Ultrastructural and metabolic profiles on single muscle fibers of different types after hindlimb suspension in rats.

Takekura, Hiroaki; Yoshioka, Toshitada

doi:10.2170/jjphysiol.39.385

Cited by 7 publications

(6 citation statements)

References 27 publications

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“…The activity of m-CK may be correlated with the mitochondrial volume and/or the area of mitochondrial cristae. The mitochondrial volumes in single muscle fibres are highest in SO, lowest in FG and intermediate in FOG fibres (Takekura & Yoshioka, 1989). In the present study, the activity of m-CK was highest in SO, lowest in FG and intermediate in FOG fibres.…”

Section: Discussionsupporting

confidence: 52%

Profiles of creatine kinase isoenzyme compositions in single muscle fibres of different types

Yamashita

Yoshioka

1991

J Muscle Res Cell Motil

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Creatine kinase (CK) isoenzyme compositions of different types of single muscle fibres dissected from soleus (SOL) and extensor digitorum longus (EDL) muscles from rats were examined. CK isoenzymes were separated into cytoplasmic (CK-MM, CK-MB, CK-BB) (muscle, brain and hybrid types, respectively) and mitochondrial (m-CK) isoenzymes. Total CK and CK-MM activities showed the highest activities in fast-twitch glycolytic fibres (FG), lower in fast-twitch oxidative glycolytic (FOG) and the lowest in slow-twitch oxidative (SO) fibres. Conversely, the activity of m-CK was highest in SO, lowest in FG and intermediate in FOG fibres. The activity of CK-MB was highest in SO and lower in FOG and FG fibres. However, the activities of total CK and CK isoenzymes in a single muscle fibre type were not distinguishable from those of another type, and the profiles of CK isoenzyme compositions from the same type of single muscle fibres overlapped over a considerable range. The relationships between the four CK isoenzymes activities in single muscle fibres of different types were not similar. These results suggest that CK isoenzymes of single muscle fibres of different types play different roles in intracellular energy metabolism. Therefore, it is supposed that the CK isoenzyme compositions of single muscle fibres are suitable for their contractive and metabolic properties.

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Section: Discussionsupporting

confidence: 52%

Profiles of creatine kinase isoenzyme compositions in single muscle fibres of different types

Yamashita

Yoshioka

1991

J Muscle Res Cell Motil

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“…Another explanation is the ability of spastic muscle to attenuate the shift in slow to fast muscle fiber transformation (25,26); slow fibers have a higher mitochondrial concentration that may be responsible for the increased fat oxidation observed in this study. However, this may not be universal finding because hind limb suspension in rats seems to reduce mitochondrial volume in all fiber types (38).…”

Section: Discussionmentioning

confidence: 97%

Relationship of Spasticity to Soft Tissue Body Composition and the Metabolic Profile in Persons With Chronic Motor Complete Spinal Cord Injury

Gorgey

Chiodo

Zemper

et al. 2010

The Journal of Spinal Cord Medicine

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Background/Objective: To determine the effects of spasticity on anthropometrics, body composition (fat mass [FM] and fat-free mass [FFM]), and metabolic profile (energy expenditure, plasma glucose, insulin concentration, and lipid panel) in individuals with motor complete spinal cord injury (SCI). Methods: Ten individuals with chronic motor complete SCI (age, 33 ± 7 years; BMI, 24 ± 4 kg/m 2 ; level of injury, C6-T11; American Spinal Injury Association A and B) underwent waist and abdominal circumferences to measure trunk adiposity. After the first visit, the participants were admitted to the general clinical research center for body composition (FFM and FM) assessment using dual energy x-ray absorptiometry. After overnight fasting, resting metabolic rate (RMR) and metabolic profile (plasma glucose, insulin, and lipid profile) were measured. Spasticity of the hip, knee, and ankle flexors and extensors was measured at 6 time points over 24 hours using the Modified Ashworth Scale. Results: Knee extensor spasticity was negatively correlated to abdominal circumferences (r 5 20.66, P 5 0.038). After accounting for leg or total FFM, spasticity was negatively related to abdominal circumference (r 5 20.67, P 5 0.03). Knee extensor spasticity was associated with greater total %FFM (r 5 0.64; P 5 0.048), lower %FM (r 5 20.66; P 5 0.03), and lower FM to FFM ratio. Increased FFM (kg) was associated with higher RMR (r 5 0.89; P 5 0.0001). Finally, spasticity may indirectly influence glucose homeostasis and lipid profile by maintaining FFM (r 5 20.5 to 20.8, P , 0.001). Conclusion: Significant relationships were noted between spasticity and variables of body composition and metabolic profile in persons with chronic motor complete SCI, suggesting that spasticity may play a role in the defense against deterioration in these variables years after injury. The exact mechanism is yet to be determined.

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“…Globally, this adaptive response is characterized by a reduction of fatty acid utilization and increased glucose utilization in rodent and human muscles (25,54,158,315,478). This shift in fuel metabolism from lipids toward glucose is related to augmented expression and activity of several glycolytic enzymes, such as PFK, hexokinase, and pyruvate kinase (47,96,536,558,574,646), and decreased expression and activity of enzymes of FAO (227,536,558,646). In contrast, mitochondrial oxidation capacity and expression of enzymes in the TCA cycle, such as CS, malate dehydrogenase, and SDH, are not (or only moderately) affected by hindlimb suspension or space flight (25,47,264,574).…”

Section: Metabolic and Functional Diversity Of Skeletal Musclementioning

confidence: 99%

Physiological Functions of Peroxisome Proliferator-Activated Receptor β

Neels

Grimaldi

2014

Physiological Reviews

150

146

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The peroxisome proliferator-activated receptors, PPARα, PPARβ, and PPARγ, are a family of transcription factors activated by a diversity of molecules including fatty acids and fatty acid metabolites. PPARs regulate the transcription of a large variety of genes implicated in metabolism, inflammation, proliferation, and differentiation in different cell types. These transcriptional regulations involve both direct transactivation and interaction with other transcriptional regulatory pathways. The functions of PPARα and PPARγ have been extensively documented mainly because these isoforms are activated by molecules clinically used as hypolipidemic and antidiabetic compounds. The physiological functions of PPARβ remained for a while less investigated, but the finding that specific synthetic agonists exert beneficial actions in obese subjects uplifted the studies aimed to elucidate the roles of this PPAR isoform. Intensive work based on pharmacological and genetic approaches and on the use of both in vitro and in vivo models has considerably improved our knowledge on the physiological roles of PPARβ in various cell types. This review will summarize the accumulated evidence for the implication of PPARβ in the regulation of development, metabolism, and inflammation in several tissues, including skeletal muscle, heart, skin, and intestine. Some of these findings indicate that pharmacological activation of PPARβ could be envisioned as a therapeutic option for the correction of metabolic disorders and a variety of inflammatory conditions. However, other experimental data suggesting that activation of PPARβ could result in serious adverse effects, such as carcinogenesis and psoriasis, raise concerns about the clinical use of potent PPARβ agonists.

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Ultrastructural and metabolic profiles on single muscle fibers of different types after hindlimb suspension in rats.

Cited by 7 publications

References 27 publications

Profiles of creatine kinase isoenzyme compositions in single muscle fibres of different types

Profiles of creatine kinase isoenzyme compositions in single muscle fibres of different types

Relationship of Spasticity to Soft Tissue Body Composition and the Metabolic Profile in Persons With Chronic Motor Complete Spinal Cord Injury

Physiological Functions of Peroxisome Proliferator-Activated Receptor β

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