| Project/Area Number |
09480224
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurochemistry/Neuropharmacology
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| Research Institution | Yokohama City University School of Medicine |
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Principal Investigator |
GOSHIMA Yoshio Yokohama City Univ.School of Med., Dept. of Pharmacol. Associate Professor, 医学部, 助教授 (00153750)
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| Co-Investigator(Kenkyū-buntansha) |
KANAI Yoshikatsu Kyorin Medical School, Dept.of Pharmacol. Associate Professor, 医学部, 助教授 (60204533)
KATSURA Isao National Institute of Genetics, DNA Research Center Professor, 構造遺伝学, 教授 (00107690)
FURUKAWA Nobuya Yokohama City Univ.School of Med., Dept. of Pharmacol. Research Associate, 医学部, 助手 (90285114)
MIYAMAE Takeaki Yokohama City Univ.School of Med., Dept. of Pharmacol. Research Associate, 医学部, 助手 (00239435)
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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 |
¥8,200,000 (Direct Cost: ¥8,200,000)
Fiscal Year 1998: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1997: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | L-DOPA / transmitter / receptor / transporter / C.Elegans / mutant / Xenopus laevis oocyte / cloning / 変異株 |
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| Research Abstract |
L-DOPA (DOPA) is proposed to be a neurotransmitter and/or neuromodulator in CNS.However, molecules which are supposed to be involved in DOPAergic transmission, for example, DOPA receptors, DOPA transpoters, remain to be identified. In this study, we have attempted to identify such molecules by genetic approach by use of Caenorhabditis elegans (C.elegans). On agar plates containing DOPA (1-10 mM), the worms showed characteristic behaviors such as foreaging behavior, back and forward movement, accelerated pharyngeal pumping and so on. We treated the worms with ethyl methanesulfonate to isolate mutants which lack such DOPA-induced behavioral responses. By screening F2 progeny, we isolated 9 mutants, and called these mutants dpa 1-9 (dopa response abnormality).
We are now doing STS mapping to determined linkage group. We also found that Xenopus laevis oocytes injected with mRNA extracted from rabbit intestinal epithelium showed 5-fold increase in DOPA-uptake activity compared to non-injected oocytes. The uptake of DOPA were Na+-dependent but not Cl--dependent. The uptake of DOPA was inhibited by tyrosine, phenylalanine, leucine and lysine at 1 mM, whereas was not inhibited by D- DOPA, DA and glutamate. Co-injection of antisense-RNA of rBAT, an activator for uptake system of large neutral amino acid, markedly depressed the DOPA uptake activity, thereby indicating that rBAT is an essential component for Na+-dependent DOPA uptake in the oocyte injected with mRNA from rabbit intestinal epithelium. We are now attempting to do expression cloning for functional DOPA transporter molecules which is probably associated with rBAT.
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