Alterations of plasmin activity, plasminogen levels and activity of antiplasmins during endotoxin shock in dogs.

Spontaneous plasmin activity and 'fast-reacting' and 'time-dependent' antiplasmin activities were determined during various stages of canine endotoxin shock by means of assays utilizing a chromogenic tripeptide derivative (S-2251, Kabi AB, Peptide Research Division, Mölndal). During shock, gradually decreasing values of both antiplasmins were found, revealing most pronounced falls of 'fast-reactin' antiplasmin. These changes of plasma antiplasmin activities were accompanied by decreasing values of plasminogen and evidence of plasmin activity. Immunochemical determination of plasma levels of alpha2-macroglobulin (alpha2-M) and alpha1-antitrypsin (alpha1-AT) and gel filtration studies, demonstrated marked falls in levels of alpha2-M and alpha2-plasmin inhibitor and small reductions of alpha1-AT in this state.