Amphetamine increases the extracellular concentration of glutamate in striatum of the awake rat: involvement of high affinity transporter mechanisms.
Using microdialysis it was found that intracerebral infusions of amphetamine increase the extracellular concentration of glutamate, and also of dopamine, aspartate, GABA, and taurine. The increases in glutamate produced by amphetamine was independent of calcium in the perfusion medium but was significantly attenuated by specific blockers of the high affinity transporters of this neurotransmitter. Amphetamine infusions also produced a decrease in the extracellular concentration of Na+, an increase in the extracellular concentration of lactate, and a decrease in haemoglobin in the area of perfusion. All these data suggest that amphetamine increases the extracellular concentration of glutamate and other neurotransmitters through a hypoxic mediated process. This study also shows that an alpha-noradrenergic receptor antagonist is able to attenuate the effects of amphetamine on the release of glutamate, dopamine, GABA and taurine, which further suggests a vasoconstrictor effect of amphetamine as a result of which hypoxia could develop.
Del Arco
A
A
Department of Physiology, Faculty of Medicine, University Complutense of Madrid, Ciudad Universitaria, Spain.
González-Mora
J L
JL
Armas
V R
VR
Mora
F
F
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D027322:Amino Acid Transport System X-AG; D000596:Amino Acids / Q000378:metabolism; D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002395:Catecholamines / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D015314:Dialysis Solutions / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D018377:Neurotransmitter Agents / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D000596:Amino Acids; D002395:Catecholamines; D015314:Dialysis Solutions; D015259:Dopamine Agents; D018691:Excitatory Amino Acid Antagonists; D006454:Hemoglobins; D018377:Neurotransmitter Agents; D019344:Lactic Acid; D018698:Glutamic Acid; D012964:Sodium; D000661:Amphetamine