PROTECTIVE EFFECTS OF THE GLUCOCORTICOID, BUDESONIDE, ON LUNG ANAPHYLAXIS IN ACTIVELY SENSITIZED GUINEA‐PIGS: INHIBITION OF IgE — BUT NOT OF IgG — MEDIATED ANAPHYLAXIS

Abstract

The effect of glucocorticoid pretreatment on antigen‐induced bronchoconstriction was studied in guinea‐pigs actively sensitized to two different ovalbumin regimens (one producing IgE‐ and IgG‐like antibodies and the other exclusively IgG‐like antibodies). Budesonide (50 mg/kg) and hydrocortisone (50 mg/kg) given as one intraperitoneal injection 15–20 h before the anaphylactic test or as two consecutive intraperitoneal injections 5 and 6 days before, led to a decreased bronchial capacity. In this respect glucocorticoid pretreatment was effective only in guinea‐pigs sensitized to produce both IgE‐like and IgG‐like antibodies. Budesonide pretreatment also reduced the capacity of anaphylactically‐challenged chopped lung tissue to release histamine in guinea‐pigs sensitized to produce both IgE‐ and IgG‐like antibodies. Budesonide pretreatment did not change the levels of circulating IgG1a and IgE‐like homocytotropic antibodies as measured by passive cutaneous anaphylaxis; nor did it affect histamine or methacholine‐induced bronchoconstriction in vivo or the capacity of histamine or methacholine to contract the guinea‐pig isolated trachea preparation or the isoprenaline‐induced relaxation of this preparation. The selective inhibitory effects of budesonide and hydrocortisone on IgE‐mediated but not IgG‐mediated anaphylaxis and the relevance to human atopic disease are discussed. 1982 British Pharmacological Society