Histamine secretion from mast cells stimulated with ATP

Adenosine 5′-triphosphate (ATP) induced a non-cytotoxic, calcium-dependent release of histamine and prostaglandin D₂ from rat serosal mast cells. The effect was tissue and species specific. In particular, tissue mast cells from the guinea pig and were totally unresponsive. The release evoked by the nucleotide was unaffected by antiasthmatic chromones but was inhibited by structurally related flavonoids and by cAMP-active drugs. Secretion was blocked both by the P_2Y-purinoceptor antagonist reactive blue 2 and the P_2x-antagonist suramin, whereas the P₂-agonists 2-methylthio ATP, α, β-and β,α-methylene ATP were inactive. These findings indicate that ATP acts through a novel purinoceptor or binding site which is present on certain types of mast cells.