Fig. 5

Expected and observed relaxant response induced by low concentrations (EC₃₀) of glycopyrronium, indacaterol and forskolin administered as double (a) or triple (b) combinations in human isolated bronchi submaximally pre-contracted with acetylcholine (EC₇₀), as predicted by the Bliss Independence theory. c Influence of low concentrations (EC₃₀) of glycopyrronium, indacaterol and forskolin administered as double and triple combinations on the delta effect between observed and expected cAMP concentrations in human isolated bronchi submaximally pre-contracted with acetylcholine (EC₇₀), as predicted by the Bliss Independence theory. d Correlation between the cAMP concentrations induced by glycopyrronium, indacaterol and forskolin combinations and relaxant response of human isolated airways submaximally pre-contracted with acetylcholine (EC₇₀). Data are expressed as mean ± SEM from experiments performed using samples from n = 3 different subjects. *P < 0.05 vs. expected additive effect as predicted by Bliss Independence equations (statistical significance assessed by t test analysis). cAMP: cyclic adenosine monophosphate; EC₇₀: dose inducing 70 % maximal effect; E_max: maximal effect; EP+: epithelium intact; EP−: epithelium denuded; FSK: forskolin; GLY: glycopyrronium bromide; IND: indacaterol fumarate