Antigen-induced bronchial anaphylaxis in actively sensitized guinea-pigs: anti-anaphylactic effects of sodium cromoglycate and aminophylline.

1 The inhibitory effects of sodium cromoglycate (SCG) and aminophylline on antigen-induced bronchial anaphylaxis in guinea-pigs, actively sensitized according to different regimens, were examined. 2 SCG (1 mg/kg administered intravenously) reduced the anaphylactic response in animals sensitized with 1 microgram ovalbumin (OA) together with A1(OH)3 100 mg, and challenged at 14 and 40 days after sensitization. If higher doses of antigen (10 micrograms OA together with A1(OH)3 or 5 mg OA on day 0 plus 10 mg OA on day 2) were used for sensitization, the protective effect of SCG was found only in animals tested 14 days after sensitization. 3 A low dose of aminophylline (0.3 mg/kg) that was without a direct bronchodilator effect when tested against a histamine (4 micrograms/kg)-induced bronchospasm, produced an anti-anaphylactic effect. The anti-anaphylactic effect of aminophylline varied slightly with the way the animals were immunized and the time at which they were tested. 4 It is concluded that bronchial anaphylaxis in guinea-pigs sensitized with low doses of ovalbumin is a suitable model for the evaluation of anti-anaphylactic properties of drugs.