title: Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.
abstract: Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.
authors.affiliation: 1. Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Fukuoka, 807-8555, Japan.
authors.forename: Kagaku
authors.initials: K
authors.lastname: Azuma
authors.affiliation: 2. Department of Prosthodontics, Asahi University School of Dentistry, Mizuho, 501-0296, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Furuzawa
authors.affiliation: 2. Department of Prosthodontics, Asahi University School of Dentistry, Mizuho, 501-0296, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: 3. Department of Anatomy and Physiology, Faculty of Domestic economy, Nagoya Women's University, Nagoya, 467-8610, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Yamada
authors.affiliation: 4. Seijoh University Graduate School of Health Care Studies, Tokai, 478-8588, Japan.
authors.forename: Kin-ya
authors.initials: KY
authors.lastname: Kubo
mesh_terms: D000818:Animals; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D016723:Bone Remodeling; D003345:Corticosterone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D008409:Mastication / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D013315:Stress, Psychological / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D055114:X-Ray Microtomography
chemical_list: D003345:Corticosterone
keywords: Chewing; Corticosterone; Osteoporosis; Psychologic stress; X-ray microtomography