ATP stimulates secretion in human neutrophils and HL60 cells via a pertussis toxin-sensitive guanine nucleotide-binding protein coupled to phospholipase C.

Human neutrophils and HL60 cells respond to extracellular ATP by causing exocytotic secretion. Secretion is accompanied by increases in inositol phosphates and a rise in cytosol Ca2+. The responses to ATP are blocked by pertussis toxin pretreatment, indicating the involvement of a guanine nucleotide regulatory protein. Other nucleotides that are active in promoting secretion are ATP gamma S, UTP, ITP and AppNHp, whilst 8-bromo-ATP, AppCH2p, ADP, AMP and adenosine are inactive.