AJP - Gastrointestinal and Liver Physiology, Vol 245, Issue 3 358-G363, Copyright © 1983 by American Physiological Society
Effects of cholecystokinin and secretin on intestinal structure and function
H. Fine, G. M. Levine and Y. F. Shiau
Cholecystokinin and secretin are believed to be trophic gastrointestinal
hormones. Studies were designed to determine whether these hormones exert
their effect through stimulation of endogenous secretion. First, four
groups of parenterally nourished rats underwent bypass of the proximal
two-thirds of the intestine. One group received secretin, another
cholecystokinin octapeptide (CCK-OP), another CCK-OP plus secretin, while
the fourth group served as control. After 1 wk, animals were killed;
pancreas and segments of intestine were removed. First, mucosal weight,
protein content, and fatty acid esterification activity were affected only
in intestine in continuity with endogenous secretions after hormone
administration. Second, the effects of these hormones were tested in
chow-fed rats. The hormone-treated group, despite pancreatic hyperplasia,
had similar indexes of intestinal mass compared with pair-fed controls. We
conclude that CCK-OP and secretin mediate their trophic effects on the
small intestine indirectly, probably through stimulation of pancreatic
secretion. In addition, the effects of luminal nutrients have complex
interactions with these hormones.
