PATHOPHYSIOLOGY OF ADYNAMIC ILEUS

We hypothesized that the inhibitory neurotransmitters nitric oxide (NO ) and vasoactive intestinal peptide (VIP) may play a role in the disru pted gastrointestinal motility of endotoxemia. Strain gauge transducer s on the stomach and small intestine of dogs determined interdigestive gastrointestinal motility. Tissue levels of NO synthase and VIP and s erum levels of nitrite/nitrate (NO2-INO3-) and VIP were measured. Foll owing completion of the baseline studies, dogs were given a single dos e of E. coli lipopolysaccharide, 200 mu g/kg intravenously, and the st udies were repeated for the next three days. Following endotoxin bolus , the migrating motor complex (MMC) was delayed for two days while ser um VIP was increased on postendotoxin day I and serum NO2-/NO3- was in creased on postendotoxin day 2. There were no changes in gut smooth mu scle levels of NO synthase or VIP. We conclude that a single, subletha l dose of endotoxin results in prolongation of the MMC with distinct b ut independent increases in serum levels of VIP and NO2-/NO3-.