As an anticoagulant, heparin sodium is a kind of mucosaccharide, which is
the sodium salt of glucosamine sulfate extracted from the intestinal mucosa of
pigs, cattle and sheep. In human body, it is secreted by mast cells and
naturally exists in the blood. Heparin sodium has the functions of preventing
platelet aggregation and damage, inhibiting the transformation of fibrinogen
into fibrin monomer, inhibiting the formation of thrombin and the formation of
hostile thrombin, and inhibiting the transformation of prothrombin into thrombin
and hostile thrombin.
Heparin sodium can delay or inhibit blood clotting in vitro and in vivo. Its mechanism of action is very messy, affecting many links in the process of blood coagulation.
Heparin sodium can be used in the treatment of acute thromboembolic disease, disseminated intravascular coagulation (DIC). In recent years, heparin has been found to eradicate blood lipids. Intravenous injection or deep intramuscular injection (or subcutaneous injection), 5000 ~ 10000 units each time. The toxicity of heparin sodium is low, and the tendency of spontaneous bleeding is the main risk of heparin overuse. If oral administration is not effective, injection is required. Intramuscular injection or subcutaneous injection is more irritating, occasionally allergic reactions may occur, exceeding the amount or even cardiac arrest; Occasional transient hair loss and diarrhea. In addition, can cause spontaneous fracture. Use for a long time sometimes can form thrombus, could be the result of anticoagulant enzyme - Ⅲ depletion. Heparin sodium is contraindicated in patients with bleeding tendency, severe liver and renal insufficiency, severe hypertension, hemophilia, intracranial hemorrhage, peptic ulcer, pregnant mother and postpartum, visceral tumor, trauma and post-operation.
Heparin sodium is white or white powder, tasteless, hygroscopic, soluble in water, insoluble in ethanol, acetone and other organic solvents. It has strong negative charge in aqueous solution and can form molecular complex with some cations. Aqueous solution is stable at pH 7.
Heparin sodium is arranged with other mucopolysaccharides to form complex with protein, so the preparation process of heparin consists of the extraction of heparin protein complex, dissociation and the separation and purification of heparin.
The heparin molecule contains sulfuric acid group and carboxyl group, which is strongly acidic and polyanion, and can react with cation to form salt. These cations contain metallic cations: Ca2+,Na+,K+, long-chain pyridine compounds of organic bases, such as cetylpyridine chloride (CPC), brucine, basic dye-cyanine A, cationic surfactants (long-chain quaternary ammonium salts) such as cetyltrimethylammonium bromide; Cation exchangers and positively charged proteins such as protamine 0 protein. The n-sulfate group in heparin structure is closely related to anticoagulant effect, and its anticoagulant activity decreases if it is damaged. N-sulfuric acid group is sensitive to acid hydrolysis and is fairly stable under alkaline conditions. The free hydroxyl group in heparin molecule is esterified, such as acidification, the anticoagulant activity also decreases, and acetylation does not affect its anticoagulant activity.