Heparin activates following factors except ?

Ans. is `b' i.e., Villa Chemical nature and preparation of Heparin Heparin is a sulfated mucopolysaccharide which occurs in the secretory granules of mast cells. It is the strongest organic acid in the body and in the solution it carries an electronegative charge. It is prepared commercially from a variety of animal tissues (generally porcine intestinal mucosa or bovine lung). Mechanism of Action of Heparin Heparin acts by activating antithrombin which is a naturally occuring inhibitor of activated coagulation factors of intrinsic and common pathway.