Mitochondrial efficiency in resting skeletal muscle in vivo: a novel non‐invasive approach using multinuclear magnetic resonance spectroscopy in humans

• DOI: 10.1113/jp287412
• Publication Date: 2025-02-17T16:10:37Z
• Authors: Muhammet Enes Erol; Sean T. Bannon; Alexs A. Matias; Triantafyllia Siokas; Rajakumar Nagarajan; Yann Le Fur; Song‐Young Park; Gwenael Layec
• Keywords: Bioenergetics

Abstract Mitochondrial efficiency is a critical metabolic parameter with far‐reaching implications for tissue homeostasis. However, the direct measurement of oxygen consumption (VO 2 ) and ATP production from large sample in vivo remains challenging. Using phosphorus ( 31 P) proton 1 H) magnetic resonance spectroscopy (MRS), this study aimed to non‐invasively quantify skeletal muscle synthesis rate VO determine mitochondrial at rest during contraction humans. We assessed plantar flexor muscles 12 healthy adults (21 ± years) using P H MRS within 3T MR system. data were acquired constant workloads oxidative (ATP ox myoglobin‐derived (Mb‐derived ). At rest, was 0.85 0.24 m min −1, Mb‐derived 0.46 0.11 −1 , resulting P/O ratio 1.95 0.68. During graded exercise, end‐exercise PCr concentration decreased 29 5.7 18 4.8 Mb oxygenation declined linearly 47 11%. increased exercise workload r = 0.65 0.31), whereas there no significant change −0.19 0.60), leading non‐physiological values (>3). The results indicate that combined P/ H‐MRS offers promising approach quantifying samples, suggesting its potential as clinical endpoint function. further refinement needed use exercise. image Key points efficiency, converting chemical energy carbon fuels into ATP, vital homeostasis, but measuring has been This used (MRS) measured, muscles. workload, did not significantly, ratios. findings suggest method assessing could be function although conditions.