Hepatic glycogen and lactate handling in dietary obese rats

Hepatic balances for glucose and its precursor, lactate, were calculated by measuring hepatic blood flows and the arteriovenous differences of these metabolites in 2 groups of overweight rats: cafeteria diet-fed rats and post-cafeteria rats. Obese rats show abnormal hepatic glycogen handling, since they do not mobilize all hepatic glycogen stores after 24-hour starvation, in a situation in which a lower rate of hepatic glucose output and a higher capacity for lactate uptake are attained. The important decrease (about 50%) in the hepatic blood flows observed in post-cafeteria rats versus control rats was similar to that caused by 24-hour starvation in control animals, suggesting that after withdrawal of the cafeteria diet, the liver blood flow of the post-cafeteria rats was adapted to the low-food intake in order to make better use of the energy consumed. The results also suggest an increased efficiency of hepatic lactate uptake in post-cafeteria rats.