Effects of dopamine antagonists in a two-way active avoidance procedure in rats: interactions with 8-OH-DPAT, ritanserin, and prazosin.
Using a conditioned avoidance procedure in rats, the present study examined the ability of 8-OH-DPAT, ritanserin, and prazosin to alter the effects of the dopamine antagonists, raclopride and haloperidol, on avoidance- and on escape responding. The 5-HT1A agonist 8-OH-DPAT (0.16 mg/kg) significantly enhanced the inhibitory effects of both raclopride and haloperidol on the conditioned avoidance response and produced a small enhancement of the effects of haloperidol on escape failures. the alpha 1-adrenoceptor antagonist prazosin (0.63 mg/kg) significantly enhanced the effects of raclopride on the conditioned avoidance response, but enhanced the effects of only a single dose of haloperidol; prazosin did not alter the effects of either dopamine antagonist on escape failures. The 5-HT2 antagonist ritanserin (0.16 mg/kg) failed significantly to alter the effects of the dopamine antagonists examined here. These findings suggest that blockade of 5-HT2 receptors may not enhance the antipsychotic efficacy of D2-like antagonists. Further, they confirm previous findings with respect to interactions between 5-HT1A agonists and neuroleptics, and support the hypothesis that combined 5-HT1A agonist/D2-like antagonist properties may be of clinical importance.
Prinssen
E P
EP
Centre de Recherche Pierre Fabre, Castres, France.
Kleven
M S
MS
Koek
W
W
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D011224:Prazosin / Q000494:pharmacology*; D020891:Raclopride; D051381:Rats; D017207:Rats, Sprague-Dawley; D016713:Ritanserin / Q000494:pharmacology*; D012457:Salicylamides / Q000494:pharmacology; D018490:Serotonin Agents / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D018492:Dopamine Antagonists; D012457:Salicylamides; D018490:Serotonin Agents; D016713:Ritanserin; D020891:Raclopride; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D006220:Haloperidol; D011224:Prazosin