title: Antihistaminic action of (--)-trans-delta 9-tetrahydrocannabinol.
abstract: THC has an antagonistic effect against histamine on the isolated perfused guinea-pig lung and rabbit kidney. This antagonism seems to be a competitive one at the concentrations used and interacts with histamine at H1-receptors. THC also antagonizes the effect of acetylcholine, PGE2, angiotensis II and histamine in the isolated continuously superfused guinea-pig ileum by a non-competitive manner. The antagonism between THC and histamine on the isolated superfused rabbit aortic strips was found to be highly specific, since 100% relaxation was obtained when the muscle contracted by histamine but not by the equipotent doses of angiotensin II and noradrenaline. THC also causes a significant increase in survival time of guinea-pigs when the animals were exposed to histamine aerosol. These results indicate a specific antagonism of THC against histamine in the preparations used in this investigation.
mesh_terms: D000336:Aerosols; D000818:Animals; D001011:Aorta / Q000187:drug effects; D002188:Cannabis / Q000494:pharmacology*; D013759:Dronabinol / Q000494:pharmacology*; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology / Q000633:toxicity; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects; D008168:Lung / Q000187:drug effects; D010477:Perfusion; D011817:Rabbits
chemical_list: D000336:Aerosols; D006634:Histamine H1 Antagonists; D013759:Dronabinol; D006632:Histamine