Specific mitochondrial responses to running training are induced in each type of rat single muscle fibers.

Takekura, Hiroaki; Yoshioka, Toshitada

doi:10.2170/jjphysiol.39.497

Cited by 14 publications

(6 citation statements)

References 35 publications

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“…The proportion of type IIa (fast-twitch fi ber with high oxidative capacity) in the R portion of SM muscle was signifi cantly (p < 0.01) decreased by the resection of STG tendons, while there were no signifi cant diff erences in type I (slow-twitch fi ber) and IIb (fast-twitch fi ber with low oxidative capacity) in the R portion of SM muscle. These changes in fi ber type compositions were not consistent with previous studies using other experimental models, such as muscle training [4,36,38] , tenotomy [43] , hypergravity [26] , denervation [29] , inactivity [47] , etc. Therefore, the transformation of fi ber type composition in the present study could not provide a type or kind of stimulus induced by the resection of STG tendons.…”

Section: Discussion ▼contrasting

confidence: 89%

“…It has been well documented that an increase in mitochondrial volume has been observed in exercise-trained skeletal muscles [44] . It has been also suggested that the responses in the mitochondrial volume to exercise-induced loading diff er according to the types of muscle fi bers [38] . Therefore, the increased mitochondrial volume might be derived from the increased demand of oxidative energy metabolism [35] as a compensational phenomenon following the resection of STG.…”

Section: Discussion ▼mentioning

confidence: 99%

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Changes of SM Muscles After STG Harvest

Fujiya¹,

Goto²,

Kohno³

et al. 2011

Int J Sports Med

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Semimembranosus (SM) muscle as well as Semitendinosus-Gracilis (STG) tendon have the same role in knee flexion and tibial internal rotation. Because STG tendons are generally used for anterior cruciate ligament (ACL) reconstruction, some compensational changes in SM muscle might have been induced. The purpose of this study was to investigate the changes of SM muscle affected by harvesting STG tendons. 10 Wistar-strain male rats were divided into control (C) and STG-dissected (STG) groups. Left STG tendons including the distal half of muscle portions were dissected in group STG and only skin incision was performed in group C. 4 weeks after the treatments, fiber types classification and ultrastructural observations were performed. In group STG the decrease of type IIa (fast-twitch fiber with high oxidative capacity) was observed in deep layers of SM muscle (p<0.01). In ultrastructural observations, the increase in lipid droplets and mitochondria and the irregularity of Z disc were observed in deep layers. These morphological changes indicated that the mechanical loading might increase in SM muscle after harvesting of STG. Because of minor injuries in SM muscle, hamstring strength exercise at early stage of rehabilitation program should be carefully performed following ACL reconstruction using STG tendons in clinical practice.

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Section: Discussion ▼contrasting

confidence: 89%

Section: Discussion ▼mentioning

confidence: 99%

Changes of SM Muscles After STG Harvest

Fujiya¹,

Goto²,

Kohno³

et al. 2011

Int J Sports Med

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“…Using the Krogh model (incorporating the capillary supply), the critical capillary PO2 did not change in the deep region, whereas it increased by 25% in the superficial region. tissue (71), indicates that atrophy is accompanied by a proportional loss of mitochondria in the deep region. The increased integrated SDH activity in the superficial region, on the other hand, indicates that although atrophy also occurred in this region, mitochondrial biogenesis was elevated.…”

Section: Region-specific Adaptation In Oxidative Capacitymentioning

confidence: 99%

Region-specific adaptations in determinants of rat skeletal muscle oxygenation to chronic hypoxia

Wüst

Jaspers²,

Heijst³

et al. 2009

American Journal of Physiology-Heart and Circulatory Physiology

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Chronic exposure to hypoxia is associated with muscle atrophy (i.e., a reduction in muscle fiber cross-sectional area), reduced oxidative capacity, and capillary growth. It is controversial whether these changes are muscle and fiber type specific. We hypothesized that different regions of the same muscle would also respond differently to chronic hypoxia. To investigate this, we compared the deep (oxidative) and superficial (glycolytic) region of the plantaris muscle of eight male rats exposed to 4 wk of hypobaric hypoxia (410 mmHg, Po(2): 11.5 kPa) with those of nine normoxic rats. Hematocrit was higher in chronic hypoxic than control rats (59% vs. 50%, P < 0.001). Using histochemistry, we observed 10% fiber atrophy (P < 0.05) in both regions of the muscle but no shift in the fiber type composition and myoglobin concentration of the fibers. In hypoxic rats, succinate dehydrogenase (SDH) activity was elevated in fibers of each type in the superficial region (25%, P < 0.05) but not in the deep region, whereas in the deep region but not the superficial region the number of capillaries supplying a fiber was elevated (14%, P < 0.05). Model calculations showed that the region-specific alterations in fiber size, SDH activity, and capillary supply to a fiber prevented the occurrence of anoxic areas in the deep region but not in the superficial region. Inclusion of reported acclimatization-induced increases in mean capillary oxygen pressure attenuated the development of anoxic tissue areas in the superficial region of the muscle. We conclude that the determinants of tissue oxygenation show region-specific adaptations, resulting in a marked differential effect on tissue Po(2).

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“…Our data suggest that lipid peroxidation is, at least partially, associated with the protein oxidative modification during physical activity with pre-conditioned runners. Since regular exercise increases the number and activity of mitochondria in muscles [15], pre-conditioned runners may have more mitochondria to produce free radicals to modify proteins. The protein 3-NT level was not significantly altered in the plasma of the marathon runners.…”

Section: Discussionmentioning

confidence: 99%

Exercise-mediated alteration of protein redox states in plasma: a possible stimulant for hormetic response

et al. 2007

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Physical exercise increases the metabolic rate and production of reactive oxygen species subsequent to elevated oxidative phosphorylation required to meet the higher ATP demand. This increased free radical generation could alter the redox state of proteins. In order to gain insight into the altered redox state during exercise, protein carbonyls, 4-hydroxylnonenal (HNE) and 3-nitrotyrosine (3-NT) levels were measured in two groups of young subjects (4 untrained controls and 6 long-distance runners). Plasma was analyzed before and after completing a treadmill run at increasing intensities up to volitional exhaustion. After the exhausting run, protein carbonyl and HNE levels were significantly increased in trained runners but not in controls. However, the protein 3-NT levels did not significantly change in either group. These results suggest that altered protein redox state occurs while running an exhausting run in relation to the physical condition of the subjects involved.

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Specific mitochondrial responses to running training are induced in each type of rat single muscle fibers.

Cited by 14 publications

References 35 publications

Changes of SM Muscles After STG Harvest

Changes of SM Muscles After STG Harvest

Region-specific adaptations in determinants of rat skeletal muscle oxygenation to chronic hypoxia

Exercise-mediated alteration of protein redox states in plasma: a possible stimulant for hormetic response

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