title: Biologically active substances in oak gall extracts. Part 11. The antihistamine-like activity of a substance (KC-18) isolated from oak gall extracts.
abstract: The effects of the newly isolated antihistamine (KC-18) from the Hungarian oak gall extracts on some actions of histamine have been investigated. Intraperitoneally administered KC-18 into guinea pigs and cats in doses of 2.5-16 mg/kg exerted a significant dose-related inhibition of histamine-induced bronchoconstriction, increase in capillary permeability and hypotension. In guinea pigs, actively sensitized with ovalbumin, 4 mg/kg KC-18 administered intraperitoneally prevented the development of anaphylactic shock following antigenic challenge. Histamine-induced gastric acid secretion in the rat was also dose-relatedly reduced by the intravenous administraton of 72 and 120 mg/kg KC-18. However, KC-18 in doses up to 100 mug/ml did not modify the histamine-induced contraction of the isolated guinea pig ileum.
mesh_terms: D000336:Aerosols / Q000494:pharmacology; D000707:Anaphylaxis / Q000517:prevention & control; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002199:Capillary Permeability / Q000187:drug effects; D002415:Cats; D005260:Female; D005750:Gastric Juice / Q000378:metabolism; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology; D010946:Plants, Medicinal; D051381:Rats
chemical_list: D000336:Aerosols; D006634:Histamine H1 Antagonists; D010936:Plant Extracts; D006632:Histamine