INTERACTIONS INVITRO AND INVIVO BETWEEN RAT SERUM PROTEASE INHIBITORS AND ANODAL AND CATHODAL RAT TRYPSIN AND CHYMOTRYPSIN

Reaction mixtures of increasing amounts of the pancreatic homologous proteases, anodal and cathodal chymotrypsin and trypsin, respectively, and normal rat serum were analyzed by immunoelectrophoretic methods in order to determine their distribution on serum protease inhibitors. This paper concerns three proteins occurring in normal serum and capable of binding protease viz. α1-macroglobulin, α1-antitrypsin and α1-inhibitor 3. The distribution of the enzymes among these protease inhibitors differed significantly from one protease to another. The distribution of the proteases among the serum protease inhibitors following intravenous injection of 125I-labelled proteases corresponded to that in vitro. Complexes formed with α1-macroglobulin and α1-inhibitor 3 were quickly eliminated irrespective of the enzymes species used, whereas those formed with α1-antitrypsin persisted much longer in the circulation. © 1979.