Exocrine pancreatic function following proximal small bowel resection in rats

Area of Science:

• Gastroenterology
• Surgical Research
• Endocrinology

Background:

• Proximal enterectomy (small bowel resection) can impact digestive organ function.
• The exocrine pancreas plays a crucial role in digestion and nutrient absorption.
• Understanding the interplay between intestinal resection and pancreatic function is vital for managing post-surgical outcomes.

Purpose of the Study:

• To investigate the functional changes in the exocrine pancreas following proximal small bowel resection.
• To determine the effects of varying resection percentages (50% and 75%) on pancreatic secretion.
• To explore the hormonal and enzymatic alterations in the pancreas post-enterectomy.

Main Methods:

• Rats underwent 50% or 75% proximal small bowel resection or sham surgery.
• Pancreatic bicarbonate output was measured using an external pancreatic fistula in conscious rats.
• Plasma secretin, gastrin, and somatostatin levels were analyzed; pancreatic enzyme activity and tissue weight were assessed.

Main Results:

• Basal pancreatic bicarbonate output significantly increased 1 week post-resection (43-78%), with elevated levels persisting at 4 weeks after 75% resection.
• Increased pancreatic secretion correlated with a 4-fold rise in plasma secretin, both effects being transient.
• Pancreatic enzyme content (amylase, chymotrypsinogen) per gram of tissue decreased 4 weeks post-resection and further at 6 months.

Conclusions:

• Extensive proximal enterectomy induces early, transient hypersecretion of pancreatic water and bicarbonate, likely due to the loss of jejunoileal inhibitors.
• Plasma secretin levels rise in response to resection but normalize over time.
• Selective reduction in pancreatic enzymes occurs post-resection, indicating long-term functional changes.