Serine protease inhibitors suppress pancreatic endogenous proteases and modulate bacterial neutral proteases

Islets. 2010 May-Jun;2(3):200-6. doi: 10.4161/isl.2.3.11714.


Pefabloc, Trasylol and Urinary Trypsin Inhibitor (UTI) have been reported to be effective serine protease inhibitors that impair pancreatic endogenous proteases resulting in improved islet yield. Here we evaluated the effect of these inhibitors on endogenous proteases (trypsin, chymotrypsin and elastase), bacterial neutral proteases (thermolysin and neutral protease) and islet isolation digestion samples. Protease activity was measured using a fluorimetric assay and islet function was assessed by dynamic perifusion. Trypsin, chymotrypsin and elastase were significantly inhibited by Pefabloc and UTI. Trasylol showed strong inhibitory effects on trypsin and chymotrypsin but also decreased thermolysin activity. UTI was found to inhibit the activity of endogenous proteases and increase the activity of bacterial neutral proteases. Human islets exposed to Pefabloc had reduced insulin response, unlike Trasylol or UTI, which had no detrimental effect on insulin secretion. Although Trasylol was an effective inhibitor of endogenous proteases, FDA regulatory issues preclude its use in clinical application and thus in the isolation process. UTI has the greatest potential because it impairs endogenous pancreatic proteases and enhances digestion enzymes.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aprotinin / pharmacology
  • Bacteria / drug effects
  • Bacteria / enzymology*
  • Bacteria / metabolism
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Drug Evaluation
  • Enzyme Activation / drug effects
  • Glycoproteins / pharmacology
  • Humans
  • Pancreas / drug effects
  • Pancreas / enzymology*
  • Peptide Hydrolases / drug effects
  • Peptide Hydrolases / metabolism
  • Serine Proteinase Inhibitors / pharmacology*
  • Sulfones / pharmacology
  • Thermolysin / antagonists & inhibitors
  • Thermolysin / metabolism
  • Tissue Extracts / metabolism


  • Glycoproteins
  • Serine Proteinase Inhibitors
  • Sulfones
  • Tissue Extracts
  • 4-(2-aminoethyl)benzenesulfonylfluoride
  • Aprotinin
  • Peptide Hydrolases
  • Thermolysin
  • urinastatin