Fig. 5.

TAS2R activation evokes ASM relaxation under conditions of β₂AR desensitization. Intact mouse trachealis were studied in the absence (Control; A and B) or after 18 h of exposure to the β-agonist Iso (Post-Iso treatment; C and D). Rings were contracted with 0.1 mM acetylcholine (ACh) and relaxed with 10 μM Iso [Iso1 (A), Iso2 (C)]. After each Iso treatment, the ring was washed and then rechallenged with the same dose of ACh, followed by 1 mM Chloro addition [Chloro1 (B), Chloro2 (D)]. ACh was maintained in the bath when Iso and Chloro were added. Results shown are from a single representative experiment of at least 4 performed.