Simultaneous manipulation of intestinal capacities and nutrient
loads in mice.
Hammond, Kimberly A., Mandy Lam, K. C. Kent Lloyd, and Jared Diamond.
Department of Physiology, UCLA School of Medicine, Los Angeles, CA
90095-1751
APStracts 3:0115G, 1996.
To study capacity/load relations of the small intestine, we
simultaneously varied dietary nutrient load and intestinal capacity
in mice. Intestinal transection alone caused an increase in
intestinal mass, because of increased serosal mass. Because virgin
mouse intestine possesses 180% reserve uptake capacity before
resection, and because the intestine regenerates after resection,
resection of up to 50% had no effect on food intake, digestive
efficiency, intestinal brush-border glucose uptake rate, or masses of
all organs measured except the cecum. Regeneration of intestinal mass
and glucose uptake capacity was quantitatively complete, because
intestinal mass 10 weeks after resection was similar to that in
unresected mice. The resected intestinal mass in lactating mice was
four times larger than that immediately after resection of virgin
mice. Cecal mass increased in 50%-resected lactating mice with high
food intakes, suggesting nutrient spillage into the distal gut as a
signal for regeneration. Mice failed to survive 70% resection of the
intestine, possibly because intestinal reserve uptake capacity was
exhausted immediately after surgery, making regeneration impossible.
Received 16 January 1996; accepted in final form 14 May 1996.
APS Manuscript Number G18-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96