title: CB1 receptor antagonist precipitates withdrawal in mice exposed to Delta9-tetrahydrocannabinol.
abstract: Although tolerance to cannabinoids has been well established, the question of cannabinoid dependence had been very controversial until the discovery of a cannabinoid antagonist, SR141716A. The objective of this study was to develop and characterize a mouse model of precipitated withdrawal indicative of cannabinoid dependence. Using a dosing regimen known to produce pharmacological and behavioral tolerance, mice were treated with Delta9-tetrahydrocannabinol (Delta9-THC) twice a day for 1 wk. SR141716A administration after the last Delta9-THC injection promptly precipitated a profound withdrawal syndrome. Typical withdrawal behavior was an increase in paw tremors and head shakes that was accompanied with a decrease in normal behavior such as grooming and scratching. Of the three Delta9-THC regimens tested, daily Delta9-THC injections of 10 and 30 mg/kg produced the greatest number of paw tremors and head shakes and the least number of grooms after challenge with SR141716A. Precipitated withdrawal was apparent after 2, 3, 7 and 14 days of treatment based on an increase in paw tremors in Delta9-THC-treated mice as compared with vehicle-treated mice. These findings are consistent with SR141716A-precipitated withdrawal in rats. Moreover, these results suggest that mice are a viable model for investigating dependence to cannabinoids.
authors.affiliation: Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Cook
authors.forename: J A
authors.initials: JA
authors.lastname: Lowe
authors.forename: B R
authors.initials: BR
authors.lastname: Martin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000932:Antiemetics / Q000009:adverse effects*; D019167:Appetite Stimulants / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D013759:Dronabinol / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D006213:Hallucinogens / Q000494:pharmacology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use*; D011720:Pyrazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000037:antagonists & inhibitors* / Q000187:drug effects; D000077285:Rimonabant; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy*
chemical_list: D000932:Antiemetics; D019167:Appetite Stimulants; D006213:Hallucinogens; D010880:Piperidines; D011720:Pyrazoles; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D013759:Dronabinol; D000077285:Rimonabant