Biting reduces acute stress-induced oxidative stress in the rat hypothalamus.
We investigated the inhibitory effect of para-masticatory activity, namely biting, on restraint stress-induced oxidative stress. A blood brain barrier-permeable nitroxyl spin probe, 3-methoxycarbonyl-2,2,5,5,-tetramethylpyrrolidine-1-oxyl (MC-PROXYL), was administered to rats and L-band electron spin resonance (ESR) and ESR-computerized tomography (ESR-CT) imaging were used to show that the decay rate constant of MC-PROXYL in the hypothalamus of isolated brain after 30 min of restraint stress was more rapid than in unrestrained control rats, suggesting that restraint was associated with oxidative stress. Interestingly, biting during restraint stress caused the decay rate constant of MC-PROXYL in isolated brain to approach that of the control group. These observations suggest that biting suppresses oxidative stress induced by restraint stress, and that the anti-stress effect of masticatory motor activity movements, such as biting, are important for reducing the adverse effects associated with exposure to psychological stressors.
Miyake
Shinjiro
S
Department of Craniofacial Growth and Development Dentistry, Kanagawa Dental College, Yokosuka, Kanagawa, Japan.
Sasaguri
Kenichi
K
Hori
Norio
N
Shoji
Hirofumi
H
Yoshino
Fumihiko
F
Miyazaki
Hiroyuki
H
Anzai
Kazunori
K
Ikota
Nobuo
N
Ozawa
Toshihiko
T
Toyoda
Minoru
M
Sato
Sadao
S
Lee
Masaichi-Chang-il
MC
D000818:Animals; D001733:Bites and Stings / Q000503:physiopathology*; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D004578:Electron Spin Resonance Spectroscopy; D007031:Hypothalamus / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007275:Injections, Intravenous; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D011759:Pyrrolidines / Q000008:administration & dosage / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000517:prevention & control*; D014057:Tomography, X-Ray Computed
D011759:Pyrrolidines