Figure 3.

Muscarine-mediated changes in constrictor force and reactivity in different parts of the trachea and extrapulmonary bronchi from cav-1^+/+ and cav-1^−/− mice. Organ bath recordings, each point represents the mean of number of animals (n) ± SEM. (A,B) Muscarine induces concentration-dependent contraction of ASM in cav-1^+/+ (A) and cav-1^−/− (B) mouse strains. (A',B') Constrictor force in all parts of the airways of cav-1^+/+ (A') and cav-1^−/− (B') mice. Following equilibration, baseline tension was adjusted to 0.5 g for all airway segments in all preparations. Baseline was set as 100% and the maximum response at each concentration was calculated. Sigmoidal concentration-response curves were plotted according to the Hill equation. Maximal responses (E_max, A”,B”) and pEC₅₀ (A”',B”') values for muscarine were estimated for each individual experiment. In cav-1^+/+ the caudal part responded with a stronger contraction, whereas there was no difference in pEC₅₀ values between segments. In cav-1^−/− the caudal part responded with a stronger contraction whereas the pEC₅₀ decreased in the bronchus. ^*p ≤ 0.05; ^**p < 0.01, One-way ANOVA followed by Tukey's multiple comparisons test with the exception of (B”') which was analyzed by Kruskall-Wallis test followed by Dunn's multiple comparisons test.