title: Self-administration of the isomers of pentobarbital and secobarbital by rhesus monkeys.
abstract: Previous studies have shown that the isomers of pentobarbital and secobarbital have behavioral effects that are qualitatively similar to those of the racemic mixture, but that the S-(-) isomers are more potent than the R-(+) isomers. The present study was designed to compare the reinforcing effects of the isomers of these compounds to those of the racemic mixtures in monkeys experienced in the intravenous self-administration of barbiturates. Rhesus monkeys (N = 3) were prepared with indwelling intravenous catheters and allowed to self-administer racemic pentobarbital in 1-hour sessions under a fixed ratio 5 schedule. When responding was stable, various doses of (+,-) pentobarbital, (+,-) secobarbital and single doses of both isomers of these compounds were substituted for the baseline drug in a mixed order. All of the compounds functioned as positive reinforcers in all monkeys. R-(+) isomer were self-administered at higher rates than the racemic mixtures which were self-administered at higher rates than the S-(-) isomers. The results demonstrate that both isomers of these barbiturates can function as positive reinforcers.
authors.affiliation: Department of Psychiatry, Pritzker School of Medicine, University of Chicago, IL 60637.
authors.forename: K E
authors.initials: KE
authors.lastname: Vanover
authors.forename: G R
authors.initials: GR
authors.lastname: Wenger
authors.forename: W L
authors.initials: WL
authors.lastname: Woolverton
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008251:Macaca / Q000502:physiology*; D008253:Macaca mulatta / Q000502:physiology*; D008297:Male; D010424:Pentobarbital / Q000008:administration & dosage*; D012631:Secobarbital / Q000008:administration & dosage*; D012646:Self Administration; D013237:Stereoisomerism
chemical_list: D012631:Secobarbital; D010424:Pentobarbital