アブストラクト（46巻1号：神奈川歯学）

神奈川歯学

Japanese

Title　： ストレスによる乳癌発症とチューイングの影響
Subtitle　： 原著
Authors　： 木村幸司
Authors（kana）　：
Organization　： 神奈川歯科大学生体機能学講座生理学分野
Journal　： 神奈川歯学
Volume　： 46
Number　： 1
Page　： 18-26
Year/Month　： 2011 / 6
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「緒言」癌発症は依然として増加の一途を辿っている. その原因の最上流には, 人口の高齢化, 社会構造の多様性に伴い疲労, 緊張, 不満, 不安, 劣等感などの心理的ストレッサーの増強と, 紫外線, 大気汚染, 環境ホルモン, 薬物, 細菌やウィルスの体内侵入などの身体的ストレッサーの増加が存在しているといわれている. ストレッサーの感受性は個々人によって異なるが, 大脳辺縁系の扁桃体がこれらのストレッサーをストレスとして受容すると, 視床下部-交感神経-副腎髄質（sympathetic nervous system; 交感神経系）と視床下部-下垂体-副腎皮質（hypothalamic pituitary adrenal axis; HPA 軸）の2つの経路が同時に開かれる1）. そして, この3経路の活動を通して身体のホメオシタシスが維持されている2, 3）. 適度なストレス負荷は, 神経系, 内分泌系, 免疫系などの生体機能に有益である4, 5)が, 過剰なストレスや小さくてもそれが持続する場合, それらの生体機能が低下し各種疾患が惹起される6～8）.
Practice　： 歯科学
Keywords　： ストレス, チューイング, 乳癌

English

Title　： Stress-enhanced onset of mammary cancer and effect of chewing on this cancer
Subtitle　：
Authors　： Kohji Kimura
Authors（kana）　：
Organization　： Department of Physiology and Neuroscience, Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 46
Number　： 1
Page　： 18-26
Year/Month　： 2011 / 6
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： It is widely known that, with sudden changes of the social and/or environmental setting, various diseases related to stress occur frequently, i.g. immune diseases, internal secretion diseases, and diseases of the autonomic nervous system. Recent studies have suggested that stress stimulates the development of many kinds of cancer, and that chewing is involved in stress relief. If these findings are true, we may deduce that chewing suppresses the onset of cancer in individuals who are vulnerable to effects of stress. In this study conducted with female Sprague-Dawley rats, we have proven this hypothesis by first showing that stress increases the rats of development of mammary cancer induced by 7,12-dimethyl-benz[a]anthracene (DMBA) and second by showing that chewing during stress inhibits the stress-induced increase in the rate of cancer development. DMBA (10 mg) was orally administered to rats at 7 weeks of age. Animals were divided into three groups. In one of the groups, (control group), the rats were not stressed. In the two other groups (stress group and chewing group), the rats were subjected to 14 sessions of immobilization stress spread over 7 weeks (30 min/session, 2 sessions/week). The rats in the chewing group were allowed to chew a wooden stick to actively cope with the stress. The plasma levels of adrenocortitrophic hormone and corticosterone, after the final session of immobilization stress, was more than 100% (p<0.01) higher in the stress group than it was, in either the control group or the chewing group, indicating that stress was in fact produced by immobilization treatment. In all groups, the mammary cancer appeared macroscopically with a different time course. The order of the three groups, according to mean time until cancer onset, from shortest to longest, was stress, chewing, and control. The same ordering of the three groups was seen in the number of carcinogenic tumors. In addition, histological images of the glandular tumors, about 70% of which showed an estrogen-dependent type, showed that the incidence of mammary cancer was about 38. 72. and 38% in the control, stress, and chewing groups, respectively. These results suggest that stress promotes the development of mammary cancer in multistage carcinogenesis and that this process is suppressed by chewing.
Practice　： Dentistry
Keywords　：