Pancreatic regeneration following an acute injury: Evidence from histological, haemato-biochemical and immunohistochemical analyses

Acute pancreatitis is a major gastrointestinal disorder and current management is largely limited to supportive and symptomatic care. The disease manifests with oedema, necrosis, haemorrhage, and inflammatory changes in the exocrine pancreas, while its chronic form represents a fibroinflammatory condition with recurrent injury, fibrosis, and increased neoplasia risk. This study assessed hematobiochemical and histomorphological alterations in a Wistar rat model of L-arginineinduced pancreatitis. Induction was achieved using two intraperitoneal injections of L-arginine (2.5 gkg, 1h apart) and the animals were sacrificed on days 8 and 15. Controls received saline. Blood samples were collected at baseline and on days 2, 8, and 15 for hematobiochemical assessment, while pancreatic tissue was subjected to biochemical, histopathological, and immunohistochemical analyses. Serum amylase and lipase sharply elevated within 24 h (amylase: 2922.93294.25 vs. 476.1137.75; lipase: 445.0870.31 vs. 12.733.88), declining to near-normal by days 8 and 15. Glucose, total erythrocytes, haemoglobin, and packed cell volume remained unchanged, with only transient leukocytosis on day 2. Persistent glutathione depletion with elevated nitrite and myeloperoxidase indicated oxidative stress. Histopathology on day 8 showed necrosis, mononuclear infiltration, haemorrhage, and fatty changes, while fibroplasia, acinar-to-ductal metaplasia, and ductal hyperplasia were evident by day 15. Immunohistochemistry confirmed regeneration through PCNA expression, whereas IL-6 exhibited moderate localisation in acinar cells. This model replicates the progression from acute to chronic pancreatic damage.