| 释义 |
prothrombinenUK
pro·throm·bin P0615900 (prō-thrŏm′bĭn)n. A plasma protein that is converted into thrombin during blood clotting.prothrombin (prəʊˈθrɒmbɪn) n (Biochemistry) biochem a zymogen found in blood that gives rise to thrombin on activation. See also phylloquinonepro•throm•bin (proʊˈθrɒm bɪn)
n. a plasma protein involved in blood coagulation that is converted to thrombin. [1895–1900] Thesaurus| Noun | 1. | prothrombin - a protein in blood plasma that is the inactive precursor of thrombinfactor IIclotting factor, coagulation factor - any of the factors in the blood whose actions are essential for blood coagulation |
Translations
ProthrombinenUK
prothrombin[prō′thräm·bən] (biochemistry) An inactive plasma protein precursor of thrombin. Also known as factor II; thrombinogen. Prothrombin (also factor II), in man and animals, a protein present in the blood plasma that is the primary component of the blood coagulation system. Chemically, prothrombin is a glycoprotein composed of approximately 12 percent carbohydrates; the protein part of the molecule is in the form of one polypeptide chain. The molecular weight of prothrombin is approximately 70,000. Prothrombin is the precursor of the enzyme thrombin, which stimulates the formation of thrombi. In an organism, prothrombin is activated into thrombin by prothrombinase, which is made up of phospholipid, Ca2+ ions, and coagulation factors V (accelerator globulin) and X (thrombokinase, autoprothrombin C). Factor X is a proteolytic enzyme and the active source of prothrombinase. Upon its conversion to thrombin, the prothrombin molecule loses approximately one-half of its former weight and three-quarters of its carbohydrate content. The biosynthesis of prothrombin occurs in the cells of the liver and is regulated by vitamin K, which is produced by intestinal flora. In instances of vitamin K deficiency, the level of prothrombin in the blood drops below the normal level of 10 mg percent, often resulting in a tendency to bleed, which can manifest itself in early childhood hemorrhaging, obstructive jaundice, and certain diseases of the liver. It is believed that vitamin K deficiency causes the biosynthesis of anomalous molecules of prothrombin and reduces the ability of prothrombin to convert into thrombin. In medical practice, the prothrombin level is measured to determine the characteristics of an individual’s blood coagulation system (prothrombin index). REFERENCEMagnusson, S. “Thrombin and Prothrombin.” In The Enzymes, 3rd ed., vol. 3. New York-London, 1971.I. P. BASKOVA prothrombinenUK
prothrombin [pro-throm´bin] a glycoprotein present in the plasma that is converted into thrombin by extrinsic thromboplastin during the second stage of blood clotting; called also factor II.prothrombin consumption a clinical laboratory test done to determine thromboplastin generating capacity, which provides information about the first stage of blood clotting. When clotting of a normal blood sample occurs, prothrombin is converted to thrombin; thus there should be little or no prothrombin in the serum after the clot is formed. If, however, there is deficiency of blood clotting (coagulation), some of the prothrombin will not be utilized (consumed). Abnormal results of the test are found in deficiencies of the first-stage coagulation factors (factors VIII and IX), and in the presence of circulating anticoagulants, thrombocytopenia, and any other condition leading to inadequate generation of thromboplastin.prothrombin consumption test a test to measure the formation of intrinsic thromboplastin by determining the residual serum prothrombin after blood clotting is complete.prothrombin time a test to measure the activity of coagulation factors I, II, V, VII, and X, which participate in the extrinsic pathway of coagulation; abbreviated Pro time or PT. Called also one-stage prothrombin time and Quick's test. Deficiency of any of these factors leads to a prolongation of the one-stage prothrombin times, as will circulating anticoagulants that are active against factors V and VII or against thromboplastin.
The test is considered basic to any study of the clotting process and is also widely used for guidance in establishing and maintaining anticoagulant therapy. Test results are best understood when both the patient's and the control times are reported. The therapeutic range for coagulation therapy is usually 2 to 3 times that of the normal (12 to 15 sec.) control.pro·throm·bin (prō-throm'bin), A glycoprotein, molecular weight approximately 72,500, formed and stored in the parenchymal cells of the liver and present in blood in a concentration of approximately 20 mg/100 mL. In the presence of thromboplastin and calcium ion, prothrombin is converted to thrombin, which in turn converts fibrinogen to fibrin, this process resulting in coagulation of blood; a deficiency of prothrombin leads to impaired blood coagulation. Synonym(s): serozyme, thrombinogen, thrombogenprothrombin (prō-thrŏm′bĭn)n. A plasma protein that is converted into thrombin during blood clotting.pro·throm·bin (prō-throm'bin) A glycoprotein formed and stored in the parenchymal cells of the liver and present in blood in a concentration of approximately 20 mg/100 mL. In the presence of thromboplastin and calcium ion, prothrombin is converted to thrombin, which in turn converts fibrinogen to fibrin, resulting in coagulation of blood; a deficiency of prothrombin leads to impaired blood coagulation. prothrombin A soluble protein in the blood that is converted to the insoluble form thrombin, under the action of the enzyme prothrombinase, at the end of the cascade of events involved in blood clotting. Thrombin is the main ingredient of the blood clot.prothrombin see BLOOD CLOTTING.ProthrombinProthrombin is a blood-clotting protein. Injury to a blood vessel produces a signal which triggers the conversion of prothrombin to thrombin. Thrombin is a protein which plays a central role in provoking the assembly of other proteins to form the blood clot.Mentioned in: Fibrinogen Test, Prothrombin Time, Vitamin K Deficiencypro·throm·bin (prō-throm'bin) A glycoprotein, formed and stored in the parenchymal cells of the liver and present in blood in a concentration of approximately 20 mg/100 mL; deficiency leads to impaired blood coagulation. prothrombinenUK
Related to prothrombin: prothrombin factor, Prothrombin complex concentrate, Prothrombin ratio, Prothrombin complexSynonyms for prothrombinnoun a protein in blood plasma that is the inactive precursor of thrombinSynonymsRelated Words- clotting factor
- coagulation factor
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