Increased oxidative capacity does not protect skeletal muscle fibers from eccentric contraction-induced injury

1998 ◽  
Vol 274 (5) ◽  
pp. R1300-R1308 ◽  
Author(s):  
T. J. Patel ◽  
D. Cuizon ◽  
O. Mathieu-Costello ◽  
J. Fridén ◽  
R. L. Lieber
Keyword(s):  
Electrical Stimulation ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Exercise Bout ◽  
Eccentric Contraction ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Training Effect ◽  
Muscle Oxidative Capacity ◽  
Tetanic Tension

Isometric electrical stimulation was delivered to rabbit dorsiflexor muscles at 10 Hz for 1 s on and 1 s off over 30 min, 5 days/wk for 3 wk to induce an increase in muscle oxidative capacity. Stimulation-trained muscles as well as untrained muscles were then subjected to a 30-min eccentric exercise bout to test whether increased oxidative capacity provided a protective effect against muscle injury. Electrical stimulation resulted in significant training of both the extensor digitorum longus (EDL) and tibialis anterior (TA) muscles, with EDL citrate synthase (CS) activity increasing an average of 67% ( P < 0.0001) and TA CS activity increasing by 27% ( P < 0.05). For all parameters measured, the magnitude of change was much greater for EDL than for TA muscle. Dorsiflexor fatigability decreased significantly during the 3-wk training period ( P < 0.0001), whereas the EDL and TA individually showed strong decreasing trends in fatigability after training. TA and EDL capillary density measured histomorphometrically increased from 839 ± 56 to 1,026 ± 71 mm−2( P = 0.07) and from 589 ± 37 to 792 ± 66 mm−2( P < 0.05), respectively. TA and EDL capillary-to-fiber ratio increased from 1.32 ± 0.10 to 1.55 ± 0.16 ( P > 0.2) and 1.08 ± 0.07 to 1.36 ± 0.14 ( P > 0.1), respectively. Type 2A fiber type percentage increased after stimulation training by 68% ( P < 0.0001) for the EDL and by 32% ( P > 0.1) for the TA at the expense of type 2D fibers. Despite the large training effect for the EDL and the modest training effect for the TA, no differences were observed between stimulation-trained and untrained groups for maximum dorsiflexion torque ( P > 0.3) or maximum tetanic tension ( P > 0.3) after eccentric contraction-induced injury. Additionally, no significant correlation was observed between CS activity and maximum tetanic tension after eccentric contraction-induced injury for either muscle ( P > 0.2). Thus we conclude that increasing muscle oxidative capacity by isometric electrical stimulation training did not protect muscle against eccentric contraction-induced injury.

scholarly journals Enhanced Skeletal Muscle Oxidative Capacity and Capillary-to-Fiber Ratio Following Moderately Increased Testosterone Exposure in Young Healthy Women

2020 ◽  
Vol 11 ◽  
Author(s):  
Daniele A. Cardinale ◽  
Oscar Horwath ◽  
Jona Elings-Knutsson ◽  
Torbjörn Helge ◽  
Manne Godhe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Complex I ◽  
Citrate Synthase ◽  
Mitochondrial Protein ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
System Capacity ◽  
Endurance Capacity ◽  
Muscle Oxidative Capacity ◽  
Before And After

Background: Recently, it was shown that exogenously administered testosterone enhances endurance capacity in women. In this study, our understanding on the effects of exogenous testosterone on key determinants of oxygen transport and utilization in skeletal muscle is expanded.Methods: In a double-blinded, randomized, placebo-controlled trial, 48 healthy active women were randomized to 10 weeks of daily application of 10 mg of testosterone cream or placebo. Before and after the intervention, VO2 max, body composition, total hemoglobin (Hb) mass and blood volumes were assessed. Biopsies from the vastus lateralis muscle were obtained before and after the intervention to assess mitochondrial protein abundance, capillary density, capillary-to-fiber (C/F) ratio, and skeletal muscle oxidative capacity.Results: Maximal oxygen consumption per muscle mass, Hb mass, blood, plasma and red blood cell volumes, capillary density, and the abundance of mitochondrial protein levels (i.e., citrate synthase, complexes I, II, III, IV-subunit 2, IV-subunit 4, and V) were unchanged by the intervention. However, the C/F ratio, specific mitochondrial respiratory flux activating complex I and linked complex I and II, uncoupled respiration and electron transport system capacity, but not leak respiration or fat respiration, were significantly increased following testosterone administration compared to placebo.Conclusion: This study provides novel insights into physiological actions of increased testosterone exposure on key determinants of oxygen diffusion and utilization in skeletal muscle of women. Our findings show that higher skeletal muscle oxidative capacity coupled to higher C/F ratio could be major contributing factors that improve endurance performance following moderately increased testosterone exposure.

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.

scholarly journals Relationships between maximal muscle oxidative capacity and blood lactate removal after supramaximal exercise and fatigue indexes in humans

2004 ◽  
Vol 97 (6) ◽  
pp. 2132-2138 ◽  
Author(s):  
C. Thomas ◽  
P. Sirvent ◽  
S. Perrey ◽  
E. Raynaud ◽  
J. Mercier
Keyword(s):  
Blood Lactate ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Oxidative Capacity ◽  
Slow Phase ◽  
Vastus Lateralis Muscle ◽  
Supramaximal Exercise ◽  
Muscle Oxidative Capacity ◽  
S Cycling ◽  
Lactate Removal

The present study investigated whether blood lactate removal after supramaximal exercise and fatigue indexes measured during continuous and intermittent supramaximal exercises are related to the maximal muscle oxidative capacity in humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (γ2), which denoted the blood lactate removal ability. Fatigue indexes were calculated during all-out (FIAO) and repeated 10-s cycling sprints (FISprint). Biopsies were taken from the vastus lateralis muscle, and maximal ADP-stimulated mitochondrial respiration ( Vmax) was evaluated in an oxygraph cell on saponin-permeabilized muscle fibers with pyruvate + malate and glutamate + malate as substrates. Significant relationships were found between γ2 and pyruvate + malate Vmax ( r = 0.60, P < 0.05), γ2 and glutamate + malate Vmax ( r = 0.66, P < 0.01), and γ2 and citrate synthase activity ( r = 0.76, P < 0.01). In addition, γ2, glutamate + malate Vmax, and pyruvate + malate Vmax were related to FIAO (γ2 − FIAO: r = 0.85; P < 0.01; glutamate + malate Vmax − FIAO: r = 0.70, P < 0.01; and pyruvate + malate Vmax − FIAO: r = 0.63, P < 0.01) and FISprint (γ2 − FISprint: r = 0.74, P < 0.01; glutamate + malate Vmax − FISprint: r = 0.64, P < 0.01; and pyruvate + malate Vmax − FISprint: r = 0.46, P < 0.01). In conclusion, these results suggested that the maximal muscle oxidative capacity was related to blood lactate removal ability after a 1-min all-out test. Moreover, maximal muscle oxidative capacity and blood lactate removal ability were associated with the delay in the fatigue observed during continuous and intermittent supramaximal exercises in well-trained subjects.

Contribution of central and peripheral adaptations to changes in maximal oxygen uptake following 4 weeks of sprint interval training

2018 ◽  
Vol 43 (10) ◽  
pp. 1059-1068 ◽  
Author(s):  
James P. Raleigh ◽  
Matthew D. Giles ◽  
Hashim Islam ◽  
Matthew Nelms ◽  
Robert F. Bentley ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Citrate Synthase ◽  
Interval Training ◽  
Maximal Activity ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Sprint Interval Training ◽  
Peripheral Arterial

The current study examined the contribution of central and peripheral adaptations to changes in maximal oxygen uptake (V̇O2max) following sprint interval training (SIT). Twenty-three males completed 4 weekly SIT sessions (8 × 20-s cycling bouts at ∼170% of work rate at V̇O2max, 10-s recovery) for 4 weeks. Following completion of training, the relationship between changes in V̇O2max and changes in central (cardiac output) and peripheral (arterial–mixed venous oxygen difference (a-vO2diff), muscle capillary density, oxidative capacity, fibre-type distribution) adaptations was determined in all participants using correlation analysis. Participants were then divided into tertiles on the basis of the magnitude of their individual V̇O2max responses, and differences in central and peripheral adaptations were examined in the top (HI; ∼10 mL·kg−1·min−1 increase in V̇O2max, p < 0.05) and bottom (LO; no change in V̇O2max, p > 0.05) tertiles (n = 8 each). Training had no impact on maximal cardiac output, and no differences were observed between the LO group and the HI group (p > 0.05). The a-vO2diff increased in the HI group only (p < 0.05) and correlated significantly (r = 0.71, p < 0.01) with changes in V̇O2max across all participants. Muscle capillary density (p < 0.02) and β-hydroxyacyl-CoA dehydrogenase maximal activity (p < 0.05) increased in both groups, with no between-group differences (p > 0.05). Citrate synthase maximal activity (p < 0.01) and type IIA fibre composition (p < 0.05) increased in the LO group only. Collectively, although the heterogeneity in the observed V̇O2max response following 4 weeks of SIT appears to be attributable to individual differences in systemic vascular and/or muscular adaptations, the markers examined in the current study were unable to explain the divergent V̇O2max responses in the LO and HI groups.

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.

Long-term isoprenaline administration produces an increase in capillarity in the soleus muscle of the rat

1987 ◽  
Vol 65 (3) ◽  
pp. 303-306 ◽  
Author(s):  
A. H. Sillau ◽  
Maria De Lourdes Philippi
Keyword(s):  
Soleus Muscle ◽  
Cross Sections ◽  
Citrate Synthase ◽  
Lactic Dehydrogenase ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Adrenergic Stimulation ◽  
Cross Sectional

The effects of isoprenaline administration (300 μg/kg for 5 weeks) on rat soleus muscle capillarity and glycolytic and oxidative capacities were evaluated. The treatment resulted in ventricular hypertrophy. The activities of lactic dehydrogenase, pyruvate kinase, citrate synthase, and cytochrome c oxidase in soleus muscle homogenates were not different between control and isoprenaline-injected animals. Capillaries were visualized in muscle cross sections treated to demonstrate ATPase activity after acid preincubation. Capillary density was higher in the experimental (873 ± 38 capillaries/mm2) than in the control (713 ± 33 capillaries/mm2) animals. Capillary to fiber ratio was also higher in the experimental (2.47 ± 0.10) than in control (2.09 ± 0.08) animals, but fiber cross-sectional area was not changed by the treatment (2836 ± 87 μm2 in controls and 2951 ± 136 μm2 in experimental). A plot of capillary to fiber ratio vs. fiber cross-sectional area showed that at a given fiber cross-sectional area the value of capillary to fiber ratio of the treated animals was higher than that of the controls. This indicates that treatment resulted in the proliferation of microvessels. The results suggest that prolonged β-adrenergic stimulation results in the development of new capillaries but that this is not accompanied by increases in the oxidative capacity of the soleus muscle of the rat.

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.

scholarly journals Sarcolipin expression is not required for the mitochondrial enzymatic response to physical activity or diet

2017 ◽  
Vol 122 (5) ◽  
pp. 1276-1283
Author(s):  
Daniel Gamu ◽  
Anton Trinh ◽  
Val A. Fajardo ◽  
Eric Bombardier ◽  
A. Russell Tupling
Keyword(s):  
Exercise Training ◽  
Citrate Synthase ◽  
Oxidative Capacity ◽  
Metabolic Phenotype ◽  
High Fat ◽  
Muscle Oxidative Capacity ◽  
Plasmic Reticulum ◽  
Voluntary Running ◽  
Fat Feeding

In mice, transgenic manipulation of Ca2+-handling proteins is sufficient to alter the metabolic phenotype of muscle. We have previously shown that ablation of sarcolipin (SLN), a regulatory protein and uncoupler of sarco(endo)plasmic reticulum Ca2+-ATPases, leads to excessive diet-induced obesity and glucose intolerance in mice. However, it is unclear how loss of SLN per se affects muscle oxidative capacity and the ability of mitochondria to adapt to physiological stimuli, such as exercise training or calorie overload. To address this question, Sln−/− and wild-type (WT) littermates were given access to voluntary running wheels or underwent a treadmill training protocol for 8 wk. Furthermore, a separate group of mice were given a high-fat diet (42% kcal from fat for 8 wk) to determine whether the excessively obese phenotype of Sln−/− mice is associated with altered oxidative capacity. While voluntary running was insufficient to elicit mitochondrial adaptations, treadmill-trained mice showed significant increases ( P < 0.05) in the maximal activities of succinate dehydrogenase (+11%), citrate synthase (+12%), cytochrome oxidase (COX: +17%), along with increased protein expression of cytochrome c (+34%) and COX IV (+28%), which were irrespective of SLN expression. Lastly, no changes in the activities of mitochondrial marker enzymes existed with high-fat feeding, regardless of genotype. Together, these findings indicate that SLN is not required for the regulation of oxidative capacity in response to physiological stress, namely exercise or caloric surfeit. NEW & NOTEWORTHY Sarcolipin (SLN) has gained considerable attention for its uncoupling role of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). Because of SLN’s ability to alter both cellular energy use and cytosolic [Ca2+], the potential exists for a regulatory role of mitochondrial biogenesis. Herein, we show skeletal muscle oxidative capacity to be unaltered in mice lacking SLN following exercise training or high-fat feeding. Our results contrast with published studies of SLN-overexpressing mice, possibly owing to supraphysiological uncoupling of SERCA.

Skeletal Muscle Oxidative Capacity, Fiber Type, and Metabolites after Lung Transplantation

1999 ◽  
Vol 160 (1) ◽  
pp. 57-63 ◽  
Author(s):  
XIAO N. WANG ◽  
TREVOR J. WILLIAMS ◽  
MICHAEL J. McKENNA ◽  
JIA L. LI ◽  
STEVEN F. FRASER ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Lung Transplantation ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Muscle Oxidative Capacity

The insulin action-fiber type relationship in humans is muscle group specific

1995 ◽  
Vol 269 (1) ◽  
pp. E150-E154 ◽  
Author(s):  
M. S. Hickey ◽  
M. D. Weidner ◽  
K. E. Gavigan ◽  
D. Zheng ◽  
G. L. Tyndall ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Action ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Oxidative Capacity ◽  
Muscle Groups ◽  
The Relationship ◽  
Male Subjects

The purpose of the present investigation was to determine the relationship between skeletal muscle characteristics, adiposity, and in vivo insulin action. Percutaneous muscle biopsies of the vastus lateralis (VL) and gastrocnemius (G) muscles were obtained from twenty-two sedentary male subjects. Insulin sensitivity (SI) and glucose effectiveness (SG) were determined from minimal model analysis, and indexes of regional and overall adiposity were obtained. SI was positively related to the citrate synthase activity from the VL (r = 0.50, P < 0.01) but unrelated to the citrate synthase activity from the G (r = 0.28). Similarly, SI was inversely related to the percentage of type IIb fibers in the VL (r = -0.47, P < 0.01) but unrelated to the percentage of type IIb fibers in the G (r = 0.06). SG was unrelated to fiber type, oxidative capacity, or adiposity. These data suggest that oxidative capacity and other characteristics related to VL skeletal muscle fiber type are determinants of in vivo insulin action but that this relationship cannot be extended to all muscle groups. Finally, neither skeletal muscle characteristics nor adiposity appears to be a determinant of SG in sedentary males.

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