RT journal article
T1 Combined changes in temperature and pH mimicking exercise results in decreased efficiency in muscle mitochondria
A1 Flensted-Jensen, Mathias
A1 Kleis-Olsen, Ann-Sofie
A1 Hassø, Rasmus Kinimond
A1 Lindtofte, Søren
A1 Corral Pérez, Juan
A1 Ortega Gómez, Sonia
A1 Larsen, Steen
A2 Didáctica de la Educación FísicaPlástica y Musical
K1 exercise
K1 mitochondria
K1 mitochondrial efficiency
K1 pH
K1 temperature
AB It is well known that exercise efficiency declines at intensities above the lactate threshold, yet the underlying mechanisms are poorly understood. Some have suggested it is due to a decline in mitochondrial efficiency, but this is difficult to examine in vivo. Therefore, the aim of the current study was to examine how changes in temperature and pH, mimicking those that occur during exercise, affect mitochondrial efficiency in skeletal muscle mitochondria. This study was performed on quadriceps muscle of 20 wild-type mice. Muscle tissue was dissected and either permeabilized (n = 10) or homogenized for isolation of mitochondria (n = 10), and oxidative phosphorylation capacity and P/O ratio were assessed using high-resolution respirometry. Samples from each muscle were analyzed in both normal physiological conditions (37°C, pH 7.4), decreased pH (6.8), increased temperature (40°C), and a combination of both. The combination of increased temperature and decreased pH resulted in a significantly lower P/O ratio, mirrored by an increase in leak respiration and a decrease in respiratory control ratio (RCR), in isolated mitochondria. In permeabilized fibers, RCR and leak were relatively unaffected, though a main effect of temperature was observed. Oxidative phosphorylation capacity was unaffected by changes in pH and temperature in both isolated mitochondria and permeabilized fibers. These results indicate that exercise-like changes in temperature and pH lead to impaired mitochondrial efficiency. These findings offer some degree of support to the concept of decreased mitochondrial efficiency during exercise, and may have implications for the assessment of mitochondrial function related to exercise.
PB American Physiological Society
SN 1522-1601
YR 2024
FD 2024
LK http://hdl.handle.net/10498/34142
UL http://hdl.handle.net/10498/34142
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026