Heparin

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** A sulfur-rich glycosaminoglycan with anticoagulant property. Heparin binds to antithrombin III to form a heparin-antithrombin III complex. The complex binds to and irreversibly inactivates thrombin and other activated clotting factors, such as factors IX, X, XI, and XII, thereby preventing the polymerization of fibrinogen to fibrin and the subsequent formation of clots.

**Synonyms:** - HEPARIN - UFH - Unfractionated Heparin - Unfractionated heparin - Unfractionated heparin - heparin