ATPase activity and adenosine measurements. (A) Flow cytometric analysis of annexin V staining (percentage of annexin V negative cells) showing cell survival before and after eATP (used at 50 µM) or sodium POM-1 (used at 100 µM) treatment. (B) ATPase activity (µMol/min per µL) after 30 minutes of exposure to eATP or eATP plus CD39 inhibitor POM-1. (C) HPLC tandem-MS adenosine measurement (µMol/L) before and after exposure to eATP or eATP plus POM-1. Data represent 3 to 5 independent experiments. Error bars show SEM, and horizontal bars show means. *P < .05 as determined by Student t test.