title: Fibrinolytic activity of lung and spleen extracts observed in conventional but not in germ-free rats.
abstract: Protease-like activity which split plasminogen-free fibrin was demonstrated in 2 M KSCN extracts of the lung and spleen of conventional rats. The activity was virtually undetectable in tissue extracts from germ-free rats. The extracts from the conventional rat tissues split fibrin and fibrinogen remarkably at neutral pH, but not casein, when examined using fibrin, fibrinogen-agar and casein-agar plates. The fibrinolytic activity was inhibited by STI and DFP, indicating a serine protease nature. The activity was not inhibited by TLCK, t-AMCHA or dansyl-L-arginine-methylpiperidine amide (a selective synthetic thrombin inhibitor, OM189). It was neither activated nor inhibited by cysteine, KCN or iodoacetic acid. The results obtained indicate that the protease-like activity of the lung and spleen extracted with 2 M KSCN from conventional rats has properties which differ from those of trypsin, plasmin, plasminogen-activator, thrombin, and cathepsin A, B and C.
mesh_terms: D000818:Animals; D004588:Electrophoresis, Cellulose Acetate; D005337:Fibrin / Q000378:metabolism; D005340:Fibrinogen; D005342:Fibrinolysis; D005856:Germ-Free Life; D008168:Lung / Q000502:physiology*; D010960:Plasminogen Activators / Q000502:physiology; D051381:Rats; D013154:Spleen / Q000502:physiology*; D014020:Tissue Extracts / Q000494:pharmacology*; D005719:gamma-Globulins
chemical_list: D014020:Tissue Extracts; D005719:gamma-Globulins; D005337:Fibrin; D005340:Fibrinogen; D010960:Plasminogen Activators