Failure of a prolyl 4-hydroxylase inhibitor to alter extracellular matrix deposition during experimental pancreatitis.

Abstract

In chronic pancreatitis the exocrine pancreatic tissue is replaced by extracellular matrix deposits from fibroblasts. We have stimulated fibrogenesis in the pancreas by inducing a single episode of cerulein pancreatitis (10 microg/kg/h for 12 h). We have used a spectrophotometrical assay to measure the tissue hydroxyproline content and immunohistochemistry to study the transient deposition of extracellular matrix in the pancreas. We have investigated whether a potent prolyl 4-hydroxylase inhibitor (HOE-077) can influence the deposition of extracellular matrix in the pancreas. Three days after the induction of the pancreatitis we found the maximum increase in pancreatic hydroxyproline content (by 63%), the maximum decrease in total protein content and amylase activity (by -39 and -86%, respectively), as well as a significant increase in DNA content and the deposition of interstitial collagen fibers on electron microscopy. By immunohistochemistry the largest expansion of extracellular matrix components was found for fibronectin. HOE 077, regardless of the concentration administered, failed to affect any of these parameters. We conclude that the induction of a single episode of cerulein pancreatitis and the serial determination of pancreatic hydroxyproline content represents a simple method to induce and monitor experimental fibrogenesis in the pancreas. Prolyl 4-hydroxylase inhibition did not affect the course of extracellular matrix deposition in the pancreas.