Evidence for specific interactions between 5-HT1A and dopamine D2 receptor mechanisms in the mediation of extrapyramidal motor functions in the rat.
Administration of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.1 mg kg-1 SC) completely antagonised the catalepsy produced by the dopamine (DA) D2 receptor antagonist raclopride (16 mg kg-1 SC). This effect by 8-OH-DPAT was in turn completely antagonised by treatment with the new 5-HT1A receptor antagonist (S)-5-fluoro-8-hydroxy-2-(di-n-propylamino)tetralin [(S)-UH-301] (3.5 mg kg-1 SC), but not by the mixed 5-HT1 receptor/beta-adrenoceptor antagonist (-)pindolol (2.0 mg kg-1 SC). The failure by (-)pindolol to antagonise the effects of 8-OH-DPAT on raclopride-induced catalepsy could be due to its beta-receptor-blocking properties, since by themselves both (-)pindolol and the selective beta-adrenoceptor antagonist betaxolol (4 mg kg-1 SC) at least partially antagonised the raclopride-induced catalepsy. The present results provide further support for specific interactions between 5-HT1A and DA D2 receptor mechanisms in the mediation of extrapyramidal motor functions in the rat.
Wadenberg
M L
ML
Department of Psychology, University of Stockholm, Sweden.
Cortizo
L
L
Ahlenius
S
S
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D015784:Betaxolol / Q000494:pharmacology; D002375:Catalepsy / Q000139:chemically induced* / Q000503:physiopathology; D065127:Dopamine D2 Receptor Antagonists; D005116:Extrapyramidal Tracts / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010869:Pindolol / Q000494:pharmacology; D020891:Raclopride; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects*; D012457:Salicylamides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D012702:Serotonin Antagonists
D065127:Dopamine D2 Receptor Antagonists; D017448:Receptors, Dopamine D2; D011985:Receptors, Serotonin; D012457:Salicylamides; D012702:Serotonin Antagonists; C064282:UH 301; D020891:Raclopride; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D010869:Pindolol; D015784:Betaxolol