Epidermal growth factor receptor is increased in rabbit intestinal brush border membrane after small bowel resection.

Abstract

A defective epidermal growth factor receptor (EGFR) abrogates adaptation, while overexpression of EGFR or exogenous epidermal growth factor (EGF) enhances adaptation following small bowel resection (SBR). EGFR is predominantly located on the enterocyte basolateral membrane, yet luminal EGF is increased in injured mucosa. We hypothesized that EGFR is both increased and redistributed to the enterocyte brush border membrane (BBM) after SBR and that parenteral EGF will reverse this redistribution. Rabbits (N = 20) were subjected to sham operation or SBR. EGF or vehicle were administrated one week postoperatively to SBR rabbits, and the gut was harvested one week later. EGFR levels in intestinal crude extracts and purified BBM were determined by Western blot analysis. No difference in EGFR level was detected in the crude extract among any of the groups. SBR more than doubled EGFR amount in BBM (P < 0.006). Parenteral EGF did not influence this redistribution. Thus, EGFR is partially redistributed to the BBM in the mucosa of SBR rabbits, and parenteral EGF does not reverse this redistribution.