Protein Chemistry: Structure, Properties, and Research Methods - Shendryk, A. N. 2022

Proteins of Blood and Muscle Tissues
Blood Coagulation System
Blood Coagulation System - Anticoagulant System of Blood

The very existence of a powerful Blood clotting system implies the presence of a corresponding anticoagulant system. Indeed, only the interplay of these two coupled, alternative processes—coagulation and anticoagulation—can maintain the blood in a stable, normal fluid state within the body. Numerous studies on the mechanisms governing the anticoagulant system have identified the key plasma, platelet, and tissue factors involved in this process. These include various antithromboplastins, antithrombins, and the fibrinolytic system. It is hypothesized that the body contains specific inhibitors for every individual clotting factor (such as antiaccelerin, anticonvertin, etc.). A decrease in The activity of these inhibitors leads to thrombosis, whereas their elevated activity impairs blood clotting, resulting in hemorrhages.

Antithrombins are the most active Components of the anticoagulant system and function as direct anticoagulants. They always circulate in an active form rather than as precursors. It is estimated that plasma contains approximately six different forms of antithrombin, with heparin being the most thoroughly studied. Heparin inhibits The conversion of prothrombin into Thrombin, effectively preventing Blood Coagulation both in vitro and in vivo.