Fig. 4

a Effect of low concentrations (EC₃₀) of glycopyrronium and indacaterol on the release of acetylcholine from intact and denuded epithelium bronchi and the influence of iberiotoxin (100 nM) and tetanus toxin (10 nM). b Effect of low concentrations (EC₃₀) of glycopyrronium and indacaterol on the release of acetylcholine from primary bronchial epithelial cells submaximally stimulated with carbachol (EC₇₀), and influence of quinine (100 μM). c Effect of low concentrations (EC₃₀) of glycopyrronium and indacaterol on the histamine-induced release of acetylcholine from intact and denuded epithelium bronchi, and the influence of tetanus toxin (10 nM). d Effect of low concentrations (EC₃₀) of glycopyrronium and indacaterol on the cAMP concentrations in intact and denuded epithelium bronchi and influence of iberiotoxin (100 nM). e Effect of low concentrations (EC₃₀) of glycopyrronium and indacaterol on the cAMP concentrations in primary bronchial epithelial cells. Data are expressed as mean ± SEM from experiments performed using samples from n = 3 different subjects. *P < 0.05, **P < 0.01 and ***P < 0.001 vs. control (dotted line) (statistical significance assessed by t test analysis). cAMP: cyclic adenosine monophosphate; EC_n: dose inducing n% maximal effect; EP+: epithelium intact; EP−: epithelium denuded; GLY: glycopyrronium bromide; IbTX: iberiotoxin; IND: indacaterol fumarate; TeTX: tetanus toxin