1997 Fiscal Year Final Research Report Summary
Changes of NMDA receptor binding nature in rat brain and spinal cord following noxious stimulation
| Project/Area Number |
08671725
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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 |
Anesthesiology/Resuscitation studies
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| Research Institution | Gifu University |
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Principal Investigator |
NIWA Masahiro Gifu University School of Medicine, Department of Pharmacology, Assistant professor, 医学部, 講師 (40156146)
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| Co-Investigator(Kenkyū-buntansha) |
DOHI Shuzi Gifu University School of Medicine, Department of Anesthesiology and Critical Ca, 医学部, 教授 (40155627)
UEMATSU Toshihiko Gifu University School of Medicine, Department of Pharmacology, Professor, 医学部, 教授 (50151832)
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| Project Period (FY) |
1996 – 1997
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| Keywords | NMDA receptor / Receptor binding assay / Nociception / Adjuvant arthritis / Spinal cord / Up regulation |
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| Research Abstract |
NMDA receptors appear to be involved in activation of nociceptive neurons. The hyperexcitability of dorsal horm nociceptive neurons produced by formalin or inflammatory agents is blocked by NMDA antagonists. But it is not clear how nociceptive activation may alter NMDA receptor binding nature. This study investigated changes in NMDA receptor level during nociception.
(1) Rats received a subcutaneous injection of Freund's complete adjuvant into planter aspect of a hindpaw. They displayd hyperalgesia to pressure and edema of the injected paw for 10-14 days. A week after this treatment, rats were decapitated and brain and spinal cord were removed rapidly.
(2) The binding of ^3H-MK801 (NMDA antagonist) to brain and spinal cord membranes prepared from nociceptive treatment and control rats was determioned Scatchard plot of the saturation binding data revealed an increase in Bmax (maximum specific binding) and no change in the Kd values (equilibrium dissociation constants) of this ligandbindings obtained fron spinal cord of inflammed rats as compared to controls. But we failed to see any change in the Bmax or Kd for binding from whole brain, cortex and hippocampus. These results indicate that spinal NMDA receptor are up-regulated in Freund's complete adjuvant injected animalsl.
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