Nucleotides and nucleosides within the airway surface liquid regulate mucociliary clearance
(MCC) activities, the primary innate defense mechanism that removes foreign particles and
pathogens from airway surfaces. Nucleotide and nucleoside actions in the airways are
mediated mainly by two purinergic receptor subtypes, the Gq-coupled ATP/UTP-sensing
P2Y2 receptor and the Gs-coupled A2b adenosine receptor. Activation of the A2b receptor
results in cyclic AMP-dependent activation of the cystic fibrosis transmembrane regulator …