Answer:
Heparin prevents blood from clotting
Step-by-step explanation:
Heparin prevents blood from clotting because the unique pentasaccharide sequence contained within its structure avidly binds to antithrombin III. Antithrombin III is a plasma protein that inhibits blood coagulation upon binding and, therefore, inhibits the enzymatic action of several activated blood coagulation factors, including factors XIa, Xa, IXa and IIa (thrombin).
The physiological function of antithrombin III, in common with other blood clotting cascade inhibitors, is to prevent blood clotting in vivo and, therefore, maintain blood flow within the intact vessels. The effect of heparin binding is to increase the activity of antithrombin III more than 1000 times.
As a consequence, fibrin formation is prevented by the coagulation cascade, a necessary requirement for blood clot formation. This anticoagulant effect of heparin occurs both in vitro and in vivo.
Since the late 1930s, the in vivo effect of heparin administered to artificially reduce blood clotting capacity has been used therapeutically. It is not absorbed from the gastrointestinal tract, so it must be administered by intravenous or subcutaneous injection.
Despite this limitation, heparin remains one of the most prescribed antithrombotic drugs, mainly used for the treatment and prevention of venous thrombosis and pulmonary embolism.
Unfractionated heparin (UFH) presented as sodium salt is the traditional one, once the only available form of heparin. However, in more recent years, more refined low molecular weight heparin (LMWH) preparations with an average molecular weight in the range of 3-5 kDa have replaced UFH (average molecular weight around 15 kDa) as the Drug of choice in many clinical studies. contexts, mainly because these new preparations are associated with fewer adverse side effects [5].
Adding more about recent development is a class of synthetic heparin drugs based on analogs of the crucial sequence of antithrombin III binding pentasaccharide. Fondaparinux (Atrixia) is the best established of these "synthetic heparin" medications.