| Abstract: | In Sprague-Dawley rats, by means of in vivo microdialysis combined with HPLC analysis it was shown that the infusion into the n. accumbens of the D2-receptor antagonist raclopride (20, 100 microM) did not affect extracellular level ofcitrulline (an NO co-product) in this brain area. The intraaccumbal infusion of NMDA, an NMDA receptor agonist (100 microM) caused a rise of the extracellular citrulline level in this brain area. This rise was prevented by intraaccumbal infusion of 0.5 mM 7-nitroindazole, a neuronal NO-synthase inhibitor, and it was significantly reduced by the infusion of raclopride (20, 100 microM) into this brain area. The data obtained suggest that the D2-receptors of the n. accumbens are implicated in the regulation of neuronal NO-synthase activity induced by local NMDA receptor stimulation. |
