EPIDERMAL GROWTH-FACTOR RECEPTOR EXPRESSION FOLLOWING SMALL-BOWEL RESECTION

Background: Adaptation following massive small bowel resection (SBR) i s an important compensatory response. While epidermal growth factor (E GF) has been shown to augment this response, the mechanism and role of EGF and its intestinal receptor (EGF-R) during adaptation are not kno wn. The purpose of this study was to determine the effect of massive S BR and adaptation on intestinal expression of EGF-R. Materials and met hods: Male Sprague-Dawley rats underwent either a 75% mid-SBR with pri mary reanastomosis or sham operation (bowel transection with reanastom osis). Real mucosa was harvested from animals of each group at 6 and 1 2 hr, 1, 3, and 5 days, and 1, 2, and 4 weeks after operation. Express ion of EGF-R protein was studied by Western blotting. Expression of EG F-R mRNA was determined by quantitative reverse-transcriptase polymera se chain reactions normalized to beta-actin. Results: When compared wi th sham, SBR resulted in a modest (32%) increase in the expression of EGF-R mRNA at 1 week (P < 0.003). A two-fold greater expression of EGF -R protein corresponded to this time point. While not statistically si gnificant, expression of EGF-R mRNA was slightly greater after SBR at every other time point measured. Conclusion: Following massive SBR, ex pression of both EGF-R mRNA and protein is slightly increased in the i leum with a more pronounced increase in protein. These findings, which have not previously beets reported, suggest that changes in EGF-R sig naling may not play a major role during the initiation and or progress ion of intestinal adaptation following massive SBR. (C) 1997 Academic Press.