Reactive blue 2 selectively inhibits P2y-purinoceptor-stimulated surfactant phospholipid secretion from rat isolated alveolar type II cells.

1. The effect of reactive blue 2 on adenosine 5'-triphosphate (ATP), 12-O-tetradecanoylphorbol 13-acetate (TPA) and terbutaline-induced surfactant phospholipid secretion from rat isolated alveolar Type II cells was studied. 2. Reactive blue 2 significantly inhibited ATP-induced surfactant phospholipid secretion, but was without effect on C-kinase agonist (TPA) or beta-adrenoceptor agonist (terbutaline)-stimulated surfactant phospholipid secretion. The IC50 for inhibition of ATP-induced surfactant secretion was 1.5 x 10(-4)M. 3. These data are consistent with a P2y-purinoceptor regulating surfactant phospholipid secretion from isolated Type II cells and support previous work suggesting reactive blue 2 is a specific inhibitor at P2y-purinoceptors.