Fig. 4. ATP_e induces the uptake of anionic dyes in macrophages but not in HEK-P2X₇ cells. Fluorescence microscopy of cells incubated for 10 minutes at 37°C in the absence (A,C,E,G) or in the presence (B,D,F,H) of 5 mM ATP. LY (3 mM) or MQAE (5 mM) were used as fluorescent dyes. (A,B) Macrophages in the presence of LY; (C,D) HEK-P2X₇ cells in the presence of LY; (E,F) Macrophages in the presence of MQAE. (G,H) HEK-P2X₇ cells in the presence of MQAE. Each result is representative of at least three independent experiments. Bar, 100 µm.