Description of the medicine: Heparin (Heparinum)
Synonyms: Liquaemin, Pularin, Thromboliquine, Vetren, etc.
Heparin is an acid mucopolysaccharide consisting of glucuronic acid and glucosamine residues esterified with sulfuric acid.
The relative molecular weight is about 16,000.
It is produced in the human and animal body by basophilic (mast) cells.
It is found in the largest quantities in the liver and lungs, less in skeletal muscles, spleen, and heart muscle. It is obtained from the lungs of cattle. For medical use, it is available in the form of sodium salt - an amorphous white powder with a yellowish tint, odorless, soluble in water and isotonic sodium chloride solution; pH of 1% aqueous solution 6, 0 - 7, 5.
Heparin activity is determined by the biological method by the ability to lengthen the coagulation time of blood plasma; expressed in units of action (UNITS), 1 mg of the international standard for heparin contains 130 UNITS (1 UNIT = 0.0077 mg). In practice, the drug is available with an activity of at least 120 PIECES in 1 mg.
A heparin solution for injection is available with an activity of 5,000; 10,000 and 20,000 units in 1 ml.
Heparin is a natural anticoagulant factor. Together with fibrinolysin, it is part of the physiological anticoagulant system.
Refers to direct-acting anticoagulants, i.e., directly affecting coagulation factors in the blood (XII, XI, X, IX, VII and II). It also blocks the thrombin biosynthesis; reduces platelet aggregation. The anticoagulant effect of heparin appears in vitro and in vivo.
Heparin has not only an anticoagulating effect, but inhibits the activity of hyaluronidase, activates to some extent the fibrinolytic properties of blood, and improves coronary blood flow.
The introduction of heparin into the body is accompanied by a certain decrease in the content of cholesterol and b-lipoproteins in the blood serum. It has an enlightening effect on lipemic plasma. The hypolipidemic effect of heparin is mainly associated with an increase in the activity of lipoprotein lipase involved in the removal of chylomicrons from the blood [See Hypolipoproteinemic (antisclerotic) agents.].
Due to the risk of bleeding, heparin as a hypocholesterolemic drug, however, is not used.
There is evidence of the presence of immunosuppressive properties in heparin, which gives grounds for its possible use in some autoimmune diseases (glomerulonephritis, hemolytic anemia, etc.), as well as for preventing rejection crises during kidney transplantation in humans. One of the mechanisms of immunosuppressive action is, apparently, the suppression of the cooperative interaction of T and B cells (see Preparations that correct immunity processes). The anticoagulant effect of heparin occurs when it is introduced into a vein, muscle and under the skin.
Heparin acts quickly, but relatively briefly.