Discriminative stimulus effects of panadiplon (U-78875), a partial agonist at the benzodiazepine site, in pentobarbital-trained rhesus monkeys.
The pentobarbital-like discriminative stimulus effects of the benzodiazepine receptor partial agonist panadiplon were assessed in rhesus monkeys trained to discriminate pentobarbital (10 mg/kg) from saline. In test sessions, pentobarbital and the benzodiazepine full agonist triazolam engendered near 100% drug-appropriate responding in all monkeys, whereas panadiplon engendered near 100% drug-appropriate responding in two of four monkeys. Panadiplon pretreatment resulted in leftward shifts in the pentobarbital dose-response function but predominantly rightward shifts of the triazolam dose-response function. These results are consistent with findings that benzodiazepine partial agonists have pentobarbital-like discriminative stimulus effects in some subjects only, and further suggest that partial agonists enhance the effects of pentobarbital but antagonize the effects of a benzodiazepine full agonist.
Rowlett
J K
JK
Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
Woolverton
W L
WL
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D004192:Discrimination, Psychological / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D018757:GABA Modulators / Q000494:pharmacology*; D008253:Macaca mulatta; D008297:Male; D010069:Oxadiazoles / Q000494:pharmacology*; D010424:Pentobarbital / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects* / Q000502:physiology; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology; D014229:Triazolam / Q000494:pharmacology
D014151:Anti-Anxiety Agents; D018757:GABA Modulators; D010069:Oxadiazoles; D011810:Quinoxalines; D011963:Receptors, GABA-A; D014229:Triazolam; D010424:Pentobarbital; C069443:panadiplon