Figure 4
Effect of atropine on 5-HT-induced bronchoconstriction (reduction of bronchial luminal area) in PCLS. Atropine blocks 5-HT-induced constriction partially at 10-6 M (A), and nearly completely at 10-4 M, even in absence of both M2 and M3 muscarinic receptors (B). The numbers in parentheses refer to the numbers of bronchi/number of lungs from which they were taken. (C) Persisting bronchoconstriction in response to 5-HT (10-6 M) in the presence of 10-4 M atropine in different wild-type and knockout strains. The initial 5-HT-induced bronchoconstriction was set as 100 %.