A serum factor(s) after small bowel resection induces intestinal epithelial cell proliferation: Effects of timing, site, and extent of resection

Background/Purpose: After small bowel resection (SBR), serum induces proliferation in rat intestinal epithelial cells (RIEC-6). This study was designed to elucidate the effects of postoperative time interval, site, and magnitude of SBR on RIEC-6 proliferation. Methods: Serum was collected from rats at various times after a 75% mid-SBR or sham operation and added to RIEC-6 cells and growth determined over 5 days. In other experiments, cell growth was recorded in the presence of serum from rats after 25%, 50%, or 75% SBR, or after jejunal or ileal SBR. Results: SBR serum enhanced RIEC-6 cell proliferation as early as 12 hours after resection. The extent of SBR directly correlated with the level of adaptation; however, the effects on cell growth by the serum were similar. SBR serum induced proliferation equally after either proximal or distal resection. Conclusions: Serum contains a factor that stimulates intestinal cell proliferation soon after SBR but independent of the degree or site of intestinal resection. Although humoral factor(s) play a role in the early induction of enterocyte proliferation after SBR, further modulation of adaptation to varied lengths or sites of intestinal resection are probably governed by mechanisms independent of factors that circulate in the serum.