NEURAL ISOLATION OF THE JEJUNOILEUM - EFFECT ON TISSUE MORPHOMETRY, MUCOSAL DISACCHARIDASE ACTIVITY, AND TISSUE PEPTIDE CONTENT

The aim of this study was to determine the effects of a model of intes tinal extrinsic denervation on mucosal structure and function. Six dog s underwent in situ neural isolation of the jejunoileum (Group 2); six other dogs served as operated controls (Group 1), and five nonoperate d dogs were naive controls (Group 3). Thirty-centimeter segments of pr oximal jejunum and distal ileum were excised before (time zero) and at 2 weeks and 8 weeks postoperatively in Groups 1 and 2, while similar regions were removed at time zero in Group 3. Tissues were analyzed fo r morphology with quantitative morphometry, mucosal disaccharidase act ivities (sucrase, maltase, and lactase), and tissue content of selecte d regulatory peptides in transmural, mucosa/submucosa, and muscularis regions. In situ neural isolation had no significant or consistent eff ects on morphology/morphometry or on mucosal disaccharidase activities . Tissue content of neuropeptide Y decreased markedly (P < 0.002) in a ll layers of the jejunal and ileal walls, but tissue content of vasoac tive inhibitory polypeptide, substance P, cholecystokinin, neurotensin , met-enkephalin, neurokinin A, somatostatin, and calcitonin gene-rela ted peptide demonstrated only minor changes. The physiologic effects o f intestinal transplantation (extrinsic denervation and disruption of intrinsic, enteric neural continuity, and lymphatic drainage) have lit tle effect on morphology, mucosal disaccharidase activity, and tissue content of most regulatory peptides. How these minor alterations might affect enteric function, however, needs to be investigated. (C) 1996 Academic Press, Inc.