Influence of Dietary Carbohydrates on Liver Content and on Serum Lipids in Relation to Age and Strain of Rat

Abstract

To determine the effect of kind of carbohydrate on the lipid metabolism of the rat as influenced by age and heredity, rats of the BHE and Wistar strains, known to differ in their lipid metabolism, were fed high cholesterol diets identical except for the dietary carbohydrate, supplied as sucrose, cornstarch, or glucose. Livers of 150- and 350-day-old rats were analyzed for moisture, protein, total lipid, cholesterol, and glycogen; blood for total serum cholesterol and for noncholesterol lipids as fatty acids. The most striking differences were in liver lipids. Cholesterol and noncholesterol lipids were generally higher in livers of sucrose-fed rats of either strain than in dextrose- or cornstarch-fed rats. Livers of BHE rats contained more cholesterol and noncholesterol lipids than those from Wistar rats. Liver lipids of sucrose fed BHE rats increased with age; no significant age effect was apparent with cornstarch or glucose. With Wistar rats, liver cholesterol decreased with age with all 3 carbohydrates; noncholesterol lipids remained relatively constant. Differences in liver size and composition between fasted and nonfasted rats suggest that the metabolic activity of this organ varies with dietary carbohydrate. Serum cholesterol levels increased with age, were higher in BHE than in Wistar rats and did not differ significantly with dietary carbohydrate. Noncholesterol lipids were generally high in sera from sucrose-fed rats.