Influence of CD73 inhibition on PMN adhesion to the posthypoxic endothelia in vitro and in vivo. HMEC-1s were subjected to normoxia (pO2 147 mm Hg for 48 h, □) or hypoxia (pO2 20 mm Hg for 48 h, ▪) followed by measurement of FMLP-stimulated PMN adhesion in the presence and absence of the CD73 inhibitor αβmethylene-ADP (APCP, 10 μM). (A) PMN adhesion was quantified by assessment of adherent BCECF-labeled PMNs to normoxic or posthypoxic HMEC-1s. Results are presented as the fold change (± SD) in BCECF fluorescence (*P < .05 compared with normoxia; #P < .025 compared with PBS control). Panel B represents immunofluorescence imaging of BCECF-labeled PMNs adherent to posthypoxic endothelia in the absence (top) and presence of APCP (10 μM; bottom). In panel C, wild-type mice were administered APCP (20 mg/kg ntraperitoneally) or PBS and subjected to either normoxia (room air) or normobaric hypoxia (8% O2 and 92% N2) for 4 hours and indicated organs (colon, Co; lung, Lu; liver, Li; or kidney, Ki) were assessed for PMN accumulation by myeloperoxidase activity (*P < .025 compared with normoxia; #P < .025 compared with wild-type). Data are presented as mean ± SEM.
