| Project/Area Number |
14571740
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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 |
Morphological basic dentistry
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| Research Institution | Kyushu Dental College |
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Principal Investigator |
TOYOSHIMA Kuniaki Kyushu Dental College, Professor, 歯学部, 教授 (10112559)
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| Co-Investigator(Kenkyū-buntansha) |
SETA Yuji Kyushu Dental College, Associate Professor, 歯学部, 助教授 (90291616)
TOYONO Takashi Kyushu Dental College, Assistant Professor, 歯学部, 助手 (10311929)
KATAOKA Shinji Kyushu Dental College, Assistant Professor, 歯学部, 助手 (80364149)
原田 英光 大阪大学, 歯学部, 助教授 (70271210)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | ATP / ATP receptors / P2X3 / P2Y1 / RT-PCR / immunohistochemistry / in situ hybridization / IP3R3 / 味蕾 / 味覚 / うま味 / P2Xs / P2Ys / mGluR4 / ガストデューシン |
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| Research Abstract |
Extracellular nucleotides such as ATP are the signaling molecules which bind to membrane receptors (P2X ligand-gated ion channels and G-protein coupled P2Y families). In the gustatory system, P2X receptors (P2X_2 and P2X_3) are expressed exclusively in nerve fibers innervating taste buds. Also, P2Y receptors are appeared to play some roles in taste signal transductions in taste bud cells on the basis of the physiological studies. However, the expression patterns of P2Y receptor subtypes have not been revealed. In this study, the expression patterns of P2Y_1 receptor subtypes were examined by using RT PCR, immunohistochemistry and in situ hybridization in rat gustatory papillae. These analyses showed that P2Y_1 receptor was expressed in taste bud cells. Furthermore, we found that P2Y_1-expressed cells coexpressed both IP3R_3 and SNAP-25 by double immunolabeling. These results suggest that ATP may activate P2Y_1 receptors resulting in Ca^<2+> release from internal stores via IP3R3. Since all SNAP-25 immunoreactive taste bud cells coexpressed P2Y_1 immunoreactive, it is suggested that P2Y_1 expressing cells may make synapses with afferent nerve fibers. In addition to P2Y_1 receptors, P2Y_4 receptors were expressed a subset of taste bud cells. We concluded that both P2Y and P2X receptors appear to be important regulators of taste bud functions.
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