title: Effect of electrical stimulation-induced resistance exercise on mitochondrial fission and fusion proteins in rat skeletal muscle.
abstract: It is well known that resistance exercise increases muscle protein synthesis and muscle strength. However, little is known about the effect of resistance exercise on mitochondrial dynamics, which is coupled with mitochondrial function. In skeletal muscle, mitochondria exist as dynamic networks that are continuously remodeling through fusion and fission. The purpose of this study was to investigate the effect of acute and chronic resistance exercise, which induces muscle hypertrophy, on the expression of proteins related to mitochondrial dynamics in rat skeletal muscle. Resistance exercise consisted of maximum isometric contraction, which was induced by percutaneous electrical stimulation of the gastrocnemius muscle. Our results revealed no change in levels of proteins that regulate mitochondrial fission (Fis1 and Drp1) or fusion (Opa1, Mfn1, and Mfn2) over the 24-h period following acute resistance exercise. Phosphorylation of Drp1 at Ser616 was increased immediately after exercise (P < 0.01). Four weeks of resistance training (3 times/week) increased Mfn1 (P < 0.01), Mfn2 (P < 0.05), and Opa1 (P < 0.01) protein levels without altering mitochondrial oxidative phosphorylation proteins. These observations suggest that resistance exercise has little effect on mitochondrial biogenesis but alters the expression of proteins involved in mitochondrial fusion and fission, which may contribute to mitochondrial quality control and improved mitochondrial function.
authors.affiliation: a Department of Sports Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kitaoka
authors.affiliation: a Department of Sports Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Riki
authors.initials: R
authors.lastname: Ogasawara
authors.affiliation: a Department of Sports Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tamura
authors.affiliation: b Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujita
authors.affiliation: a Department of Sports Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Hatta
mesh_terms: D000818:Animals; D034281:Dynamins / Q000378:metabolism; D004558:Electric Stimulation; D004734:Energy Metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism; D007537:Isometric Contraction; D008565:Membrane Proteins / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000378:metabolism*; D063154:Mitochondrial Dynamics; D024101:Mitochondrial Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism*; D010766:Phosphorylation; D017207:Rats, Sprague-Dawley; D055070:Resistance Training; D013997:Time Factors
chemical_list: C503403:Fis1 protein, rat; D008565:Membrane Proteins; C489709:Mfn1 protein, rat; D024101:Mitochondrial Proteins; D020558:GTP Phosphohydrolases; C489710:Mfn2 protein, rat; C498811:Opa1 protein, rat; C519851:Dnm1l protein, rat; D034281:Dynamins
keywords: Drp1; Fis1; Mfn; Opa1; dynamique mitochondriale; exercice contre résistance; mitochondrial dynamics; muscle squelettique; resistance exercise; skeletal muscle