Fig. 1.
C48/80 elicits release of mast cell renin, triggering ANG II-induced contraction of rat bronchial rings. (A–G) Representative experimental traces of the C48/80-induced contractile responses in rat bronchial rings. (A, C, and E) Administration of C48/80 (300 μg/ml) elicits release of mast cell renin and induces smooth muscle contraction in bronchial rings (n = 12). The effect of C48/80 is attenuated by the mast cell stabilizer cromolyn (300 μM; n = 6) (B); the renin inhibitor BILA2157 (1 μM; n = 12) (D); and an AT1R antagonist, EXP3174 (100 nM; n = 12) (F). y axis, Contractile responses to C48/80 were expressed as percentage of the response to K+ (80 mM). (G) Bar graph summarizing data from all experiments represented by traces in A–F. Bars indicate means ± SEM. **, Significantly different from own control; P < 0.01 by one-way ANOVA with Dunnett's procedure. W, wash.