title: Time courses of the anti-anaphylactic and anti-inflammatory effects of dexamethasone in the rat and mouse.
abstract: 1 The time course of the activity of dexamethasone has been studied in a variety of anaphylactic and inflammatory reactions in the rat and the mouse. 2 The times of peak activity of dexamethasone, expressed as time between oral dosage and induction of response, and the approximate ED50 values (mg/kg) found were: anaphylactic bronchoconstriction in rats, 12-24 h, ED50 1.8; passive cutaneous anaphylaxis in rats, 6 h, ED50 0.04; cutaneous reactions to histamine in rats, 4 h, ED50 0.01; carrageenin-induced paw oedema in rats, 4 h, ED50 0.03; pinnal anaphylaxis in mice, 6 h, ED50 0.82; histamine-induced pinnal reactions in mice, 6 h, ED50 0.05. 3 In rats, the characteristics of the inhibitory effects of dexamethasone indicate a differential activity against anaphylactic and inflammatory reactions and between different types of inflammatory reactions. Possible reasons for these differences are discussed. 4 In mice there was little difference between the inhibition by dexamethasone of cutaneous allergic and histamine-induced reactions. 5 Pinnal anaphylaxis in mice was potentiated by dexamethasone given 1-2 h before challenge.
mesh_terms: D000707:Anaphylaxis / Q000150:complications / Q000503:physiopathology*; D000818:Animals; D000893:Anti-Inflammatory Agents; D001986:Bronchial Spasm / Q000209:etiology / Q000503:physiopathology; D003907:Dexamethasone / Q000494:pharmacology*; D004487:Edema / Q000503:physiopathology; D008297:Male; D051379:Mice; D010323:Passive Cutaneous Anaphylaxis / Q000187:drug effects; D051381:Rats; D012867:Skin / Q000187:drug effects; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D003907:Dexamethasone