Acute effects of direct dopamine agonists in the mouse behavioral despair test.
All the dopamine agonists (apomorphine, dipropylamino-5,6-dihydroxytetrahydronaphtalene, piribedil, bromocriptine, CBM 36-733) tested in the 'behavioral despair' test performed in mice had a dose-dependent anti-immobility effect, with the exception of the D-1 dopamine agonist, SKF 38393. This effect occurred at doses that reduced locomotor activity and decreased colonic temperature. A profound hypothermia of the same amplitude resulted from the immersion in water of the control and apomorphine (Apo)-treated mice. The anti-immobility effect of dopamine agonists depends on the stimulation of central dopamine receptors; this effect was antagonized more easily by haloperidol than by domperidone, and dipropylamino-5,6-dihydroxytetrahydronaphtalene was more effective than amino-5,6-dihydroxytetrahydronaphtalene. Their high sensitivity to sulpiride make it likely that the receptors involved correspond to the D-4 subtype. Blockade of dopamine receptors by haloperidol for about 5 days induced a slight hypersensitivity to the Apo effects. In contrast, tolerance to Apo occurred after administration of Apo, 5 mg/kg s.c., 24 and 16 h before testing. These data might reflect the potential antidepressant activity of direct dopamine agonists.
Duterte-Boucher
D
D
U.A. 1170 du C.N.R.S., U.F.R. de Médecine et Pharmacie de Rouen, Saint Etienne du Rouvray, France.
Leclère
J F
JF
Panissaud
C
C
Costentin
J
J
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D015259:Dopamine Agents / Q000494:pharmacology*; D006380:Helplessness, Learned; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects
D015259:Dopamine Agents; D001058:Apomorphine