title: Oxidative stress participates in quadriceps muscle dysfunction during the initiation of osteoarthritis in rats.
abstract: Osteoarthritis is the most common form of arthritis, affecting approximately 15% of the population. Quadriceps muscle weakness is one of the risk factors of osteoarthritis development. Oxidative stress has been reported to play an important role in the pathogenesis of various muscle dysfunction; however, whether it is involved in osteoarthritis-associated quadriceps muscle weakness has never been investigated. The aim of the present study is to examine the involvement of oxidative stress in quadriceps muscle dysfunction in the initiation of osteoarthritis in rats. Rat osteoarthritis was initiated by conducting meniscectomy (MNX). Quadriceps muscle dysfunction was evaluated by assessing muscular interleukin-6, citrate synthase activity, and myosin heavy chain IIa mRNA expression levels. Muscular oxidative stress was assessed by determining lipid peroxidation, Nrf2 expression, reactive oxygen species, and circulating antioxidants. Increased muscular interleukin-6 production as well as decreased citrate synthase activity and myosin heavy chain IIa mRNA expression were observed at 7 and 14 days after MNX. Biomarkers of oxidative stress were significantly increased after MNX. Muscular free radical counts were increased while glutathione and glutathione peroxidase expression were decreased in MNX-treated rats. We conclude that oxidative stress may be involved in the pathogenesis of muscle dysfunction in MNX-induced osteoarthritis.
authors.affiliation: Department of Orthopedics, National Cheng Kung University Hospital Tainan, Taiwan.
authors.forename: Dur-Zong
authors.initials: DZ
authors.lastname: Hsu
authors.affiliation: Department of Orthopedics, National Cheng Kung University Hospital Tainan, Taiwan ; Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University Tainan, Taiwan.
authors.forename: Pei-Yi
authors.initials: PY
authors.lastname: Chu
authors.affiliation: Department of Orthopedics, National Cheng Kung University Hospital Tainan, Taiwan.
authors.forename: Po-Ting
authors.initials: PT
authors.lastname: Wu
authors.affiliation: Department of Orthopedics, National Cheng Kung University Hospital Tainan, Taiwan.
authors.forename: Po-Chuan
authors.initials: PC
authors.lastname: Shen
authors.affiliation: Department of Orthopedics, National Cheng Kung University Hospital Tainan, Taiwan.
authors.forename: I-Ming
authors.initials: IM
authors.lastname: Jou
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000150:complications; D015153:Blotting, Western; D008297:Male; D018908:Muscle Weakness / Q000209:etiology* / Q000503:physiopathology*; D010003:Osteoarthritis / Q000150:complications*; D018384:Oxidative Stress / Q000502:physiology*; D052097:Quadriceps Muscle / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley
keywords: Muscle dysfunciton; osteoarthritis; oxidative stress; rats; sesame oil