| Project/Area Number |
16592074
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Periodontal dentistry
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| Research Institution | Kyushu Dental College |
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Principal Investigator |
KUBOTA Kozo Kyushu Dental College, Dental School, Assistant Prof., 歯学部, 助手 (60161676)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOTA Makoto Kyushu Dental College, Dental School, Professor, 歯学部, 教授 (40107298)
INENAGA Kiyotoshi Kyushu Dental College, Dental School, Professor, 歯学部, 教授 (90131903)
ONO Kentaro Kyushu Dental College, Dental School, Assistant Prof., 歯学部, 助手 (40316154)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Periodontal disease / Smoking / Circumventricular organs / Nicotine / Gingival blood flow / c-fos / Subfornical organ |
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| Research Abstract |
The central effects of nicotine on gingival blood flow (GBF) and vascular conductance (GVC) were investigated. Nicotine is a material absorbed in cigarette smoking and a risk factor for the periodontal disease. Although studies show peripheral effects of nicotine on GBF and GVC, little is known about its central effects. We investigated the change of GBF by intracerebroventricular (i.c.v) injection of (-)-nicotine ditartrate for 5 min, using laser Doppler flowmetry in urethane and a-chloralose anaesthetized rats with or without the measurement of BP from the femoral artery. The i.c.v. injection of nicotine at 15, 50 and 150 μg significantly reduced the GBF, compared with the saline. The maximal reduction was in a dose-dependent manner. Next, the BP was also measured with the GBF in the i.c.v injection of 50 pg nicotine, to evaluate GVC which is calculated from the BP and GBF. While the BP was reduced with the change of GBF immediately after the injection, the GVC was decreased with a certain time-lag. These results suggest that the reduction of GBF by central nicotinic stimulation is accompanied in part with a change of vascular tonus in the gingival site.
Additionally, we have found c-fos expression in brain regions, especially, circumventricular organs and hypothalamic nuclei, by i.c.v. injection of nicotine.
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