Figure 1.

Method of rat sensitization. Ovalbumin (OA), 1 mg/kg+100 mg Al(OH)₃ as adjuvant in 0.9% sterile saline were intraperitonaly (IP) injected on days 1, 2 and 3. Then rats were exposed to 1% OA aerosol for 20 min on days 6, 9, 12, 15, 18 and 21 with animal normal-breathing. OA aerosol was produced by a DeVilbiss PulmoSonic nebulizer (DeVilbiss Health Care Ltd, Feltham, U.K) with an air flow of 8 lit/min in a 0.8 m³ chamber