A comparison of the microcirculation in rat fast glycolytic and slow oxidative muscles at rest and during contractions

Dawson, J. M.; Tyler, K. R.; Hudlická, O

doi:10.1016/0026-2862(87)90015-x

Cited by 71 publications

(41 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The number of capillary vessels surrounding a muscle fiber is higher for slow than for fast fibers. For example, in rat muscles, the capillary to fiber ratio is 2.85 in soleus (slow muscle) and 1.46 in peroneus (fast muscle) (67), and the number of capillary per fiber actually perfused at rest is 0.98 in soleus and 0.66 in fast superficial part of tibialis anterior (182). In human muscles, capillary-to-fiber ratio is 4.92 for slow fibers, 4.52 for fast 2A, and 3.52 for fast 2X fibers (23, 739).…”

Section: Structural Basis Of Metabolic Diversity Of Muscle Fibersmentioning

confidence: 99%

Fiber Types in Mammalian Skeletal Muscles

Schiaffino

Reggiani

2011

Physiological Reviews

2,313

2,465

View full text Add to dashboard Cite

Mammalian skeletal muscle comprises different fiber types, whose identity is first established during embryonic development by intrinsic myogenic control mechanisms and is later modulated by neural and hormonal factors. The relative proportion of the different fiber types varies strikingly between species, and in humans shows significant variability between individuals. Myosin heavy chain isoforms, whose complete inventory and expression pattern are now available, provide a useful marker for fiber types, both for the four major forms present in trunk and limb muscles and the minor forms present in head and neck muscles. However, muscle fiber diversity involves all functional muscle cell compartments, including membrane excitation, excitation-contraction coupling, contractile machinery, cytoskeleton scaffold, and energy supply systems. Variations within each compartment are limited by the need of matching fiber type properties between different compartments. Nerve activity is a major control mechanism of the fiber type profile, and multiple signaling pathways are implicated in activity-dependent changes of muscle fibers. The characterization of these pathways is raising increasing interest in clinical medicine, given the potentially beneficial effects of muscle fiber type switching in the prevention and treatment of metabolic diseases.

show abstract

Section: Structural Basis Of Metabolic Diversity Of Muscle Fibersmentioning

confidence: 99%

Fiber Types in Mammalian Skeletal Muscles

Schiaffino

Reggiani

2011

Physiological Reviews

2,313

2,465

View full text Add to dashboard Cite

show abstract

“…These results indicate that muscle atrophy by HU generates structural alterations in the capillary network, and apoptosis appears to occur in the endothelial cell of the muscle capillaries. intercapllary anastomosis; tortuosity; capillary volume; capillary lumen; erythrocyte velocity; disuse atrophy; endothelial terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling SKELETAL MUSCLE CAPILLARIES run tortuously along muscle fibers in the relaxed resting state (2,4,18,20,33). These capillaries are connected with anastomoses, which run orthogonally to muscle fiber direction like parallel rungs of ladder (12, 33).…”

mentioning

confidence: 99%

“…SKELETAL MUSCLE CAPILLARIES run tortuously along muscle fibers in the relaxed resting state (2,4,18,20,33). These capillaries are connected with anastomoses, which run orthogonally to muscle fiber direction like parallel rungs of ladder (12,33).…”

mentioning

confidence: 99%

Regression of capillary network in atrophied soleus muscle induced by hindlimb unweighting

Fujino¹,

Kohzuki²,

Takeda³

et al. 2005

Journal of Applied Physiology

View full text Add to dashboard Cite

Little is known about the mechanisms responsible for the adaptation and changes in the capillary network of hindlimb unweighting (HU)-induced atrophied skeletal muscle, especially the coupling between functional and structural alterations of intercapillary anastomoses and tortuosity of capillaries. We hypothesized that muscle atrophy by HU leads to the apoptotic regression of the capillaries and intercapillary anastomoses with their functional alteration in hemodynamics. To clarify the three-dimensional architecture of the capillary network, contrast medium-injected rat soleus muscles were visualized clearly using a confocal laser scanning microscope, and sections were stained by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) and with anti-von Willebrand factor. In vivo, the red blood cell velocity of soleus muscle capillaries were determined with a pencil-lens intravital microscope brought into direct contact with the soleus surface. After HU, the total muscle mass, myofibril protein mass, and slow-type myosin heavy chain content were significantly lower. The number of capillaries paralleling muscle fiber and red blood cells velocity were higher in atrophied soleus. However, the mean capillary volume and capillary luminal diameter were significantly smaller after HU than in the age-matched control group. In addition, we found that the number of anastomoses and the tortuosity were significantly lower and TUNEL-positive endothelial cells were observed in atrophied soleus muscles, especially the anastomoses and/or tortuous capillaries. These results indicate that muscle atrophy by HU generates structural alterations in the capillary network, and apoptosis appears to occur in the endothelial cell of the muscle capillaries. intercapllary anastomosis; tortuosity; capillary volume; capillary lumen; erythrocyte velocity; disuse atrophy; endothelial terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling SKELETAL MUSCLE CAPILLARIES run tortuously along muscle fibers in the relaxed resting state (2,4,18,20,33). These capillaries are connected with anastomoses, which run orthogonally to muscle fiber direction like parallel rungs of ladder (12, 33). Capillary-to-fiber (C/F) ratio is frequently used to evaluate O 2 supply capacity in skeletal muscle (27). In fact, the C/F ratio is higher in rat soleus muscle, which mainly contains slow oxidative fibers (type I), than in extensor digitorum longus, which is predominantly comprised of fast glycolytic fibers (type IIb) (1, 8, 13). C/F ratio was increased by the augmentation of muscle activity, e.g., exercise or electrical stimulation (9,14,20,25), and was decreased by disuse (14, 31, 33). Histological sections from earlier studies of capillary remodeling in skeletal muscle with disuse atrophy demonstrate a decrease in capillary luminal diameter (16,36) and in the C/F ratio (13, 31, 32) despite an increase in capillary density (13,31,32).Although the regression of anastomoses in atrophied skeletal muscle has not been well studied, it wa...

show abstract

“…In contrast, chronic stimulation, which activates all muscle fibres, resulted in higher shear stress in capillaries even at rest, and shear stress was also higher in capillaries in animals in which capillary growth was induced by long-term administration of the á1-adrenoceptor blocker prazosin (Dawson & Hudlick a, 1993). Dawson et al (1987) showed a greater increase in the velocity of blood flow during muscle contraction in capillaries supplying the glycolytic part of TA than in those supplying the oxidative soleus, and, since capillary diameters were not changed, shear stress was increased as well (Hudlick a et al 1999). Using the same protocol as the present study, Hargreaves et al (1990) described a preferential increase in capillary perfusion in the glycolytic region of TA following acute stimulation, which elicited capillary growth.…”

Section: Discussionmentioning

confidence: 99%

Selective Long‐Term Electrical Stimulation of Fast Glycolytic Fibres Increases Capillary Supply but not Oxidative Enzyme Activity in Rat Skeletal Muscles

Egginton

Hudlická

2000

Experimental Physiology

View full text Add to dashboard Cite

Glycolytic fibres in rat extensor digitorum longus (EDL) and tibialis anterior (TA) were selectively activated, as demonstrated by glycogen depletion, by indirect electrical stimulation via electrodes implanted in the vicinity of the peroneal nerve using high frequency (40 Hz) trains (250 ms at 1 Hz) and low voltage (threshold of palpable contractions). This regime was applied 10 times per day, each bout being of 15 min duration with 60 min recovery, for 2 weeks. Cryostat sections of muscles were stained for alkaline phosphatase to depict capillaries, succinate dehydrogenase (SDH) to demonstrate oxidative fibres, and periodic acid‐Schiff reagent (PAS) to verify glycogen depletion. Specific activity of hexokinase (HK), 6‐phosphofructokinase, pyruvate kinase, glycogen phosphorylase and cytochrome c oxidase (COX) were estimated separately in homogenates of the EDL and the predominantly glycolytic cortex and oxidative core of the TA. Stimulation increased the activity of HK but not that of oxidative enzymes in fast muscles. Comparison of changes in oxidative capacity and capillary supply showed a dissociation in the predominantly glycolytic TA cortex. Here, COX was 3.9 ± 0.68 μM min‐1 (g wet wt)‐1 in stimulated muscles compared with 3.7 ± 0.52 μM min‐1 (g wet wt)‐1 in contralateral muscles (difference not significant), while the percentage of oxidative fibres (those positively stained for SDH) was also similar in stimulated (14.0 ± 2.8%) and contralateral (12.2 ± 1.9%) muscles. In contrast, the capillary to fibre ratio was significantly increased (2.01 ± 0.12 vs. 1.55 ± 0.04, P < 0.01). We conclude that capillary supply can be increased independently of oxidative capacity, possibly due to haemodynamic factors, and serves metabolite removal to a greater extent than substrate delivery.

show abstract

A comparison of the microcirculation in rat fast glycolytic and slow oxidative muscles at rest and during contractions

Cited by 71 publications

References 23 publications

Fiber Types in Mammalian Skeletal Muscles

Fiber Types in Mammalian Skeletal Muscles

Regression of capillary network in atrophied soleus muscle induced by hindlimb unweighting

Selective Long‐Term Electrical Stimulation of Fast Glycolytic Fibres Increases Capillary Supply but not Oxidative Enzyme Activity in Rat Skeletal Muscles

Contact Info

Product

Resources

About