Experimental design of <sup>31</sup>P MRS assessment of human forearm muscle function: Restrictions imposed by functional anatomy

Jeneson, Jeroen A. L.; Dobbenburgh, J. Onno van; Echteld, C.J.A. van; Lekkerkerk, C.; Janssen, Willemijn J.M.; Dorland, L.; Berger, Ruud; Brown, Truman R.

doi:10.1002/mrm.1910300515

Cited by 20 publications

(11 citation statements)

References 15 publications

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“…However, due to their costs and/or specific application demands, there are many more built-in-the-lab devices used worldwide [20], [104], [131], [132], [133], [134], [135], [136], [137], [138], [139]. Basic designs apply mechanical or pneumatic workload settings.…”

Section: P-mrs Of Skeletal Musclementioning

confidence: 99%

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Valkovič

Chmelík

Krššák

2017

Analytical Biochemistry

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In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.

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Section: P-mrs Of Skeletal Musclementioning

confidence: 99%

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Valkovič

Chmelík

Krššák

2017

Analytical Biochemistry

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“…Binding constants are obtained from the literature; enzyme activities for reactions maintained near equilibrium are set to arbitrarily high values. 31 P-NMR spectroscopic measurements of phosphate metabolites in the ulnar finger flexor muscle in the human forearm were acquired at 1.5 T at rest and during voluntary ramp exercise using 1 H imagingguided localization in all subjects and analyzed according to the methods described in detail elsewhere (12).…”

Section: Model Parameter Valuesmentioning

confidence: 99%

Oxidative ATP synthesis in skeletal muscle is controlled by substrate feedback

Wu¹,

Jeneson²,

Beard³

2007

American Journal of Physiology-Cell Physiology

108

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Data from 31 P-nuclear magnetic resonance spectroscopy of human forearm flexor muscle were analyzed based on a previously developed model of mitochondrial oxidative phosphorylation (PLoS Comp Bio 1: e36, 2005) to test the hypothesis that substrate level (concentrations of ADP and inorganic phosphate) represents the primary signal governing the rate of mitochondrial ATP synthesis and maintaining the cellular ATP hydrolysis potential in skeletal muscle. Model-based predictions of cytoplasmic concentrations of phosphate metabolites (ATP, ADP, and Pi) matched data obtained from 20 healthy volunteers and indicated that as work rate is varied from rest to submaximal exercise commensurate increases in the rate of mitochondrial ATP synthesis are effected by changes in concentrations of available ADP and Pi. Additional data from patients with a defect of complex I of the respiratory chain and a patient with a deficiency in the mitochondrial adenine nucleotide translocase were also predicted the by the model by making the appropriate adjustments to the activities of the affected proteins associates with the defects, providing both further validation of the biophysical model of the control of oxidative phosphorylation and insight into the impact of these diseases on the ability of the cell to maintain its energetic state. computational model; mitochondria; cellular energetics; oxidative phosphorylation; 31 P-NMR spectroscopy MITOCHONDRIAL OXIDATIVE ADP phosphorylation is the primary source of ATP in skeletal muscle during aerobic exercise. Thus, to maintain the free energy state of the cytoplasmic phosphoenergetic compounds ATP, ADP, and P i , oxidative phosphorylation is modulated to match the rate of ATP utilization during exercise. It has recently been shown through computational model-based analysis of data obtained from 31 P-NMR spectroscopy of working in vivo dog hearts that the primary control mechanism operating in cardiomyocytes is feedback of substrate concentrations for ATP synthesis (5). In other words, changes in the concentrations of the products generated by the utilization of ATP in the cell, ADP and P i , effect changes in the rate at which mitochondria utilize those products to resynthesize ATP (5).Here the question of whether this same mechanism can explain the observed data on the control of oxidative metabolism in skeletal muscle is investigated. Previous analyses of 31 P-NMR spectroscopy ( 31 P-MRS) data on energy balance in exercising skeletal muscle have mainly focused on testing ADP feedback control of mitochondrial ATP synthesis using black box descriptions of the mitochondrial ATP synthetic pathway (8, 14 -16, 28), P i acceptor control (7), and thermodynamic control involving quasi-linear relations between cytoplasmic Gibbs free energy of ATP hydrolysis and mitochondrial ATP synthesis flux (13,18, 31). Yet, to date, these 31 P-MRS data have not been adequately explained based on a detailed mechanistic model of oxidative phosphorylation and cellular energetics.To analyze and interpret data from s...

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“…Magnetic resonance imaging [6,7,35] and localized spectroscopy [36] have been used to examine the heterogeneity in muscle recruitment and metabolism in individual muscles. The resolution of magnetic resonance imaging is excellent, although it is limited to providing information on muscle activation levels [6,7,37].…”

Section: Fig 3 Typical Changes For Nir-o 2 Saturation (Top)mentioning

confidence: 99%

Regional Difference of Muscle Oxygen Saturation and Blood Volume during Exercise Determined by Near Infrared Imaging Device.

Miura

McCully²,

Liang³

et al. 2001

JJP

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During exercise, the metabolic need for oxygen in muscles increases many times above the resting level. To meet this oxygen demand, oxygen supply to the contracting muscle must increase; this is accomplished by an increased cardiac output and a redistribution of the blood supply. During exercise, heteroJapanese Journal of Physiology Vol. 51, No. 5, 2001 599Japanese Journal of Physiology, 51, 599-606, 2001 Key words: near infrared light, imaging, oxygen saturation, blood volume, heterogeneity.Abstract: Using a near infrared (NIR) imaging device, we tested the hypothesis that regional differences in oxygen status could be detected in the gastrocnemius muscle during exercise and recovery. Six healthy subjects performed the standing plantar flexion exercises for 2 min; the frequency was one contraction per second. The NIR imaging device was placed over the medial head of the right gastrocnemius muscle and the signals from two optical sensors situated on the middle proximal and middle distal portions were used. The NIR-O 2 saturation (difference between deoxygenated and oxygenated Hb signals) and NIR-blood volume (sum of the oxygenated and deoxygenated Hb signals) were calculated in optical density units. Plantar flexion resulted in more deoxygenation during exercise and more reoxygenation during recovery in the distal portion compared with the proximal portion. The changes in NIR-O 2 between rest and a 2 min exercise, and between a 2 min exercise and a 3 min recovery were 0.11 and Ϫ0.23, respectively, in the distal portion, which were significantly larger than proximal values (0.05 and Ϫ0.10, pϽ0.05). Plantar flexion resulted in lower NIR-blood volumes during exercise and greater recovery of blood after exercise in the distal portion compared with the proximal portion. The changes in NIR blood volume between rest and a 2 min exercise and between a 2 min exercise and a 3 min recovery were Ϫ0.19 and 0.31, respectively, in the distal portion, significantly larger than proximal values (Ϫ0.07 and 0.12, pϽ0.05 for all comparisons). These findings indicate that the distal portion of the medial gastrocnemius had larger changes in NIR-O 2 saturation and NIR-blood volume than the proximal portion had. This is consistent with the distal portion having a greater impairment of blood flow possibly because of the higher intramuscular pressure during exercise. In conclusion: (1) regional differences in oxygen status in the gastrocnemius muscle were detected with exercise, with the distal portion having greater NIR-O 2 saturation and NIR-blood volume changes, and (2) the NIR imaging device might be a useful method to detect the regional differences of oxygen status in the muscle.

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Experimental design of ³¹P MRS assessment of human forearm muscle function: Restrictions imposed by functional anatomy

Cited by 20 publications

References 15 publications

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Oxidative ATP synthesis in skeletal muscle is controlled by substrate feedback

Regional Difference of Muscle Oxygen Saturation and Blood Volume during Exercise Determined by Near Infrared Imaging Device.

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Experimental design of 31P MRS assessment of human forearm muscle function: Restrictions imposed by functional anatomy

Cited by 20 publications

References 15 publications

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism

Oxidative ATP synthesis in skeletal muscle is controlled by substrate feedback

Regional Difference of Muscle Oxygen Saturation and Blood Volume during Exercise Determined by Near Infrared Imaging Device.

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Experimental design of ³¹P MRS assessment of human forearm muscle function: Restrictions imposed by functional anatomy