scholarly journals Myoglobin levels in individual human skeletal muscle fibers of different types.

1984 ◽  
Vol 32 (11) ◽  
pp. 1211-1216 ◽  
Author(s):  
P M Nemeth ◽  
O H Lowry
Keyword(s):  
Lactate Dehydrogenase ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Human Muscle ◽  
Oxidative Enzymes ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Trained Athlete ◽  
Fiber Types

An attempt was made to determine the relationship of myoglobin content to specific fiber types in human muscle. Biopsies were obtained from biceps brachii, vastus lateralis, and gastrocnemius muscles of untrained subjects and from the vastus lateralis muscle of a highly trained athlete at peak training and at intervals of no training (detraining). Individual muscle fibers were assayed, by quantitative microanalytical methods, for myoglobin, lactate dehydrogenase, malate dehydrogenase, citrate synthase, beta-hydroxyacyl-coenzyme A dehydrogenase, and adenylokinase activities all on the same fiber. The enzyme levels were used to classify the fibers into type I or II. The results show that the content of myoglobin in human muscle does not differ greatly between fiber types in contrast to other species. The type II fibers contained, on the average, at least two-thirds as much myoglobin as type I fibers. The concentration of myoglobin did not change in either fiber type during detraining (84 days), despite marked changes in lactate dehydrogenase, adenylokinase and the three oxidative enzymes.

Effects of detraining on enzymes of energy metabolism in individual human muscle fibers

1983 ◽  
Vol 244 (3) ◽  
pp. C276-C287 ◽  
Author(s):  
M. M. Chi ◽  
C. S. Hintz ◽  
E. F. Coyle ◽  
W. H. Martin ◽  
J. L. Ivy ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Adenylate Kinase ◽  
Citrate Synthase ◽  
Oxidative Enzymes ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Intensive Training ◽  
Beta Hydroxybutyrate ◽  
Type Ii Fibers

Muscle biopsies were obtained from three cyclists and four runners at the end of 10-24 mo of intensive training and after intervals of detraining up to 12 wk. Control samples came from four untrained persons and four former athletes. Macro mixed fiber samples were assayed for lactate dehydrogenase, adenylate kinase, glycogen phosphorylase, citrate synthase, malate dehydrogenase, beta-hydroxyacyl-CoA dehydrogenase, succinate dehydrogenase, beta-hydroxybutyrate dehydrogenase, creatine kinase, hexokinase, 1-phosphofructokinase, fructosebisphosphatase, protein, and total creatine. In the case of three trained persons and two controls, the first six of the enzymes were also measured in individual fibers. Before detraining, enzymes of oxidative metabolism were substantially higher than in controls, and differences in levels between type I and type II fibers were smaller. During detraining, oxidative enzymes were decreased in both fiber types but the type II fibers did not fall to control levels even after 12 wk. Phosphorylase increased with detraining in both fiber types. The same is true for lactate dehydrogenase and adenylate kinase, except in the case of the type I fibers of one individual. Among the other six enzymes (measured in mixed fiber samples), only hexokinase was consistently affected (decreased) by detraining.

Acute effects of taurine on sarcoplasmic reticulum Ca2+ accumulation and contractility in human type I and type II skeletal muscle fibers

2014 ◽  
Vol 117 (7) ◽  
pp. 797-805 ◽  
Author(s):  
T. L. Dutka ◽  
C. R. Lamboley ◽  
R. M. Murphy ◽  
G. D. Lamb
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Contractile Apparatus ◽  
Type Ii Fibers

Taurine occurs in high concentrations in muscle and is implicated in numerous physiological processes, yet its effects on many aspects of contractility remain unclear. Using mechanically skinned segments of human vastus lateralis muscle fibers, we characterized the effects of taurine on sarcoplasmic reticulum (SR) Ca2+ accumulation and contractile apparatus properties in type I and type II fibers. Prolonged myoplasmic exposure (>10 min) to taurine substantially increased the rate of accumulation of Ca2+ by the SR in both fiber types, with no change in the maximum amount accumulated; no such effect was found with carnosine. SR Ca2+ accumulation was similar with 10 or 20 mM taurine, but was significantly slower at 5 mM taurine. Cytoplasmic taurine (20 mM) had no detectable effects on the responsiveness of the Ca2+ release channels in either fiber type. Taurine caused a small increase in Ca2+ sensitivity of the contractile apparatus in type I fibers, but type II fibers were unaffected; maximum Ca2+-activated force was unchanged in both cases. The effects of taurine on SR Ca2+ accumulation 1) only became apparent after prolonged cytoplasmic exposure, and 2) persisted for some minutes after complete removal of taurine from the cytoplasm, consistent with the hypothesis that the effects were due to an action of taurine from inside the SR. In summary, taurine potentiates the rate of SR Ca2+ uptake in both type I and type II human fibers, possibly via an action from within the SR lumen, with the degree of potentiation being significantly reduced at low physiological taurine levels.

scholarly journals Carbonic anhydrase III in skeletal muscle fibers: an immunocytochemical and biochemical study.

1988 ◽  
Vol 36 (7) ◽  
pp. 775-782 ◽  
Author(s):  
P Frémont ◽  
P M Charest ◽  
C Côté ◽  
P A Rogers
Keyword(s):  
Skeletal Muscle ◽  
Carbonic Anhydrase ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Water Soluble ◽  
Type I ◽  
Fiber Types ◽  
Thin Sections ◽  
Carbonic Anhydrase Iii ◽  
Skeletal Muscle Fibers

The objectives of the present study were to determine if carbonic anhydrase III (CA III) demonstrated a specific association for any particular organelle or structure of the skeletal muscle cell and to quantify the activity and content of this enzyme in different types of skeletal muscle fibers. Ultrastructural localization of CA III in the soleus (SOL), deep vastus lateralis (DVL), and superficial vastus lateralis (SVL), composed of predominantly type I, IIa, and IIb fibers, respectively, was performed using a high-resolution immunocytochemical technique and antibody specific for CA III on ultra-thin sections of skeletal muscle embedded in the water-soluble medium polyvinyl alcohol (PVA). The results indicated a uniform distribution of CA III within the sarcomere. Mitochondria, nuclei, triads, Z-, and M-bands were not specifically labeled. Immunoblotting of washed myofibril preparations did not show any detectable CA III associated with this structure. In addition to quantification of the immunogold labeling, CA III activity and content were assayed in the post-mitochondrial supernatant of the three muscles. In the SOL, these values were found to be 3.6-7.6 times higher than in the DVL. The SVL showed a labeling intensity slightly higher than background level, while the enzyme activity and content were indistinguishable from background levels. We therefore conclude that CA III is randomly distributed in the cytoplasm of the three muscle fiber types and that the relative CA III content and activity in the three muscles studied is SOL greater than DVL greater than SVL approximately equal to 0.

scholarly journals Metabolic and morphometric profile of muscle fibers in chronic hemodialysis patients

2012 ◽  
Vol 112 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Michael I. Lewis ◽  
Mario Fournier ◽  
Huiyuan Wang ◽  
Thomas W. Storer ◽  
Richard Casaburi ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Muscle Fibers ◽  
Exercise Intolerance ◽  
Maintenance Hemodialysis ◽  
Muscle Fiber Types ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Dense Matrix ◽  
Individual Fiber

Muscle weakness and effort intolerance are common in maintenance hemodialysis (MHD) patients. This study characterized morphometric, histochemical, and biochemical properties of limb muscle in MHD patients compared with controls (CTL) with similar age, gender, and ethnicity. Vastus lateralis muscle biopsies were obtained from 60 MHD patients, 1 day after dialysis, and from 21 CTL. Muscle fiber types and capillaries were identified immunohistochemically. Individual muscle fiber cross-sectional areas (CSA) were quantified. Individual fiber oxidative capacities were determined (microdensitometric assay) to measure succinate dehydrogenase (SDH) activity. Mean CSAs of type I, IIA, and IIX fibers were 33, 26, and 28% larger in MHD patients compared with CTL. SDH activities for type I, IIA, and IIX fibers were reduced by 29, 40, and 47%, respectively, in MHD. Capillary to fiber ratio was increased by 11% in MHD. The number of capillaries surrounding individual fiber types were also increased (type I: 9%; IIA: 10%; IIX: 23%) in MHD patients. However, capillary density (capillaries per unit muscle fiber area) was reduced by 34% in MHD patients, compared with CTL. Ultrastuctural analysis revealed swollen mitochondria with dense matrix in MHD patients. These results highlight impaired oxidative capacity and capillarity in MHD patients. This would be expected to impair energy production as well as substrate and oxygen delivery and exchange and contribute to exercise intolerance. The enlarged CSA of muscle fibers may, in part, be accounted for by edema. We speculate that these changes contribute to reduce limb strength in MHD patients by reducing specific force.

CK and LD isozymes in human single muscle fibers in trained athletes

1989 ◽  
Vol 66 (6) ◽  
pp. 2717-2720 ◽  
Author(s):  
F. S. Apple ◽  
P. A. Tesch
Keyword(s):  
Citrate Synthase ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Oxidative Capacity ◽  
Metabolic Adaptation ◽  
Fiber Types ◽  
Trained Group ◽  
Energy Demands ◽  
The Individual

Individual human muscle fibers from the vastus lateralis were isolated from age-matched endurance-trained and strength-trained athletes and untrained controls. Slow- (ST) and fast-twitch (FT) fibers were assayed for total creatine kinase (CK), CK-MB, total lactate dehydrogenase (LD), the LD isozyme that predominates in the heart muscle of most vertebrates (LD1), and citrate synthase (CS). Regardless of training of the athletes, both CK-MB and CS were higher in ST than in FT fibers. Also, irrespective of fiber type, CK-MB and CS were greatest in the endurance-trained group. A positive correlation existed between CK-MB and CS, relating oxidative capacity of individual fibers with CK-MB. Total CK varied little among the fiber types, trained groups, or controls. Total LD in FT fibers was greater than in ST fibers in all groups, with only ST fibers from the endurance-trained group containing substantial amounts of LD1. These findings suggest that specific training, endurance exercise, causes a favorable metabolic adaptation of CK and LD isozymes at the individual fiber level, allowing for the muscle to cope with increased energy demands during prolonged exercise.

Phosphocreatine content in single fibers of human muscle after sustained submaximal exercise

1997 ◽  
Vol 273 (1) ◽  
pp. C172-C178 ◽  
Author(s):  
K. Sahlin ◽  
K. Soderlund ◽  
M. Tonkonogi ◽  
K. Hirakoba
Keyword(s):  
Vastus Lateralis ◽  
Submaximal Exercise ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Slow Recovery ◽  
Muscle Energetics ◽  
Single Fibers ◽  
Rapid Reversal ◽  
Type I Fibers

The effect of sustained submaximal exercise on muscle energetics has been studied on the single-fiber level in human skeletal muscle. Seven subjects cycled to fatigue (mean 77 min) at a work rate corresponding to approximately 75% of maximal O2 uptake. Biopsies were taken from the vastus lateralis muscle at rest, at fatigue, and after 5 min of recovery. Muscle glycogen decreased from 444 +/- 40 (SE) mmol glucosyl units/kg dry wt at rest to 94 +/- 16. Postexercise glycogen was inversely correlated (P < 0.01) to muscle content of inosine monophosphate, a catabolite of ATP. Phosphocreatine (PCr) in mixed-fiber muscle decreased at fatigue to 37% but was restored above the initial value (106.5%, P < 0.025) after 5 min of recovery. The overshoot was localized to type I fibers. The rapid reversal of PCr is in contrast to the slow recovery in contraction force. Pi increased at fatigue but less than that expected from the changes in PCr and other phosphate compounds. Mean PCr at rest was approximately 20% higher in type II than in type I fibers (86.4 +/- 3.6 and 71.6 +/- 1.8 mmol/kg dry wt, respectively, P < 0.05), but at fatigue similar PCr contents were observed in the two fiber types. Reduction in PCr in all fibers at fatigue suggests that all fibers were recruited at the end of exercise. PCr content in single fibers showed a great variability in samples at rest, exercise, and recovery. The variability was more pronounced than for ATP, and the data suggest that it is due to interfiber physiological-biochemical differences. At fatigue ATP was maintained relatively high in all single fibers, but a pronounced depletion of PCr was observed in a large number of fibers, and this may contribute to fatigue through the associated increases in Pi or/and free ADP. It is noteworthy that the increase in calculated free ADP at fatigue was similar to that after high-intensity exercise.

scholarly journals New records in aerobic power among octogenarian lifelong endurance athletes

2013 ◽  
Vol 114 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Scott Trappe ◽  
Erik Hayes ◽  
Andrew Galpin ◽  
Leonard Kaminsky ◽  
Bozena Jemiolo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Capacity ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Endurance Athletes ◽  
Whole Body ◽  
Oxidative Enzymes ◽  
Vastus Lateralis Muscle ◽  
Peroxisome Proliferator ◽  
Mrna Targets

We examined whole body aerobic capacity and myocellular markers of oxidative metabolism in lifelong endurance athletes [ n = 9, 81 ± 1 yr, 68 ± 3 kg, body mass index (BMI) = 23 ± 1 kg/m2] and age-matched, healthy, untrained men ( n = 6; 82 ± 1 y, 77 ± 5 kg, BMI = 26 ± 1 kg/m2). The endurance athletes were cross-country skiers, including a former Olympic champion and several national/regional champions, with a history of aerobic exercise and participation in endurance events throughout their lives. Each subject performed a maximal cycle test to assess aerobic capacity (V̇o2max). Subjects had a resting vastus lateralis muscle biopsy to assess oxidative enzymes (citrate synthase and βHAD) and molecular (mRNA) targets associated with mitochondrial biogenesis [peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) and mitochondrial transcription factor A (Tfam)]. The octogenarian athletes had a higher ( P < 0.05) absolute (2.6 ± 0.1 vs. 1.6 ± 0.1 l/min) and relative (38 ± 1 vs. 21 ± 1 ml·kg−1·min−1) V̇o2max, ventilation (79 ± 3 vs. 64 ± 7 l/min), heart rate (160 ± 5 vs. 146 ± 8 beats per minute), and final workload (182 ± 4 vs. 131 ± 14 W). Skeletal muscle oxidative enzymes were 54% (citrate synthase) and 42% (βHAD) higher ( P < 0.05) in the octogenarian athletes. Likewise, basal PGC-1α and Tfam mRNA were 135% and 80% greater ( P < 0.05) in the octogenarian athletes. To our knowledge, the V̇o2max of the lifelong endurance athletes is the highest recorded in humans >80 yr of age and comparable to nonendurance trained men 40 years younger. The superior cardiovascular and skeletal muscle health profile of the octogenarian athletes provides a large functional reserve above the aerobic frailty threshold and is associated with lower risk for disability and mortality.

scholarly journals Histochemical, biochemical, and ultrastructural analyses of single human muscle fibers, with special reference to the C-fiber population.

1992 ◽  
Vol 40 (4) ◽  
pp. 563-568 ◽  
Author(s):  
R S Staron ◽  
R S Hikida
Keyword(s):  
Fiber Type ◽  
Vastus Lateralis ◽  
Oxidative Capacity ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Heavy Chains ◽  
C Fibers ◽  
C Fiber ◽  
Ph Range

A muscle biopsy from the vastus lateralis muscle of a strength-trained woman was found to contain an unusual fiber type composition and was analyzed by histochemical, biochemical, and ultrastructural techniques. Special attention was given to the C-fibers, which comprised over 15% of the total fiber number in the biopsy. The mATPase activity of the C-fibers remained stable to varying degrees over the pH range normally used for routine mATPase histochemistry. Although a continuum existed, the C-fibers were histochemically subdivided into three main fiber types: IC, IIC, and IIAC. The IC fibers were histochemically more similar to the Type I, the IIAC were more similar to the Type IIA, and the IIC were darkly stained throughout the pH range. Biochemical analysis revealed that all C-fibers coexpressed myosin heavy chains (MHC) I and IIa in variable ratios. The histochemical staining intensity correlated with the myosin heavy chain composition such that the Type IC fibers contained a greater ratio of MHCI/MHCIIa, the IIAC contained a greater ratio of MHCIIa/MHCI, and the Type IIC contained equal amounts of these two heavy chains. Ultrastructural data of the C-fiber population revealed an oxidative capacity between fiber Types I and IIA and suggested a range of mitochondrial volume percent from highest to lowest such that I greater than IC greater than IIC greater than IIA-C greater than IIA. Under physiological conditions, it appears that the IC fibers represent Type I fibers that additionally express some fast characteristics, whereas the Type IIAC are Type IIA fibers that additionally express some slow characteristics. Fibers expressing a 50:50 mixture of MHCI and MHCIIa (IIC fibers) were rarely found. It is not known whether C-fibers represent a distinct population between the fast- and slow-twitch fibers that is specifically adapted to a particular usage or whether they are transforming fibers in the process of going from fast to slow or slow to fast.

Endurance training, expression, and physiology of LDH, MCT1, and MCT4 in human skeletal muscle

2000 ◽  
Vol 278 (4) ◽  
pp. E571-E579 ◽  
Author(s):  
Hervé Dubouchaud ◽  
Gail E. Butterfield ◽  
Eugene E. Wolfel ◽  
Bryan C. Bergman ◽  
George A. Brooks
Keyword(s):  
Endurance Training ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Peak Oxygen Consumption ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Western Blots ◽  
Lactate Shuttle ◽  
Lactate Release ◽  
Before And After

To evaluate the effects of endurance training on the expression of monocarboxylate transporters (MCT) in human vastus lateralis muscle, we compared the amounts of MCT1 and MCT4 in total muscle preparations (MU) and sarcolemma-enriched (SL) and mitochondria-enriched (MI) fractions before and after training. To determine if changes in muscle lactate release and oxidation were associated with training-induced changes in MCT expression, we correlated band densities in Western blots to lactate kinetics determined in vivo. Nine weeks of leg cycle endurance training [75% peak oxygen consumption (V˙o 2 peak)] increased muscle citrate synthase activity (+75%, P < 0.05) and percentage of type I myosin heavy chain (+50%, P < 0.05); percentage of MU lactate dehydrogenase-5 (M4) isozyme decreased (−12%, P < 0.05). MCT1 was detected in SL and MI fractions, and MCT4 was localized to the SL. Muscle MCT1 contents were consistent among subjects both before and after training; in contrast, MCT4 contents showed large interindividual variations. MCT1 amounts significantly increased in MU, SL, and MI after training (+90%, +60%, and +78%, respectively), whereas SL but not MU MCT4 content increased after training (+47%, P < 0.05). Mitochondrial MCT1 content was negatively correlated to net leg lactate release at rest ( r = −0.85, P < 0.02). Sarcolemmal MCT1 and MCT4 contents correlated positively to net leg lactate release at 5 min of exercise at 65%V˙o 2 peak ( r = 0.76, P < 0.03 and r = 0.86, P < 0.01, respectively). Results support the conclusions that 1) endurance training increases expression of MCT1 in muscle because of insertion of MCT1 into both sarcolemmal and mitochondrial membranes, 2) training has variable effects on sarcolemmal MCT4, and 3) both MCT1 and MCT4 participate in the cell-cell lactate shuttle, whereas MCT1 facilitates operation of the intracellular lactate shuttle.

scholarly journals Cytoskeletal structure of skeletal muscle: identification of an intricate exosarcomeric microtubule lattice in slow- and fast-twitch muscle fibers.

1993 ◽  
Vol 41 (7) ◽  
pp. 1013-1021 ◽  
Author(s):  
S Boudriau ◽  
M Vincent ◽  
C H Côté ◽  
P A Rogers
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Vastus Lateralis ◽  
Muscle Fiber Types ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Mammalian Skeletal Muscle ◽  
Microtubule Network ◽  
Fast Twitch

We used immunochemical quantification and indirect immunofluorescence to investigate the cell content, distribution, and organization of microtubules in adult rat slow-twitch soleus and fast-twitch vastus lateralis muscles. An immunoblotting assay demonstrated that the soleus muscle (primarily Type I fibers) was found to have a 1.7-fold higher relative content of alpha-tubulin compared with the superficial portion of the vastus lateralis muscle (primarily Type IIb fibers). Both physiological muscle types revealed a complex arrangement of microtubules which displayed oblique, longitudinal, and transverse orientations within the sarcoplasmic space. The predominance of any one particular orientation varied significantly from one muscle tissue section to another. Nuclei were completely surrounded by a dense net-like structure of microtubules. Both muscle fiber types were found to possess a higher density of microtubules in the subsarcolemmal region. These microtubules followed the contour of the sarcolemma in slightly contracted fibers and showed a fine punctate appearance indicative of a restricted distribution. The immunofluorescence results indicate that microtubules are associated with the sarcolemma and therefore may form a part of the membrane cytoskeletal domain of the muscle fiber. We conclude that the microtubule network of the adult mammalian skeletal muscle fiber constitutes a bone fide component of the exosarcomeric cytoskeletal lattice domain along with the intermediate filaments, and as such could therefore participate in the mechanical integration of the various organelles of the myofibers during the contraction-relaxation cycle.

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