Effects of Plasma Kallikrein Infusions into Pigs on Haemodynamic and Haemostatic Variables

Abstract The effects of infusions of purified plasma kallikrein were studied in minipigs. The immediate circulatory effects were similar to those described for bradykinin infusions, an elevation of pulmonary artery blood pressure and a transient fall of the systemic blood pressure. However, during a 3 h postinfusion period a progressive decrease of the systemic blood pressure was observed. Haemostatic variables (factor X11, prekallikrein, fibrinogen, platelet count) showed a progressive decrease over the entire observation period. Similar continuous decreases were also seen for the protease inhibitors C 1s -inhibitor, antithrombin, alpha 1 -antitrypsin and alpha 2 -macroglobulin. A continuous fall over the 3 h period was also demonstrated for plasminogen and alpha 2 -antiplasmin indicating an activation of the fibrinolytic system. Immediately after the kallikrein infusion the leucocyte count fell rapidly reaching a minimum of about 30% of the initial value within 2 h. The findings reported could be explained by a kallikrein activation of the intrinsic coagulation system and its direct and/or indirect activation of the fibrinolytic system.