Cerulein-induced in vitro activation of trypsinogen in rat pancreatic acini is mediated by cathepsin B

AK Saluja, EA Donovan, K Yamanaka, Y Yamaguchi… - Gastroenterology, 1997 - Elsevier
AK Saluja, EA Donovan, K Yamanaka, Y Yamaguchi, B Hofbauer, ML Steer
Gastroenterology, 1997Elsevier
BACKGROUND & AIMS: One of the central, unresolved issues in the pathogenesis of acute
pancreatitis is the uncertainty regarding the mechanisms responsible for the premature
intrapancreatic activation of digestive enzyme zymogens. The aim of the current study was to
develop and characterize an in vitro system that might mimic the events leading to
trypsinogen activation within the pancreas during pancreatitis. METHODS: Activation of
trypsinogen in response to stimulation with cerulein was quantitated in isolated rat …
BACKGROUND & AIMS
One of the central, unresolved issues in the pathogenesis of acute pancreatitis is the uncertainty regarding the mechanisms responsible for the premature intrapancreatic activation of digestive enzyme zymogens. The aim of the current study was to develop and characterize an in vitro system that might mimic the events leading to trypsinogen activation within the pancreas during pancreatitis.
METHODS
Activation of trypsinogen in response to stimulation with cerulein was quantitated in isolated rat pancreatic acini.
RESULTS
Activation of trypsinogen was detected within 10 minutes of exposing isolated rat pancreatic acini, in Ca2+-containing buffer, to a supramaximally stimulating concentration of cerulein in vitro. Complete inhibition of pancreatic cathepsin B activity with E-64d, a specific, potent and irreversible cathepsin B inhibitor, prevents cerulein- induced in vitro trypsinogen activation.
CONCLUSIONS
In vitro activation of trypsinogen can be detected when pancreatic acini are exposed to a supramaximally stimulating dose of cerulein. The results using this in vitro system support the hypothesis that the appearance of active trypsin within the pancreas during the early stages of cerulein-induced pancreatitis reflects activation of trypsinogen by the lysosomal hydrolase cathepsin B. (Gastroenterology 1997 Jul;113(1):304-10)
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