In this article, we will familiarize ourselves with the answer to the question that this is fibrinolysis. Here we will try to study the definition of this term, its meaning in the life of living beings, the phases of the process and some features. Also, the article will pay special attention to the question of its norm in the body, in particular during pregnancy of women.
Introduction
Fibrinolysis is a process during which dissolution of blood clots and / or blood clots occurs. It is an integral part of the device mechanism of homeostasis and is always accompanied by coagulation of fluid - blood. This process includes many cultivating factors that accompany it.
Fibrinolysis is one of the most important protective reactions of the body, preventing the clogging of fibrin vessels, which serve as a highway for the movement of blood. Another important function is recanalization, which can be observed after the bleeding has been stopped. Fibrinolysis includes fibrin cleavage, which is accomplished through the use of plasmin. The plasmin protein is in the blood, but in an inactive form called plasminogen.
External activation
Fibrinolysis phases are divided according to the form of activation, which is divided into external and internal.
An external activation mechanism is possible only if there is a set of tissue activators. As a rule, the latter are synthesized in the vascular endothelium. These types of molecules include the following substances:
- Urokinase is a human serine protease encoded by the PLAU gene (10 chromosome).
- TAP is a tissue plasminogen activator.
Internal activation
The implementation of internal activation occurs through the use of plasma activators and shaped blood elements, such as white blood cells, red blood cells and platelets. The internal system of the activation mechanism is divided into a Hageman-dependent and independent form. The latter type (independent) is carried out only in the presence of proteins C and S, which have a direct effect on it. Dependent fibrinolysis is determined by the influence of the XIIa coagulation factor. The presence of kallikrein, which causes the transformation of plasminogens into plasmin, is also necessary. The main purpose of the Hageman-dependent form is to purify the vascular bed from fibrin in an unstable form.
Inhibition process
Fibrinolysis is a process that, together with a number of certain inhibitory and activating substances, determines the phenomenon of fibrinolytic activity and determines its properties through the relationship between each other.
Blood plasma includes a set of inhibitors that slow down the process of fibrinolysis. One of the most significant inhibitors is alpha2-plasmin, which binds plasmin, trypsin, kallikrein, urokinase, and TAP. Other strong inhibitory substances are: alpha-protease, alpha-2-macroglobulin, C1-protease inhibitor and many others. They can be produced not only by blood plasma, but also fibroblasts, macrophages and monocytes.
Form of regulation
The processes of coagulation and fibrinolysis are in constant balance with each other.
The phenomenon of increased fibrinolysis is caused by changes in the sympathetic nervous system (increased tone) and increased release of hormones such as adrenaline and norepinephrine. These three causes lead to the activation of the Hageman factor. The latter, in turn, launches both internal and external mechanisms. The main efferent regulators of the processes of fibrinolysis and blood coagulation are the vascular walls.
Pregnancy rates
The rate of fibrinolysis during pregnancy is a very important point that a future mother should pay attention to. This will avoid unnecessary complications that may occur in the fetus if its norm is exceeded or lowered.
Fibrinolysis is the dissolution of blood clots and blood clots. It directly affects the formation of the human child in the womb. After conception, the indicator of fibrinogen associated with the phenomenon of fibrinolysis can change its value in the body from extremely small to huge quantities. To clearly determine its level, it is necessary to do a clinical study.
Childbirth is accompanied by large blood loss and in the absence of a sufficient amount of fibrinogen, this can lead to the loss of large blood resources. The process of fibrinolysis is extremely important for placental activity, as is the content of fibrinogen itself. Both factors can cause extremely undesirable complications, such as a delay in fetal development.
Based on data on the level of fibrinogen and the rate of fibrinolysis, doctors can draw conclusions about the presence of pronounced inflammatory processes in the mother, as well as necrotic tissue configuration. Nature solved this problem by increasing the level of fibrinogen during the period of gestation.
Fibrinogen rate
The norm for women before pregnancy is an indicator of two to four grams per liter. After the fruit has been conceived, this figure rises to six grams. This indicator is still considered the norm. A significant excess of fibrinogen is observed in the third trimester.
Despite the fact that an increase in fibrinogen during pregnancy is a normal reaction of the body to the formation of the fetus, its value (fibrinogen) still has its own limit, the presence of which may indicate the formation of pathological processes. In such cases, a patient examination is prescribed using a hemostasiogram.
Fibrinolysis - what does it mean? Answering this question, we also touched on the concept of fibrinogen. So what are the consequences of a decrease in fibrinogen and a change in the process of fibrinolysis?
The above changes in the mother's body can lead to premature detachment of the placental tissues that form its walls, as well as cause hypoxia and malnutrition of the fetus.
A low fibrinogen value can cause these painful conditions:
- hepatitis;
- acute shortage of vitamins B2 and C;
- preeclampsia;
- intravascular disseminated coagulation.
As a rule, the lack of a blood component of fibrinogen is caused by the phenomenon of late toxicosis - gestosis.