Evidence of reactive oxygen species generation in synovial fluid from patients with temporomandibular disease by electron spin resonance spectroscopy.
Reactive oxygen species (ROS) have been implicated in the pathogenesis of temporomandibular disorders. In the present study, we provide the first evidence of ROS generation in the synovial fluid from human temporomandibular disorder patients, as shown by electron spin resonance (ESR) and spin trapping. Three distinct ESR spectra of DMPO spin adducts were observed in the synovial fluid. They corresponded to three free radical species: hydroxyl radical (HO(*)), hydrogen radical (H(*)), and carbon-center radical (R(*)). Among them, the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OH spectrum was the most prominent, suggesting that HO(*) was dominantly generated in the synovial fluid from temporomandibular disorder patients. Desferrioxamine (DFO), an iron chelator, strongly depressed the DMPO-OH signal intensity in the synovial fluid from patients with temporomandibular disorders. We successfully demonstrated ROS-induced oxidative stress in the synovial fluid from temporomandibular disorder patients. ROS generation in the temporomandibular joint could lead to exacerbation of inflammation and activation of cartilage matrix degrading enzymes that proceed to degenerative change of the temporomandibular joint. Thus, iron-dependent generation of HO( *) might have a crucial role in the pathogenesis of temporomandibular disorders.
Lee
Masaichi-Chang-Il
MC
Department of Clinical Care Medicine, Division of Pharmacology and ESR Laboratories, Yokosuka, Japan.
Kawai
Yoshiaki
Y
Shoji
Hirofumi
H
Yoshino
Fumihiko
F
Miyazaki
Hiroyuki
H
Kato
Hiroharu
H
Suga
Masako
M
Kubota
Eiro
E
D000293:Adolescent; D000328:Adult; D003676:Deferoxamine / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D006801:Humans; D017665:Hydroxyl Radical / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013113:Spin Labels; D013482:Superoxide Dismutase / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D013705:Temporomandibular Joint Disorders / Q000209:etiology / Q000378:metabolism*
D017382:Reactive Oxygen Species; D013113:Spin Labels; D017665:Hydroxyl Radical; D013482:Superoxide Dismutase; D003676:Deferoxamine