This article describes a safe and reliable method to induce and quantify exertional skeletal muscle damage in human subjects.
les dommages musculaires induits par Contraction-via excentrique (allongement) des contractions volontaires offre un excellent modèle pour étudier l'adaptation musculaire et la récupération chez les humains. Ici, nous discutons de la conception d'un protocole d'exercice excentrique pour provoquer des lésions dans les muscles quadriceps, marqués par des changements dans la force, la douleur, et les niveaux de créatine kinase plasmatique. Cette méthode est simple, éthique, et largement applicable car elle est effectuée dans des participants humains et élimine la traduction des résultats interspécifique. Les sujets effectuent 300 contractions excentriques maximales des muscles extenseurs du genou à une vitesse de 120 ° / sec sur un dynamomètre isocinétique. L'ampleur des dégâts est mesurable à l'aide des mesures isocinétiques et isométriques relativement non-invasive de la perte de la force, la douleur, et le taux de créatine plasmatique kinase sur plusieurs jours suite à l'exercice. Par conséquent, son application peut être dirigée vers des populations spécifiques dans le but d'identifier les mécanismes de musclel'adaptation et la régénération.
The overall goal of this procedure is to induce exertional damage to the quadriceps femoris muscles using voluntary lengthening (eccentric) contractions in human subjects.
Contraction-induced skeletal muscle damage is a common consequence of exercise that is marked by delayed onset muscle soreness1, transient strength loss, and elevated muscle-specific enzymes in the blood2. Exertional muscle damage is most pronounced following exercise to which the subject is unaccustomed, particularly when eccentric contractions are involved3. Exertional muscle damage is typically benign. Soreness subsides, and both serum proteins and strength typically return to pre-damage levels within a few days to weeks after the damaging insult. In extreme cases, exertional muscle damage can lead to a life-threatening syndrome know as rhabdomyolysis. However, exertional muscle damage is usually insufficient to cause clinical rhabdomyolysis in healthy individuals4 in the absence of compounding factors including heat stress, dehydration5, infection6 or rare genetic predispositions7.
Contraction-induced muscle damage is typically less severe than toxin-induced or freezing-induced injury, methods often used in rodent studies8,9. Yet, contraction-induced injury provides a useful method to study the muscle damage response with notable advantages. First, it is a safe and ethical method for use with human subjects1-3. Thus, interspecies translation of the results is not needed as data can be obtained directly from human subjects. Moreover, translating data obtained from rodent studies is very difficult given that the severity of injury seen in the rodent injury models exceeds the level of damage that would be ethical to induce in human subjects. Second, contraction-induced damage is commonly experienced and a natural process of exercise. Therefore, this mode of damage induction is useful for studying muscle damage in the context of exercise, adaptation to exercise as well as overt muscle injury. Here we describe a safe and reliable method to induce and evaluate skeletal muscle damage using lengthening contractions in humans.
Plusieurs étapes sont essentielles à l'obtention des résultats escomptés de ce protocole. Tout d'abord, les sujets doivent être familiarisés adéquatement aux protocoles de contraction, en particulier les mesures de force. Assurez-vous que le sujet comprend exactement ce qu'ils sont censés faire et leur donner l'occasion de pratiquer les tests de résistance avant la collecte des données. Les sujets qui ne sont pas suffisamment familiarisés avec ces procédures peuvent montrer une courbe d'a…
The authors have nothing to disclose.
The authors have no acknowledgements.
Biodex Dynomometer | Biodex Medical Systems | 850-000 | Other models are available and should produce similar results |
Creatine Kinase kit | Sigma-Aldrich | MAK116 | |
Serum Vacutainers | BD Bioscience | 367812 | |
Winged safety push button blood collection set | BD Bioscience | 367338 | |
Cryogenic vials | Sigma-Aldrich | V5007 | We use the 2mL vials to store serum aliquots |