Changes in biomarker levels and myofiber constitution in rat soleus muscle at different exercise intensities
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Although exercise affects the function and structure of skeletal muscle, our knowledge regarding the biomedical alterations induced by different intensities of exercise is incomplete. Here we report on the changes in biomarker levels and myofiber constitution in the rat soleus muscle induced by exercise intensity. Male adult rats at 7 weeks of age were divided into 3 groups by exercise intensity, which was set based on the accumulated lactate levels in the blood using a treadmill: stationary control (0 m/min), aerobic exercise (15 m/min), and anaerobic exercise (25 m/min). The rats underwent 30 min/day treadmill training at different exercise intensities for 14 days. Immediately after the last training session, the soleus muscle was dissected out in order to measure the muscle biomarker levels and evaluate the changes in the myofibers. The mRNA expression of citrate synthase, glucose-6-phosphate dehydrogenase, and Myo D increased with aerobic exercise, while the mRNA expression of myosin heavy-chain I and Myo D increased in anaerobic exercise. These results suggest that muscle biomarkers can be used as parameters for the muscle adaptation process in aerobic/anaerobic exercise. Interestingly, by 14 days after the anaerobic exercise, the number of type II (fast-twitch) myofibers had decreased by about 20%. Furthermore, many macrophages and regenerated fibers were observed in addition to the injured fibers 14 days after the anaerobic exercise. Constitutional changes in myofibers due to damage incurred during anaerobic exercise are necessary for at least about 2 weeks. These results indicate that the changes in the biomarker levels and myofiber constitution by exercise intensity are extremely important for understanding the metabolic adaptations of skeletal muscle during physical exercise.
KeywordsAerobic Anaerobic Exercise intensity Muscle regeneration
We would like to thank Drs. Hideaki Soya and Hiroshi Yorifuji for critical discussion and Drs. Lu Yu and Tsuyoshi Ichinose for technical assistance. This study was supported in part by a Grant-in-Aid for Challenging Exploratory Research (No. 24659449) and Grant-in-Aid for Scientific Research (No. 21390065) to N.K. and T.I. from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and DIKTI-PUPT (2016) from Indonesian Ministry of Education to R.L. and R.F.
Compliance with ethical standards
Conflict of interest
The authors declare that there are no conflicts of interest.
- 3.Ishido M, Uda M, Masuhara M, Kami K (2006) Alterations of M-cadherin, neural cell adhesion molecule and beta-catenin expression in satellite cells during overload-induced skeletal muscle hypertrophy. Acta Physiol 187(3):407–418. https://doi.org/10.1111/j.1748-1716.2006.01577.x CrossRefGoogle Scholar
- 4.Ishido M, Kasuga N, Masuhara M (2008) Time Course Changes of the Expression of IGF-I, Phosphorylated Akt and Phosphorylated mTOR in Myofibers of the Early Stage of Functionally Overloaded Skeletal Muscle. Adv Exerc Sports Physiol 14(2):25–29Google Scholar
- 12.Tarnopolsky MA, Rennie CD, Robertshaw HA, Fedak-Tarnopolsky SN, Devries MC, Hamadeh MJ (2007) Influence of endurance exercise training and sex on intramyocellular lipid and mitochondrial ultrastructure, substrate use, and mitochondrial enzyme activity. Am J Physiol Regul Integr Comp Physiol 292(3):R1271–R1278. https://doi.org/10.1152/ajpregu.00472.2006 CrossRefGoogle Scholar
- 15.Soya H, Mukai A, Deocaris CC, Ohiwa N, Chang H, Nishijima T, Fujikawa T, Togashi K, Saito T (2007) Threshold-like pattern of neuronal activation in the hypothalamus during treadmill running: establishment of a minimum running stress (MRS) rat model. Neurosci Res 58(4):341–348. https://doi.org/10.1016/j.neures.2007.04.004 CrossRefGoogle Scholar
- 18.Malaguti M, Angeloni C, Garatachea N, Baldini M, Leoncini E, Collado PS, Teti G, Falconi M, Gonzalez-Gallego J, Hrelia S (2009) Sulforaphane treatment protects skeletal muscle against damage induced by exhaustive exercise in rats. J Appl Physiol 107(4):1028–1036. https://doi.org/10.1152/japplphysiol.00293.2009 CrossRefGoogle Scholar
- 21.Lehmann M, Foster C, Gastmann U, Keizer H, Steinacker JM (1999) Definition, types, symptoms, findings, underlying mechanisms, and frequency of overtraining and overtraining syndrome. In: Lehmann M, Foster C, Gastmann U, Keizer H, Steinacker JM (eds) Overload, Performance Incompetence, and Regeneration in Sport. Springer, New York, pp 1–6CrossRefGoogle Scholar
- 24.Palacios G, Pedrero-Chamizo R, Palacios N, Maroto-Sánchez B, Aznar S, González-Gross M, EXERNET Study Group (2015) Biomarkers of physical activity and exercise. Nutr Hosp 31(Suppl 3):237–244Google Scholar
- 27.Valberg SJ, Borgia L (2009) Muscle adaptations during growth and early training. In: Pagan JD (ed) Advances in equine nutrition IV. Kentucky Equine Research, Kentucky, pp 193–202Google Scholar
- 29.Spodaryk K, Miszta H, Dabrowski Z, Gawroński W (1989) Metabolism of red blood cells after short-term exercise in rats. Acta Physiol Pol 40(4):381–386Google Scholar
- 31.Short KR, Vittone JL, Bigelow ML, Proctor DN, Coenen-Schimke JM, Rys P, Nair KS (2005) Changes in myosin heavy chain mRNA and protein expression in human skeletal muscle with age and endurance exercise training. J Appl Physiol 99(1):95–102. https://doi.org/10.1152/japplphysiol.00129.2005 CrossRefGoogle Scholar
- 32.Eigendorf J, May M, Friedrich J, Engeli S, Maassen N, Gros G, Meissner JD (2018) High intensity high volume interval training improves endurance performance and induces a nearly complete slow-to-fast fiber transformation on the mRNA level. Front Physiol 9:601. https://doi.org/10.3389/fphys.2018.00601 CrossRefGoogle Scholar
- 33.Yoseph B, Soker S (2015) Redefining the satellite cell as the motor of skeletal muscle regeneration. J Sci Appl: Biomed 3(5):76–82Google Scholar