Functional and Structural Changes after Disuse of Human Muscle

1977 ◽  
Vol 52 (4) ◽  
pp. 337-342 ◽  
Author(s):  
A. J. Sargeant ◽  
C. T. M. Davies ◽  
R. H. T. Edwards ◽  
C. Maunder ◽  
A. Young

1. Seven patients who had suffered unilateral leg fracture were studied after removal of immobilizing plaster casts. 2. Leg volume measured anthropometrically was reduced by 12% in the injured leg (5·68 ± 1·05 litres) compared with the uninjured (6·43 ± 0·87 litres). Associated with this loss was a similar reduction in the net maximum oxygen uptake achieved in one-leg cycling, from 1·89 ± 0·21 l/min in the uninjured leg to 1·57±0·18 l/min in the injured. 3. Measured by a percutaneous needle biopsy technique, a reduction of 42% was found in the cross-sectional area of the muscle fibres sampled from the vastus lateralis of the injured compared with the uninjured leg. 4. Staining for myosin adenosine triphosphatase activity showed that both type I and II fibres were affected, being reduced respectively from 3410 to 1840 μm2 and from 3810 to 2390 μm2 cross-sectional area. 5. Possible reasons and implications are discussed for the discrepancy between the magnitude of the difference observed in the gross measurement of leg function (maximum oxygen uptake) and structure (leg volume) as compared with the cellular level (cross-sectional fibre area).

2020 ◽  
Vol 45 (4) ◽  
pp. 368-375 ◽  
Author(s):  
Joshua P. Nederveen ◽  
George Ibrahim ◽  
Stephen A. Fortino ◽  
Tim Snijders ◽  
Dinesh Kumbhare ◽  
...  

The percutaneous muscle biopsy procedure is an invaluable tool for characterizing skeletal muscle and capillarization. Little is known about methodological or biological variation stemming from the technique in heterogeneous muscle. Five muscle biopsies were taken from the vastus lateralis of a group of young men (n = 29, 22 ± 1 years) over a 96-h period. We investigated the repeatability of fibre distribution, indices of muscle capillarization and perfusion, and myofibre characteristics. No differences between the biopsies were reported in myofibre type distribution, cross-sectional area (CSA), and perimeter. Capillary-to-fibre perimeter exchange index and individual capillary-fibre contacts were unchanged with respect to the location of the muscle biopsy and index of capillarization. The variability in the sampling distribution of fibre type specific muscle CSA increased when fewer than 150 muscle fibres were quantified. Variability in fibre type distribution increased when fewer than 150 muscle fibres were quantified. Myofibre characteristics and indices of capillarization are largely consistent throughout the vastus lateralis when assessed via the skeletal muscle biopsy technique. Novelty Markers of muscle capillarization and perfusion were unchanged across multiple sites of the human vastus lateralis. Myofibre characteristics such as muscle cross-sectional area, perimeter, and fibre type distribution were also unchanged. Variation of muscle CSA was higher when fewer than 150 muscle fibres were quantified.


1996 ◽  
Vol 5 (6) ◽  
pp. 593-600 ◽  
Author(s):  
Marita Ruusunen ◽  
Marja-Liisa Sevon-Aimonen ◽  
Eero Puolanne

The muscle fibre-type properties of longissimus were compared between Landrace and Yorkshire breeds and between the sexes in an attempt to shed light on the relationship of these histochemical parameters to animal growth and carcass composition. Muscle fibres were classified into three groups, type I, type lIA and type 11B, using the myosin ATPase method. At a given live weight, the cross-sectional area of type I fibres (CSA1) was smaller (p


2006 ◽  
Vol 7 (3) ◽  
pp. 163-174 ◽  
Author(s):  
Myoung-Ae Choe ◽  
Gyeong Ju An ◽  
Yoon-Kyong Lee ◽  
Ji Hye Im ◽  
Smi Choi-Kwon ◽  
...  

This study examined the effects of daily low-intensity exercise following acute stroke on mass, Type I and II fiber cross-sectional area, and myofibrillar protein content of hind-limb muscles in a rat model. Adult male Sprague-Dawley rats were randomly assigned to 1 of 4 groups (n = 7-9 per group): stroke (occlusion of the right middle cerebral artery [RMCA]), control (sham RMCA procedure), exercise, and stroke-exercise. Beginning 48 hours post-stroke induction/sham operation, rats in the exercise group had 6 sessions of exercise in which they ran on a treadmill at grade 10 for 20 min/day at 10 m/min. At 8 days poststroke, all rats were anesthetized and soleus, plantaris, and gastrocnemius muscles were dissected from both the affected and unaffected sides. After 6 sessions of exercise following acute ischemic stroke, the stroke-exercise group showed the following significant (p < .05) increases compared to the stroke-only group: body weight and dietary intake, muscle weight of affected soleus and both affected and unaffected gastrocnemius muscle, Type I fiber cross-sectional area of affected soleus and both affected and unaffected gastrocnemius muscle, Type II fiber cross-sectional area of the unaffected soleus, both affected and unaffected plantaris and gastrocnemius muscle, Type II fiber distribution of affected gastrocnemius muscle, and myofibrillar protein content of both affected and unaffected soleus muscle. Daily low-intensity exercise following acute stroke attenuates hind-limb muscle atrophy in both affected and unaffected sides. The effects of exercise are more pronounced in the soleus and gastrocnemius as compared to the plantaris muscle.


1999 ◽  
Vol 276 (2) ◽  
pp. R591-R596 ◽  
Author(s):  
H. Green ◽  
C. Goreham ◽  
J. Ouyang ◽  
M. Ball-Burnett ◽  
D. Ranney

To examine the hypothesis that increases in fiber cross-sectional area mediated by high-resistance training (HRT) would result in a decrease in fiber capillarization and oxidative potential, regardless of fiber type, we studied six untrained males (maximum oxygen consumption, 45.6 ± 2.3 ml ⋅ kg−1 ⋅ min−1; mean ± SE) participating in a 12-wk program designed to produce a progressive hypertrophy of the quadriceps muscle. The training sessions, which were conducted 3 times/wk, consisted of three sets of three exercises, each performed for 6–8 repetitions maximum (RM). Measurements of fiber-type distribution obtained from tissue extracted from the vastus lateralis at 0, 4, 7, and 12 wk indicated reductions ( P < 0.05) in type IIB fibers (15.1 ± 2.1% vs. 7.2 ± 1.3%) by 4 wk in the absence of changes in the other fiber types (types I, IIA, and IIAB). Training culminated in a 17% increase ( P < 0.05) in cross-sectional area by 12 wk with initial increases observed at 4 wk. The increase was independent of fiber type-specific changes. The number of capillaries in contact with each fiber type increased by 12 wk, whereas capillary contacts-to-fiber area ratios remained unchanged. In a defined cross-sectional field, HRT also increased the capillaries per fiber at 12 wk. Training failed to alter cellular oxidative potential, as measured by succinic dehydrogenase (SDH) activity, regardless of fiber type and training duration. It is concluded that modest hypertrophy induced by HRT does not compromise cellular tissue capillarization and oxidative potential regardless of fiber type.


2020 ◽  
Vol 22 (2) ◽  
pp. 152 ◽  
Author(s):  
Chrysostomos Sahinis ◽  
Eleftherios Kellis ◽  
Nikiforos Galanis ◽  
Konstantinos Dafkou ◽  
Athanasios Ellinoudis

Aim: Τo examine the inter- and intra-muscular differences in the anatomical cross-sectional area (CSA) of the quadricep muscles, using extended - field of view (EFOV) ultrasonography (US).Material and methods: Panoramic transverse US images of the thigh were acquired from 10 young participants at five different locations across the thigh, in two sessions, spaced a week apart. The CSA of the vastus medialis (VM), rectus femoris (RF), vastus intermedius (VI), vastus lateralis (VL) and tensor vastus intermedius (TVI) was quantified.Results: The intraclass correlation coefficients ranged from 0.75 to 0.97 and the standard error of measurement ranged from 0.78% to 6.61%, indicating high test-retest reliability. Analysis of the variance indicated that among the 5 quadriceps muscles the VL and the RF displayed the greater CSA proximally, the VI medially and the VM distally across the thigh (p <0.05). No differences in the quadriceps CSA measured with and without including the TVI were found (p >0.05).Conclusions: The EFOV US technique provides transverse scans of the quadriceps muscle in vivo and allowed a reliable and non-invasive determination of CSA at a low cost. Evaluation of CSA along the thigh largely depends on the measurement site. Future studies that examine the quadriceps CSA using EFOV after any form of intervention should consider changes of at least 6.5% as meaningful.


1977 ◽  
Vol 23 (1) ◽  
pp. 269-284 ◽  
Author(s):  
I.G. Burleigh

Nuclei have been enumerated in muscle fibres of different physiological properties within adult rats and rabbits. Almost invariably, and regardless of muscle type, there is a direct relationship between the cross-sectional area (or fibre breadth) of muscle fibres and the number of nuclei within them. The one exception occurred in muscles of older rats where increased nuclear numbers do not always appear to result in broader muscle fibres. The greater complement of nuclei in broader fibres is accompanied by larger amounts of cell substance per nucleus. Confirming early observations in the literature, red fibres of the slow-phasic type have more nuclei than have white, fast-phasic fibres of similar breadth. These conclusions are not vitiated by differences in the number of nuclei within capillaries or in satellite cells, by differences in nuclear length or by variation in the degree to which fibres are contracted. In respect of their complement of nuclei, and the average amount of cell substance formed per nucleus the small red fibres that occur within muscles of predominantly fast-phasic character appear to be fast-rather than slow-phasic in type. When the number of nuclei observed per fibre is plotted against fibre cross-sectional area, the shapes of the resulting distributions suggest that estimates of muscle nuclei may be valuable not only as an index of growth potential, but of the extent to which that potential is expressed. In one muscle, the above distribution was of a form which indicated that some fibres may have formed abnormally large amounts of protein per nucleus. However, this was not adequately confirmed. Various factors have been investigated that are relevant to the accuracy of enumerating nuclei and measuring fibre breadths.


1994 ◽  
Vol 77 (2) ◽  
pp. 947-955 ◽  
Author(s):  
M. I. Lewis ◽  
S. A. Monn ◽  
W. Z. Zhan ◽  
G. C. Sieck

Interactive effects of emphysema (EMP) and prolonged nutritional deprivation (ND) on contractile, morphometric, and metabolic properties of hamster diaphragm muscle (DIA) were examined. Six months after induction of EMP (intratracheal elastase), saline-treated controls (CTL) and EMP hamsters of similar body weights were subjected to ND over 6 wk. Isometric contractile and fatigue properties of costal DIA were determined in vitro. DIA fibers were histochemically classified as type I or II, and fiber succinate dehydrogenase activity and cross-sectional area were determined using quantitative microscopic procedures. From histochemical sections, the number of capillaries per fiber (C/F) and per fiber cross-sectional area (C/A) were determined. ND resulted in progressive loss of body weight (ND-CTL, 23.8%; ND-EMP, 28.4%; P = NS). ND did not affect reduction in optimal length (Lo) of DIA fibers in EMP compared with CTL and ND-CTL hamsters. Maximum specific force (i.e., force/unit area) was reduced by approximately 25% in EMP animals compared with CTL. ND did not improve or exacerbate the reduction in specific force with EMP. ND attenuated improved fatigue resistance of DIA in EMP animals. No differences in fiber type proportions were noted among experimental groups. Significant atrophy of type I and II DIA fibers was noted after ND. Atrophy was proportionately greater in type II fibers of ND-EMP when referenced to EMP animals. Thus adaptive hypertrophy of type II DIA fibers in EMP animals was abolished. Fiber succinate dehydrogenase activity was significantly increased in type I and II fibers in EMP DIA. ND did not affect this metabolic adaptation of DIA fibers to persistent loads imposed by EMP.(ABSTRACT TRUNCATED AT 250 WORDS)


1996 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
MD Fratacci ◽  
M Levame ◽  
A Rauss ◽  
H Bousbaa ◽  
G Atlan

The changes occurring in the histochemical characteristics of the rat diaphragm during the postnatal period were examined. Fibre-type distribution, fibre oxidative capacity, i.e. succinate-dehydrogenase (SDH) activity, and cross-sectional area were compared in the costal (COS) and crural (CRU) regions, and across their abdominal and thoracic surfaces. The proportions of type I and IIb fibres in both COS and CRU increased with age, while the proportion of type IIa fibres progressively decreased. For COS, fibre distribution was homogeneous over the entire muscle and did not change after 4 weeks. For CRU, it was heterogeneous with a higher proportion of type I fibres on the thoracic surface as from the first week. All fibre types significantly increased in cross-sectional area between 1 and 8 weeks, with no significant differences in COS and CRU. Mean SDH activity did not differ between COS and CRU or across the muscles. Mean SDH activities-were low and identical in all fibre types at birth, and then increased, peaking at the 6th week in type I and IIa fibres. When total muscle fibre oxidative capacity was calculated from an index including fibre-type proportion, cross-sectional area and mean SDH activity, it was significantly higher at 1 than at 8 weeks after birth; this might have functional implications for the newborn.


1994 ◽  
Vol 77 (5) ◽  
pp. 2385-2390 ◽  
Author(s):  
C. A. Allemeier ◽  
A. C. Fry ◽  
P. Johnson ◽  
R. S. Hikida ◽  
F. C. Hagerman ◽  
...  

Eleven men sprint trained two to three times per week for 6 wk to investigate possible exercise-induced slow-to-fast fiber type conversions. Six individuals served as controls. Both groups were tested at the beginning and end of the study to determine anaerobic performance and maximal oxygen consumption. In addition, pre- and postbiopsies were extracted from the vastus lateralis muscle and were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain (MHC) content. No significant changes were found in anaerobic or aerobic performance variables for either group. Although a trend was found for a decrease in the percentage of type IIb fibers, high-intensity sprint cycle training caused no significant changes in the fiber type distribution or cross-sectional area. However, the training protocol did result in a significant decrease in MHC IIb with a concomitant increase in MHC IIa for the training men. These data appear to support previous investigations that have suggested exercise-induced adaptations within the fast fiber population (IIb-->IIa) after various types of training (endurance and strength).


Author(s):  
Eric C. Leszczynski ◽  
Christopher Kuenze ◽  
Brett Brazier ◽  
Joseph Visker ◽  
David P. Ferguson

AbstractQuadriceps muscle weakness is a commonly reported issue post anterior cruciate ligament reconstruction (ACLR), with minimal information related to skeletal muscle morphology following surgery. The purpose is to examine the morphological and functional differences in the vastus lateralis muscle from patient's ACLR and contralateral leg. Three physically active ACLR participants were recruited and secured to a dynamometer to perform maximal voluntary isometric knee extension contractions (MVIC) of the ACLR and contralateral limb. Muscle biopsies of the ACLR and contralateral vastus lateralis were performed, then sectioned, and stained for myosin isoforms to determine fiber type. Confocal images were acquired, and ImageJ software was used to determine the fiber type and cross-sectional area (CSA). There was a significant reduction in CSA of the type IIa and type IIx muscle fiber cells between healthy (IIa: 7,718 ± 1,295 µm2; IIx; 5,800 ± 601 µm2) and ACLR legs (IIa: 4,139 ± 709 µm2; IIx: 3,708 ± 618 µm2) (p < 0.05), while there was no significant difference in knee extension MVIC torque between legs (healthy limb: 2.42 ± 0.52 Nm/kg; ACLR limb: 2.05 ± 0.24 Nm/kg, p = 0.11). The reduction in the cross-sectional area of the ACLR type II fibers could impair function and increase secondary injury risk.


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