Comparative effects of a glucocorticosteroid, theophylline and the peptido-leukotriene-antagonist CGP 45715A on antigen-induced early and late phase airway response and inflammatory cell influx in sensitised guinea pigs

A novel model of allergic early and late-phase reaction in the airways of conscious guinea pigs was developed and the effect of established and novel antiasthmatic drugs on peak of immediate response, late phase response and associated inflammatory cell influx investigated. Guinea pigs were sensitised twice in adjuvant (50 mg/kg silica+0.1 ml/kg Bordetella pertussis). Under cover of 10 mg/kg i.p. mepyramine guinea pigs exhibited still a pronounced immediate reaction. During a screening phase about 75% of guinea pigs demonstrated a late phase reaction of decrease of tidal volume between 4–10 h after ovalbumin inhalation. In a cross over study theophylline at 50 mg/kg p.o. (−1 h before ovalbumin) tended to attenuate not only the peak of the immediate reaction by about 69% ( P>0.05, n=12), but inhibited the airway late phase response significantly ( P