AJP - Regulatory, Integrative and Comparative Physiology, Vol 255, Issue 1 123-R127, Copyright © 1988 by American Physiological Society
Satiating effect of fat in diabetic rats: gastrointestinal and postabsorptive factors
N. K. Edens and M. I. Friedman
Rockefeller University, New York, New York 10021.
Streptozotocin-diabetic rats decrease food intake more than normal animals
in response to a fat test meal. To determine the physiological basis of
this differential response, we examined the effects of an ingested corn oil
meal on food intake, gastrointestinal fill, and plasma triglycerides,
glycerol, and ketone bodies. Hyperphagic diabetic rats decreased intake of
a high-carbohydrate, low-fat stock diet starting 2-4 h after the fat meal,
whereas normal rats did not. Gastric emptying was accelerated and
intestinal mass and contents were increased in diabetic rats. The fat meal
reduced gastric emptying and increased stomach contents in diabetic and
normal rats starting within 2 h of ingestion. Intestinal fill decreased in
diabetic animals after the oil meal. Triglycerides and glycerol increased
transiently after fat ingestion in normal and diabetic rats, whereas ketone
body concentrations rose only in diabetic rats starting 1-3 h after fat
ingestion. The results indicate that the differential effect of a fat meal
on food intake in normal and diabetic rats is related to differences in the
postabsorptive metabolism of the ingested fat rather than to effects of fat
feeding on gastrointestinal fill or clearance.
