title: Delta-9-tetrahydrocannabinol on isolated human bronchioles.
abstract: Experiments were conducted to investigate the bronchodilating action of delta-9-tetrahydrocannabinol (THC) using normal human lung tissue obtained post mortem. Isolated rings of human bronchioles contracted to histamine, carbachol, and prostaglandin F(2a)(PGF(2a)) and relaxed to isoproterenol. THC (5 X 10(-4)M) did not alter the responses of the bronchial rings to histamine, whereas methapyrilene (10(-6)M) antagonized these responses. Atropine (2 X 10(-6)M) had a highly significant effect on the responses of the bronchioles to carbachol: there was also a significant effect of THC (5 X 10(-4)M), but to a much lesser extent than atropine. Propranolol (10(-6)M) pretreatment significantly antagonized the relaxant responses of the bronchioles to isoproternol: THC antagonized these responses to a smaller degree. Incubation with THC did not cause relaxation of resting tissues or tissues in which a spasm had been induced. These data suggest that THC does not have significant direct effects in human bronchial smooth muscle and that bronchoactivity observed in vivo is likely to be of a nondirect or central origin.
mesh_terms: D000293:Adolescent; D000368:Aged; D001993:Bronchodilator Agents; D002217:Carbachol / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D013759:Dronabinol / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology
chemical_list: D001993:Bronchodilator Agents; D011460:Prostaglandins F; D013759:Dronabinol; D006632:Histamine; D002217:Carbachol; D011433:Propranolol; D007545:Isoproterenol