title: Effects of chronic administration of arachidonic acid on lipid profiles and morphology in the skeletal muscles of aged rats.
abstract: Arachidonic acid (20:4n-6, ARA) is a major component of the cell membrane, whereas ARA-derived eicosanoids are formed when cells are damaged. Aging is associated with an accretion of oxidative stress in skeletal muscles. In this study, we examined the effects of chronic administration (13 weeks) of ARA (240 mg/kg/day) on fatty acid composition, antioxidative status, and morphology of slow (soleus muscles) and fast (extensor digitorum longus muscles; EDL)-twitch muscles in aged rats (21 months old). The level of reactive oxygen species was higher in the EDL of ARA-administered rats than in that of control rats. ARA administration decreased the muscle cell volumes and increased the number of slow myosin heavy chain (MHC)-positive cells in the EDL. The relative content of MHC2X was increased whereas the relative content of MHC2B was decreased in the EDL of ARA-administered rats. These results suggest that ARA deposition in the fast-twitch muscle of aged rats reduced cell volume with an increase in oxidative stress.
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan; Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan. Electronic address: michio1@med.shimane-u.ac.jp.
authors.forename: Michio
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Katakura
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tanabe
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Al Mamun
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Matsuzaki
authors.affiliation: Department of Developmental Biology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Otani
authors.affiliation: Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Shido
mesh_terms: D000375:Aging / Q000378:metabolism / Q000502:physiology; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D043371:Fatty Acids, Omega-6 / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D043371:Fatty Acids, Omega-6; D016718:Arachidonic Acid; D018995:Myosin Heavy Chains
keywords: Aging; Myosin heavy chain; Oxidative stress; Skeletal muscles; n-6 fatty acid