Time course of immediate release and relationships between thrombin-like proteinase, other proteinases, histamine, protein and dye extravasation in rat passive peritoneal anaphylaxis.

A thrombin-like proteinase (THROLP) was detected colorimetrically as the main proteolytic activity (PROA) in the lavage fluid some minutes after antigen challenge of rats for passive peritoneal anaphylaxis (PPA) reaction. THROLP is equivalent to histamine (H) as parameter for the early phase of PPA: both increased significantly after 6 min, but decreased to prechallenge levels 20 min after challenge. H was released from serosal mast cells, in contrast THROLP originates predominantly from plasma leakage and activation of the clotting reaction in PPA. These findings underline the importance of PROA in the sequence of allergic reactions.