Adaptive changes in rat exocrine pancreas following subtotal colectomy

Subtotal colectomy was performed in 17 rats. After 2 or 4 weeks the entire pancreas was excised and isolated pancreatic lobules were incubated for 60 min in Krebs-Ringer-Hepes solution either with or without addition of ceruletide (5 X 10(-10) g/ml). Amylase was determined every 15 min in the supernatant medium. Amylase, trypsin, DNA and total protein were measured in homogenized pancreatic tissue. Morphology was performed via light-microscopy analysis. Two weeks after subtotal colectomy we found an increase in pancreatic wet weight, enzyme and protein content, cellular size and secretion capacity in vitro, whereas DNA concentration in relation to pancreatic tissue weight in grams decreased. These changes pointed to pancreatic hypertrophy. Four weeks after surgery, pancreatic wet weight, enzyme content and DNA content as well as in vitro amylase discharge increased, whereas cellular size remained unchanged compared to controls and sham-operated rats. These changes were indicative of pancreatic hyperplasia.