A2BAR and vascular permeability during hypoxia in vivo. (A) A2BAR−/− mice or age-, weight-, and sex-matched littermate controls were administered intravenous Evan blue dye (0.2 mL of 0.5% in PBS per mouse) and exposed to room temperature air or normobaric hypoxia (8% O2, 92% N2) for 4 hours. Representative images of abdominal dissections are shown. Images were obtained using a Canon Power Shot G9 digital camera (Canon, Krefeld, Germany). (B) Age-, weight-, and sex-matched wild type mice were administered a selective A2BAR antagonist (PSB1115, 20 mg/kg intraperitoneally) or an equal volume of PBS and lung water content was measured. In other experiments, mice were injected with intravenous Evan blue dye (0.2 mL of 0.5% in PBS per mouse) after PBS1115 or vehicle treatment and exposed to room air or to normobaric hypoxia (8% O2, 92% N2) for 4 hours. Animals were killed and the heart (Ht), colon (Co), kidney (Kd), lung (Lg), spleen (Sp), brain (Br), muscle (Mu) and liver were harvested. Organ Evan blue dye concentrations were quantified as described in “In vivo hypoxia model.” Data are expressed as means plus or minus SD of Evan blue OD/50 mg wet tissue; n = 6 animals/condition (*P < .05, compared with normoxia; **P < .05, compared with normoxic −PSB1115 controls; and #P < .05, compared with normoxia and −PSB115 controls). (C) Age-, weight-, and sex-matched wild type mice were administered a selective A2BAR agonist (BAY 60-6583, 80 μg/kg.) or an equal volume of PBS and lung water content was measured. In other experiments, mice were injected with intravenous Evan blue dye (0.2 mL of 0.5% in PBS per mouse) after BAY 60-6583 or vehicle treatment and exposed to room air or to normobaric hypoxia (8% O2, 92% N2) for 4 hours. Data are expressed as means plus or minus SD of Evans blue OD/50 mg wet tissue; n = 6 animals/condition (*P < .05, compared with normoxia; **P < .05, compared with −BAY 60-6583 normoxic controls and #P < .01, compared with −BAY 60-6583 hypoxic controls).
