Grant-in-Aid for Scientific Research (C)
|Aichi Gakuin University
YOSHINARI Nobuo Aichi-Gakuin Univ., Dept. of Periodontology, Sch. of Dent., Assistant Professor, 歯学部, 講師 (20231699)
KAWASE Hitoshi Aichi-Gakuin Univ., Dept. of Periodontology, Sch. of Dent., Assistant Professor, 歯学部, 講師 (60329612)
高田 哲夫 愛知学院大学, 歯学部, 助手 (50308780)
|Project Period (FY)
2001 – 2003
Completed (Fiscal Year 2003)
|Budget Amount *help
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
|experimental periodontitis / restraint stress / in situ hybridization / substance P receptor / in situ hybridization
Periodontal disease is an inflammatory disease caused by the infection of periodontitis related microorganisms. The progression is modified by the host immune response.
We have previously reported that the restraint stress induced the remarkable alveolar bone resorption in the furcation area of the maxillary right second molar (M2) of rat. On the other hand, it is reported that there exist positive link between emotional and/or psychological stress and bruxism. And it is also reported bruxism may have effects on the progression of periodontal disease. However, we have not been clarified the effect of occlusion on this bone resorption. Therefore, we confirmed that the alveolar bone resorption was progressed even in the condition without occlusal force in rats. These results suggest that the restraint stress may induce the severe alveolar bone loss together with periodontal inflammation, and such bone loss may not be influenced by occlusal force.
On the other hand, an increase in beaded ne
rve terminals occurred around the vessels in the furcation area when the rats were exposed to a restraint stress.
Substance P (SP) is one of neuropeptides that work as neurotransmitters or neuromodulators. The SP-positive nerve fibers are distributed in the brain, intestine, immune system, bone and gingival tissue, and SP receptors (SPR) are also distributed in many kinds of cells. These distribution suggests that SP may directly modulate immune response and bone netabolism through SPR.
In this study, we investigated the expression of the messenger RNA (mRNA) of SPR in the cells around the alveolar e of the furcation area under restraint-stressful condition in rats by using in situ hybridization method.
The results of this study were as follows: The number of SPR-positive cells around the alveolar bone in the furcation area of M2 in stress rat were significantly increased and TRAP-positive cells around the alveolar bone in the furcation area of M2 had significantly increased.
These results suggests that the restraint stress may release. SP from the endings of the peripheral nerve, induce the expression of SPR mRNA in the cells around the alveolar bone and be related to the enhancement of alveolar bone loss.
We conclude that the restraint stress modulates the progression of periodontal inflammation and SP is one of the key substances for interaciting the association between stress and periodontal disease. Less