[Trypsin inhibitors in human urine (author's transl)]

By using ammonium sulfate, Arg-Sepharose and gel filtration, an urinary trypsin inhibitor (UTI) with molecular weight of 67,000 (UTI7) was isolated from normal human urine. The yield of UTI7 was about 3,200 U per liter of urine. When urine was acidified, an uropepsin-like substance was activated which caused molecular weight change of UTI7. New UTIs had molecular weight of 45,000 and 22,000 (UTI4-5 and UTI-2-2), respectively. These inhibitors showed a strong effect on trypsin, alpha--chymotrypsin and lesser extent on plasmin and elastase, but had no effect on esterolytic activity on thrombin and the first components of complement Cls an Clr.