Figure 1.

MCh-induced isometric force produced by Cav-1 KO and wild-type tracheal rings in the presence of epithelium. Trachea from Cav-1 KO and wild-type mice was isolated and sliced to obtain four equal-sized segments containing three to four cartilage rings. Tissues were equilibrated for 90–120 min with intermittent (∼20 min) instillation of 63 mM KCl-substituted K-H solution to obtain a stable resting tension at ∼0.6 mN. Isometric force was measured with increasing cumulative concentrations of methacholine (10⁻⁹–10⁻³ M). (A) Some tissues were incubated with indomethacin (INDO;) (n= 12 rings from 6 Cav-1 KO and n= 9 rings from 5 wild-type mice) while others received DMSO (vehicle) alone (n= 21 rings from 13 Cav-1 KO and n= 31 rings from 17 wild-type mice). With indomethacin treatment, there were larger responses in Cav-1 KO preparations, compared with indomethacin-free Cav-1 KO tissues, to methacholine between 10⁻⁶ and 10⁻³ M. *P < 0.05; **P < 0.01; ***P < 0.001: one-way ANOVA. (B) Tracheal rings were incubated for 30 min with montelukast (10 µM) alone before performing methacholine concentration-response studies. No significant differences were seen between Cav-1 KO and wild-type groups (n= 8 rings from 4 mice; one-way anova). (C) Tracheal rings were incubated for 30 min with zileuton (10 µM) alone before performing methacholine concentration-response studies. No significant differences were seen between Cav-1 KO and wild-type groups (n= 7 rings from 4 mice; one-way anova). (D). Tracheal rings were incubated for 30 min with indomethacin in the presence or absence of montelukast or zileuton (10 µM) before performing methacholine concentration-response studies. Compared with indomethacin-treated Cav-1 KO rings, montelukast (n= 8 rings from 8 mice, *P < 0.05, one-way ANOVA) and zileuton (n= 4 rings from 4 mice, **P < 0.01, one-way ANOVA) both significantly reversed indomethacin-induced responses in Cav-1 KO mice.