Fig. 9. The P2 antagonist RB2 attenuates epithelial wound closure and HB-EGF shedding. (A,B) Growth factor-starved THCE cells were pretreated with 100 µM RB2 for 1 hour and then wounded with a 0.1-10 µl pipette tip. Cells were allowed to heal in KBM with (RB2) or without (control) RB2 for 24 hours. Cell migration was monitored by photographing the wound immediately (0 h) or 24 hours post wounding (24 h). Micrographs in A represent one of three samples performed each time. Statistical analysis of healing extent is shown in B. Values are the mean ± s.e.m. (n=3), ^**P<0.01. (C) Cells expressing HB-EGF-AP were pretreated with (RB2) or without (NT) 10 µm RB2 and stimulated with 100 µM ATP--S. AP activity was measured and expressed as RLU. ^**P<0.01, significant inhibition in AP release by RB2 in the control or ATP--S-treated cells.