Separation of the antihemophilic factor (F. 8) from fibrinogen with thrombin and manganese chloride.

Abstract

Discussion and SummaryThese experiments show that the AHF activity of plasma is enhanced by dialysis, especially against MnCl2, and that thrombic destruction of AHF can be prevented by prior dialysis of plasma against MnCl2. Manganese chloride is clearly the most effective cation tested with respect to protection of AHF against thrombic destruction and 0.02 M is the optimal concentration. Manganese does not protect AHF, however, by destroying thrombin or by altering the thrombin destroying properties of antithrombin. This specific effect of Mn++ in protecting AHF is not surprising because others have observed that Mn++ both activates and stabilizes AHF in plasma (11,12). Our experiments suggest that the protective action of MnCl2 may be related in some manner to changes induced in the AHF molecule. The nature of any such change remains to be clarified.Identification of the AHF activity in the treated plasmas was established by injection into both normal and hemophilia dogs. These experiments showed that t...