IMPORTANCE OF VASOACTIVE-INTESTINAL-PEPTIDE AND SOMATOSTATIN FOR FLUID LOSSES IN SMALL-BOWEL OBSTRUCTION

Background: Previous observations have shown vasoactive intestinal pep tide (VIP) to be an important secretagogue in the gut, whereas somatos tatin has been reported to inhibit VIP release and fluid secretion. Me thods: The possible role of VIP as mediator of the inflammation and fl uid 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 s ecretion was measured by a gravimetric technique. VIP antiserum was us ed to inhibit the effects of endogenous VIP. A somatostatin analogue, octreotide, was used to inhibit the release of VIP. Results: Results s howed 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 administratio n of octreotide (p < 0.01) or VIP antiserum (p < 0.05). Net fluid secr etion in control animals remained constant. Conclusions: These finding s suggest that VIP is an important mediator of the pathophysiology in mechanical intestinal obstruction and that somatostatin may be involve d in the endogenous control of fluid losses.