Changes in capillary distribution in rat fast muscles following nerve crush and reinnervation.

Large, J; Tyler, K. R.

doi:10.1113/jphysiol.1985.sp015659

Cited by 13 publications

(14 citation statements)

References 18 publications

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“…1 and 2). For fiber-type-specific vascular geometries (G2, G4), we follow experimental observations in rat skeletal muscle that muscle fibers with a high oxidative potential are generally associated with a denser capillary network [36], [37], although not all studies agree with this finding [38]. In this type of fiber-type-specific geometry (Fig.…”

Section: Methodssupporting

confidence: 73%

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

2012

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The process of oxygen delivery from capillary to muscle fiber is essential for a tissue with variable oxygen demand, such as skeletal muscle. Oxygen distribution in exercising skeletal muscle is regulated by convective oxygen transport in the blood vessels, oxygen diffusion and consumption in the tissue. Spatial heterogeneities in oxygen supply, such as microvascular architecture and hemodynamic variables, had been observed experimentally and their marked effects on oxygen exchange had been confirmed using mathematical models. In this study, we investigate the effects of heterogeneities in oxygen demand on tissue oxygenation distribution using a multiscale oxygen transport model. Muscles are composed of different ratios of the various fiber types. Each fiber type has characteristic values of several parameters, including fiber size, oxygen consumption, myoglobin concentration, and oxygen diffusivity. Using experimentally measured parameters for different fiber types and applying them to the rat extensor digitorum longus muscle, we evaluated the effects of heterogeneous fiber size and fiber type properties on the oxygen distribution profile. Our simulation results suggest a marked increase in spatial heterogeneity of oxygen due to fiber size distribution in a mixed muscle. Our simulations also suggest that the combined effects of fiber type properties, except size, do not contribute significantly to the tissue oxygen spatial heterogeneity. However, the incorporation of the difference in oxygen consumption rates of different fiber types alone causes higher oxygen heterogeneity compared to control cases with uniform fiber properties. In contrast, incorporating variation in other fiber type-specific properties, such as myoglobin concentration, causes little change in spatial tissue oxygenation profiles.

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Section: Methodssupporting

confidence: 73%

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

2012

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“…However, the results are difficult to compare, since the effect on capillarity depends on the duration of disuse and on muscle type. Data concerning the effect of early reinnervation on the capillary network are limited and contradictory: Large and Tyler (1985) report no changes in C/F and CD between control and reinnervated muscles, with the exception of the more glycolytic fibres in which the C/F is lower than in the control. In contrast, Ziada et al (1989) have found a higher C/F in EDL and tibialis anterior (TA) muscle after a 5-week application of prazosin.…”

Section: Introductionmentioning

confidence: 89%

“…Experiments have involved mechanical and chemical denervation, and muscles have been excised at various time intervals after denervation (cf. Mrazkova and Puzanova 1971;Chernukh and Alexeeva 1975;Carpenter and Karpati 1982;Large and Tyler 1985;Ziada et al 1989;Tyml et al 1999;Borisov et al 2000;Dedkov et al 2002;Wagatsuma et al 2005). The capillary network has only been studied in two-dimensional muscle sections.…”

Section: Introductionmentioning

confidence: 95%

Adaptation of muscle fibre types and capillary network to acute denervation and shortlasting reinnervation

et al. 2007

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We postulated that, in rat extensor digitorum longus muscle (EDL), the length of capillaries per fibre surface area (Lcap/Sfib) and per fibre volume (Lcap/Vfib) could reflect fibre-type transformations accompanied by changes in oxidative metabolic profile and selective fibre-type atrophy. We excised rat EDL muscle 2 weeks after the sciatic nerve was cut (acute denervation; DEDL) and 4 weeks after the nerve was crushed (early reinnervation; REDL) and characterised muscle fibre-type transformation by the expression of myosin heavy-chain isoforms and by succinate dehydrogenase (SDH) and nicotinoamide adenine dinucleotide-tetrazolium reductase (NADH-TR) reactions. The numerical percentage (N/N) and area percentage (A/A) of pure and hybrid fibres and their diameter were determined, as was the A/A of SDH- and NADH-TR-positive fibres. The length of capillaries per fibre length (Lcap/Lfib), Lcap/Sfib and Lcap/Vfib were estimated in REDL and Lcap/Vfib in DEDL. In DEDL, the type 2x and 2b fibres evidently atrophied, with the N/N of type 2x fibres being lower and that of hybrid fibres higher. In REDL, the N/N of hybrid fibres was even higher, consequent to a lower N/N of type 2b fibres; however, fibre diameters approached values of the control EDL. Compared with control EDL, denervated and reinnervated muscles exhibited a higher A/A of oxidative fibres. This is probably the result of fibre-type transformation and selective fibre atrophy. We conclude that capillary length does not change during acute denervation and early reinnervation. The obtained higher values of Lcap/Sfib and Lcap/Vfib are related to changes in muscle fibre cross-sectional area.

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“…The existing studies (Mrazkova and Puzanova 1971;Engel and Stonnington 1974;Chernukh and Alekseeva 1975;Large and Tyler 1985;Tyml et al 1999) are difficult to compare, because the denervation procedures were different and different parameters were measured.…”

Section: Introductionmentioning

confidence: 99%

Nerve injury affects the capillary supply in rat slow and fast muscles differently

et al. 2005

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The goal of this study was to determine the acute effects of permanent denervation on the length density of the capillary network in rat slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles and the effect of short-lasting reinnervation in slow muscle only. Denervation was performed by cutting the sciatic nerve. Both muscles were excised 2 weeks later. Reinnervation was studied 4 weeks after nerve crush in SOL muscle only. Capillaries and muscle fibres were visualised by triple immunofluorescent staining with antibodies against CD31 and laminin and with fluorescein-labelled Griffonia (Bandeira) simplicifolia lectin. A recently developed stereological approach allowing the estimation of the length of capillaries adjacent to each individual fibre (Lcap/Lfib) was employed. Three-dimensional virtual test grids were applied to stacks of optical images captured with a confocal microscope and their intersections with capillaries and muscle fibres were counted. Interrelationships among capillaries and muscle fibres were demonstrated with maximum intensity projection of the acquired stacks of optical images. The course of capillaries in EDL seemed to be parallel to the fibre axes, whereas in SOL, their preferential direction deviated from the fibre axes and formed more cross-connections among neighbouring capillaries. Lcap/Lfib was clearly reduced in denervated SOL but remained unchanged in EDL, although the muscle fibres significantly atrophied in both muscle types. When soleus muscle was reinnervated, capillary length per unit fibre length was completely restored. The physiological background for the different responses of the capillary network in slow and fast muscle is discussed.

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Changes in capillary distribution in rat fast muscles following nerve crush and reinnervation.

Cited by 13 publications

References 18 publications

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

Effects of Fiber Type and Size on the Heterogeneity of Oxygen Distribution in Exercising Skeletal Muscle

Adaptation of muscle fibre types and capillary network to acute denervation and shortlasting reinnervation

Nerve injury affects the capillary supply in rat slow and fast muscles differently

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