全血凝固過程中のヒト第Ⅸ因子の動態

Abstract

Changes of FactorⅨ activity (F. Ⅸ : C) and FactorⅨ antigen (F. Ⅸ : Ag) during the whole blood coagulation process were studied in the presence of saline, Platelin, Simplastin or Thrombin. When saline, as a control, was added to whole blood, F. Ⅸ : C was gradually increased with a peak at 40 min after clotting. When various concentrations of Platelin, Simplastin or Thrombin were added to whole blood, F. Ⅸ : C was rapidly and transiently increased with a peak at 1 hr. With every addition of saline, Platelin, Simplastin or Thrombin, the levels of F. Ⅸ : Ag were gradually decreased down to 74～84% 24 hrs after clotting. Therefore, there was discrepancy between the changes of F. Ⅸ : C and F. Ⅸ : Ag. In order to investigate the proteolytic activation of F. Ⅸ during the clotting process, F. Ⅸ was partially purified by BaCl₂ adsorption and elution with sodium citrate, and then analyzed using Western blot technique. When SDS-PAGE was performed in reduced condition, a faint band with M. W. of 50,000 (F. Ⅸ aβ) appeared at 1/2～1 min after clotting. The new band, a small portion of whole F. Ⅸ, did not change for 24 hrs. These results suggest the conclusion that the proteolytic activation of F. Ⅸ during the whole blood coagulation process starts partially at 1 min after clotting and that, with every addition of Platelin, Simplastin or Thrombin, its activation is accelerated and exaggerated, but the quantity of F. Ⅸ aβ is a small portion of whole F. Ⅸ.