AJP - Regulatory, Integrative and Comparative Physiology, Vol 244, Issue 6 872-R881, Copyright © 1983 by American Physiological Society
Postgastric satiety in the sham-feeding rat
R. D. Reidelberger, T. J. Kalogeris, P. M. Leung and V. E. Mendel
A sham-feeding model using rats fitted with gastric and duodenal cannulas
was employed to investigate the role of postgastric mechanisms of satiety
in the short-term control of food intake. When fasted rats sham fed a
liquid diet [Vivonex High Nitrogen (VHN), 0.5 kcal/ml], food drained freely
from gastric fistulas, and mean first-meal size and 90-min intake increased
more than threefold. Varying the rate of duodenal infusion of diet during
sham feeding (0.06-0.44 kcal/min) decreased first-meal size and total
intake in a dose-dependent manner. First meals ended when mean loads of 2-3
kcal had been delivered. The threshold rate (0.11 kcal/min) decreased meal
size and total intake by more than 50%. When fasted rats consumed VHN to
satiety with closed gastric fistulas, rate of gastric emptying of diet
during feeding averaged 0.32 +/- 0.02 kcal/min and the load emptied by meal
termination averaged 3.8 +/- 0.2 kcal. These results indicate that rates of
gastric emptying of diet and loads delivered to the small intestine
following ingestion of liquid food are sufficient to elicit postgastric
satiety in the absence of gastric distension.
