Serum from mice after small bowel resection enhances intestinal epithelialcell growth

Background/Purpose: The adaptive response of the intestine to massive small bowel resection (SBR) is remarkably complex. An in vitro model of adaptati on may facilitate the elucidation of signaling pathways involved in this pr ocess. In an effort to establish such a model, the effects of serum from re sected mice on cultured intestinal epithelial cells were studied. Methods: Serum was collected and pooled from male ICR mice 3 days after eit her 50% SBR or sham operation. Rat intestinal epithelial cells (RIEC-6) wer e plated at equal density and grown in the presence of 1% fetal bovine seru m (FBS), 10% FBS, 1% FBS plus 9% sham serum, or 1% FBS plus 9% SBR serum. C ell number, proliferation, and caspase-3 activity were determined. Results: RIEC-6 cell growth was reduced significantly in 1% FBS or sham ser um. SBR serum markedly accelerated cell growth and proliferation when compa red with all other groups and significantly suppressed caspase-3 activity. Conclusions: Massive intestinal resection in mice results in a serum factor that induces intestinal cell growth in vitro. This in vitro model of troph ic signaling will permit further detailed investigations into the mechanism s of intestinal adaptation. J Pediatr Surg 36:184-189. Copyright (C) 2001 b y W.B. Saunders Company.