OBSTRUCTIVE ILEUS OF LARGE-BOWEL IS ASSOCIATED WITH LOW TISSUE-LEVELSOF NEUROPEPTIDES IN PRESTENOTIC BOWEL SEGMENT

The neuropeptides substance P, vasoactive intestinal polypeptide, and the recently discovered peptide secretoneurin are neurotransmitters of the intrinsic nervous system of the gut and effect gut motility. The aim of this study was to investigate whether these neuropeptides are i nvolved in the pathophysiology of large bowel ileus. Five patients und erwent colonic resections for obstructive cancer of the colon. Full-th ickness specimens of the resected colon were taken 10 cm proximal and 10 cm distal to the site of tumor obstruction. Substance P-, vasoactiv e intestinal polypeptide-, and secretoneurin-like immunoreactivities w ere measured in the specimens by radioimmunoassay. In addition immunoc ytochemistry was performed. Tissue levels of substance P, vasoactive i ntestinal polypeptide, and secretoneurin were lower in the prestenotic than in the poststenotic bowel segment. In accordance, immunocytochem istry revealed a denser staining of ganglion cells and fibers for all three neuropeptides in the poststenotic bowel. The decreased tissue le vels of substance P, vasoactive intestinal polypeptide, and secretoneu rin in the prestenotic bowel segment may contribute to the final decom pensation of obstructive ileus.