[Influence of local administration of apomorphine on citrulline extracellular level in the striatum: participation of the dopamine D1 and D2 receptors].
By means of in vivo microdialysis combined with HPLC analysis, we have shown that local infusions of 1 mM N-nitro-L-arginine (NO-synthase inhibitors) in the rat striatum reduced, and infusions of 100 microM apomorphine (agonists of the dopamine receptors) increased the level of citrulline (a NO co-product) in extracellular space of this structure. The apomorphine-induced increase in citrulline extracellular levels in the striatum was completely prevented by infusions of N-nitro-L-arginine in this structure, and 10 microM raclopride (dopamine D2 receptor blocker), but not by infusions of 50 microM SCH-23390 (dopamine D1 receptor blocker). The data obtained suggest that the increase in citrulline extracellular levels in striatum resulted from local activation of NO-synthase, and this effect is mediated by D2 rather than D1 dopamine receptors.
Savel'ev
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D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001552:Benzazepines / Q000494:pharmacology; D002853:Chromatography, Liquid; D002956:Citrulline / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D065127:Dopamine D2 Receptor Antagonists; D008297:Male; D017551:Microdialysis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D020891:Raclopride / Q000494:pharmacology; D051381:Rats; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000378:metabolism*
D001552:Benzazepines; D065127:Dopamine D2 Receptor Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D019335:Nitroarginine; D002956:Citrulline; D020891:Raclopride; D019001:Nitric Oxide Synthase; D001058:Apomorphine