Secretin release from the isolated, vascularly perfused pig duodenum

Area of Science:

• Gastroenterology
• Physiology
• Endocrinology

Background:

• The pancreas and duodenum play crucial roles in digestion and hormone secretion.
• Studying the duodenum's physiological functions, particularly its endocrine secretion, requires a suitable experimental model.

Purpose of the Study:

• To develop and validate a method for the isolation and vascular perfusion of the porcine pancreas and duodenum.
• To investigate the respiratory function and glucose absorption of the isolated duodenum.
• To characterize the secretin release from the duodenum in response to various stimuli.

Main Methods:

• Isolation and vascular perfusion of the porcine pancreas and duodenum.
• Measurement of oxygen consumption and arteriovenous oxygen deficit.
• Assessment of luminally administered radioactive glucose absorption.
• Stimulation of secretin release using hydrochloric acid, lipids, proteins, carbohydrates, bile, and acetylcholine.
• Analysis of released secretin using gel permeation chromatography.

Main Results:

• The isolated porcine pancreas and duodenum preparation demonstrated adequate duodenal respiration.
• The duodenum efficiently absorbed radioactive glucose, with absorption inhibited by ouabain and phloridzin.
• Secretin release was rapid and specific to luminal hydrochloric acid; other stimuli were ineffective.
• Intra-arterial acetylcholine did not stimulate secretin release.
• Released immunoreactive secretin exhibited identical molecular size to pure natural secretin.

Conclusions:

• The developed model allows for the study of the porcine pancreas and duodenum in a perfused state.
• The duodenum exhibits significant glucose absorption capabilities and specific secretin secretion in response to acid.
• This model provides a unique platform for investigating duodenal endocrine secretion and its regulation.