Nitric oxide induces neurotransmitter release from hippocampal slices.
Hydroxylamine (1-300 microM), a nitric oxide generator, stimulated the release of [3H]norepinephrine ([3H]NE) and [14C]acetylcholine ([14C]ACh) from rat hippocampal slices in a concentration-dependent manner (EC50 approximately 30 microM). A maximally effective concentration of hydroxylamine (300 microM) produced a 24-fold increase in the basal [3H]NE and 3.6-fold increase in the in the basal [14C]ACh efflux. Sodium nitroprusside (SNP), also stimulated the release of [3H]NE, but only at high concentrations (10-30 mM). Calcium-free experimental buffer (1 mM EGTA) abolished the response. Hemoglobin (0.3 microM) inhibited the effect of 100 microM hydroxylamine in a manner which was specific for nitric oxide. In addition, 100 microM hydroxylamine increased the efflux of endogenous GABA and glutamate by 3- and 6-fold, respectively.
Lonart
G
G
Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555-1031.
Wang
J
J
Johnson
K M
KM
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009599:Nitroprusside; D009569:Nitric Oxide; D000109:Acetylcholine; D009638:Norepinephrine