Resection-induced colonic adaptation is augmented by igf-i and is
associated with upregulation of colonic igf-i mrna.
Mantell, Mark P., Thomas R. Zeigler, William T. Adamson, Jonathan A.
Roth, Wei Zhang, Wendy Frankel, Allison Bain, Jesse C. Chow, Robert
J. Smith, John L. Rombeau.
Department of Surgery and Harrison Department of Surgical Research,
Hospital of the University of Pennsylvania, Philadelphia, PA, 19104;
Joslin Diabetes Center and the Department of Medicine of the Brigham
and Women's Hospital, Harvard Medical School, Boston, MA 02215
APStracts 2:0113G, 1995.
The effects of exogenous insulin-like growth factor-I (IGF-I) on
colonic adaptation were examined in male SD rats (n=60, 225-275 mg)
after either a 60% small bowel and cecal resection (RES) or mid-small
bowel transection with reanastomosis (TX). Animals received a seven
day treatment with either IGF-I (2.4 mg/kg/day) or vehicle (V=0.1
mol/L acetic acid). Body weight decreased significantly following
resection (-25.6 +/- 4.0 gm, p<0.05 vs TX/V). IGF-I treatment
significantly reduced weight loss following resection (-12.4 +/- 3.8
gm, p<0.01 vs RES/V) and induced significant weight gain after
transection (15.6 +/- 4.0 gm, p<0.05 vs TX/V). Plasma IGF-I
decreased with resection (TX/V 526 +/- 41 vs RES/V 344 +/- 17 ng/ml,
p<0.01). IGF-I treatment significantly increased plasma IGF-I
levels (TX/IGF 805 +/- 100, RES/IGF 677 +/- 56). Following resection,
IGF-I treatment significantly increased colonic mucosal weight, DNA,
protein content, and crypt depth when compared with resection alone
(p<0.05). Colonic water absorption, measured by an in vivo 3H
-PEG assay, was significantly increased by IGF-I treatment in resected
animals (RES/IGF 399 +/- 23 vs RES/V 306 +/- 32 [mu]l/cm/hr,
p<0.05). Resection resulted in increased steady state colonic
IGF-I mRNA (182% of TX/V, p<0.01) without significantly
affecting IGF-I receptor mRNA expression. Regulation of IGF binding
protein (IGFBP)-3 and -4 was discoordinate, with IGFBP-3 mRNA tending
to decrease with resection (67% of TX/V, p=NS) and IGFBP-4 increasing
significantly (191% of TX/V, p<0.05). An important role for IGF
-I in colonic adaptation after massive intestinal resection is
suggested by (1) significantly enhanced colonic mucosal growth and
water absorption with IGF-I treatment and (2) post-resection
upregulation of colonic IGF-I mRNA and alteration of IGFBP-3 and
IGFBP-4 mRNA expression.
Received 23 May 1994; accepted in final form 26 May 1995.
APS Manuscript Number G193-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 July 1995.