| Project/Area Number |
05557011
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General pharmacology
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| Research Institution | Nagasaki University |
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Principal Investigator |
TANIYAMA Kohtaro Nagasaki University, School of Medicine, Professor, 医学部, 教授 (70030898)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASHITA Kimihiro Nagasaki University, School of Medicine, Instructor, 医学部, 講師 (50192399)
KATAOKA Yasufumi Faculty of Medicine, Kyushu University, Assistant Professor, 医学部, 助教授 (70136513)
NIWA Masami Nagasaki University, School of Medicine, Professor, 医学部, 教授 (20136641)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 1995: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1993: ¥8,700,000 (Direct Cost: ¥8,700,000)
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| Keywords | mRNA-injected reconstituted system / Xenopus oocytes / Expressin of nerve terminal function / GABA release / Dopamine release / Exocytosis / Protein kinase C / Synaptophysin / 神経終末機能の発見 / ドパミン取込み |
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| Research Abstract |
I.Expression of dopaminergic nerve terminals
When the mRNA-injected oocytes and water-injected oocytes were incubated in medium containing DA,the mRNA-injected oocytes, but not water-injected oocytes showed evidence of DA uptake, which was dependent on incubation time and external DA concentrations. Stimulation with high KCl (10 mM-50 mM) produced an increase in DA release from mRNA-injected, but not from water-injected oocytes, over that immediately seen before stimulation and in a concentration dependent manner. Oocytes injected with mRNA expressed the apparatus of native dopaminergic nerve terminals and DA in the mRNA-injected oocytes may be released mainly in a vesicular manner.
II.Expression of GABAergic nerve terminals
The Xenopus laevis oocytes injected with rat brain mRNA preloaded with [^3H] GABA showed spontaneous release of [^3H] GABA,approximately 0.5% of GABA content in the oocytes per 1 min. Stimulation with Ca^<2+> ionophore (A23187) produced increse in the release of [^3H] GABA from the mRNA-injected oocytes. 12-0-tetradecanoy1phorbol 13-acetate (TPA)(10 nM-300 nM), but not 4alpha-phorbol-12,13-didecanoate (300 nM) potentiated the A23187-evoked release of [^3H] GABA from the mRNA-injected oocytes, in a concentration dependent manner, thereby indicating that the functional GABAergic nerve terminals were expressed in the oocytes by injecting mRNA extracted from the rat brain. The A23187-evoked release of [^3H] GABA was reduced by treatment with anti-synaptophysin. Thus, synaptophysin may play a role in the exocytotic release of GABA.
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