Role of dopamine D-1 and D-2 receptors in the regulation of neurotensin systems of the neostriatum and the nucleus accumbens.
Activation of dopamine D-1 receptors with multiple administrations of SKF 38393 significantly increased the level of neurotensin-like immunoreactivity in the striatum and the nucleus accumbens. However, a similar treatment with the D-2 receptor-selective agonist, LY 171555, decreased the same in both structures; when the two drugs were administered concurrently, their individual effects were blocked. These results suggest that dopamine D-1 and D-2 receptors antagonistically regulate neurotensin systems of the striatum and nucleus accumbens. On the other hand, blockade of D-2 receptors (with sulpiride) elevated, while D-1 receptors blockade (with SCH 23390) caused no change in the level of neurotensin in both these structures. Dopamine D-1 receptors did not appear to contribute to the sulpiride-mediated effect as concurrent administration of SCH 23390 did not alter the response.
Merchant
K M
KM
Department of Pharmacology and Toxicology, University of Utah, Salt Lake City 84112.
Gibb
J W
JW
Hanson
G R
GR
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology*; D004873:Ergolines / Q000494:pharmacology; D008297:Male; D009496:Neurotensin / Q000502:physiology*; D009714:Nucleus Accumbens / Q000378:metabolism*; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology*; D012686:Septal Nuclei / Q000378:metabolism*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D015259:Dopamine Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D019257:Quinpirole; D009496:Neurotensin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D013469:Sulpiride