Prematurity in the rat. II. Effect of hypothermia

The time-courses of liver glycogen, plasma glucose, lactate, alanine and glycerol concentrations in term and preterm rats undergoing hypothermia (30 degrees C) during the first 2 h after delivery have been studied. Hypothermia prevented liver glycogenolysis and the neonatal decrease of plasma glucose concentration in term and preterm rats during the first 2 h after delivery. Hypothermia decreased plasma glucose, lactate and alanine utilization but increased plasma glycerol concentration. These results suggest that hypothermia blunts the utilization of the main metabolic substrates but increases brown adipose tissue lipolysis for thermogenesis.