Figure 6.

Average single concentration‐contraction curves to (A) sarafotoxin S6c or (B) endothelin‐1 in rat isolated trachea with intact epithelium in the absence (Control, 0 μmol L⁻¹) or presence of bosentan 3, 10, or 30 μmol L⁻¹. (C‐D) Corresponding agonist curves in trachea with epithelium denuded. Data are expressed as % KPSS maximum contraction (y axis). Error bars in (A‐D) are ± 1 SEM (those not shown are contained within the symbol). (E‐F) Clark plot displays for the relationship in the rat trachea between the (E) sarafotoxin S6c or (F) endothelin‐1 pEC ₅₀ values (y axis; −log M) and −log(B + K_B) where B is concentration of bosentan (0, 3, 10, or 30 μmol L⁻¹) and K_B is the global‐fitted dissociation constant (see legend for Figure 1C). n, number of tracheal rings isolated from separate animals. Variations in n are due to violation of a predetermined criterion: tracheae that contracted to KPSS with <1 g force