A SENSITIVE, ACCURATE ASSAY FOR EXTRINSIC PATHWAY INHIBITOR (EPI) ACTIVITY IN RABBIT PLASMA - PARADOXICAL EFFECT OF EXCESS EXOGENOUS FACTOR-X

被引：8

作者：

WARR, TA ^{[1
]}

RAO, LVM ^{[1
]}

RAPAPORT, SI ^{[1
]}

机构：

[1] UNIV CALIF SAN DIEGO,DEPT PATHOL,LA JOLLA,CA 92093

来源：

THROMBOSIS RESEARCH | 1990年 / 59卷 / 04期

关键词：

blood coagulation; factor VII; factor X; rabbits; Thromboplastin;

D O I：

10.1016/0049-3848(90)90058-K

中图分类号：

R5 [内科学];

学科分类号：

1002 ; 100201 ;

摘要：

A sensitive assay is described for the measurement of rabbit plasma EPI activity in experimental studies of induced hypercoagulable states in this species. It is based upon the ability of a dilution of rabbit plasma to inhibit human factor VIIa/rabbit brain tissue factor (TF) catalyzed activation of human factor IX (tritiated activation peptide release assay). Addition of 3H-factor IX to the reaction mixture is delayed for 45 minutes to allow full inhibition by EPI/factor Xa complex before the residual catalytic activity of factor VIIa/TF is measured. Although the diluted rabbit plasma test sample contains both EPI and factor X, supplemental factor X is added to the reaction mixture to assure that only EPI content of the test sample affects the assay result. However, the final concentration of factor X in the reaction mixture is critical. Too high a concentration of factor X diminishes the sensitivity of the assay. The reason for this phenomenon, which was observed with both human and rabbit factor X preparations, is unknown. © 1990.

引用

页码：773 / 782

页数：10

共 17 条

[1] DECREASED INDUCIBILITY OF TISSUE FACTOR ACTIVITY ON HUMAN UMBILICAL VEIN ENDOTHELIAL-CELLS CULTURED WITH ENDOTHELIAL-CELL GROWTH-FACTOR AND HEPARIN [J].