Facilitates hematophagy by inhibiting ADP-dependent platelet aggregation in the host. Shows potential for antithrombotic activity. May reduce probing time by facilitating the speed of locating blood. a ribonucleoside 5'-triphosphate + 2 H2O = a ribonucleoside 5'-phosphate + 2 H(+) + 2 phosphate Salivary gland specific. Causes an allergic reaction in human. Binds to IgE. Belongs to the 5'-nucleotidase family.