Fiber Type Composition In Semitendinous Muscle Of Wistar Rats And Effects Of Intermittent Training On Its Hypertrophy

Skeletal muscles respond to several stimuli changing their phenotype. Muscular fibers adaptation capability is related to the presence of several myosin heavy chains (MHC). These express four types of pure fibers: I, IIA, IID and IIB containing MHCI, IIa, IId and IIb, respectively. Among pure fibers, there are hybrid fibers, which can express two or more types of myosins. In this study, types of fibers constituting male Wistar rats semitendinous and their myosin heavy chains, as well as influence of intermittent training on hypertrophy of these fibers have been checked through MATPase histochemical technique and electrophoretic proteins separation. All types of pure and hybrid muscular fiber have been found, however the fibers of the types IIA, IID and IIB were predominant, featuring muscle as a fast-contracting one. Training has promoted muscular fibers transition with a significant increase of fibers of IC, IIAD and IIDB type. A cross-section increase of fibers of IIDB and IIB type has also been noticed. In summary, semitendinous muscle is essentially constituted by fast-contracting fibers and training could promote transition and hypertrophy of these fast fibers.2616367Andersen, J.L., Schjerling, P., Saltin, B., Muscle, genes, and athletic performance (2000) Sci. Am, 283, pp. 48-55Blum, H., Beier, H., Gross, H.J., Improved silver staining of plant-proteins, RNA and DNA in polyacrylamide gels (1987) Electrophoresis, 8 (2), pp. 93-99Bottinelli, R., Reggianni, C., Human skeletal muscle fibres: Molecular and functional diversity (2000) Prog. Biophys. Mol. Bio, 73, pp. 195-262Brooke, M.H., Kaiser, K.K., Three "myosin adenosine triphosphatase" systems: The nature of their pH lability and sulfhydryl dependence (1970) J. Histochem. Cytochem, 18, pp. 670-672Caiozzo, V.J., Baker, M.J., Huang, K., Chou, H., Wu, Y.Z., Baldwin, K.M., Single-fiber myosin heavy chain polymorphism: How many patterns and what proportions? (2003) Am. J. Physiol. Regul. Integr. Comp. Physiol, 285, pp. R570-R580Campos, G.E.R., Luecke, T., Wendeln, H.K., Toma, K., Hagerman, F.C., Murray, T.F., Ragg, K.E., Staron, R.S., Muscular adaptationsin response to three different resistance training regimens: Specificity of repetition maximum training zones (2002) Eur. J. Appl. Physiol, 88, pp. 50-60Delp, M.D., Duan, C., Composition and size of type I, IIA, IID/X and IIB fibers and citrate synthase activity of rat muscle (1996) J. Appl. Physiol, 80, pp. 261-270Demirel, H.A., Powers, S.K., Naito, H., Hughes, M., Coombes, J.S., Exercise-induced alterations in skeletal muscle myosin heavy chain phenotype: Dose-response relationship (1999) J. Appl. Physiol, 86 (3), pp. 1002-1008Goldispink, G., Gene expression in muscle in response to exercise (2003) J. Muscle Res. Cell, 24, pp. 121-126Guth, L., Samaha, F.J., Procedure for the histochemical demonstration of actomyosin ATPase (1970) Exp. Neurol, 28, pp. 365-367Harrison, B.C., Bell, M.L., Allen, D.L., Byrnes, W.C., Leinwand, L.A., Skeletal muscle adaptations in response to voluntary wheel running in myosin heavy chain null mice (2002) J. Appl. Physiol, 92, pp. 313-322Jurie, C., Picard, B., Geay, Y., Influences of the method of housing bulls on their body composition and muscle fibre types (1998) Meat Science, 50, pp. 457-469Lin, J., Wu, H., Tarr, P.T., Zhang, C.Y., Wu, Z., Boss, O., Michael, L.F., Spiegelman, B., Transcriptional co-activator PGC-1a drives the formation of slow-twich muscle fibres (2002) Nature, 418, pp. 797-801Pette, D., Staron, R.S., Transitions of muscle fiber phenotypic profiles (2001) Histochem. Cell Biol, 115, pp. 359-372Smolka, M.B., Zoppi, C.C., Alvez, A.A., Silveira, L.R., Marangoni, S., Silva, L.P., Novello, J., Macedo, D.V., HSP72 as a complymentary protection against oxidative stress induced by exercise in the soleus muscle of rats (2000) Am. J. Physiol. Regulatory Integrative Comp. Physiol, 279, pp. R1539-R1545Staron, R.S., Kraemer, W.J., Hikida, R.S., Fry, A.C., Murray, J.D., Campos, G.E.R., Fiber type composition of four hindlimb muscles of adult Fisher 344 rats (1999) Histochem. Cell Biol, 111, pp. 117-123Tajsharghi, H., Sunnerhagen, K.S., Darin, N., Kyllerman, M., Oldfors, A., Induced shift in myosin heavy chain expression in myosin myopathy by endurance training (2004) J. Neurol, 251, pp. 179-183Talmadge, R.J., Myosin heavy chain isoform expression following reduced neuromuscular activity: Potential regulatory mechanisms (2000) Muscle Nerve, 23, pp. 661-67