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Updated: May 14, 2026

Measurement of Mitochondrial Respiration in Human and Mouse Skeletal Muscle Fibers by High-Resolution Respirometry
Published on: October 4, 2024
Fast-twitch glycolytic skeletal muscle is predisposed to age-induced impairments in mitochondrial function
Robert A Jacobs1, Víctor Díaz, Lavinia Soldini
1Institute of Veterinary Physiology and Zurich Center for Integrative Human Physiology, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland. jacobs@vetphys.uzh.ch
Abstract:
The etiology of mammalian senescence is suggested to involve the progressive impairment of mitochondrial function; however, direct observations of age-induced alterations in actual respiratory chain function are lacking. Accordingly, we assessed mitochondrial function via high-resolution respirometry and mitochondrial protein expression in soleus, quadricep, and lateral gastrocnemius skeletal muscles, which represent type 1 slow-twitch oxidative muscle (soleus) and type 2 fast-twitch glycolytic muscle (quadricep and gastrocnemius), respectively, in young (10-12 weeks) and mature (74-76 weeks) mice. Electron transport through mitochondrial complexes I and III increases with age in quadricep and gastrocnemius, which is not observed in soleus. Mitochondrial coupling efficiency during respiration through complex I also deteriorates with age in gastrocnemius and shows a tendency (p = .085) to worsen in quadricep. These data demonstrate actual alterations in electron transport function that occurs with age and are dependent on skeletal muscle type.
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