Modulation of phagocytosis by P2-purinergic receptors in mouse peritoneal macrophages

The effects of adenosine 5'-triphosphate (ATP) and other nucleotides on phagocytosis of peritoneal macrophages were examined by means of flow cytometry (FCM). ATP and uridine 5'-triphosphate (UTP) enhanced phagocytosis in a dose-dependent manner. Control phagocytosis was partially suppressed in Ca(2+)-free solution. Phagocytosis was suppressed by ATP in Ca(2+)-free solution but not by UTP. Agonist potency order revealed that ATP enhanced phagocytosis through P2u receptors in normal external solution (NES) and inhibited it through P2z receptors in Ca(2+)-free solution. The present study showed that ATP modulates the phagocytosis of macrophages, and that two types of receptors were identified by pharmacological experiments.