Effect of concanavalin A on 5'-nucleotidase activity of rabbit blood platelets.

Abstract
Ecto-5''-nucleotidase (ecto-5''-NU) of platelets was enhanced by concanavalin A (Con A). This effect of Con A was antagonized by .alpha.-methyl-D-mannose, a specific antagonist of Con A binding to glycoprotein. Coformycin, an adenosine deaminase inhibitor, did not change the effect of Con A on the ecto-5''-NU. Uptake of adenosine by platelets was not affected by Con A. It was suggested that the ecto-5''-NU of platelet might be a direct and primary site of action of Con A.