Inhibitory effect of human urinary trypsin inhibitor (urinastatin) on lysosomal thiol proteinases.

Effects of human urinary trypsin inhibitor, urinastatin, a compound clinically prescribed for treatment of acute pancreatitis, on lysosomal thiol proteinases were studied. Urinastatin had inhibitory effect on the activities of cathepsins B and H in vitro. In the experimental acute pancreatitis induced by a closed duodenal loop, urinastatin prevented the enhancement of esterolytic activity and the activities of cathepsins B and H. Urinastatin also improved the activities of inhibitors of cathepsins B and H in the case of pancreatitis.