Figure 5.

Induction of macrophage inflammatory protein-2 (MIP-2) in peritoneal exudate macrophages (PEMs) incubated with ATP requires functional P2 receptors. (a) The PEMs were stimulated with 300 μm ATP or different concentrations of 2′-O-(4-benzoyl-benzoyl) ATP and 3′-O-(4-benzoyl-benzoyl) ATP (BzATP; a P2X₇R agonist) for 24 hr. (b) B6 and P2X₇R^−/− PEMs were stimulated with 300 μm ATP for 24 hr. (c) PEMs were stimulated with 300 μm ATP, BzATP or UTP for 24 hr. Data represent the mean ± SEM of triplicate samples. The experiments were repeated three times. (d) B6 mice and P2X₇R^−/− mice were injected intraperitoneally with 100 μg ATP. Peritoneal exudate cells were harvested 4 hr later and assayed by flow cytometry. The granulocyte population was gated on Mac-1⁺ Gr-1^high cells. One result from five representative experiments is shown. (e) The absolute numbers of granulocytes were calculated from five repeated experiments. Data represent the mean ± SEM.