Small bowel adaptation is dependent on site of massive enterectomy

Background: Changes in amino acid transport after massive enterectomy occur in a nutrient-dependent fashion and may affect long-term outcome. Epiderma l growth factor (EGF) can enhance nutrient transport and a defective epider mal growth factor receptor (EGF-R) has been noted to attenuate adaptation. Most animal studies, however, have examined only a single site of resection . This does not mimic the clinical situation where disease dictates the sit e of resection leading to proximal, middle, or distal enterectomies. We hyp othesize that the site of massive enterectomy will alter nutrient transport and EGF-R levels in the residual gut. Materials and methods. New Zealand White rabbits were randomized to control , midgut division, or 70% resection (proximal, midgut, or distal). After 1 week, sodium-dependent transport of glucose, glutamine, alanine, and leucin e into brush border membrane vesicles was quantitated. EGF-R protein was de termined by Western blot analysis, Results. At baseline, amino acid transport was greater in ileum than jejunu m. Surgery alone elevated glutamine and leucine jejunal transport by 130 an d 97%, respectively, over controls (P < 0.05). Midgut resection increased j ejunal glutamine transport 61% over control (P < 0.05). In contrast, distal resection increased jejunal alanine transport by 150% over controls with n o change in glutamine (P < 0.05). After midgut resection, EGF-R was signifi cantly greater (124%) in ileum then in jejunum in whole mucosa homogenates. Proximal resection significantly lowered ileal EGF-R compared to that seen in midgut resected residual ileum. Conclusions. Site of massive resection is important in determining postoper ative changes in nutrient transport and EGF-R. (C) 1999 Academic Press.