[Activation of antihemophilic globulin A (factor VIII). 1. Activation by ampholine]

In vitro ampholine leads to an activation of the antihaemophilic globulin A (factor VIII). The effect is bound to the positive charge of the ampholine molecule. Negatively charged molecules of the same structure do not have such an effect. The increase of the activity of factor VIII depends on the ampholine concentration and is possible about twice as much. In great ampholine concentrations the factor VIII is again inhibited. The plasma of patients with haemophilia A and of patients with v. Willebrand's disease does not show any differences in the increase of activity. The activation is no time-depending reaction, but begins at once.