This study aimed to assess the role of
oxygen free radicals in
acute pancreatitis.
Acute pancreatitis was induced in rats by infusion of the CCK-analogue
cerulein (5 micrograms/kg per hour) for 30 minutes, 3.5 hours, and 12 hours. After the infusion, serum
enzymes and conjugated tissue dienes and
malondialdehyde were measured and tissue samples were subjected to electron and light microscopy. Electron microscopy after 30 minutes showed moderate intracellular alterations. After 3.5 hours of
cerulein infusion interstitial oedema and intravascular margination of granulocytes in the pancreatic gland were seen. After 12 hours histological evaluation showed pronounced
zymogen degranulation, extensive tissue
necrosis, and migration of granulocytes into the tissue.
Amylase and
lipase activities increased 15 and 35-fold respectively during this time. After 30 minutes of
cerulein infusion conjugated dienes and
malondialdehyde increased, they reached their peak after 3.5 hours and decreased to normal values after 12 hours. Treatment with
superoxide dismutase (100,000 U/kg/hour) and
catalase (400,000 U/kg/hour) either before or after the start of the
cerulein infusion prevented lipid peroxidation and reduced
zymogen degranulation and tissue
necrosis. Tissue oedema and inflammatory response, however, were not affected in any of the treated rats.
Oxygen free radicals are instrumental in the development of
acute pancreatitis. Even after its onset, scavenger treatment reduced the tissue damage normally observed.