Phencyclidine pharmacokinetics and concentration-response relationships in the pigeon

• Published in: Pharmacology, biochemistry and behavior Vol. 35; no. 4; pp. 797 - 801
• Main Authors: Michael Owens, S., McMillan, D.E., Hardwick, William C., Wessinger, William D.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.04.1990; Elsevier Science
• Subjects: Animals; Behavior, Animal - drug effects; Biological and medical sciences; Columbidae - metabolism; Columbidae - physiology; Discrimination (Psychology); Dose-Response Relationship, Drug; Drug addictions; Drug discrimination; Injections, Intramuscular; Intramuscular dosing; Kinetics of response; Male; Medical sciences; Pharmacokinetics; Phencyclidine; Phencyclidine - blood; Phencyclidine - pharmacokinetics; Phencyclidine - pharmacology; Pigeons; Toxicology; Intramuscular dosing; Drug discrimination; Kinetics of response; Phencyclidine; Pharmacokinetics; Pigeons; Vertebrata; Activity concentration relation; Animal; 11β-Hydroxysteroid dehydrogenase; Psychodysleptic; Drug of abuse; Aves; Pigeon; Discrimination task; Intramuscular administration
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(90)90361-K

Phencyclidine (PCP) pharmacokinetics and drug discrimination were examined in pigeons (n=6 in both groups) after intramuscular doses of 1.48 mg/kg. PCP absorption was rapid with maximum measured plasma concentrations ranging from 559 to 1450 ng/ml at 10–30 min after dosing, which corresponded to the time of maximum PCP stimulus effects in the drug discrimination studies. The terminal elimination half-life was 0.88 hr (harmonic mean). Average values for the volume of distribution and total body clearance were 1.6 1/kg and 18.2 ml/min/kg, respectively. In the behavioral studies, pigeons discriminated PCP-like effects from about 2 min to 2 hr after dosing. An average value for response on the PCP-appropriate key and for PCP concentration at each time point from 2 min to 2 hr was calculated from the individual subject data. Least-squares linear regression analysis of these data showed a highly significant relationship between the ability to discriminate PCP and log PCP concentration (y = 103 x − 219, r 2 = .810, p<0.005). This analysis suggests PCP concentration is a good predictor of behavioral efficacy.