Effects of plasma kallikrein and bradykinin infusions into pigs on plasma fibrinolytic variables and urinary excretion of thromboxane and prostacyclin metabolites

Abstract Hemodynamic and hemostatic changes induced by iv infusions of plasma kallikrein and bradykinin were compared in minipigs. Both substances caused immediate and dramatic falls of the systemic blood pressure whereas only kallikrein caused a marked rise of pulmonary artery pressure. Both pressures were almost normalised in about 5 min. Infusions of both substances caused a marked decrease of the leucocyte count, reaching a minimum after 15–60 min. The platelet count was moderately affected by both agents, but plasma fibrinogen decreased progressively during 3 h after kallikrein whereas it was essentially unchanged after bradykinin infusion. A pronounced increase of plasma tissue plasminogen activator was observed with both kallikrein and bradykinin. The effect with bradykinin was immediate, but with kallikrein, a delay of about 1 h was observed. Three hours after the infusion of kallikrein a marked increase of plasminogen activator inhibitor was observed. Both kallikrein and bradykinin infusions caused several-fold increases in urinary excretion of the major metabolites of both thromboxane and prostacyclin.