Influence of Dietary Fat Level on the Enzymatic and Lipogenic Adaptations in Adipose Tissue of Meal-fed Rats
- 1 February 1967
- journal article
- research article
- Published by Elsevier in Journal of Nutrition
- Vol. 91 (2), 267-274
- https://doi.org/10.1093/jn/91.2.267
Abstract
The effect of increasing dietary fat levels on the response to meal-eating (restriction of food ingestion to a single daily 2-hour meal) in the rat was investigated. The studies were conducted with diets supplying fat up to levels which would approximate the percentage of fat calories supplied in human diets. These levels were selected to evaluate whether the typical response to meal-eating observed in the rat could be anticipated in human subjects consuming diets considerably higher in fat content. Male rats were fed diets containing 10, 20 or 30% fat, these levels supplying from 21 to 52% of the ingested calories. Increasing the level of fat from 10 to 30% appeared to facilitate the adjustment of food consumption in meal-fed rats. Following the first week of the experiment, during which meal-eaters fed the 10 or 20% fat diets lost weight, meal-fed animals gained weight at essentially the same rate as did nibbling (ad libitum-fed) rats, despite a reduced food intake. The activities of the enzymes studied (glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and malic enzyme) and of fatty acid synthesis from acetate-1-14C or glucose-U-14C were increased by meal-feeding in rats fed diets containing 10 or 20% fat levels, but not in animals consuming 30% fat diets. The activities of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and malic enzyme and the lipogenic capacity decreased with increasing levels of dietary fat in adipose tissue of both meal-fed and nibbling rats. The significance of these observations in relation to the homeostatic control of lipid metabolism is discussed. It is suggested that the inability to demonstrate meal-feeding effects in human subjects may be due to the high level of fat in normal human diets.Keywords
This publication has 33 references indexed in Scilit:
- Insulin: Inducer of glucose 6-phosphate dehydrogenaseLife Sciences, 1966
- INFLUENCE OF PERIODICITY OF EATING ON ADIPOSE TISSUE METABOLISM IN THE RATCanadian Journal of Physiology and Pharmacology, 1965
- Glucose repression and induction of enzyme synthesis in rat liverAdvances in Enzyme Regulation, 1964
- Metabolic Control of Enzymes Involved in Lipogenesis and Gluconeogenesis*Biochemistry, 1964
- MALIC ENZYME AND LIPOGENESISProceedings of the National Academy of Sciences, 1964
- A simple scintillation counting technique for assaying C14O2 in a Warburg flaskAnalytical Biochemistry, 1962
- Selective response of liver enzymes to the administration of different diets after fastingArchives of Biochemistry and Biophysics, 1962
- METABOLIC ADAPTATIONS TO A “STUFF AND STARVE” FEEDING PROGRAM. I. STUDIES OF ADIPOSE TISSUE AND LIVER GLYCOGEN IN RATS LIMITED TO A SHORT DAILY FEEDING PERIOD*JCI Insight, 1962
- Role of bulk in the control of eating.Journal of Comparative and Physiological Psychology, 1962
- A simple efficient liquid scintillator for counting aqueous solutions in a liquid scintillation counterAnalytical Biochemistry, 1960