The mGlu5 receptor agonist CHPG stimulates striatal glutamate release: possible involvement of A2A receptors.
The intrastriatal perfusion of the selective metabotropic glutamate (mGlu)5 receptor agonist (RS)-2-chloro-5-hydroxy-phenylglycine (CHPG, 1000 microM) significantly increased (approximately + 100%, p < 0.05) glutamate extracellular levels with respect to basal values. The potentiating effect of CHPG was prevented by the selective mGlu5 receptor antagonist 2-methyl-6(phenyl-ethynyl)-pyridine (MPEP, 250 microM)) and by the adenosine A2A receptor antagonist SCH 58261 (2 mg/kg, i.p.). The results show that mGlu5 receptors are involved in the regulation of striatal glutamate release and suggest an involvement of adenosine A2A receptors in mGlu5 receptor-mediated effects.
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Pharmacology Department, Istituto Superiore di Sanitá, Roma, Italy.
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D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D018696:Neuroprotective Agents / Q000494:pharmacology; D010648:Phenylacetates / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists* / Q000037:antagonists & inhibitors; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000502:physiology*; D014230:Triazoles / Q000494:pharmacology
C107349:2-chloro-5-hydroxyphenylglycine; C098657:5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo(4,3-e)-1,2,4-triazolo(1,5-c)pyrimidine; D018691:Excitatory Amino Acid Antagonists; D018696:Neuroprotective Agents; D010648:Phenylacetates; D011725:Pyridines; D011743:Pyrimidines; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; D018047:Receptors, Purinergic P1; D014230:Triazoles; D018698:Glutamic Acid; C121465:6-methyl-2-(phenylethynyl)pyridine; D005998:Glycine