The effect of severe food restriction since birth on regulation of fasting glycemia in male Wistar rats was
investigated. The control group (CG) had free supply of chow, while the restriction group (RG) received 50% of the
amount ingested by the CG. The experiments were done in adult (60 days) overnight fasted rats in which glycemia,
liver free glucose levels and hepatic glycogen concentration were measured. In part of the experiments in situ liver
perfusion was done. The results showed that livers from the RG had higher glycogenolysis rates but lower
gluconeogenesis rates from L-alanine (10 mM). Since RG showed maintained glycemia during fasting, it could be
concluded that livers from RG produced glucose preferentially from glycogenolysis in detriment of gluconeogenesis.
These findings demonstrated that in spite of severe caloric restriction, the metabolic adaptations of the liver did
exist to assure the maintenance of blood glucose for brain supply during fasting.
