Evidence that the stimulatory effect of neurotensin on dopamine release in rat nucleus accumbens slices is independent of dopamine D2-receptor activation.
Neurotensin (NT, 10(-9) M and 10(-7) M) increased the electrically stimulated release of [3H]dopamine (DA) in rat nucleus accumbens slices. This effect was not altered by activation of DA D2-receptors with high or low concentrations of quinpirole (10(-6) M and 10(-8) M) or blockade of DA D2-receptors with near maximal concentrations of sulpiride (10(-6) M and 10(-5) M). The sulpiride-mediated increase in [3H]DA release and the release induced by NT were additive. These results suggest that NT functions independently of DA D2-receptor activation to modulate DA release in the nucleus accumbens. NT did not modulate the simultaneous release of [14C]acetylcholine.
Reyneke
L
L
Department of Chemical Pathology, University of Stellenbosch, Tygerberg Hospital, South Africa.
Russell
V A
VA
Taljaard
J J
JJ
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology; D004558:Electric Stimulation; D004873:Ergolines / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009496:Neurotensin / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D017448:Receptors, Dopamine D2; D013469:Sulpiride / Q000494:pharmacology
D015259:Dopamine Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D009496:Neurotensin; D013469:Sulpiride; D000109:Acetylcholine; D004298:Dopamine