Discriminative stimulus effects of anandamide in rats.
Anandamide (arachidonylethanolamide), a putative endogenous ligand for the cannabinoid receptor, produces a tetrad of behavioral effects in mice characteristic of psychoactive cannabinoids including catalepsy, antinociception, hypothermia, and hypomobility. The present study examined the discriminative stimulus effects of anandamide in rats trained to discriminate delta 9-tetrahydrocannabinol or the potent cannabinoid receptor ligand CP 55,940 [(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)-phenyl]-trans-4-(3- hydroxypropyl)cyclohexanol)] from vehicle. Intraperitoneal injections of anandamide substituted for delta 9-tetrahydrocannabinol and for CP 55,940; however, unlike substitution dose-effect curves with the training drugs, anandamide substitution occurred at a single dose (30 or 45 mg/kg) and was accompanied by severe decreases in response rates. The results of the present study suggest that, although systemic anandamide administration may have cannabimimetic effects similar to those of delta 9-tetrahydrocannabinol and CP 55,940, some differences in the behavioral effects of anandamide and other psychoactive cannabinoids also are apparent.
Wiley
J
J
Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0613, USA.
Balster
R
R
Martin
B
B
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D002186:Cannabinoids / Q000494:pharmacology*; D003511:Cyclohexanols / Q000494:pharmacology; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000494:pharmacology; D063388:Endocannabinoids; D008297:Male; D053284:Polyunsaturated Alkamides; D051381:Rats; D017207:Rats, Sprague-Dawley
D001095:Arachidonic Acids; D002186:Cannabinoids; D003511:Cyclohexanols; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D013759:Dronabinol; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol; C078814:anandamide