THE ACTIVATION OF FACTOR X BY EXTRACTS OF RABBIT BRAIN.
THE ACTIVATION OF FACTOR X BY EXTRACTS OF RABBIT BRAIN.
复制标题
兔脑提取物对 X 因子的激活。
作者：
Yale Nemerson;Theodore H. Spaet
当血液在不添加其他试剂的情况下在体外凝结时，会发生一系列复杂的事件，其中涉及许多凝血因子的参与，所有这些因子都源自血液本身。这个过程现在通常被称为“内在凝固”。组织提取物绕过“内在”系统的几个步骤，显着加速凝血。此类提取物统称为“组织凝血活酶”；当它们来自肺、胎盘或大脑时，它们特别活跃。在组织凝血活酶存在的情况下发生的凝血称为“外源性凝血”，只有因子 VII 才参与这些反应。有人提出，内在和外在系统的最终共同途径是X因子（Stuart-Prower因子）的激活。 � 激活的因子 X 随后与磷脂和因子 V 反应，产生能够将凝血酶原转化为凝血酶的试剂。脑凝血活酶的分级是凝血研究的早期步骤。 Howell 于 19122 年制备了一种可溶于氯仿的试剂（脑磷脂），可加速凝血，现在已知可作为替代品
W HEN BLOOD is allowed to clot in vitro without the addition of other reagents, a complex sequence of events occurs which involves the participation of numerous coagulation factors, all of which are derived from the blood itself. This process is now generally known as “intrinsic coagulation.” Extracts of tissues markedly accelerate coagulation by bypassing several steps of the “intrinsic” system. Such extracts have been collectively called “tissue thromboplastin”; they are particularly active when derived from lung, placenta, or brain. The clotting that occurs in the presence of tissue thromboplastin is called “extrinsic coagulation,” and it is only in these reactions that factor VII participates. It has been suggested that the final cornmon pathway of both the intrinsic and extrinsic systems is activation of factor X ( Stuart-Prower factor ) . � Activated factor X subsequently reacts with phosphatides and factor V to produce an agent capable of converting prothrornhin to thrombin. Fractionation of brain thromboplastin was an early step in coagulation research. Howell in 19122 prepared a chloroform-soluble reagent ( cephalin) which accelerated clotting, and is now known to serve as an alternative to