[Energy metabolism of newborn rats during the first hours of extrauterine life].

The metabolism of the main metabolic fuels in newborn rat during the suckling and presuckling period has been studied. The presuckling newborn utilized glucose from glycogen and plasma lactate as the relevant substrates. No fatty acids on ketone bodies were utilized or released during this period. The utilization of glucose, lactate and alanine strictly depends on the oxygen supply, a fact consistent with the idea that the oxidative metabolism plays an important role in the energy homeostasis of the presuckling newborn.