Dopaminergic control of kynurenate levels and N-methyl-D-aspartate toxicity in the developing rat striatum.
This study was designed to examine the effects of d-amphetamine (D-AMPH) and D1- and D2-selective dopaminergic drugs on the concentration of the broad-spectrum excitatory amino acid receptor antagonist kynurenic acid (KYNA) in the striatum of developing and adult rats. At all ages, KYNA levels were significantly reduced 1 h after the systemic administration of D-AMPH (5 mg/kg). SKF 38393 (5 mg/kg) and quinpirole (2 mg/kg) also caused a rapid decrease in striatal KYNA, but only in postnatal day (PND) 7 and 14 rats. All these effects were readily prevented by specific dopamine receptor antagonists. The possible functional significance of the reduction in KYNA levels was tested in PND 14 animals. When pretreated with D-AMPH (5 mg/kg), these rats showed markedly increased vulnerability to an intrastriatal injection of the excitotoxin NMDA. These data suggest that KYNA plays a role as a mediator of dopamine-glutamate interactions in the rat striatum.
Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA.
B
B
Poeggeler
A
A
Rassoulpour
P
P
Guidetti
H Q
HQ
Wu
R
R
Schwarcz
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D003913:Dextroamphetamine / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D015259:Dopamine Agents / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000506:poisoning*; D006220:Haloperidol / Q000494:pharmacology; D007267:Injections; D007736:Kynurenic Acid / Q000378:metabolism*; D008024:Ligands; D008297:Male; D016202:N-Methylaspartate / Q000506:poisoning*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism
D015259:Dopamine Agents; D018492:Dopamine Antagonists; D018690:Excitatory Amino Acid Agonists; D008024:Ligands; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D016202:N-Methylaspartate; D007736:Kynurenic Acid; D006220:Haloperidol; D003913:Dextroamphetamine; D004298:Dopamine