Guglielmone H A, Vides M A
Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Thromb Haemost. 1992 Jan 23;67(1):46-9.
A simple and fast method for the quantitative determination of protein C activity in plasma is here described. The first step consists in the conversion of protein C in the test sample into activated protein C by means of an activator isolated from Southern Copperhead venom. Subsequently, the degradation of factor Va, in presence of protein C-deficient plasma, is measured by the prolongation of the prothrombin time which is proportional to the amount of protein C in the sample. The dose-response curve showed a linear relationship from 6 to 150% protein C activity and the inter- and intra-assay reproducibility was 3.5% and 5.6% respectively. In normal subjects, a mean of protein C level of 98 +/- 15% of normal pooled plasma was found. Comparison with the anticoagulant assay in samples of patients with oral anticoagulant, liver cirrhosis, disseminated intravascular coagulation and severe preeclampsia revealed an excellent correlation (r = 0.94, p less than 0.001). Also, a similar correlation (r = 0.93, p less than 0.001) existed between amidolytic assay and the method here proposed for all the samples studied without including the oral anticoagulant group. These results allowed us to infer that this method evaluates the ability of protein C to interact with protein S, phospholipids, calcium ions and factor Va.
本文描述了一种简单快速的定量测定血浆中蛋白C活性的方法。第一步是通过从南铜头蝰蛇毒液中分离出的激活剂将测试样品中的蛋白C转化为活化蛋白C。随后，在缺乏蛋白C的血浆存在下，通过与样品中蛋白C量成比例的凝血酶原时间延长来测量因子Va的降解。剂量反应曲线显示蛋白C活性在6%至150%之间呈线性关系，测定间和测定内的重现性分别为3.5%和5.6%。在正常受试者中，发现蛋白C水平平均为正常混合血浆的98±15%。与口服抗凝剂、肝硬化、弥散性血管内凝血和重度先兆子痫患者样本中的抗凝测定法比较，显示出极好的相关性（r = 0.94，p＜0.001）。此外，对于所有研究样本（不包括口服抗凝剂组），酰胺水解测定法与本文提出的方法之间也存在类似的相关性（r = 0.93，p＜0.001）。这些结果使我们能够推断，该方法评估了蛋白C与蛋白S、磷脂、钙离子和因子Va相互作用的能力。
