Biphasic effects of D3-receptor agonists, 7-OH-DPAT and PD128907, on the D1-receptor agonist-induced hyperactivity in mice.
Effects of D3-receptor agonists, 7-OH-DPAT and PD128907, on the D1-receptor agonist SKF81297-induced hyperactivity in mice were examined. 7-OH-DPAT and PD128907 significantly suppressed the SKF81297-induced hyperactivity at low doses, but significantly potentiated the hyperactivity at high doses. These D3-agonists alone had no effect on the motor activity. A kappa-receptor agonist that reduces dopamine release had no effect on the SKF81297-induced hyperactivity. These results suggest that lower doses of 7-OH-DPAT and PD128907 may negatively influence the D1-receptor mediated behaviors via post synaptic D3-receptors. On the other hand, higher doses of these compounds may positively influence these behaviors via D2- or D3-receptors.
Mori
T
T
Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., Yokohama, Japan.
Murase
K
K
Tanaka
J
J
Ichimaru
Y
Y
D000704:Analysis of Variance; D000818:Animals; D001552:Benzazepines / Q000008:administration & dosage / Q000494:pharmacology*; D001578:Benzopyrans / Q000008:administration & dosage / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D010078:Oxazines / Q000008:administration & dosage / Q000494:pharmacology*; D017447:Receptors, Dopamine D1 / Q000819:agonists*; D017448:Receptors, Dopamine D2 / Q000819:agonists*; D050637:Receptors, Dopamine D3; D017473:Receptors, Opioid, kappa / Q000819:agonists; D013764:Tetrahydronaphthalenes / Q000008:administration & dosage / Q000494:pharmacology*
D001552:Benzazepines; D001578:Benzopyrans; D018491:Dopamine Agonists; C493594:Drd3 protein, mouse; D010078:Oxazines; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D017473:Receptors, Opioid, kappa; D013764:Tetrahydronaphthalenes; C062458:3,4,4a,10b-tetrahydro-4-propyl-2H,5H-(1)benzopyrano(4,3-b)-1,4-oxazin-9-ol; C067113:SK&F 81297; C031349:7-hydroxy-2-N,N-dipropylaminotetralin