title: Intestinal adaptation after extensive small bowel resection: differential changes in growth and insulin-like growth factor system messenger ribonucleic acids in jejunum and ileum.
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/kgXday) 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.
authors.affiliation: Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Ziegler
authors.forename: M P
authors.initials: MP
authors.lastname: Mantell
authors.forename: J C
authors.initials: JC
authors.lastname: Chow
authors.forename: J L
authors.initials: JL
authors.lastname: Rombeau
authors.forename: R J
authors.initials: RJ
authors.lastname: Smith
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001835:Body Weight; D004247:DNA / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007421:Intestine, Small / Q000254:growth & development / Q000503:physiopathology* / Q000601:surgery*; D007583:Jejunum / Q000378:metabolism; D008297:Male; D009929:Organ Size; D011184:Postoperative Period; D011506:Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013002:Somatomedins / Q000235:genetics* / Q000378:metabolism
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D013002:Somatomedins; D004247:DNA