Involvement of ecto-5′-NT in the inhibition of platelet aggregation induced by ADP 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 1-75 μmol/L ADP at 37°C for 15 minutes. (A) Platelet aggregation induced by ADP buffer preincubated on HUVECs pretreated with APCP (▴) induced platelet aggregation more than that on APCP-untreated HUVECs (●). ○ denotes the data of ADP buffer preincubated on blank wells. The results are the mean ± SD of 3 separate experiments. The asterisk indicates the meanP < .01, and the dagger indicates the meanP < .02. (B) Pi was liberated on HUVECs in a dose-dependent manner relative to the concentration of ADP added (●). Pretreatment of HUVECs with APCP partially inhibited Pi liberation from ADP (▴) (P < .01, at 10-100 μmol/L ADP). ○ indicates data from the blank wells. The results are the mean ± SD of 3 separate experiments.