Fragility of subcellular organelles induced by pancreatic duct obstruction in rabbits.
The effects of short-term (6 hours) pancreatic duct obstruction on the possible secretion of lysosomal enzyme into pancreatic juice and subcellular lysosomal and mitochondrial fragility were investigated in rabbits. Caerulein stimulated the secretion of amylase and cathepsin B into pancreatic juice in controls. Blockage of the pancreatic duct for 6 hours caused a significant decrease of amylase and cathepsin B output into pancreatic juice, and a significant rise in portal serum amylase and cathepsin B levels, and pancreatic amylase content and an accelerated leakage of cathepsin B from lysosomes and malate dehydrogenase from mitochondria in in-vitro preparations, as well as redistribution of cathepsin B in acinar cells. These changes tended to continue for up to 12 hours after removal of the pancreatic duct obstruction. These results indicate that under physiological conditions, lysosomal enzymes are secreted into the pancreatic juice in response to stimulation by gut hormones and that increased lysosomal fragility, mitochondrial fragility and impaired pancreatic energy charge levels are closely related to the pathogenesis of pancreatic injury in this model. Moreover, zymogen colocalized with lysosomal enzyme after duct obstruction was secreted into pancreatic juice in increased amount together with digestive enzymes; these findings suggest that lysosomal enzymes play important pathophysiological roles in pancreatic juice.
D000681:Amylases / Q000378:metabolism; D000818:Animals; D002401:Cathepsin B / Q000378:metabolism; D004734:Energy Metabolism; D008026:Ligation; D008247:Lysosomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D015388:Organelles / Q000378:metabolism; D009996:Osmotic Fragility; D010179:Pancreas / Q000378:metabolism*; D010183:Pancreatic Ducts; D010189:Pancreatic Juice / Q000378:metabolism; D011817:Rabbits
D000681:Amylases; D002401:Cathepsin B