[Importance of the thrombocyte count and form for contact activation of the blood kallikrein-kinin system in vitro].

The importance of the platelet count and intactness for contact Hageman's factor-dependent activation of blood plasma kallikrein has been demonstrated. The degree of kallikrein activation was in agreement with the count of platelets contained by the sample. Kallikrein activation was also found to be potentiated by the membrane fraction of washed platelets and of those destroyed by freezing and thawing. The cellular contents did not produce any significant effect on the activation in question.