| Project/Area Number |
09670029
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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 |
General anatomy (including Histology/Embryology)
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| Research Institution | Showa University |
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Principal Investigator |
NAKAI Yasumitsu Showa University, School of Medicine, Professor, 医学部, 教授 (60053807)
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| Co-Investigator(Kenkyū-buntansha) |
SHIODA Seiji Showa University, School of Medicine, Associate Professor, 医学部, 助教授 (80102375)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | PACAP / Noradrenalin / Vasopressin / Siganal transduction / Calcium channel / Neuroendocrine cells / バイプレシン / 神経内分泌細胞 / 神経支配 / アミン / レセプター / 免疫組織化学 / in situハイブリダイゼーション / 細胞内伝達機構 |
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| Research Abstract |
Although the pathway arising from PACAP (Pituitary Adenylate Cydase-Activating Polypeptide) INA (Noradrenalin)-containing neurons in the ventrolateral medulla is invoked in the regulation of arginine vasopressin (AVP), the precise mechanism of action and physiological significance of the coexistence of PACAP and NA still need to be investigated. Both PACAP and NA induced large increases in the [Ca^<2+>]i in isolated AVP-containing neurons. When PACAP and NA were added together, they evoked larger increase in [Ca^<2+>]i in AVP neurons. An inhibitor of PKA (protein kinase A) completely inhibited the PACAP-induced increase in [Ca^<2+>]i, and partly the NA-induced increase in AVP-containing neurons. We found that T-type calcium channels might contribute to Ca^<2+> influx during action potentials through cAMP-PKA signaling pathway and L-type currents might contribute to the generation of bursting activity. PACAP and NA, co-released from the same axon terminals, may act synergistically to stimulate calcium signaling in AVP neurons, which is mediated by both cAMP-PKA pathway and L-type Ca^<2+> channel. It is hypothesized that PACAP/NA regulate the functions of AVP-containing neurons which participate in the control of plasma osmolarity and blood pressure.
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