Fast-twitch glycolytic skeletal muscle is predisposed to age-induced impairments in mitochondrial function.
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.
Institute of Veterinary Physiology and Zurich Center for Integrative Human Physiology, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland. jacobs@vetphys.uzh.ch
Robert A
RA
Jacobs
Víctor
V
Díaz
Lavinia
L
Soldini
Thomas
T
Haider
Martin
M
Thomassen
Nikolai B
NB
Nordsborg
Max
M
Gassmann
Carsten
C
Lundby
D000375:Aging / Q000378:metabolism*; D000818:Animals; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000378:metabolism; D014450:Electron Transport Complex III / Q000378:metabolism; D006019:Glycolysis; D050356:Lipid Metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008931:Mitochondria, Muscle / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D052097:Quadriceps Muscle / Q000378:metabolism
D024101:Mitochondrial Proteins; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III
Function theory of aging.; Mitochondria; Respiratory chain