![]() |
|
|
Department of Food Science and Human Nutrition, Michigan State University, East Lansing Michigan 48824
The influence of glycerol on the rates of fatty acid synthesis in liver slices from rats and chickens and in pieces of adipose tissue from rats was first studied. Then the effect of dietary glycerol on lipid metabolism in rats and chickens was examined. Media containing 3 or 10 mM glycerol depressed the rate of glucose conversion to fatty acids in rat liver slices. However, media containing up to 25 mM glycerol did not influence the rate of fatty acid synthesis in chick liver slices. The inhibitory action of glycerol in rat liver slices might occur at the level of glucose (or glycogen) conversion to pyruvate because glycerol did not inhibit pyruvate or acetate conversion to fatty acids. Rats and chickens were fed glycerol containing diets for either 3 days or 3 weeks. Feeding diets containing 20.5 parts glycerol (22% of dietary energy) to rats or chickens did not influence the growth rate of the animals. However, substitution of 42.2 parts glycerol (43% of dietary energy) for glucose in the diet significantly depressed food intake and growth rate in both rats and chickens. The activities of citrate cleavage enzyme, fatty acid synthetase and malic enzyme in livers of rats fed the glycerol-containing diets were dramatically increased. However, this stimulation of enzyme activity occurred without a concomitant increase in the in vivo rate of fatty acid synthesis in the rat liver. In the chicken, unlike the rat, dietary glycerol did not stimulate but instead decreased hepatic malic enzyme and fatty acid synthetase activities. No significant differences in adipose tissue lipogenic enzyme activities or in the rates of fatty acid synthesis were observed in rats fed glycerolcontaining diets. The lipogenic response to glycerol feeding depends on the species as well as the organ.
KEY WORDS: rat chick liver adipose tissue glycerol lipogenic enzymes fatty acid synthesis
1 Supported in part by Public Health Service Grants HL 14677 and AM 18957. DRR is the recipient of Career Development Award NIH KO4 AM 00112. Michigan Agricultural Experiment Station Journal Article No. 7653.
Manuscript received 14 April 1976.
This article has been cited by other articles:
![]() |
W. A. Dozier III, B. J. Kerr, A. Corzo, M. T. Kidd, T. E. Weber, and K. Bregendahl Apparent Metabolizable Energy of Glycerin for Broiler Chickens Poult. Sci., February 1, 2008; 87(2): 317 - 322. [Abstract] [Full Text] [PDF] |
||||
![]() |
D Wirtshafter and J. Davis Body weight: reduction by long-term glycerol treatment Science, December 23, 1977; 198(4323): 1271 - 1274. [Abstract] [PDF] |
||||