Figure 1.

cAMP responses, over a range of concentrations, to isoprenaline, formoterol, indacaterol, salbutamol, sibenadet, salmeterol, picumeterol and AA1 during a 15 min stimulation in the presence of 0.5 mmol·L⁻¹ IBMX in (A) primary HASMC (n= 6, cells from 3 donors), (B) NHBEC (n= 12 for isoprenaline, formoterol, indacaterol and salmeterol and n= 6 for salbutamol, sibenadet and picumeterol, cells from 2 donors) and (C) NCI-H292 cells (n= 6). Error bars represent SEM. cAMP levels are expressed relative to the maximal response obtained by isoprenaline stimulation. Potencies and intrinsic activities of the agonists are listed in Table 2. HASMC, human airway smooth muscle cells; IBMX, isobutyl methylxanthine; SEM, standard error of the mean.