Experimental models in asthma

Histamine is an important mediator released from activated mast cells in ac ute bronchoconstriction provoked by allergen, exercise, hypertonic stimuli and inhaled adenosine. Histamine may also contribute to the allergen-induce d late asthmatic response probably following the recruitment and activation of basophils. H-1-receptor antagonists partially attenuate these responses but greater inhibition when these drugs are combined with cysteinyl LT1-re ceptor antagonists indicative of an interaction between mast cell-derived m ediators. The combination of two or more selective mediator antagonists in the treatment of allergic disorders such as asthma offers a new therapeutic approach worthy of careful appraisal.