1999 Fiscal Year Final Research Report Summary
Mechanisms of non-quantal amino acid release by nitric oxide
| Project/Area Number |
10670081
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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 pharmacology
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
YOSHIOKA Koichi Tokyo Medical and Dental University Department of Basic Medical Science Assistant Professor, 医学部, 助教授 (00143579)
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| Project Period (FY) |
1998 – 1999
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| Keywords | neurotransmitters / nitric oxide / amino acids / transporters |
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| Research Abstract |
The mechanisms of actions of substance P and nitric oxide (NO) and associated substances on the release of amino acids from neonatal rat spinal cord preparations were examined and the possibility of involvement of amino acid transporters in the release was explored.
Application of substance P (10 μM) by perfusion to the spinal cord induced a release of glutamate, aspartate, GABA, glycine and taurine. The NO donor, SNAP (300 μM) and SIN-1 (300 μM) also released these amino acids in a similar manner. The amino acid release evoked by substance P did not change in the presence of calcium-free medium. However, perfusion of a low-Na medium significantly reduced the amino acid release. The release of GABA, glycine and taurine was reduced by perfusion of a low-Cl medium. The substance P-evoked release of GABA was also suppressed by an inhibitor of GABA transporter. Similar findings were found in the amino acid release evoked by the NO donors.
These results suggest that substance P as well as NO and its donors evoke a release of amino acids from the neonatal rat spinal cord and reversal operation of transporters of amino acids is involved in the mechanism of release.
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