Cold activation of complement and kinin.

Differences between serum and plasma complement, which now is called as the cold activation of complement, was investigated in relation with the phenomenon reported as the cold promoted activation of factor VII, to which kallikrein and Hageman factor are known to participate. Despite the presence of several similarities in these two phenomena, it is concluded that the cold activation of complement is not related to the coagulation nor the kinin system. Evidence that tranexamic acid, a potent antiplasmin compound, provided an inhibitory effect on the cold activation of complement, suggested that the phenomenon could not be explained by a single mechanism, and plasmin might be involved in the phenomenon in a limited case.