Metabolic Adaptation to Dietary Carbohydrates in Two Strains of Rats at Three Ages

Abstract

The effect of kind of dietary carbohydrate on enzyme activities and lipid metabolism was investigated in two strains of male weanling rats maintained on diets containing 16% fat and 50% sucrose, glucose or cornstarch. Groups of rats fed each diet were killed at 3, 6, and 9 months of age. Animals fed the sucrose diet showed relatively high activities of glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, and aldolase, as well as an elevation of liver fat. The BHE strain showed a higher body and liver weight and more liver fat than did the Wistar animals. The two strains differed at the earliest age in the increased activities of the three hepatic enzymes mentioned above. These enzymes showed a strain-age interaction but not a strain-diet or a diet-age interaction. The results suggest that the kind of dietary carbohydrate influences metabolic pathways and lipid metabolism, regardless of the age or strain of the animal, even when a moderately high level of fat is fed.