Prothrombin


Prothrombin
Prothrombin is a coagulation (clotting) factor. It is needed for the normal clotting of blood. There is a cascade of biochemical events that leads to the formation of the final clot. In this cascade, prothrombin is a precursor to thrombin. Because prothrombin comes before thrombin, it is called prothrombin. The prothrombin time is a clotting test. A test done to test the integrity of part of the clotting scheme. Familiarly called the "pro time," the test is the time needed for clot formation after a substance called thromboplastin (+ calcium) has been added to plasma. Prothrombin is also known as thrombinogen.
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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, p. is converted to thrombin, which in turn converts fibrinogen to fibrin, this process resulting in coagulation of blood; a deficiency of p. leads to impaired blood coagulation. SYN: serozyme, thrombinogen, thrombogen.

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pro·throm·bin (')prō-'thräm-bən n a plasma protein produced in the liver in the presence of vitamin K and converted into thrombin by the action of various activators (as thromboplastin) in the clotting of blood
pro·throm·bic -bik adj

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n.
a substance, present in blood plasma, that is the inactive precursor from which the enzyme thrombin is derived during the process of blood coagulation. See also coagulation factors.

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pro·throm·bin (pro-thromґbin) [pro- + thrombo- + -in chemical suffix] factor II; see under coagulation factors, at factor.

Medical dictionary. 2011.

Look at other dictionaries:

  • prothrombin — prothrombin. См. фактор II свертывания крови. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Prothrombīn — Prothrombīn, s. Fibrin …   Meyers Großes Konversations-Lexikon

  • Prothrombin — ⇒ Thrombin …   Deutsch wörterbuch der biologie

  • prothrombin — [prōthräm′bin] n. [ PRO 1 + THROMBIN] a factor in the blood plasma that combines with calcium to form thrombin during blood clotting: it is a precursor of thrombin and is synthesized by the liver in the presence of vitamin K …   English World dictionary

  • Prothrombin — Thrombin Oberflächenmodell nach PDB  …   Deutsch Wikipedia

  • prothrombin — /proh throm bin/, n. Biochem. a plasma protein involved in blood coagulation that on activation by factors in the plasma is converted to thrombin. Also called thrombogen. [1895 1900; PRO 1 + THROMBIN] * * * Carbohydrate protein compound in plasma …   Universalium

  • Prothrombin — Pro|throm|bin [↑ pro u. ↑ Thrombin] Syn.: Thrombogen, Faktor II: in der Leber gebildetes Glykoprotein vom MG 72 000, das unter Einwirkung verschiedener Blutgerinnungsfaktoren zum Gerinnungsenzym Thrombin abgebaut wird. * * * Prothrombin,   im… …   Universal-Lexikon

  • prothrombin — protrombinas statusas T sritis chemija apibrėžtis Trombino pirmtakas, kraujo plazmos baltymas. atitikmenys: angl. prothrombin rus. протромбин …   Chemijos terminų aiškinamasis žodynas

  • prothrombin — trombinas statusas T sritis ekologija ir aplinkotyra apibrėžtis Hidrolazių klasės fermentas – kraujo krešėjimo reakcijos fermentas, fibrinogeną verčiantis fibrinu. atitikmenys: angl. prothrombin; thrombin; thrombosin vok. Thrombin, n;… …   Ekologijos terminų aiškinamasis žodynas

  • prothrombin — noun Etymology: International Scientific Vocabulary Date: 1898 a plasma protein produced in the liver in the presence of vitamin K and converted into thrombin in the clotting of blood …   New Collegiate Dictionary


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