Involvement of ecto-5′-NT in the inhibition of ADP-induced platelet aggregation by AMP preincubated on HUVECs.

HUVEC-containing wells and blank wells were pretreated with 100 μmol/L APCP, an inhibitor of ecto-5′-NT, then incubated with a phosphate-free buffer containing 1-100 μmol/L AMP at 37°C for 15 minutes. (A) The inhibitory activity of the AMP buffer preincubated on HUVECs for ADP-induced platelet aggregation (●) was completely blocked by the treatment of HUVECs with APCP (▴) to the levels found for the blank wells (○). The results are the mean ± SD of 3 separate experiments. (B) Pi was liberated on HUVECs in a dose-dependent manner relative to the concentration of the AMP added (●). The treatment of the HUVECs with APCP completely inhibited Pi liberation from AMP (▴), comparable to the results from the blank wells (○). The results are the mean ± SD of 3 separate experiments.