N6022 attenuated MCh-induced contraction in isolated tracheal rings. Rat tracheal rings were mounted in a small vessel wire myograph and pretreated with PBS vehicle, N6022, or albuterol for 30 min, after which cumulative doses of MCh were added to induce contraction (A). In other tests, tracheal rings were contracted with 1 μM MCh (EC40) followed by cumulative dose additions of N6022 or GSNO to induce relaxation (B). Values are the means ± SEM of 6 to 8 tracheal rings per treatment for (A) and 4 to 16 tracheal rings per treatment for (B). *p < 0.05 N6022 vs. vehicle at MCh doses ≥ 5 μM and *p < 0.05 Albuterol vs. vehicle at MCh doses ≥ 1 μM, Two-way ANOVA, Bonferroni’s for (A). *p < 0.05 N6022 vs. vehicle at N6022 doses of 100 μM and *p < 0.05 GSNO vs. vehicle at GSNO doses≥≥ 3 μM, Two-way ANOVA, Bonferroni’s for (B).