Evidence of the involvement of D1 dopamine receptors in PCP-induced stereotypy and ataxia in rabbits.
A behavioural study on the effects of D1 and D2 dopamine receptor antagonists (SCH 23390 and sulpiride respectively) and of an A1 adenosine receptor agonist (N6-L-phenylisopropyladenosine, L-PIA) against phencyclidine (PCP)-induced effects was assessed in adult male rabbits. SCH 23390 (0.003-0.01 mg/kg i.v.) and sulpiride (12.5 mg/kg i.v.) were able to significantly prevent PCP-induced stereotypy. Ataxia was reduced by SCH 23390 (0.003 mg/kg i.v.), while it was potentiated by sulpiride (12.5 mg/kg i.v.). Given alone at 12.5 mg/kg, sulpiride induced some EEG and behavioural effects in rabbits, while SCH 23390 (0.003 and 0.01 mg/kg) did not. L-PIA prevented both PCP-induced stereotypy and ataxia at the dose (0.1 mg/kg i.v.) devoid of behavioural or EEG effects by itself. Our results suggest that D1 dopamine receptors might play a more important role than D2 receptors in the expression of PCP-induced behaviour. They also propose that A1 adenosine receptors might be involved (e.g. via an influence on the dopamine release) in the behavioural effects of PCP.
Laboratorio di Farmacologia, Instituto Superiore di Sanità, Roma, Italy.
P
P
Popoli
M G
MG
Caporali
A
A
Scotti de Carolis
D000818:Animals; D001259:Ataxia / Q000139:chemically induced* / Q000503:physiopathology; D001552:Benzazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D008297:Male; D010622:Phencyclidine / Q000494:pharmacology*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D011817:Rabbits; D011954:Receptors, Dopamine / Q000187:drug effects*; D013239:Stereotyped Behavior / Q000187:drug effects*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D011954:Receptors, Dopamine; D010660:Phenylisopropyladenosine; D013469:Sulpiride; D010622:Phencyclidine