Oxidative capacity varies along the length of healthy human tibialis anterior

摘要

Key points class="unordered" style="list-style-type:disc" id="tjp12872-list-0001">During exercise skeletal muscles use the energy buffer phosphocreatine.The post‐exercise recovery of phosphocreatine is a measure of the oxidative capacity of muscles and is traditionally assessed by ³¹P magnetic resonance spectroscopy of a large tissue region, assuming homogeneous energy metabolism.To test this assumption, we collected spatially resolved spectra along the length of human tibialis anterior using a home‐built array of ³¹P detection coils, and observed a striking gradient in the recovery rate of phosphocreatine, decreasing along the proximo‐distal axis of the muscle.A similar gradient along this muscle was observed in signal changes recorded by ¹H muscle functional MRI.These findings identify intra‐muscular variation in the physiology of muscles in action and highlight the importance of localized sampling for any methodology investigating oxidative metabolism of this, and potentially other muscles.