Potentiating effect of adenosine on thrombin-induced vWF release. Confluent HUVECs were incubated for 30 minutes at 37°C with adenosine at the indicated concentrations alone (□) or together with 100 μmol/L IBMX (•), 1 U/mL thrombin (Thr, ▵), or Thr/IBMX (▾). Results are the mean ± SEM of four experiments. *P < .05v corresponding control without adenosine.