[Energy homeostasis in the early premature newborn rat].

Changes in liver glycogen, plasma glucose and lactate and blood oxygen concentrations were studied in term, preterm and severe preterm newborn rats during the first two hours after delivery. Severe preterm newborn rats showed lower glucogen concentrations than term newborns at delivery. No differences were observed in the rates of postnatal glycogenolysis between the groups of newborns studied. Plasma lactate concentration increased after birth in severe preterm newborns. This increase closely parallels to the time-course of postnatal hypoxia undergone by severe preterm newborns during the early neonatal period.