A dopamine D3 receptor agonist, 7-OH-DPAT, causes vomiting in the dog.
R(+)7-hydroxy-N,N-di-n-propyl-2-aminotetralin (R(+)-7-OH-DPAT), a selective dopamine D3 receptor agonist, (0.03-0.3 mg/kg, s.c.) dose-relatedly caused emesis, whereas S (-)-7-OH-DPAT at even 1 mg/kg did not induce emesis in dogs. Apomorphine (0.03-0.3 mg/kg, s.c.) or quinpirole (0.03-0.1 mg/kg, s.c.) also caused emesis in a dose-dependent manner. The potency of R(+)-7-OH-DPAT in inducing emesis was the same as that of apomorphine and quinpirole. On the other hand, SKF-38393 (1 and 3 mg/kg, s.c.), a selective D1 receptor agonist, failed to induce emesis in dogs. The emesis induced by R(+)-7-OH-DPAT (0.3 mg/kg, s.c.) was inhibited by S(-)-eticlopride (0.01-0.1 mg/kg, s.c.), a potent D2 and D3 receptor antagonist but not by SCH-23390 (1 mg/kg, s.c.), a selective D1 receptor antagonist or clozapine (1 mg/kg, s.c.), a D4 receptor antagonist. These results indicate that dopamine D3 receptors play an important role in the genesis of emesis in dogs.
D000818:Animals; D004285:Dogs; D018491:Dopamine Agonists / Q000633:toxicity*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D011954:Receptors, Dopamine / Q000187:drug effects*; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013764:Tetrahydronaphthalenes / Q000633:toxicity*; D014839:Vomiting / Q000139:chemically induced*
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013764:Tetrahydronaphthalenes; C031349:7-hydroxy-2-N,N-dipropylaminotetralin