Effect of Early Sucrose Feeding on the Metabolic Patterns of Mature Rats

Abstract
Studies of the influence of early diet experience on the metabolic responses of adult BHE rat were conducted. Weanling male BHE rats were fed either a 65% sucrose diet or a 65% starch diet until 50 days of age. At this time, half of the starch-fed animals were switched to the sucrose diet while half of the sucrose-fed animals were switched to the starch diet. Animals were killed at 50, 100, and 142 days of age. Levels of serum insulin, glucose, cholesterol and glycerides were determined as were the activities of the hepatic NADP-linked dehydrogenases, and citrate cleavage enzyme and the levels of liver lipid and cholesterol. The 142-day-old rats fed sucrose during the initial postweaning period (from weaning to 50 days of age) had higher serum insulin and triglyceride levels and greater hepatic L-α-glycerol phosphate dehydrogenase activity than those fed starch. At 142 days of age, the animals initially fed sucrose and switched to starch had higher liver lipid and cholesterol levels than animals either fed starch or sucrose continuously or fed starch and switched to sucrose at 50 days of age. The activities of the cytosolic enzymes appeared to be most influenced by the type of carbohydrate fed just prior to sacrifice. The activities of the pentose shunt enzymes and malic enzyme in 100-day-old animals were affected by an interaction of the initial and second dietary treatments. The results of these studies indicate that the kind of carbohydrate fed during the initial postweaning period may have important and long-lasting effects on the metabolic patterns of rats even when that carbohydrate has not been fed after 50 days of age.