Common heparin and low molecular weight heparin are non-oral anticoagulants commonly used in clinic, mainly used for the prevention and treatment of thrombotic or embolic diseases, such as myocardial infarction, cerebral infarction, thrombophlebitis, pulmonary embolism, etc. They are also used in hemodialysis, cardiopulmonary bypass, catheterization, microvascular surgery and other procedures.
Heparin, so named because it was first found in the liver. As a natural anticoagulant, it is found in many organs of mammals, with the highest concentrations of lung and intestinal mucosa.
Heparin, also known as plain heparin, is a refined aminoglycan sulfate extracted from pig intestine mucosa or bovine lungs. Heparin is a mixture with a molecular weight between 3000 and 30000 kiloltons, with an average molecular weight of about 15000 kiloltons.
Low molecular weight heparin
Low molecular weight heparin, including low molecular weight heparin sodium/calcium, enoxaparin, nastrol heparin, dapalin and so on. Is the amino glucan sulfuric acid fragment of ordinary heparin after lysis. The average molecular weight range is 3000-8000 kilolton.
Antithrombin III is the antithrombin in plasma, which can inhibit the activation of factor X, factor ⅱ A (thrombin), factor A and so on. Among them, the clotting factor ⅱ A in plasma is closely related to coagulation, and the clotting factor X A is closely related to thrombosis.
Ordinary heparin and low molecular heparin combined with antithrombin iii, can increase antithrombin iii and blood coagulation factor x a affinity, play to the role of the anticoagulant factor x a, but only the high molecular weight, molecular weight > > 5400 kd) heparin can antithrombin iii, at the same time and blood coagulation factor to a combination of 2, play the role of clotting factor 2 a.
Application of anticoagulant factor ⅱ A: anticoagulant of ordinary heparin > low molecular weight heparin.
The anticoagulant factor X A was more effective in low molecular weight heparin than ordinary heparin. The anti-x ratio of heparin was 1:1, and the anti-X ratio of low molecular weight heparin was (2-4):1. Therefore, low molecular weight heparin has strong antithrombotic effect.