Mechanism for thromboprotection in BKB2R^-/- mice. This figure shows that in the absence of the BKB2R^-/- receptor, plasma prekallikrein, bradykinin 1-5, and angiotensin II are elevated. Angiotensin II interacts with an overexpressed AT₂R receptor to liberate increased NO and prostacyclin. The increased production of these endothelial-cell products lengthens the animals' bleeding time and lengthens the time to thrombosis on the Rose Bengal model for carotid artery thrombosis. HK indicates high-molecular-weight kininogen; PRCP, prolylcarboxypeptidase; AT₁R, angiotensin AT₁ receptor; AT₂R, angiotensin AT₂ receptor; NO, nitric oxide; PGI₂, prostaglandin I₂ or prostacyclin.