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,pM.The relative potency order among adenine nucleotides was ATP > ADP > AMP = adenosine.3 ATP, 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 > a,4-methylene ATP > fy-methylene ATP. Reactive blue 2, a putative P2y-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.

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