Effect of weaning on different diets on hepatic gluconeogenesis in the rat

The capacity of gluconeogenesis from lactate (10 mmol/l) was studied on isolated hepatocytes in 15-day-old suckling and in 28-day-old rats weaned at the age of 19 days on various diets. Weaning on a high-fat carbohydrate-free diet allowed to maintain a high gluconeogenic rate. By contrast, as soon as the carbohydrate content of the weaning diet was sufficient to meet the glucose needs of the newborn, the gluconeogenic capacity was reduced. The amount of fat in the weaning diet had no influence on the gluconeogenic capacity. Changes in the hepatic gluconeogenic rate at weaning were inversely correlated with the plasma insulin/glucagon molar ratio.