Evidence for a role of kallikrein-P6nin system in patients with shock after blunt trauma.

Bradykinin (BK) is activated via plasma and/or tissue kallikrein-kinin (K-K) system pathways during hypotension after blunt trauma. The precise role of the K-K system in human subjects has not been defined. We developed a new method for measuring levels of BK in the blood and examined the role of the K-K system in patients with shock after trauma. Eight patients were entered into this study. We measured the levels of a high-molecular-weight kininogen (HMWK), a low-molecular-weight kininogen (LMWK), BK, and (1-5)-BK in the blood of patients in an unstable state (Pre) and a stable state (Post). At Pre, the blood BK level was significantly elevated, the HMWK and LMWK levels were significantly lower, and the (1-5)-BK level was significantly higher than the respective levels at Post. Our data suggest a significant role for the K-K system in the pathogenesis of shock after blunt trauma. This newly developed method for determination of the activation of the plasma K-K system appears to be useful for determining the severity of a trauma.