scholarly journals Composition and cross-sectional area of muscle fibre types in relation to daily gain and lean and fat content of carcass in Landrace and Yorkshire pigs

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

2020 ◽  
Vol 16 (5) ◽  
pp. 377-385
Author(s):  
W. Isobe ◽  
S. Murakami ◽  
T. Saito ◽  
S. Kumagai ◽  
M. Sakita

Aging and physical inactivity lead to histochemical changes in muscles. The expression of many muscle proteins, including brain-derived neurotrophic factor (BDNF), silent information regulator of transcription 1 (SIRT1), and peroxisome proliferator-activated receptor γγ coactivator-1α (PGC-1a), declines with age. However, the effect of aerobic exercise on muscle structure and the expression profile of these proteins in elderly rats is unknown. Here, we investigated whether short-term aerobic exercise improves muscle structure and increases BDNF, SIRT1, and PGC-1a levels in aged rats. Ten male Wistar rats (95-week-old) were assigned to sedentary (SED) or exercise (Ex) groups. The Ex group performed running on a treadmill for 1 h, 6 times per week, for 2 weeks. The extensor digitorum longus muscles were removed to examine the muscle fibre type composition, cross-sectional area, and capillary-to-fibre (C/F) ratio. BDNF, SIRT1, and PGC-1a levels were evaluated by western blotting. Relative to the SED group, the Ex group showed increased proportion of Type I fibres (P<0.05), cross-sectional area of all muscle fibre types (P<0.05), succinate dehydrogenase activity (P<0.001), C/F ratio (P<0.05), and expression of BDNF, SIRT1, and PGC-1a (P<0.05).Thus, 2 weeks of aerobic exercise is sufficient to improve muscle histology and hypertrophic marker protein expression, indicating that it could prevent skeletal muscle atrophy in elderly rats.


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.


2008 ◽  
Vol 16 (3) ◽  
pp. 259 ◽  
Author(s):  
M. RUUSUNEN ◽  
E. PUOLANNE ◽  
K. PARTANEN

One of the aims in domestic pig breeding has been to increase the size of litters resulting in variation in birth weight of piglets. Pig breeding has also resulted in increased body muscle mass. Muscles with the same size can consist either of large number of thin muscle fibres or small number of thick muscle fibres. Larger body muscle content means that in living animal the heart must pump blood to larger muscle mass than earlier. Our interest in this study was to investigate the relationship between the pig’s birth weight and (i) growth performance and carcass composition, (ii) the size of organs, and (iii) the mean muscle fibre cross-sectional area at slaughter. The study consisted of twenty pigs slaughtered at the age of 165±2 days. The day after the slaughter, the carcass composition was determined by dissecting the chilled carcass into lean, fat, bones, and skin and organs were weighed. The average cross sectional area of muscle fibres was determined from three fast-twitch muscles longissimus dorsi, semimembranosus, gluteus superficialis, and two slow-twitch muscles infraspinatus and masseter. The birth weight of pigs ranged from 0.9 to 2.2 kg. We found no clear relationships between the birth weight and the pig’s growth performance from birth to slaughter. When the birth weight increased the heart weight at slaughter increased as well (P < 0.01). The heart weight was higher in those pigs with high carcass weight (P < 0.05) and with the high weight of total muscle mass in the carcass (P < 0.001). The cross sectional area of muscle fibres in M. longissimus dorsi (P < 0.05), M. semimembranosus (P < 0.10), and M. gluteus superficialis (P < 0.05) was larger in those pigs with low birth weight compared to those found in pigs with high birth weight.;


1998 ◽  
Vol 66 (2) ◽  
pp. 341-348 ◽  
Author(s):  
C. A. Maltin ◽  
K. D. Sinclair ◽  
P. D. Warriss ◽  
C. M. Grant ◽  
A. D. Porter ◽  
...  

AbstractMuscle fibre characteristics and biochemical properties of muscle recovered from young bulls of two genotypes (Aberdeen Angus × and Charolais ×), reared on two different diets (silage-based and barley-based) and slaughtered at varying ages between 10 and 19 months of age were established. These analyses were restricted to samples ofm. longissimus lumborum (LI) recovered at 48 h post mortem, vacuum packed and stored at 2°C for 14 days. Biochemical measurements included intramuscular fat content, intramuscular collagen content and its solubility, haem pigment concentration, sarcomere length and myofibril fragmentation. Muscle fibre type was classified according to the contractile nature of thefibres and their metabolic properties.Intramuscular fat content increased (P < 0·01) with age at slaughter and at a fixed age was greater for Angus × than Charolais × bulls (211·5 v. 295·8 mg/g dry matter, P < 0·01). Total intramuscular collagen and its solubility tended to decrease with age (P < 0·01). Differences in haem pigment concentration in samples of LI were detected between genotype (3·99 v. 3·59 mg/g for Angus × and Charolais × bulls; P × 0·01) and diet (3·97 v. 3·62 mg/g for bulls given barley and silage; P < 0·01), and increased with age at slaughter (P < 0·01). There was a significant increase in eye muscle cross-sectional area with increasing slaughter date (P < 0·01) and this was paralleled by an increase in cross-sectional area of individual muscle fibres (P < 0·001). Differences in cross-sectional area of individual muscle fibres between genotype and diet were small and inconsistent. Charolais × bulls had a greater percentage area of fast twitch glycolytic fibres than Angus × bulls (54·3 v. 49·3%; P < 0·01) and a smaller percentage area of slow twitch oxidative fibres (15·8 v. 18·9%; P < 0·05). Beef tenderness was positively correlated (r = 0·48; P < 0·01) with the frequency of slow twitch oxidative fibres and negatively correlated (r = -0·38; P < 0·05) with the frequency offast twitch glycolytic fibres.


1998 ◽  
Vol 66 (3) ◽  
pp. 733-740 ◽  
Author(s):  
J. S. Petersen ◽  
P. Henckel ◽  
N. Oksbjerg ◽  
M. T. Sørensen

AbstractThe influence of regular exercise training and physical activity on distribution of muscle fibre types, fibre cross-sectional areas and the number of adjacent capillaries per fibre type and per fibre (capillarization) was studied in five muscles from 48 female and 48 entire male pigs. In the growth interval from 30 to 100 kg, the pigs were subjected to one of three treatments: individual housing in pens of 2·5 m2 (treatment C), individual housing and treadmill training for 15 minlday at a speed of 4 kmlh, 5 days/week for a period of 70 days (treatment T), and housing in large pens (36 m2, 40 pigs per pen) allowing for spontaneous physical activity (treatment F). In m. longissimus dorsi, treatment F increased the ratio of fast-twitch oxidative (FTa-) to fast twitch glycolytic (FTb-) fibres, elevated the mean fibre cross-sectional area and the number of capillaries per fibre. In m. biceps femoris (BF) from female pigs, the only adaptation found was a marked training-induced (treatment T) increase in the cross-sectional area of the slow-twitch (ST-) fibres. In m. semitendinosus and BF from male pigs, treatments T and F increased the ratio of FTa- to FTb-fibres. Both training and spontaneous activity increased the proportion of ST-fibres in m. trapezius thoracis (0·48 in treatment C, 0·53 in T and 0·52 in F). Conversely in m. psoas major, treatment F increased the proportion of FTa-fibres (0·15 in C and 0·19 in F) at the expense of ST- and intermediate FTc-fibres. Spontaneous activity induced ST-fibre hypertrophy in the five muscles. For several muscles, the mean fibre cross-sectional area was significantly higher in female than in male pigs.


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).


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.


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 80 (3) ◽  
pp. 981-987 ◽  
Author(s):  
J. J. Widrick ◽  
J. J. Bangart ◽  
M. Karhanek ◽  
R. H. Fitts

This study examined the effectiveness of intermittent weight bearing (IWB) as a countermeasure to non-weight-bearing (NWB)-induced alterations in soleus type I fiber force (in mN), tension (Po; force per fiber cross-sectional area in kN/m-2), and maximal unloaded shortening velocity (Vo, in fiber lengths/s). Adult rats were assigned to one of the following groups: normal weight bearing (WB), 14 days of hindlimb NWB (NWB group), and 14 days of hindlimb NWB with IWB treatments (IWB group). The IWB treatment consisted of four 10-min periods of standing WB each day. Single, chemically permeabilized soleus fiber segments were mounted between a force transducer and position motor and were studied at maximal Ca2+ activation, after which type I fiber myosin heavy-chain composition was confirmed by sodium dodecyl sufate-polyacrylamide gel electrophoresis. NWB resulted in a loss in relative soleus mass (-45%), with type I fibers displaying reductions in diameter (-28%) and peak isometric force (-55%) and an increase in Vo (+33%). In addition, NWB induced a 16% reduction in type I fiber Po, a 41% reduction in type I fiber peak elastic modulus [Eo, defined as (delta force/delta length) x (fiber length/fiber cross-sectional area] and a significant increase in the Po/Eo ratio. In contrast to NWB, IWB reduced the loss of relative soleus mass (by 22%) and attenuated alterations in type I fiber diameter (by 36%), peak force (by 29%), and Vo (by 48%) but had no significant effect on Po, Eo, or Po/Eo. These results indicate that a modest restoration of WB activity during 14 days of NWB is sufficient to attenuate type I fiber atrophy and to partially restore type I peak isometric force and Vo to WB levels. However, the NWB-induced reductions in Po and Eo, which we hypothesize to be due to a decline in the number and stiffness of cross bridges, respectively, are considerably less responsive to this countermeasure treatment.


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