Importance of Vasoactive Intestinal Peptide and Somatostatin for Fluid Losses in Small-Bowel Obstruction

Abstract

Background: Previous observations have shown vasoactive intestinal peptide (VIP) to be an important secretagogue in the gut, whereas somatostatin has been reported to inhibit VIP release and fluid secretion. Methods: The possible role of VIP as mediator of the inflammation and fluid losses in obstructive ileus was investigated in vivo in a chronic rat model with thread ligation of the jejunum. Extravasated Evans blue (Eb)-stained albumin was quantified by spectrophotometry. Net fluid secretion was measured by a gravimetric technique. VIP antiserum was used to inhibit the effects of endogenous VIP. A somatostatin analogue, octreotide, was used to inhibit the release of VIP. Results: Results showed a pronounced plasma Eb-albumin extravasation in the wall of the obstructed gut, which was significantly inhibited by VIP antiserum (p < 0.05) or octreotide (p < 0.01). Obstruction of the jejunum resulted in net fluid secretion that was significantly reduced by administration of octreotide (p < 0.01) or VIP antiserum (p < 0.05). Net fluid secretion in control animals remained constant. Conclusions: These findings suggest that VIP is an important mediator of the pathophysiology in mechanical intestinal obstruction and that somatostatin may be involved in the endogenous control of fluid losses.

Key Words:

• Inflammation
• intestinal obstruction
• intestinal secretions
• octreotide
• oedema
• rat
• somatostatin
• spectrophotometry
• vasoactive intestinal polypeptide
• vasoactive intestinal polypeptide antiserum