Correlation of reciprocal and autoactivation pathways of contact phase initiation of blood coagulation

The aim of the present work was, first, to clarify the question of which part of factor XIIa is formed in blood plasma by the reciprocal mechanism (reactions 1, 2); second, it was required to determine which of the two agents - factor XIIa inhibitor from corn or kallikrein inhibitor contrical - was more effective for inhibition of factor XII and precallikrein activation at the contact surface. A pool of platelet-poor citrate plasma obtained from donor blood was used in the experiments. In order to reduce contact activation of blood, fluoroplastic dishes and plastic dispensers were used when obtaining, processing, and storing it.