scholarly journals Oxygen delivery and the restoration of the muscle energetic balance following exercise: implications for delayed muscle recovery in patients with COPD

2017 ◽  
Vol 313 (1) ◽  
pp. E94-E104 ◽  
Author(s):  
Gwenael Layec ◽  
Corey R. Hart ◽  
Joel D. Trinity ◽  
Oh-Sung Kwon ◽  
Matthew J. Rossman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Time Constant ◽  
Plantar Flexion ◽  
Chronic Obstructive ◽  
Resonance Spectroscopy ◽  
Proton Efflux ◽  
Muscle Recovery ◽  
Delayed Recovery ◽  
Plantar Flexion Exercise

Patients with chronic obstructive pulmonary disease (COPD) experience a delayed recovery from skeletal muscle fatigue following exhaustive exercise that likely contributes to their progressive loss of mobility. As this phenomenon is not well understood, this study sought to examine postexercise peripheral oxygen (O2) transport and muscle metabolism dynamics in patients with COPD, two important determinants of muscle recovery. Twenty-four subjects, 12 nonhypoxemic patients with COPD and 12 healthy subjects with a sedentary lifestyle, performed dynamic plantar flexion exercise at 40% of the maximal work rate (WRmax) with phosphorus magnetic resonance spectroscopy (31P-MRS), near-infrared spectroscopy (NIRS), and vascular Doppler ultrasound assessments. The mean response time of limb blood flow at the offset of exercise was significantly prolonged in patients with COPD (controls: 56 ± 27 s; COPD: 120 ± 87 s; P < 0.05). In contrast, the postexercise time constant for capillary blood flow was not significantly different between groups (controls: 49 ± 23 s; COPD: 51 ± 21 s; P > 0.05). The initial postexercise convective O2 delivery (controls: 0.15 ± 0.06 l/min; COPD: 0.15 ± 0.06 l/min) and the corresponding oxidative adenosine triphosphate (ATP) demand (controls: 14 ± 6 mM/min; COPD: 14 ± 6 mM/min) in the calf were not significantly different between controls and patients with COPD ( P > 0.05). The phosphocreatine resynthesis time constant (controls: 46 ± 20 s; COPD: 49 ± 21 s), peak mitochondrial phosphorylation rate, and initial proton efflux were also not significantly different between groups ( P > 0.05). Therefore, despite perturbed peripheral hemodynamics, intracellular O2 availability, proton efflux, and aerobic metabolism recovery in the skeletal muscle of nonhypoxemic patients with COPD are preserved following plantar flexion exercise and thus are unlikely to contribute to the delayed recovery from exercise in this population.

scholarly journals Evidence that a higher ATP cost of muscular contraction contributes to the lower mechanical efficiency associated with COPD: preliminary findings

2011 ◽  
Vol 300 (5) ◽  
pp. R1142-R1147 ◽  
Author(s):  
Gwenael Layec ◽  
Luke J. Haseler ◽  
Jan Hoff ◽  
Russell S. Richardson
Keyword(s):  
Skeletal Muscle ◽  
Muscle Contraction ◽  
Energy Cost ◽  
Plantar Flexion ◽  
Mechanical Efficiency ◽  
Exercise Intolerance ◽  
Chronic Obstructive ◽  
Small Subset ◽  
Resonance Spectroscopy ◽  
Muscle Energetics

Impaired metabolism in peripheral skeletal muscles potentially contributes to exercise intolerance in chronic obstructive pulmonary disease (COPD). We used 31P-magnetic resonance spectroscopy (31P-MRS) to examine the energy cost and skeletal muscle energetics in six patients with COPD during dynamic plantar flexion exercise compared with six well-matched healthy control subjects. Patients with COPD displayed a higher energy cost of muscle contraction compared with the controls (control: 6.1 ± 3.1% of rest·min−1·W−1, COPD: 13.6 ± 8.3% of rest·min−1·W−1, P = 0.01). Although, the initial phosphocreatine resynthesis rate was also significantly attenuated in patients with COPD compared with controls (control: 74 ± 17% of rest/min, COPD: 52 ± 13% of rest/min, P = 0.04), when scaled to power output, oxidative ATP synthesis was similar between groups (6.5 ± 2.3% of rest·min−1·W−1 in control and 7.8 ± 3.9% of rest·min−1·W−1 in COPD, P = 0.52). Therefore, our results reveal, for the first time that in a small subset of patients with COPD a higher ATP cost of muscle contraction may substantially contribute to the lower mechanical efficiency previously reported in this population. In addition, it appears that some patients with COPD have preserved mitochondrial function and normal energy supply in lower limb skeletal muscle.

Interrelationship of oxidative metabolism and local perfusion demonstrated by NMR in human skeletal muscle

1996 ◽  
Vol 81 (5) ◽  
pp. 2221-2228 ◽  
Author(s):  
Jean-François Toussaint ◽  
Kenneth K. Kwong ◽  
Fidelis M’Kparu ◽  
Robert M. Weisskoff ◽  
Paul J. Laraia ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Magnetic Resonance ◽  
Time Constant ◽  
Oxidative Metabolism ◽  
Human Skeletal Muscle ◽  
Plantar Flexion ◽  
High Energy ◽  
Resonance Spectroscopy ◽  
Mean Flow ◽  
Normal Volunteers

Toussaint, Jean-François, Kenneth K. Kwong, Fidelis M’Kparu, Robert M. Weisskoff, Paul J. LaRaia, and Howard L. Kantor.Interrelationship of oxidative metabolism and local perfusion demonstrated by NMR in human skeletal muscle. J. Appl. Physiol. 81(5): 2221–2228, 1996.—Using nuclear magnetic resonance (NMR), we have examined the relationship of high-energy phosphate metabolism and perfusion in human soleus and gastrocnemius muscles. With31P-NMR spectroscopy, we monitored phosphocreatine (PCr) decay and recovery in eight normal volunteers and four heart failure patients performing ischemic plantar flexion. By using echo-planar imaging, perfusion was independently measured by a local [inversion-recovery (T1-flow)] and a regional technique (NMR-plethysmography). After correction for its pH dependence, PCr recovery time constant is 27.5 ± 8.0 s in normal volunteers, with mean flow 118 ± 75 (soleus and gastrocnemius T1-flow) and 30.2 ± 9.7 ml ⋅ 100 ml−1 ⋅ min−1(NMR-plethysmography-flow). We demonstrate a positive correlation between PCr time constant and local perfusion given by y = 50 − 0.15 x( r 2 = 0.68, P = 0.01) for the 8 normal subjects, and y = 64 − 0.24 x( r 2 = 0.83, P = 0.0001) for the 12 subjects recruited in the study. Regional perfusion techniques also show a significant but weaker correlation. Using this totally noninvasive method, we conclude that aerobic ATP resynthesis is related to the magnitude of perfusion, i.e., O2availability, and demonstrate that magnetic resonance imaging and magnetic resonance spectroscopy together can accurately assess muscle functional status.

scholarly journals Enhanced muscle blood flow with intermittent pneumatic compression of the lower leg during plantar flexion exercise and recovery

2018 ◽  
Vol 124 (2) ◽  
pp. 302-311 ◽  
Author(s):  
K. A. Zuj ◽  
C. N. Prince ◽  
R. L. Hughson ◽  
S. D. Peterson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Performance ◽  
Muscle Blood Flow ◽  
Plantar Flexion ◽  
Intermittent Pneumatic Compression ◽  
Muscle Pump ◽  
Intermittent Compression ◽  
Postexercise Recovery ◽  
Plantar Flexion Exercise

This study tested the hypothesis that intermittent compression of the lower limb would increase blood flow during exercise and postexercise recovery. Data were collected from 12 healthy individuals (8 men) who performed 3 min of standing plantar flexion exercise. The following three conditions were tested: no applied compression (NoComp), compression during the exercise period only (ExComp), and compression during 2 min of standing postexercise recovery. Doppler ultrasound was used to determine superficial femoral artery (SFA) blood flow responses. Mean arterial pressure (MAP) and cardiac stroke volume (SV) were assessed using finger photoplethysmography, with vascular conductance (VC) calculated as VC = SFA flow/MAP. Compared with the NoComp condition, compression resulted in increased MAP during exercise [+3.5 ± 4.1 mmHg (mean ± SD)] but not during postexercise recovery (+1.6 ± 5.9 mmHg). SV increased with compression during both exercise (+4.8 ± 5.1 ml) and recovery (+8.0 ± 6.6 ml) compared with NoComp. There was a greater increase in SFA flow with compression during exercise (+52.1 ± 57.2 ml/min) and during recovery (+58.6 ± 56.7 ml/min). VC immediately following exercise was also significantly greater in the ExComp condition compared with the NoComp condition (+0.57 ± 0.42 ml·min−1·mmHg−1), suggesting the observed increase in blood flow during exercise was in part because of changes in VC. Results from this study support the hypothesis that intermittent compression applied during exercise and recovery from exercise results in increased limb blood flow, potentially contributing to changes in exercise performance and recovery. NEW & NOTEWORTHY Blood flow to working skeletal muscle is achieved in part through the rhythmic actions of the skeletal muscle pump. This study demonstrated that the application of intermittent pneumatic compression during the diastolic phase of the cardiac cycle, to mimic the mechanical actions of the muscle pump, accentuates muscle blood flow during exercise and elevates blood flow during the postexercise recovery period. Intermittent compression during and after exercise might have implications for exercise performance and recovery.

Skeletal muscle phosphocreatine recovery in exercise-trained humans is dependent on O2availability

1999 ◽  
Vol 86 (6) ◽  
pp. 2013-2018 ◽  
Author(s):  
Luke J. Haseler ◽  
Michael C. Hogan ◽  
Russell S. Richardson
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Metabolism ◽  
Gastrocnemius Muscle ◽  
Plantar Flexion ◽  
Oxidative Capacity ◽  
Submaximal Exercise ◽  
Resonance Spectroscopy ◽  
The Relationship ◽  
Male Subjects ◽  
Plantar Flexion Exercise

In skeletal muscle, phosphocreatine (PCr) recovery from submaximal exercise has become a reliable and accepted measure of muscle oxidative capacity. During exercise, O2 availability plays a role in determining maximal oxidative metabolism, but the relationship between O2 availability and oxidative metabolism measured by31P-magnetic resonance spectroscopy (MRS) during recovery from exercise has never been studied. We used 31P-MRS to study exercising human gastrocnemius muscle under conditions of varied fractions of inspired O2 [Formula: see text]) to test the hypothesis that varied O2availability modulates PCr recovery from submaximal exercise. Six male subjects performed three bouts of 5-min steady-state submaximal plantar flexion exercise followed by 5 min of recovery in a 1.5-T magnet while breathing three different[Formula: see text] concentrations (0.10, 0.21, and 1.00). Under each[Formula: see text] treatment, the PCr recovery time constants were significantly different, being longer in hypoxia [33.5 ± 4.1 s (SE)] and shorter in hyperoxia (20.0 ± 1.8 s) than in normoxia (25.0 ± 2.7 s) ( P ≤ 0.05). End-exercise pH was not significantly different among the three treatments (7.08 ± 0.01 for 0.10, 7.04 ± 0.01 for 0.21, and 7.04 ± 0.02 for 1.00). These results demonstrate that PCr recovery is significantly altered by[Formula: see text] and suggest that, after submaximal exercise, PCr recovery, under normoxic conditions, is limited by O2 availability.

scholarly journals A cross-validation of near-infrared spectroscopy measurements of skeletal muscle oxidative capacity with phosphorus magnetic resonance spectroscopy

2013 ◽  
Vol 115 (12) ◽  
pp. 1757-1766 ◽  
Author(s):  
Terence E. Ryan ◽  
W. Michael Southern ◽  
Mary Ann Reynolds ◽  
Kevin K. McCully
Keyword(s):  
Skeletal Muscle ◽  
Near Infrared ◽  
Plantar Flexion ◽  
Oxidative Capacity ◽  
Resonance Spectroscopy ◽  
Time Constants ◽  
Muscle Oxidative Capacity ◽  
Muscle Oxygen ◽  
Muscle Oxygen Consumption ◽  
Plantar Flexion Exercise

The purpose of this study was to cross-validate measurements of skeletal muscle oxidative capacity made with near-infrared spectroscopy (NIRS) measurements to those made with phosphorus magnetic resonance spectroscopy (31P-MRS). Sixteen young (age = 22.5 ± 3.0 yr), healthy individuals were tested with both 31P-MRS and NIRS during a single testing session. The recovery rate of phosphocreatine was measured inside the bore of a 3-Tesla MRI scanner, after short-duration (∼10 s) plantar flexion exercise as an index of skeletal muscle oxidative capacity. Using NIRS, the recovery rate of muscle oxygen consumption was also measured using repeated, transient arterial occlusions outside the MRI scanner, after short-duration (∼10 s) plantar flexion exercise as another index of skeletal muscle oxidative capacity. The average recovery time constant was 31.5 ± 8.5 s for phosphocreatine and 31.5 ± 8.9 s for muscle oxygen consumption for all participants ( P = 0.709). 31P-MRS time constants correlated well with NIRS time constants for both channel 1 (Pearson's r = 0.88, P < 0.0001) and channel 2 (Pearson's r = 0.95, P < 0.0001). Furthermore, both 31P-MRS and NIRS exhibit good repeatability between trials (coefficient of variation = 8.1, 6.9, and 7.9% for NIRS channel 1, NIRS channel 2, and 31P-MRS, respectively). The good agreement between NIRS and 31P-MRS indexes of skeletal muscle oxidative capacity suggest that NIRS is a valid method for assessing mitochondrial function, and that direct comparisons between NIRS and 31P-MRS measurements may be possible.

scholarly journals Folic acid ingestion improves skeletal muscle blood flow during graded handgrip and plantar flexion exercise in aged humans

2017 ◽  
Vol 313 (3) ◽  
pp. H658-H666 ◽  
Author(s):  
Steven A. Romero ◽  
Daniel Gagnon ◽  
Amy N. Adams ◽  
Gilbert Moralez ◽  
Ken Kouda ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Folic Acid ◽  
Muscle Blood Flow ◽  
Plantar Flexion ◽  
Serum Folate ◽  
Whole Body ◽  
Vascular Conductance ◽  
Skeletal Muscle Blood Flow ◽  
Plantar Flexion Exercise

Skeletal muscle blood flow is attenuated in aged humans performing dynamic exercise, which is due, in part, to impaired local vasodilatory mechanisms. Recent evidence suggests that folic acid improves cutaneous vasodilation during localized and whole body heating through nitric oxide-dependent mechanisms. However, it is unclear whether folic acid improves vasodilation in other vascular beds during conditions of increased metabolism (i.e., exercise). The purpose of this study was to test the hypothesis that folic acid ingestion improves skeletal muscle blood flow in aged adults performing graded handgrip and plantar flexion exercise via increased vascular conductance. Nine healthy, aged adults (two men and seven women; age: 68 ± 5 yr) performed graded handgrip and plantar flexion exercise before (control), 2 h after (acute, 5 mg), and after 6 wk (chronic, 5 mg/day) folic acid ingestion. Forearm (brachial artery) and leg (superficial femoral artery) blood velocity and diameter were measured via Duplex ultrasonography and used to calculate blood flow. Acute and chronic folic acid ingestion increased serum folate (both P < 0.05 vs. control). During handgrip exercise, acute and chronic folic acid ingestion increased forearm blood flow (both conditions P < 0.05 vs. control) and vascular conductance (both P < 0.05 vs. control). During plantar flexion exercise, acute and chronic folic acid ingestion increased leg blood flow (both P < 0.05 vs. control), but only acute folic acid ingestion increased vascular conductance ( P < 0.05 vs. control). Taken together, folic acid ingestion increases blood flow to active skeletal muscle primarily via improved local vasodilation in aged adults. NEW & NOTEWORTHY Our findings demonstrate that folic acid ingestion improves blood flow via enhanced vascular conductance in the exercising skeletal muscle of aged humans. These findings provide evidence for the therapeutic use of folic acid to improve skeletal muscle blood flow, and perhaps exercise and functional capacity, in human primary aging. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/folic-acid-and-exercise-hyperemia-in-aging/ .

scholarly journals Systemic oxidative stress is associated with lower aerobic capacity and impaired skeletal muscle energy metabolism in heart failure patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takashi Yokota ◽  
Shintaro Kinugawa ◽  
Kagami Hirabayashi ◽  
Mayumi Yamato ◽  
Shingo Takada ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Aerobic Capacity ◽  
Plantar Flexion ◽  
Exercise Intolerance ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Systemic Oxidative Stress

AbstractOxidative stress plays a role in the progression of chronic heart failure (CHF). We investigated whether systemic oxidative stress is linked to exercise intolerance and skeletal muscle abnormalities in patients with CHF. We recruited 30 males: 17 CHF patients, 13 healthy controls. All participants underwent blood testing, cardiopulmonary exercise testing, and magnetic resonance spectroscopy (MRS). The serum thiobarbituric acid reactive substances (TBARS; lipid peroxides) were significantly higher (5.1 ± 1.1 vs. 3.4 ± 0.7 μmol/L, p < 0.01) and the serum activities of superoxide dismutase (SOD), an antioxidant, were significantly lower (9.2 ± 7.1 vs. 29.4 ± 9.7 units/L, p < 0.01) in the CHF cohort versus the controls. The oxygen uptake (VO2) at both peak exercise and anaerobic threshold was significantly depressed in the CHF patients; the parameters of aerobic capacity were inversely correlated with serum TBARS and positively correlated with serum SOD activity. The phosphocreatine loss during plantar-flexion exercise and intramyocellular lipid content in the participants' leg muscle measured by 31phosphorus- and 1proton-MRS, respectively, were significantly elevated in the CHF patients, indicating abnormal intramuscular energy metabolism. Notably, the skeletal muscle abnormalities were related to the enhanced systemic oxidative stress. Our analyses revealed that systemic oxidative stress is related to lowered whole-body aerobic capacity and skeletal muscle dysfunction in CHF patients.

Simultaneous in vivo measurements of HbO2 saturation and PCr kinetics after exercise in normal humans

1994 ◽  
Vol 77 (1) ◽  
pp. 5-10 ◽  
Author(s):  
K. K. McCully ◽  
S. Iotti ◽  
K. Kendrick ◽  
Z. Wang ◽  
J. D. Posner ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Time Constant ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Plantar Flexion ◽  
Resonance Spectroscopy ◽  
Ph Values

Simultaneous measurements of phosphocreatine (PCr) and oxyhemoglobin (HbO2) saturation were made during recovery from exercise in calf muscles of five male subjects. PCr was measured using magnetic resonance spectroscopy in a 2.0-T 78-cm-bore magnet with a 9-cm-diam surface coil. Relative HbO2 saturation was measured as the difference in absorption of 750- and 850-nm light with use of near-infrared spectroscopy. The light source and detectors were 3 cm apart. Exercise consisted of isokinetic plantar flexion in a supine position. Two 5-min submaximal protocols were performed with PCr depletion to 60% of resting values and with pH values of > 7.0. Then two 1-min protocols of rapid plantar flexion were performed to deplete PCr values to 5–20% of resting values with pH values of < 6.8. Areas of PCr peaks (every 8 s) and HbO2 saturation (every 1 s) were fit to a monoexponential function, and a time constant was calculated. The PCr time constant was larger after maximal exercise (68.3 +/- 10.5 s) than after submaximal exercise (36.0 +/- 6.5 s), which is consistent with the effects of low pH on PCr recovery. HbO2 resaturation approximated submaximal PCr recovery and was not different between maximal (29.4 +/- 5.5 s) and submaximal (27.6 +/- 6.0 s) exercise. We conclude that magnetic resonance spectroscopy measurements of PCr recovery and near-infrared spectroscopy measurements of recovery of HbO2 saturation provide similar information as long as muscle pH remains near 7.0.

scholarly journals Normalized metabolic stress for31P-MR spectroscopy studies of human skeletal muscle: MVC vs. muscle volume

1997 ◽  
Vol 83 (3) ◽  
pp. 875-883 ◽  
Author(s):  
M. D. Fowler ◽  
T. W. Ryschon ◽  
R. E. Wysong ◽  
C. A. Combs ◽  
R. S. Balaban
Keyword(s):  
Skeletal Muscle ◽  
Power Output ◽  
Mr Spectroscopy ◽  
Human Skeletal Muscle ◽  
Plantar Flexion ◽  
Metabolic Stress ◽  
Muscle Volume ◽  
Resonance Spectroscopy ◽  
Plantar Flexor ◽  
Spectroscopy Studies

Fowler, M. D., T. W. Ryschon, R. E. Wysong, C. A. Combs, and R. S. Balaban. Normalized metabolic stress for31P-MR spectroscopy studies of human skeletal muscle: MVC vs. muscle volume. J. Appl. Physiol. 83(3): 875–883, 1997.—A critical requirement of submaximal exercise tests is the comparability of workload and associated metabolic stress between subjects. In this study, 31P-magnetic resonance spectroscopy was used to estimate metabolic strain in the soleus muscle during dynamic, submaximal plantar flexion in which target torque was 10 and 15% of a maximal voluntary contraction (MVC). In 10 healthy, normally active adults, (PCr + Pi)/PCr, where PCr is phosphocreatine, was highly correlated with power output normalized to the volume of muscle in the plantar flexor compartment ( r = 0.89, P < 0.001). The same variable was also correlated, although less strongly ( r = 0.78, P < 0.001), with power normalized to plantar flexor cross-sectional area. These findings suggest that comparable levels of metabolic strain can be obtained in subjects of different size when the power output, or stress, for dynamic plantar flexion is selected as a function of plantar flexor muscle volume. In contrast, selecting power output as a function of MVC resulted in a positive linear relationship between (PCr + Pi)/PCr and the torque produced, indicating that metabolic strain was increasing rather than achieving constancy as a function of MVC. These findings provide new insight into the design of dynamic muscle contraction protocols aimed at detecting metabolic differences between subjects of different body size but having similar blood flow capacity and mitochondrial volume per unit of muscle.

Muscle metabolism in older subjects using 31P magnetic resonance spectroscopy

1991 ◽  
Vol 69 (5) ◽  
pp. 576-580 ◽  
Author(s):  
Kevin K. McCully ◽  
Mary Ann Forciea ◽  
Laurita M. Hack ◽  
Eileen Donlon ◽  
Roger W. Wheatley ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Time Constant ◽  
Plantar Flexion ◽  
Muscle Metabolism ◽  
The Elderly ◽  
Elderly Subjects ◽  
Resonance Spectroscopy ◽  
Medical Problems ◽  
Age Related

We used phosphorus magnetic resonance spectroscopy to study the calf muscles of elderly normal (mean ± SD) (80.0 ± 5.12 years), elderly impaired (80.7 ± 0.58 years), old normal (66.8 ± 1.92 years), and young normal people (24.6 ± 4.72 years). Relative levels of inorganic phosphate (Pi), phosphocreatine (PCr), and adenosine triphosphate were measured with a 1.9-tesla, 30-cm bore magnet at rest and following plantra flexon exercise. No differences were found at rest or during recovery from exercise in the elderly normal subjects with respect to gender or the presence of stable medical problems treated with medication. At rest there was an age-related decrease in the ratio of PCr/Pi. After exercise, the time constant of PCr recovery increased with age. A mild 7-week exercise regimen consisting of plantar flexion had no effect on time constant of PCr recovery in the elderly subjects. Four elderly impaired subjects had lower PCr/Pi ratios at rest and slower time constant of PCr recovery after exercise than normal elderly subjects. We conclude that gender and the presence of stable medical problems had no effect on muscle metabolism in the elderly and that the elderly recovered slower than young controls. This slower recovery was not corrected with a mild exercise program.Key words: human muscle, aging, exercise, nuclear magnetic resonance, gastrocnemius.

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