Hafen 2019 J Appl Physiol (1985)
|Hafen PS, Abbott K, Bowden JA, Lopiano R, Hancock CR, Hyldahl RD (2019) Daily heat treatment maintains mitochondrial function and attenuates atrophy in human skeletal muscle subjected to immobilization. J Appl Physiol (1985) [Epub ahead of print].|
Abstract: Skeletal muscle immobilization leads to atrophy, decreased metabolic health and substantial losses in function. Animal models suggest that heat stress can provide protection against atrophy in skeletal muscle. This study investigated the effects of daily heat therapy on human skeletal muscle subjected to immobilization. Muscle biopsies were collected, and MRI images were analyzed from the vastus lateralis of 23 healthy volunteers (11 females, 12 males) before and after either 10 days of immobilization with a daily sham treatment (Imm), or with a targeted daily 2-hr heat treatment using pulsed shortwave diathermy (Imm + H). Diathermy increased intramuscular temperature 4.2 ± 0.29°C (p < 0.0001). As a result, HSP70 and HSP90 increased (p < 0.05) following Imm + H (25 ± 6.6 and 20 ± 7.4%, respectively). Heat treatment prevented the immobilization-induced loss of coupled (-27 ± 5.2% vs. -8 ± 6.0%, p = 0.0041), and uncoupled (-25 ± 7.0% vs. -10 ± 3.9%, p = 0.0302) myofiber respiratory capacity. Likewise, heat treatment prevented the immobilation-induced loss of proteins associated with all 5 mitochondrial respiratory complexes (p < 0.05). Furthermore, decreases in muscle cross-sectional area following Imm were greater than Imm + H at both the level of the whole-muscle (-7.6 ± 0.96% vs. -4.5 ± 1.09%, p = 0.0374) and myofiber (-10.8 ± 1.52% vs. -5.8 ± 1.49%, p = 0.0322). Our findings demonstrate that daily heat treatments, applied during 10 days of immobilization, prevent the loss of mitochondrial function and attenuate atrophy in human skeletal muscle.
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style
Stress:Temperature Organism: Human Tissue;cell: Skeletal muscle Preparation: Permeabilized tissue Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase
Coupling state: LEAK, OXPHOS, ET Pathway: N, S, NS, ROX HRR: Oxygraph-2k