The effect of epidermal growth factor on differentiation of isolated enterocytes after small bowel resection

Background/Purpose: In previous studies using mucosal scrapings or whole-bo wel homogenates, epidermal growth factor (EGF) augments adaptation after ma ssive small bowel resection (SBR). The purpose of this study was to determi ne directly the effect of adaptation and EGF on enterocyte differentiation using an explicit enterocyte cell population. Methods: Male ICR mice underwent 50% proximal SBR or sham (bowel transectio n-reanastomosis) and were selected randomly to either orogastric saline or EGF (50 mu g/kg/d). After 3 days, enterocytes were isolated from the remnan t ileum by mechanical vibration and assayed for DNA and protein content as well as sucrase and alkaline phosphatase (AlkP) activity. Results: Ileal wet weight, enterocyte protein, and DNA content were increas ed significantly after SBR and boosted even further with EGF. When normaliz ed for protein, SBR caused an increase in AlkP and sucrase activity, and EG F treatment caused AlkP and sucrase activity to return to baseline. Conclusions: EGF enhances adaptation; however, when normalized for protein, the activity of two enterocyte-specific enzymes was not significantly alte red by EGF. This analysis of an explicit enterocyte population supports the notion that the beneficial effects of EGF are more likely caused by increa sed numbers of enterocytes rather than an increase in the functional activi ty of each individual cell. J Pediatr Surg 34:209-213. Copyright (C) 1999 b y W.B. Saunders Company.