AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 3 559-R563, Copyright © 1992 by American Physiological Society
The effect of dietary fat on diet selection may involve central serotonin
B. J. Mullen and R. J. Martin
Department of Foods and Nutrition, University of Georgia, Athens 30602.
Rats consuming a diet of 34% tallow select more protein and less
carbohydrate than rats fed either 5% corn oil or tallow or 34% corn oil
(25). To examine potential mechanism(s) of this phenomenon, we fed rats
diets containing either tallow or corn oil at levels of 5 or 34% for 2
days. Sera were analyzed, and rats fed 34% tallow had higher serum insulin
compared with those fed 34% corn oil. In a second experiment, rats were fed
either 34% corn oil or tallow for 2 days. Brain tissues were analyzed, and
rats fed 34% tallow had elevated serotonin in the raphe area compared with
those fed 34% corn oil. In a third experiment, rats were fed either 34%
corn oil or tallow for 2 days and then given dl-fenfluramine before diet
selection. Fenfluramine depressed food intake to a greater degree in rats
fed 34% tallow compared with those fed corn oil. These findings suggest
that the diet selection behavior observed in tallow-fed rats may be
mediated by a central serotonin system.
