Figure 27: SH-053-2′F-R-CH3 (2) mediated activation of 5 subunit containing channels induces relaxation of precontracted airway smooth muscle. (a) SH-053-2′F-R-CH3 (2) (SH-053) potentiates β-agonist-mediated relaxation of human airway smooth muscle. Cotreatment of human airway smooth muscle strips with SH-053-2′F-R-CH3 (2) (50 μM) significantly enhances isoproterenol (10 nM) mediated relaxation of an acetylcholine EC50 contraction compared to isoproterenol alone (/group, $$ = ). Modified from [6675]. (b) SH-053-2′F-R-CH3 (2) activation of α5 containing receptors induces direct relaxation of substance P-induced airway smooth muscle contraction. Compiled results demonstrating enhanced spontaneous relaxation (expressed as % remaining force at 30 minutes following a 1 μM substance P mediated contraction) following treatment with SH-053-2′F-R-CH3 (2) compared to treatment with vehicle control (-5/group, $$ = ) [6675].