A study was carried out on the alternate activation of factor IX （FIX） by bovine FVII and human tissue factor （TF） rather than by activated factor XI （FXI）. The reaction product of bovine FVII and human TF funct...A study was carried out on the alternate activation of factor IX （FIX） by bovine FVII and human tissue factor （TF） rather than by activated factor XI （FXI）. The reaction product of bovine FVII and human TF functioned as a FIX activator in the assay system used. Published studies suggest that in the presence of Caions, the complex of human FVII-TF readily activates both human FIX and human FX,and at low TF concentrations, FIX appears to be the preferred substrate for the reaction product of FVII and TF. This may explain the discrepancy between the mild bleeding of hereditary FXI deficiency and the severe bleeding of hereditery FIX deficieney. The results obtained with bovine FVII and a crude human TF preparation confirm that at low TF concentrations,bovine FIX is the preferred substrate rather than FX. At higher TF concentrations, bovine FX was rapidly activated.展开更多
文摘A study was carried out on the alternate activation of factor IX （FIX） by bovine FVII and human tissue factor （TF） rather than by activated factor XI （FXI）. The reaction product of bovine FVII and human TF functioned as a FIX activator in the assay system used. Published studies suggest that in the presence of Caions, the complex of human FVII-TF readily activates both human FIX and human FX,and at low TF concentrations, FIX appears to be the preferred substrate for the reaction product of FVII and TF. This may explain the discrepancy between the mild bleeding of hereditary FXI deficiency and the severe bleeding of hereditery FIX deficieney. The results obtained with bovine FVII and a crude human TF preparation confirm that at low TF concentrations,bovine FIX is the preferred substrate rather than FX. At higher TF concentrations, bovine FX was rapidly activated.
