Abstract
Intracerebroventricular (i.c.v.) administration to mice of delta9-tetrahydrocannabinol (delta9-THC), WIN 55,212-2 or the endogenous cannabinoid anandamide induced dose-related antinociception in the 55 degrees C warm-water tail-flick test. Pretreatment (24 h, i.c.v.) with pertussis toxin dose-dependently reduced the antinociceptive effect of delta9-THC (955 nmol), WIN 55,212-2 (30 nmol) and anandamide (135 nmol) (IC50 = 0.13, 5.5, and 0.32 nmol, respectively). In contrast, pretreatment (24 h, i.c.v.) with cholera toxin (0.1-3.0 mg) reduced the antinociception of WIN 55,212-2, had minimal effect on delta9-THC, and dose-dependently increased the antinociception of anandamide (ED50 = 0.50 nmol). These data suggest differences in the receptor-effector coupling of delta9-THC, WIN 55,212-2 and anandamide in supraspinal-induced antinociception in mice.
MeSH terms
-
Analgesics / administration & dosage
-
Analgesics / pharmacology*
-
Animals
-
Arachidonic Acids / administration & dosage
-
Arachidonic Acids / pharmacology*
-
Benzoxazines
-
Cannabinoids / administration & dosage
-
Cannabinoids / pharmacology*
-
Cerebral Ventricles / drug effects
-
Cerebral Ventricles / physiology*
-
Cholera Toxin / administration & dosage
-
Cholera Toxin / pharmacology*
-
Endocannabinoids
-
Injections, Intraventricular
-
Male
-
Mice
-
Mice, Inbred ICR
-
Morpholines / administration & dosage
-
Morpholines / pharmacology*
-
Naphthalenes / administration & dosage
-
Naphthalenes / pharmacology*
-
Pain / physiopathology*
-
Pain / prevention & control
-
Polyunsaturated Alkamides
-
Spinal Cord / drug effects
-
Spinal Cord / physiology*
-
Spinal Cord / physiopathology
Substances
-
Analgesics
-
Arachidonic Acids
-
Benzoxazines
-
Cannabinoids
-
Endocannabinoids
-
Morpholines
-
Naphthalenes
-
Polyunsaturated Alkamides
-
(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone
-
Cholera Toxin
-
anandamide