describe a method of isolating the murine left anterior papillary muscle to investigate cardiac contractility in an organ bath setup. In contrast to a muscle strip preparation isolated from the ventricular wall, the papillary muscle can be prepared in toto without damaging the muscle tissue severely. The organ bath setup consists of several temperature-controlled, gassed and electrode-equipped organ bath chambers. The isolated papillary muscle is fixed in the organ bath chamber and electrically stimulated. The evoked twitch force is recorded using a pressure transducer and parameters such as twitch force amplitude and twitch kinetics are analyzed. Different experimental protocols can be performed to investigate the calcium- and frequency-dependent contractility as well as dose-response curves of contractile agents such as catecholamines or other pharmaceuticals. Additionally, pathologic conditions like acute ischemia can be simulated.

Murine left ventricular papillary muscle can be used to investigate cardiac contractility in vitro. This article describes in detail the isolation and experimental protocols to study cardiac contractile characteristics.

Medidas de contratilidade no isolado músculos papilares de Investigação de Cardiac inotropia em Ratos

Papillary muscle isolated from adult mouse hearts can be used to study cardiac contractility during different physiological/pathological conditions. The ...

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, is expressed in neurons in response to various stimuli. The protein product can be readily detected with immunohistochemical techniques leading to the use of c-FOS detection to map groups of neurons that display changes in their activity. In this article, we focused on the identification of brainstem neuronal populations involved in the ventilatory adaptation to hypoxia or hypercapnia. Two approaches were described to identify involved neuronal populations in vivo in animals and ex vivo in deafferented brainstem preparations. In vivo, animals were exposed to hypercapnic or hypoxic gas mixtures. Ex vivo, deafferented preparations were superfused with hypoxic or hypercapnic artificial cerebrospinal fluid. In both cases, either control in vivo animals or ex vivo preparations were maintained under normoxic and normocapnic conditions. The comparison of these two approaches allows the determination of the origin of the neuronal activation i.e., peripheral and/or central. In vivo and ex vivo, brainstems were collected, fixed, and sliced into sections. Once sections were prepared, immunohistochemical detection of the c-FOS protein was made in order to identify the brainstem groups of cells activated by hypoxic or hypercapnic stimulations. Labeled cells were counted in brainstem respiratory structures. In comparison to the control condition, hypoxia or hypercapnia increased the number of c-FOS labeled cells in several specific brainstem sites that are thus constitutive of the neuronal pathways involved in the adaptation of the central respiratory drive.

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo.

A proteína c-Fos Detecção imuno: Uma ferramenta útil como um marcador de vias centrais envolvidos em respostas fisiológicas específicas<em&gt; In Vivo</em&gt; e<em&gt; Ex Vivo</em

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

Medindo a rigidez<em&gt; Ex Vivo</em&gt; Mouse aortas Usando Microscopia de Força Atômica

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice

Skeletal muscle is an insulin-responsive tissue and typically takes up most of the glucose that enters the blood after a meal. Moreover, it has been reported that skeletal muscle may increase the extraction of glucose from the blood by up to 50-fold during exercise compared to resting conditions. The increase in muscle glucose uptake during exercise and insulin stimulation is dependent on the translocation of glucose transporter 4 (GLUT4) from intracellular compartments to the muscle cell surface membrane, as well as phosphorylation of glucose to glucose-6-phosphate by hexokinase II. Isolation and incubation of mouse muscles such as m. soleus and m. extensor digitorum longus (EDL) is an appropriate ex vivo model to study the effects of insulin and electrically-induced contraction (a model for exercise) on glucose uptake in mature skeletal muscle. Thus, the ex vivo model permits evaluation of muscle insulin sensitivity and makes it possible to match muscle force production during contraction ensuring uniform recruitment of muscle fibers during measurements of muscle glucose uptake. Moreover, the described model is suitable for pharmacological compound testing that may have an impact on muscle insulin sensitivity or may be of help when trying to delineate the regulatory complexity of skeletal muscle glucose uptake.
Here we describe and provide a detailed protocol on how to measure insulin- and contraction-stimulated glucose uptake in isolated and incubated soleus and EDL muscle preparations from mice using radiolabeled [3H]2-deoxy-D-glucose and [14C]mannitol as an extracellular marker. This allows accurate assessment of glucose uptake in mature skeletal muscle in the absence of confounding factors that may interfere in the intact animal model. In addition, we provide information on metabolic viability of incubated mouse skeletal muscle suggesting that the method&#160;applied possesses some caveats under certain conditions when studying muscle energy metabolism.

Intact regulation of muscle glucose uptake is important for maintaining whole body glucose homeostasis. This protocol presents assessment of insulin- and contraction-stimulated glucose uptake in isolated and incubated mature skeletal muscle when delineating the impact of various physiological interventions on whole body glucose metabolism.

Medição da absorção de glicose estimulada por insulina e contração em músculo esquelético maduro isolado e incubado de camundongos

Skeletal muscle is an insulin-responsive tissue and typically takes up most of the glucose that enters the blood after a meal. Moreover, it has been ...

Single Myofiber Culture Assay for the Assessment of Adult Muscle Stem Cell Functionality Ex Vivo

Adult skeletal muscle tissue harbors a stem cell population that is indispensable for its ability to regenerate. Upon muscle damage, muscle stem cells leave their quiescent state and activate the myogenic program ultimately leading to the repair of damaged tissue concomitant with the replenishment of the muscle stem cell pool. Various factors influence muscle stem cell activity, among them intrinsic stimuli but also signals from the direct muscle stem cell environment, the stem cell niche. The isolation and culture of single myofibers with their associated muscle stem cells preserves most of the interaction of the stem cell with its niche and is, therefore, the closest possibility to study muscle stem cell functionality ex vivo. Here, a protocol for the isolation, culture, siRNA transfection and immunostaining of muscle stem cells on their respective myofibers from mouse EDL (extensor digitorum longus) muscles is provided. The experimental conditions outlined here allow the study and manipulation of muscle stem cells ex vivo including investigation of myogenic activity without the inherent need for in vivo animal experiments.

In this protocol an in vitro culturing and functional analysis method for muscle stem cells is described, which preserves most of their interactions with their endogenous niche.

Ensaio de cultura de myofibra única para a avaliação da funcionalidade de células-tronco musculares adultas Ex Vivo

Adult skeletal muscle tissue harbors a stem cell population that is indispensable for its ability to regenerate. Upon muscle damage, muscle stem cells ...