Facilitation of N-methyl-D-aspartate-evoked acetylcholine release by hydroxyl radical scavengers.
Effects of hydroxyl radical scavengers such as dimethylthiourea (DMTU), uric acid and mannitol on acetylcholine (ACh) release evoked by N-methyl-D-aspartate (NMDA) were examined in cerebral cortical neurones. NMDA increased dose-dependently ACh release. This increase in the release was significantly suppressed by MK-801, N omega-nitro-L-arginine and haemoglobin, indicating that NMDA evokes ACh release via the formation of NO subsequent to NMDA receptor activation. DMTU dose-dependently enhanced the NMDA-induced ACh release. Uric acid (100 microM) and mannitol (1 mM) facilitated significantly the NMDA-induced ACh release, although these scavengers themselves showed no effects on ACh release in the absence of NMDA. These results indicate that the removal of hydroxyl radical facilitates the NO-induced ACh release.
Ohkuma
S
S
Department of Pharmacology, Kyoto Prefectural University of Medicine, Japan.
Katsura
M
M
Chen
D Z
DZ
Narihara
H
H
Kuriyama
K
K
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology*; D008353:Mannitol / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D016202:N-Methylaspartate / Q000494:pharmacology*; D009474:Neurons / Q000378:metabolism; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology; D014527:Uric Acid / Q000494:pharmacology
D016166:Free Radical Scavengers; D014527:Uric Acid; D008353:Mannitol; D016202:N-Methylaspartate; C038983:1,3-dimethylthiourea; D013890:Thiourea; D000109:Acetylcholine