Intestinal Adaptation after Extensive Small Bowel Resection: Differential Changes in Growth and Insulin-Like Growth Factor System Messenger Ribonucleic Acids in Jejunum and Ileum

• Published in: Endocrinology (Philadelphia) 1998-07, Vol.139 (7), p.3119-3126
• Main Authors: Ziegler, Thomas R., Mantell, Mark P., Chow, Jessie C., Rombeau, John L., Smith, Robert J.
• Format: Article
• Language: English
• Subjects: Adaptation; Adaptation, Physiological - physiology; Adaptive systems; Animals; Body Weight; Cell proliferation; DNA - metabolism; Growth factors; Ileum; Ileum - metabolism; Insulin; Insulin-like growth factor I; Insulin-like growth factor-binding protein 3; Insulin-like growth factor-binding protein 4; Insulin-like growth factors; Intestinal adaptation; Intestine; Intestine, Small - growth & development; Intestine, Small - physiopathology; Intestine, Small - surgery; Jejunum; Jejunum - metabolism; Male; Organ Size; Ostomy; Postoperative Period; Proteins - metabolism; Rats; Rats, Sprague-Dawley; RNA, Messenger - metabolism; Small intestine; Somatomedins - genetics; Somatomedins - metabolism
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/endo.139.7.6097

Abstract The distal small bowel exhibits greater adaptive growth than proximal segments after partial small intestine resection. To explore this process, we evaluated adaptive cellularity, intestinal insulin-like growth factor (IGF) system messenger RNA (mRNA) transcripts, and effects of recombinant IGF-I treatment in jejunum and ileum of adult rats. Gastrostomy-fed animals underwent 80% jejuno-ileal resection or intestinal transection and reanastomosis without resection, followed by infusion of human recombinant IGF-I (2.4 mg/kg·day) or vehicle. After 7 days, resected rats demonstrated modest adaptive growth in jejunum and marked cell proliferation in ileum. Resection increased IGF-I mRNA in both jejunum (183%) and ileum (249%) and up-regulated IGFBP-4 mRNA levels in both tissues. IGFBP-3 mRNA fell significantly in ileum after resection. IGF-I infusion modestly increased ileal cellularity after resection, but had no effect in jejunum. IGF-I markedly increased IGFBP-3 mRNA levels in jejunum after both transection and resection. These data confirm that bowel resection induces greater adaptive growth in ileum than jejunum. IGF-I administration modestly increases ileal, but not jejunal, growth after resection. Increased levels of intestinal IGF-I and IGFBP-4 mRNA suggest roles for IGF-I and IGFBP-4 in mediating small bowel adaptation. Higher levels of jejunal IGFBP-3 mRNA may be related to limited jejunal vs. ileal growth after extensive jejuno-ileal resection.