Fiber type changes in rat skeletal muscle after intense interval training

Luginbuhl, Amy; Dudley, Gary A.; Staron, Robert S.

doi:10.1007/bf00495401

Cited by 62 publications

(22 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Approximately half (52.8%) of the ®bres expressing MHCd also reacted positively for MHCf and MHCs, whereas 27.6% reacted with only the MHCf, and 17.8% with only the MHCs. The remaining 1.8% of MHCd + ®bres did not react for the presence of adult The adult ®bre type distribution of all S muscles was similar to that previously reported for this muscle (Ho et al 1983;Armstrong and Phelps 1984;Luginbuhl et al 1984), with 79.3% of ®bres reacting for MHCs, 12.2% for MHCf, and 6.9% reacting for both adult MHCs and MHCf isoforms.…”

Section: Co-expression Of Mhc Isoforms Within ®Bressupporting

confidence: 85%

Expression of developmental myosin and morphological characteristics in adult rat skeletal muscle following exercise-induced injury

et al. 1999

View full text Add to dashboard Cite

The extent and stability of the expression of developmental isoforms of myosin heavy chain (MHCd), and their association with cellular morphology, were determined in adult rat skeletal muscle fibres following injury induced by eccentrically-biased exercise. Adult female Wistar rats [274 (10) g] were either assigned as non-exercised controls or subjected to 30 min of treadmill exercise (grade, -16 degrees; speed, 15 m x min(-1)), and then sacrificed following 1, 2, 4, 7, or 12 days of recovery (n = 5-6 per group). Histologically and immunohistologically stained serial, transverse cryosections of the soleus (S), vastus intermedius (VI), and tibialis anterior (TA) muscles were examined using light microscopy and digital imaging. Fibres staining positively for MHCd (MHCd+) were seldom detected in the TA. In the VI and S, higher proportions of MHCd+ fibres (0.8% and 2.5%, respectively) were observed in rats at 4 and 7 days post-exercise, in comparison to all other groups combined (0.2%, 1.2%; P< or = 0.01). In S, MHCd+ fibres were observed less frequently by 12 days (0.7%) than at 7 days (2.6%) following exercise. The majority (85.1%) of the MHCd+ fibres had morphological characteristics indicative of either damage, degeneration, repair or regeneration. Most of the MHCd+ fibres also expressed adult slow, and/or fast myosin heavy chain. Quantitatively, the MHCd+ fibres were smaller (< 2500 microm2) and more angular than fibres not expressing MHCd. Thus, there was a transient increase in a small, but distinct population of MHCd+ fibres following unaccustomed, functional exercise in adult rat S and VI muscles. The observed close coupling of MHCd expression with morphological changes within muscle fibres suggests that these characteristics have a common, initial exercise-induced injury-related stimulus.

show abstract

Section: Co-expression Of Mhc Isoforms Within ®Bressupporting

confidence: 85%

Expression of developmental myosin and morphological characteristics in adult rat skeletal muscle following exercise-induced injury

et al. 1999

View full text Add to dashboard Cite

show abstract

“…The statistically significant shift from type II to type I fibers and from subtype liB to subtype IIA fibers in the two heads of the triceps brachii muscle of the runners served as a positive control (a prime mover muscle) for the multifidus muscles. The response of these muscles is consistent with earlier reports on the effects of endurance training on muscle fibers [19,20,27,29].…”

Section: Discussionsupporting

confidence: 91%

Running training alters fiber type composition in spinal muscles

et al. 1994

View full text Add to dashboard Cite

The issue of whether exercise can induce changes in muscle fiber types has been long debated. Knowledge about the alterations in spinal muscle fiber types is scarce. In this study, the alterations initiated by long-distance running on spinal muscle fiber type distribution was studied. Ten young dogs were run on a treadmill for 55 weeks, 5 days a week, and ten dogs from the same litters served as controls. The daily running distance was gradually increased to 40 km and maintained at that level for the final 15 weeks. Histological sections were prepared from the cervical, thoracic, and lumbar multifidus muscles and the medial and lateral heads of triceps brachii and analyzed for the fiber type composition and cross-sectional area of fibers. In the lumbar multifidus, the numerical percentage of the muscle fibers with low oxidative capacity (type II) increased significantly in the running group. However, in the thoracic and cervical spine multifidus, the response to running resembled more of the significant shift from type II to type I fibers (with high oxidative capacity), which was also observed in the triceps brachii muscle. In these muscles, the quantitative image analysis of nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) reaction also demonstrated a shift towards a higher oxidative capacity within the type II fibers. The results show that training can induce changes in fiber type composition not only in limb muscles but also in the stabilizing spinal muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

“…However, in the present study exercise training did not increase the percentage of type I fibers, possibly because the training duration or intensity advocated in the present study was not enough to induce a muscle fiber type transition in SHR. On the other hand, it has been shown that, even when an exercise-induced fiber type transition from type II to type I does not take place in soleus muscle, it occurs in other skeletal muscles [27]. Thus, we cannot exclude the possibility that fiber type transition in skeletal muscles other than soleus muscle contributed to the improved exercise capacity in EX.…”

Section: Discussionmentioning

confidence: 85%