Influence of electrical stimulation on the morphological and metabolic properties of paralyzed muscle

1992 ◽  
Vol 72 (4) ◽  
pp. 1401-1406 ◽  
Author(s):  
T. P. Martin ◽  
R. B. Stein ◽  
P. H. Hoeppner ◽  
D. C. Reid
Keyword(s):  
Electrical Stimulation ◽  
Succinate Dehydrogenase ◽  
Normal Control ◽  
Oxidative Capacity ◽  
Type I ◽  
Fiber Types ◽  
Cross Sectional ◽  
Metabolic Properties ◽  
Type I Fibers ◽  
Spinal Cord Injured

Selected morphological and metabolic properties of single fibers were studied in biopsy samples from the tibialis anterior of normal control and spinal cord-injured (SCI) subjects. In the SCI subjects, one muscle was electrically stimulated progressively over 24 wk, in 6-wk blocks for less than or equal to 8 h/day, while the contralateral muscle remained untreated. The percentage of fibers classified as type I [qualitative alkaline preincubation myofibrillar adenosinetriphosphatase (ATPase)] was significantly less in the unstimulated paralyzed muscles than in the muscles of normal control subjects. Electrical stimulation increased the proportion of type I fibers in the SCI subjects. For both type I and type II fibers, the cross-sectional area, activities of myofibrillar ATPase and succinate dehydrogenase, and the capillary-to-fiber ratio were also significantly less in the paralyzed muscles than in the normal control muscles. Electrical stimulation increased only the activity of succinate dehydrogenase in both fiber types of the SCI subjects. These data are discussed in relation to the electromechanical properties of the respective muscles described in an accompanying paper (J. Appl. Physiol. 72: 1393–1400, 1992). In general, the electrical stimulation protocol used in this study enhanced the oxidative capacity and endurance properties of the paralyzed muscles but had no effect on fiber size and strength.

Rostrocaudal pattern of fiber-type changes in an overloaded rat ankle extensor

1991 ◽  
Vol 71 (2) ◽  
pp. 558-564 ◽  
Author(s):  
P. F. Gardiner ◽  
B. J. Jasmin ◽  
P. Corriveau
Keyword(s):  
Fiber Type ◽  
Muscle Length ◽  
Similar Degree ◽  
Complex Nature ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Cross Sectional ◽  
Hypertrophic Response ◽  
Type I Fibers

Our aim was to quantify the overload-induced hypertrophy and conversion of fiber types (type II to I) occurring in the medial head of the gastrocnemius muscle (MG). Overload of MG was induced by a bilateral tenotomy/retraction of synergists, followed by 12–18 wk of regular treadmill locomotion (2 h of walking/running per day on 3 of 4 days). We counted all type I fibers and determined type I and II mean fiber areas in eight equidistant sections taken along the length of control and overloaded MG. Increase in muscle weights (31%), as well as in total muscle cross-sectional areas (37%) and fiber areas (type I, 57%; type II, 34%), attested to a significant hypertrophic response in overloaded MG. An increase in type I fiber composition of MG from 7.0 to 11.5% occurred as a result of overload, with the greatest and only statistically significant changes (approximately 70–100%) being found in sections taken from the most rostral 45% of the muscle length. Results of analysis of sections taken from the largest muscle girth showed that it significantly underestimated the extent of fiber conversion that occurred throughout the muscle as a whole. These data obtained on the MG, which possesses a compartmentalization of fiber types, support the notion that all fiber types respond to this model with a similar degree of hypertrophy. Also, they emphasize the complex nature of the adaptive changes that occur in these types of muscles as a result of overload.

Exercise-induced cellular alterations in the diaphragm

1992 ◽  
Vol 263 (5) ◽  
pp. R1093-R1098 ◽  
Author(s):  
S. K. Powers ◽  
D. Criswell ◽  
F. K. Lieu ◽  
S. Dodd ◽  
H. Silverman
Keyword(s):  
Exercise Training ◽  
Endurance Training ◽  
Fiber Type ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Control Group ◽  
Type I ◽  
Fiber Types ◽  
Image Analysis System ◽  
Cross Sectional

Limited data exist concerning the effects of exercise training on cellular oxidative capacity in the diaphragm of senescent animals. In this study we examined the changes in cellular oxidative capacity, muscle cell cross-sectional area (CSA), and capillarity within the costal diaphragm of senescent animals after a 10-wk endurance-training program. Twelve 24-mo-old female Fischer 344 rats were divided into either a sedentary control group (n = 6) or exercise training group (n = 6). The trained animals exercised on a motor-driven treadmill (60 min/day, 5 days/wk) at a work rate equal to approximately 55-65% VO2max. Capillaries were identified histologically and fiber types determined using adenosinetriphosphatase (ATPase) histochemistry. Succinate dehydrogenase (SDH) activity and CSA in individual fibers were measured using a computerized image analysis system. Exercise training did not increase (P > 0.05) the capillary-to-fiber ratio for any fiber type. However, training significantly decreased CSA (P < 0.05) and increased capillary density (capillary number/CSA) (P < 0.05) in type I, type IIa, and type IIb fibers. Furthermore, exercise training resulted in small but significant increase in SDH activity (P < 0.05) in type I and IIa fibers, whereas training did not alter SDH activity (P > 0.05) in type IIb fibers. These data demonstrate that endurance training in senescent animals results in small relative improvements in both oxidative capacity and capillary density in costal diaphragmatic type I and IIa muscle fibers. The increase in both capillary density and fiber SDH activity was largely due to a reduction in fiber CSA.

Metabolic responses of muscle to exercise

2004 ◽  
Vol 32 ◽  
pp. 1-9
Author(s):  
B Essén–Gustavsson
Keyword(s):  
Treadmill Exercise ◽  
Metabolic Response ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Metabolic Responses ◽  
Type I ◽  
Cross Sectional ◽  
Fibre Type Composition ◽  
Metabolic Properties ◽  
Biochemical Analyses

AbstractMuscle is a tissue with a great plasticity due to the fact that it is composed of fibres having different contractile and metabolic properties. In horses, muscle metabolic responses to exercise are studied by taking biopsies from the gluteus medius muscle. Histochemical stains are used to identify slow contracting type I fibres and fast contracting type IIA and type IIB fibres and to evaluate fibre areas, capillary supply, oxidative capacity, glycogen and lipid content in a muscle. Biochemical analyses of substrates, metabolites and enzyme activities are performed either on a whole piece of muscle, on pools of fibres or on single fibres of identified type.All fibres contain glycogen whereas lipid is mainly found in type I and type IIA fibres that have smaller cross–sectional areas and a higher oxidative capacity than type IIB fibres. Large variations can be seen in metabolic profile between and within fibre types. The most common muscular adaptation to training is an increase in oxidative capacity, capillary density and an increase in the type IIA/IIB ratio. The order of recruitment of fibres during most types of exercise is from type I to type IIA and type IIB.The higher the intensity of exercise, the faster is the breakdown of glycogen. After racing (1640-2640m), and after high intense treadmill exercise, concentrations of lactate and inosine monophosphate (IMP) are increased in the muscle and concentrations of glycogen, adenosine triphosphate (ATP) and creatine phosphate (CP) decreased. Extremely low ATP and high IMP concentrations especially in some type II fibres are observed after racing.After exercise of low intensity and long duration glycogen and triglyceride stores in muscle are utilised, amino acid metabolism is enhanced and protein degradation may occur. After submaximal treadmill exercise to fatigue and after endurance rides glycogen is degraded and depletion occurs mainly in type I and type IIA fibres.Fibre type composition, substrate sources and differences in metabolic properties among fibres and the extent to which fibres are recruited are all factors that influence the metabolic responses of muscle to exercise. Biochemical analyses on whole muscle must be interpreted with caution since large variations in metabolic response to exercise occur among different fibres.

Absence of regional differences in the size and oxidative capacity of diaphragm muscle fibers

1987 ◽  
Vol 63 (3) ◽  
pp. 1076-1082 ◽  
Author(s):  
G. C. Sieck ◽  
R. D. Sacks ◽  
C. E. Blanco
Keyword(s):  
Muscle Fibers ◽  
Continuous Distribution ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Diaphragm Muscle ◽  
Type I ◽  
Fiber Types ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fast Twitch

The oxidative capacity and cross-sectional area of muscle fibers were compared between the costal and crural regions of the cat diaphragm and across the abdominal-thoracic extent of the muscle. Succinate dehydrogenase (SDH) activity of individual fibers was quantified using a microphotometric procedure implemented on an image-processing system. In both costal and crural regions, population distributions of SDH activities were unimodal for both type I and II fibers. The continuous distribution of SDH activities for type II fibers indicated that no clear threshold exists for the subclassification of fibers based on differences in oxidative capacity (e.g., the classification of fast-twitch glycolytic and fast-twitch oxidative glycolytic fiber types). No differences in either SDH activity or cross-sectional area were noted between fiber populations of the costal and crural regions. Differences in SDH activity and cross-sectional area were noted, however, between fiber populations located on the abdominal and thoracic sides of the costal region. Both type I and II fibers on the abdominal side of the costal diaphragm were larger and more oxidative than comparable fibers on the thoracic side.

scholarly journals Fiber Composition and Oxidative Capacity of Hamster Skeletal Muscle

2002 ◽  
Vol 50 (12) ◽  
pp. 1685-1692 ◽  
Author(s):  
John P. Mattson ◽  
Todd A. Miller ◽  
David C. Poole ◽  
Michael D. Delp
Keyword(s):  
Skeletal Muscle ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Rank Order ◽  
Oxidative Capacity ◽  
Type I ◽  
Cross Sectional ◽  
Physiological Investigation ◽  
Combining Data ◽  
Type I Fibers

The hamster is a valuable biological model for physiological investigation. Despite the obvious importance of the integration of cardiorespiratory and muscular system function, little information is available regarding hamster muscle fiber type and oxidative capacity, both of which are key determinants of muscle function. The purpose of this investigation was to measure immunohistochemically the relative composition and size of muscle fibers composed of types I, IIA, IIX, and IIB fibers in hamster skeletal muscle. The oxidative capacity of each muscle was also assessed by measuring citrate synthase activity. Twenty-eight hindlimb, respiratory, and facial muscles or muscle parts from adult (144–147 g bw) male Syrian golden hamsters ( n=3) were dissected bilaterally, weighed, and frozen for immunohistochemical and biochemical analysis. Combining data from all 28 muscles analyzed, type I fibers made up 5% of the muscle mass, type IIA fibers 16%, type IIX fibers 39%, and type IIB fibers 40%. Mean fiber cross-sectional area across muscles was 1665 ± 328 μm2 for type I fibers, 1900 ± 417 μm2 for type IIA fibers, 3230 ± 784 μm2 for type IIX fibers, and 4171 ± 864 μm2 for type IIB fibers. Citrate synthase activity was most closely related to the population of type IIA fibers ( r=0.68, p<0.0001) and was in the rank order of type IIA > I > IIX > IIB. These data demonstrate that hamster skeletal muscle is predominantly composed of type IIB and IIX fibers.

Statistical Analysis of Fiber Area in Human Skeletal Muscle

2002 ◽  
Vol 27 (4) ◽  
pp. 415-422 ◽  
Author(s):  
Michael R.M. Mcguigan ◽  
William J. Kraemer ◽  
Michael R. Deschenes ◽  
Scott E. Gordon ◽  
Takashi Kitaura ◽  
...  
Keyword(s):  
Fiber Type ◽  
Cross Sectional Area ◽  
Type I ◽  
Fiber Types ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fiber Area ◽  
Random Block ◽  
Type I Fibers ◽  
Accurate Reflection

Previous research has indicated that 50 fiber measurements per individual for type I and II fibers would be sufficient to characterize the fiber areas. This study replicated the work of McCall et al. (1998) using the three major fiber types (I, IIA, and IIB) and sampling larger populations of fibers. Random blocks of fibers were also examined to investigate how well they correlated with the overall mean average fiber area. Using random blocks of 50 fibers provided an accurate reflection of the type IIB fibers (r = 0.96-0.98) but not for the type I (r = 0.85-0.94) or IIA fibers (r = 0.80-0.91). Type I fibers were consistently reflected by a random block of 150 fibers (r = 0.95-0.98) while type IIA fibers required random blocks of 200 fibers (r = 0.94-0.98), which appeared to provide an accurate reflection of the cross-sectional area. These results indicate that for a needle biopsy different numbers of fibers are needed depending on the fiber type to accurately characterize the mean fiber population. Key words: fiber type, sample size, cross-sectional area, biopsy

Oxidative capacity of human muscle fiber types: effects of age and training status

1995 ◽  
Vol 78 (6) ◽  
pp. 2033-2038 ◽  
Author(s):  
D. N. Proctor ◽  
W. E. Sinning ◽  
J. M. Walro ◽  
G. C. Sieck ◽  
P. W. Lemon
Keyword(s):  
Succinate Dehydrogenase ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Oxidative Capacity ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Training Status ◽  
Type Ii ◽  
And Training

Morphometry and oxidative capacity of slow-twitch (type I) and fast-twitch (type IIa and IIb) muscle fibers obtained from vastus lateralis needle biopsies were compared between younger (21-30 yr) and older (51-62 yr) normal fit (maximal O2 uptake = 47.0 vs. 32.3 ml.kg-1.min-1) and endurance-trained (66.3 vs. 52.7 ml.kg-1.min-1) men (n = 6/group). The older groups had smaller type IIa (31%) and IIb (40%) fiber areas and fewer capillaries surrounding these fibers than did younger groups. The reduced type II fiber areas and capillary contacts associated with aging were also observed in the older trained men. However, the capillary supply per unit type II fiber area was not affected by age but was enhanced by training. Additionally, on the basis of quantitative histochemical analysis, succinate dehydrogenase activities of type IIa fibers in the older trained men [4.07 +/- 0.68 (SD) mmol.min-1.l-1] were similar to those observed in younger trained men (4.00 +/- 0.48 mmol.min-1.l-1) and twofold higher than in older normal fit men (2.01 +/- 0.65 mmol.min-1.l-1; age x fitness interaction, P < 0.05). Type I muscle fibers were unaffected by age but were larger and had more capillary contacts and higher succinate dehydrogenase activities in the trained groups. The findings of this study suggest that aging results in a decrease in type II fiber size and oxidative capacity in healthy men and that this latter effect can be prevented by endurance training. Conclusions regarding the effects of age and training status on muscle capillarization depend largely on how these data are expressed.

scholarly journals Aging reduces succinate dehydrogenase activity in rat type IIx/IIb diaphragm muscle fibers

2020 ◽  
Vol 128 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Matthew J. Fogarty ◽  
Natalia Marin Mathieu ◽  
Carlos B. Mantilla ◽  
Gary C. Sieck
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Diaphragm Muscle ◽  
Type I ◽  
Specific Force ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
Fresh Frozen

In aged rats, diaphragm muscle (DIAm) reduced specific force and fiber cross-sectional area, sarcopenia, is selective for vulnerable type IIx and/or IIb DIAm fibers, with type I and IIa fibers being resilient. In humans, the oxidative capacity [as measured by maximum succinate dehydrogenase (SDHmax) activity] of fast-type muscle is reduced with aging, with slow-type muscle being unaffected. We hypothesized that in aged Fischer rat DIAm exhibiting sarcopenia, reduced SDHmax activity would occur in type IIx and/or IIb fibers. Rats obtained from the NIA colony (6, 18, and 24 mo old) were euthanized, and ~2-mm-wide DIAm strips were obtained. For SDHmax and fiber type assessments, DIAm strips were stretched (approximately optimal length), fresh frozen in isopentane, and sectioned on a cryostat at 6 μm. SDHmax, quantified by intensity of nitroblue tetrazolium diformazan precipitation, was assessed in a fiber type-specific manner by comparing serial sections labeled with myosin heavy chain (MyHC) antibodies differentiating type I (MyHCSlow), IIa (MyHC2A), and IIx and/or IIb fibers. Isometric DIAm force and fatigue were assessed in DIAm strips by muscle stimulation with supramaximal pulses at a variety of frequencies (5–100 Hz) delivered in 1-s trains. By 24 mo, DIAm sarcopenia was apparent and SDHmax in type IIx and/or IIb fibers activity was reduced ~35% compared with 6-mo-old control DIAm. These results underscore the remarkable fiber type selectivity of type IIx and/or IIb fibers to age-associated perturbations and suggest that reduced mitochondrial oxidative capacity is associated with DIAm sarcopenia. NEW & NOTEWORTHY We examined the oxidative capacity as measured by maximum succinate dehydrogenase activity in older (18 or 24 mo old) Fischer 344 rat diaphragm muscle (DIAm) compared with young rats (6 mo old). In 24-mo-old rats, SDH activity was reduced in type IIx/b DIAm fibers. These SDH changes were concomitant with sarcopenia (reduced specific force and atrophy of type IIx/b DIAm fibers) at 24 mo old. At 18 mo old, there was no change in SDH activity and no evidence of sarcopenia.

Structural and functional responses to prolonged hindlimb suspension in rat muscle

1987 ◽  
Vol 63 (2) ◽  
pp. 558-563 ◽  
Author(s):  
D. Desplanches ◽  
M. H. Mayet ◽  
B. Sempore ◽  
R. Flandrois
Keyword(s):  
Citrate Synthase ◽  
Energy Charge ◽  
Hindlimb Suspension ◽  
Type I ◽  
Fiber Types ◽  
Functional Responses ◽  
Cross Sectional ◽  
Lactate Dehydrogenase Activity ◽  
Structural And Functional Properties ◽  
Type I Fibers

The purpose of this study was to investigate alterations in structural and functional properties in the soleus (SOL) and extensor digitorum longus (EDL) muscles of rats after 1, 2, and 5 wk of tail suspension. Maximal O2 uptake was 19% lower after 5 wk suspension. Loss of muscle mass was greater in SOL (63%) than in EDL (22%) muscle. A reduction of type I distribution was accompanied by an increase of intermediate fiber subgroups (int I in SOL, int II in EDL). The cross-sectional area of all three fiber types was reduced by hypokinesia. The decrease in capillaries per fiber in SOL was greater than the decrease in citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities after 5 wk. No alteration in lactate dehydrogenase activity was noted. In EDL, no changes in fiber area, capillarization, and enzymatic activities occurred. Energy charge remained unchanged (0.91) whatever the muscle. These results suggest that type I fibers showed an earlier and greater susceptibility than type II fibers to suspension which is also accompanied by a decreased aerobic capacity.

Congestive heart failure: differential adaptation of the diaphragm and latissimus dorsi

1995 ◽  
Vol 79 (2) ◽  
pp. 389-397 ◽  
Author(s):  
S. Howell ◽  
J. M. Maarek ◽  
M. Fournier ◽  
K. Sullivan ◽  
W. Z. Zhan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Relaxation Time ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Latissimus Dorsi ◽  
Type I ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
Type I Fibers

Diaphragm and latissimus dorsi muscle functions, histochemistries, and morphometries were studied in anesthetized male Yucatan minipigs with congestive heart failure (CHF) induced by supraventricular tachycardia (n = 5). Sham-operated animals served as a control group (n = 5). In CHF animals, transdiaphragmatic pressure measured during supramaximal phrenic stimulation was reduced by 40% at low frequencies (< or = 20 Hz) and by 60% at higher frequencies. Twitch amplitude and half-relaxation time were also decreased. The cross-sectional areas of type I, IIa, and IIb fibers were reduced in the diaphragm. The proportion of type I fibers increased, whereas type IIa fibers decreased. Succinate dehydrogenase activity was elevated in type IIa and IIb fibers, but diaphragmatic fatigability was not altered. CHF reduced latissimus dorsi isometric force by 40% for stimulation frequencies > or = 30 Hz. The cross-sectional area of latissimus dorsi type IIb fibers was decreased, but twitch characteristics, fiber type composition, succinate dehydrogenase activity, and fatigability were unchanged. Experimental CHF appears to cause greater intrinsic adaptive changes in the diaphragm compared with those in the latissimus dorsi in the minipig. For both muscles, reduced contractile function was associated with atrophy. Impaired performance of the diaphragm may also be attributed to an increase in the relative contribution of type I fibers to the total tension-generating capacity of the muscle and to the pathophysiological mechanisms underlying the shortened relaxation time of the twitch response.

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