P2 PURINOCEPTOR REGULATION OF MUCIN RELEASE BY AIRWAY GOBLET CELLS IN PRIMARY CULTURE

1 The effects of adenine analogues on mucin release by airway goblet cells have been examined in a hamster primary tracheal epithelial cell culture. 2 Adenosine, a P1 receptor agonist, had no effect on mucin release even at 2 mM, while ATP, a P2 receptor agonist, stimulated mucin release in a dose-dependent fashion with an apparent EC50 of 20-mu-M. The relative potency order among adenine nucleotides was ATP > ADP > AMP = adenosine. 3 ATP-gamma-S, a non-hydrolyzable analogue of ATP, was equipotent with ATP in stimulating mucin release. The potency order among some ATP analogues was ATP > 2-methylthio ATP > alpha,beta-methylene ATP > beta,gamma-methylene ATP. Reactive blue 2, a putative P2-gamma-purinoceptor antagonist, did not block the ATP-induced mucin release. 4 The present results indicate that mucin release by airway goblet cells is stimulated by extracellular ATP via P2 receptor-mediated mechanism. We suggest that this mechanism may be important in the physiological regulation of airway goblet cell mucin release in vivo.