Inhibitory effects of noradrenaline and dopamine on calcium influx and neurotransmitter glutamate release in mammalian brain slices.
Noradrenaline and dopamine (0.1-100 microM) inhibited 45Ca2+ uptake and glutamate release induced by veratrine (25 microM) in cortical and striatal slices but were without effect when added alone. Each parameter was inhibited in a dose-dependent manner by noradrenaline in cortical slices (IC50 = 0.05 microM) and by dopamine in striatal slices (IC50 = 0.08 microM). Noradrenaline (0.01-100 microM) was without influence on veratrine-induced 45Ca2+ influx or glutamate release in the striatal preparation, and likewise dopamine was inactive in cortex slices. The use of adrenoceptor antagonists suggests that the action of noradrenaline is mediated by the alpha 2-receptor which is thought to be adenylate cyclase linked. Dopamine appeared to be acting through the D-2 receptor.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005971:Glutamates / Q000378:metabolism*; D066298:In Vitro Techniques; D009419:Nerve Tissue Proteins / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013565:Sympatholytics / Q000494:pharmacology; D014702:Veratrine / Q000494:pharmacology
D002132:Calcium Radioisotopes; D005971:Glutamates; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D013565:Sympatholytics; D014702:Veratrine; D011188:Potassium; D002118:Calcium; D004298:Dopamine; D009638:Norepinephrine