title: Alteration of masticatory function by diet change induces stress responses in Wistar rats.
abstract: The occlusion-mastication system has extradigestive functions; however, whether liquid feeding evokes stress responses remains unclear. In this study, reactions to low masticatory performance were analyzed using a diet-alteration model in Wistar rats. Seven days after the diet of the rats was changed from solid to liquid, serum epinephrine and norepinephrine concentrations were found to be elevated by 205% and 158% compared to baseline values, respectively. Superoxide production by peritoneal neutrophils was higher in rats fed with a liquid diet than in those fed with a solid diet. Serum superoxide dismutase activity (i.e. the potential to eradicate serum superoxide) was lower in rats fed with liquid than in those fed with a solid diet, indicating that the former experienced oxidative stress. Conversely, the oxidative stress was removed following reversion of the liquid diet to solid diet. These results suggest that liquid diet mastication can cause mental stress, including an oxidative stress response.
authors.affiliation: Division of Occlusion and Removable Prosthodontics, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Suzuki
authors.forename: Maki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kawanishi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Koshino
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Hirotada
authors.initials: H
authors.lastname: Fujii
authors.forename: Hidekatsu
authors.initials: H
authors.lastname: Takeda
authors.forename: Kageaki
authors.initials: K
authors.lastname: Kuribayashi
authors.forename: Naoki
authors.initials: N
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000097:blood; D004032:Diet; D008297:Male; D008409:Mastication / Q000502:physiology*; D018384:Oxidative Stress; D051381:Rats; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000097:blood / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D002395:Catecholamines; D013481:Superoxides; D013482:Superoxide Dismutase
keywords: Dental occlusion; animal experiment; catecholamines; occlusion–mastication system; oxidative stress; superoxide dismutase