(redirected from Fibrinolytic agents)
Also found in: Dictionary, Thesaurus, Medical.


Liquefaction of coagulated blood by the action of plasmin on fibrin.



the dissolution of intravascular thrombi and extravascular deposits of fibrin by the enzyme fibrinolysin. Fibrinolysis is important for keeping the blood liquid and the blood vessels and glandular ducts patent. The term was proposed by the French physiologist A. Dastre in 1893.

Uncoagulated blood was first discovered in the blood vessels of persons who died suddenly by the Italian physician G. Morgagni (1769) and the Scotch anatomist J. Hunter (1794). In 1906 the German researcher P. Morawitz showed that such blood lacks fibrinogen and fibrin. He attributed the absence of these proteins in plasma to the action of a specific enzyme. The enzymatic nature of fibrinolysis was demonstrated by the Soviet scientist V. S. Il’in between 1948 and 1955.

The fibrinolysis system consists of four components: profibrinolysin (or plasminogen), fibrinolysin (or plasmin), profibrinolysin activators, and fibrinolysin inhibitors. Profibrinolysin is converted in the body by the action of enzymatic activators (plasma and tissue activators and urokinase) to fibrinolysin, which under normal physiological conditions is bound by inhibitors—antiplasmins. In certain pathological conditions—thromboses—caused by the breakdown of the clotting mechanism, the bond with the antiplasmins is broken, and fibrinolysin hydrolyzes the fibrin of thrombi. Normally, the activity of the fibrinolysis enzymatic system in the body is low. In the presence of stress, during physical exertion, or after the injection of adrenaline, it may increase sharply. The formation of excessive fibrinolysin by the release of large quantities of tissue activator, resulting from changes in the permeability of blood vessels or injury to them, produces extreme activation of fibrinolysis, which causes bleeding, for example, during obstetrical complications, in cirrhosis of the liver, and during transfusions of incompatible blood. Bleeding is arrested by injection of artificial fibrinolysin inhibitors. A decrease in activity of the fibrinolysis system is associated with the development of atherosclerosis and thromboembolic complications. In such conditions, fibrinolysis is used for thrombolytic therapy.


Andreenko, G. V. Fibrinoliz: Khimiia i fiziologiia protsessa. Moscow, 1967.
Andreenko, G. V. “Sovremennye predstavleniia o sistemakh gemostaza i fibrinoliza.” Klinicheskaia meditsina, 1974, vol. 52.
Kudriashov, B. A. Biologicheskie problemy reguliatsii zhidkogo sostoianiia krovi i ee svertyvaniia. Moscow, 1975.
Astedt, B. “On Fibrinolysis.” Acta Obstetricia et Gynecologica Scandinavica, 1972, no. 51, suppl. 18.
Rickli, E. E. “Human Plasminogen: A Summary of Studies on Its Isolation, Characterization and Activation Mechanism.” Immunochemistry, 1975, vol. 12, nos. 6–7.


Mentioned in ?
References in periodicals archive ?
Patient demographic and clinical characteristics included sociodemographic variables (gender, age); medical history (hypertension, diabetes, dyslipidemia); the admission time of day (day, evening, or night); and admission day of week (weekday or weekend), the presence of chest pain, the location of myocardial infarction, the fibrinolytic agent used, the percentages of post-fibrinolytic TIMI-3 flow, and post-fibrinolytic CABG.
1,3,11-13) Because blood clots often obstruct the external ventriculostomies, however, there are significant technical difficulties associated with this procedure, (1,3,11-13) Several investigators have reported the use of various fibrinolytic agents in the management of this problem, with varying results.
The study evaluated the combination of half the standard dose of the clot-dissolving fibrinolytic agent RETAVASE(R) (reteplase) and a standard dose of ReoPro(R) (abciximab), a drug that prevents the formation of blood clots, as a potential new treatment regimen for heart attack.
Early studies in the 1980s showed that performing PCI after treating patients with clot-busting drugs -- also known as thrombolytic or fibrinolytic agents -- offered no benefit and might even be harmful.
Previous studies of full-dose fibrinolytic agents, commonly referred to as clot busters, have reported that less than 50 percent of heart attack patients achieved normal restoration of blood flow within 60 minutes.
Another Biolex protein, BLX-155, belongs to a new class of direct acting fibrinolytic agents and is expected to enter the clinic in 2006.
Fibrinolytic agents are used to treat patients who suffer from heart attacks.