Journal of Morphological Sciences
Journal of Morphological Sciences
Original Article

Effects of long-term physical exercise in the skeletal muscles of rats


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Introdcution: The effects of long-term physical exercise in the skeletal muscles were evaluated. Methods: 30 male Wistar rats, 25 days old each, were divided in 2 groups: trained (TG, n=21) and sedentary (SG, n=9). The TG group was subdivided in 3 groups: TGI, TGII and TGIII, n=7 in each group, and the SG was also subdivided in 3 groups: SGI, SGII and SGIII, n=3. The animals of the TG (I, II and III) performed running exercise on a electric running machine for 3, 6 and 9 weeks respectively. The animals of the sedentary groups remained without any exercise. After the experimental period the soleus (SOL), the extensor digitorum longus (EDL) and the plantaris (PL) muscles were extracted, weighed and analyzed by the histochemichal technique of mATPase to observe possible changes. Results: The TGIII showed a significant increase in the absolute values of muscle weight when compared to the TGI and TGII. There was an increase in the distribution of type I fibers and a decrease in types IIC and IIA in the SOL muscle. The EDL muscle showed an increase in IIA fibers and a decrease in IID IIB types. As for the PL muscle there was an increase in types IIA and IIAD and a decrease in IID type fibers. Conclusion: Physical exercise causes changes in the distribution of fiber types in the skeletal muscles of rats and confirms the capacity of the fibers to adapt to the requirements of the proposed physical exercise in order to achieve a better performance.


fiber types, physical exercise, muscle plasticity


BALDWIN, KM. and HADDAD, F. Plasticity in skeletal, cardiac, and smooth muscle invited review: effects of different activity and inactivity paradigms on myosin heavy chain gene expression in striated muscle. Journal of Applied Physiology, 2001, no. 90, p. 345-357.

BROOKE, MH. and KAISER, KK. Three “myosin adenosine tryphosphatase” systems: the nature of their pH hability and sulfhydryl dependence. Journal of Histochemistry & Cytochemistry, 1970, n. 18, p. 670-672.

CARTER, SL., RENNIE, CD., HAMILTON, SJ. and TARNOPOLSKY. Changes in skeletal muscle in males and females following endurance training. Canadian Journal of Physiology and Pharmacology, 2001, vol. 79, n. 5, p. 386-392.

DEMIREL, HA., POWERS, SK., NAITO, H., HUGHES, M. and COOMBES, JS. Exercise-induced alterations in skeletal muscle myosin heavy chain phenotype: dose-response relationship. Journal of Applied Physiology, 1999, vol. 86, n. 3, p. 1002-1008. PMid:10066716.

GUTH, L. and SAMAHA, FJ. Procedure for the histochemical. demonstration of actomyosin ATPase. Experimental Neurology, 1970, vol. 28, n. 2, p. 365-367. PMid:4248172.

HAWLEY, JA. Adaptations of skeletal muscle to prolonged, intense endurance training. Clinical and Experimental Pharmacology & Physiology, 2002, vol. 29, n. 3, p. 218-222. PMid:11906487.

KADI, F., ERIKSSON, A., HOLMNER, S., BUTLER-BROWNE, GS. and THORNELL, LE. Cellular adaptation of the trapezius muscle in strength-trained athletes. Histochemistry and Cell Biology, 1999, n. 111, p. 189-195.

MCAINCH, AJ., LEE, JS., BRUCE, CR., TUNSTALL, RJ., HAWLEY, JA. and CAMERON-SMITH, D. Dietary regulation of fat oxidative gene expression in different skeletal muscle fiber types. Obesity Research, 2003, vol. 11, n. 11, p. 1471-147. PMid:14694211.

MURGIA, M., NAGARAJ, N., DESHMUKH, AS., ZEILER, M., PASQUA CANCELLARA, P., MORETTI, I., REGGIANI, C., SCHIAFFINO, S. and MANN, M. Single muscle fiber proteomics reveals unexpected mitochondrial specialization. EMBO Reports, 2015, vol. 16, n. 3, p. 387-395. PMid:25643707.

PETTE, D. and STARON, RS. The continuum of pure and hybrid myosin heavy chain based types in rat skeletal muscle. Histochemistry, 1993, vol. 100, n. 2, p. 149-153. PMid:8244766.

PETTE, D. and STARON, RS. Myosin isoforms, muscle fiber types, and transitions. Microscopy Research and Technique, 2000, vol. 50, n. 6, p. 500-509. PETTE, D. and STARON, RS. Transitions of muscle fiber phenotypic profiles. Histochemistry and Cell Biology, 2001, vol. 115, n. 5, p. 359-372.

POWERS, SK., CRISWELL, D., LAWLER, J., MARTIN, D., JI, LL., HERB, RA. and DUDLEY, G. Influence of exercise and fiber type on antioxidant enzyme activity in rat skeletal muscle. The American Journal of Physiology, 1994, vol. 266, n. 2 Pt 2, p. R375-R380. PMid:8141392.

SALMONS, S. The adaptive response of skeletal muscle: what is the evidence? Muscle & Nerve, 2017, In press. PMid:28857207.

SCHIAFFINO, S. and REGGIANI, C. Fiber types in mammalian skeletal muscles. Physiological Reviews, 2011, vol. 91, n. 4, p. 1447-1531. PMid:22013216.

SULLIVAN, V., POWERS, S., CRISWELL, D., TUMER, N., LAROCHELLE, J. and LOWENTHAL, D. Myosin heavy chain composition in young and old rat skeletal muscle: effects of endurance exercise. Journal of Applied Physiology, 1995, vol. 78, n. 6, p. 2115-2120. PMid:7665407.

TARPENNING, KM., HAMILTON-WESSLER, M., WISWELL, RA. and HAWKINS, SA. Endurance training delays age of decline in leg strength and muscle morphology. Medicine and Science in Sports and Exercise, 2004, vol. 36, n. 1, p. 74-78. PMid:14707771.

VÍVOLO, MA. and FIORETTI, AMB. Metabolismo hormonal e de glícides nas atividades física e esportiva. In: GHORAYEB, N. and BARROS NETO, TL. O exercício: preparação fisiológica, avaliação médica, aspectos especiais e preventivos. São Paulo: Atheneu, 1999.

WAHRMANN, JP., WINAND, R. and RIEU, M. Plasticity of skeletal myosin in endurance-trained rats (I). A quantitative study. European Journal of Applied Physiology, 2001, n. 84, p. 367-372.

WIDRICK, JJ., STELZER, JE., SHOEPE, TC. and GARNER, DP. Functional properties of human muscle fibers after short-term resistance exercise training. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 2002, vol. 283, n. 2, p. 408-416. PMid:12121854.

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