title: Pharmacologic profile of a new antiallergic compound PRD-92-Ea.
abstract: PRD-92-Ea [5,5-Dimethyl-11-oxo-5H, 11H-(2) benzopyrano (4,3-g) (1) benzopyran-9-carboxylic acid ethanolamine], was an active antiallergic compound in rat and monkey experimental models of immediate hypersensitivity. It inhibited, in a dose-dependent manner, the rat PCA reaction after both intravenous and oral administration. It also inhibited the degranulation of rat peritoneal mast cells after antigenic challenge. PRD-92-Ea was also active in preventing bronchoconstriction in Ascaris-sensitive Rhesus monkeys after intravenous, topical and oral administration. Using chopped monkey tissues, it was found that PRD-92-Ea prevented histamine release from the respiratory mast cells, but not from the cutaneous mast cells. No reason for this dichotomy of effect is known. PRD-92-Ea showed antagonistic activity against the allergic mediators released from mast cells. In order of decreasing potency it was active against SRS-A (monkey lung), PGF2alpha, PGE2, serotonin, bradykinin and histamine. Apart from its antiallergic effects PRD-92-Ea had no other significant pharmacological activity.
mesh_terms: D000818:Animals; D001249:Asthma / Q000517:prevention & control; D001578:Benzopyrans / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D004205:Cromolyn Sodium / Q000494:pharmacology; D004195:Disease Models, Animal; D000882:Haplorhini; D006636:Histamine Release / Q000187:drug effects; D006967:Hypersensitivity / Q000517:prevention & control*; D007545:Isoproterenol / Q000494:pharmacology; D008253:Macaca mulatta; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology; D010047:Ovalbumin / Q000494:pharmacology; D010323:Passive Cutaneous Anaphylaxis; D051381:Rats
chemical_list: D001578:Benzopyrans; D010047:Ovalbumin; D007545:Isoproterenol; D004205:Cromolyn Sodium