UPTAKE OF GLUCOSE AND RELEASE OF GLUCONEOGENIC PRECURSORS BY THE HINDLIMB OF THE FASTING BABOON NEONATE

Uptake of glucose and release of gluconeogenic precursors by the hindlimb of the fasting baboon infant was evaluated in 6 baboon neonates after delivery by cesarean section at term and 8 6-week-old baboon infants. Arteriovenous (AV) differences across the hindlimb were determined by measuring substrate levels in the aorta and the inferior vena cava below the level of the renal veins and above a unilaterally occluded femoral vein.There were no significant AV differences for pyruvate, beta-hydroxybutyrate, glutamate or glutamine. Production and uptake was calculated using hindlimb blood flows determined by the radioactive microsphere method. Glucose consumption by the hindlimb in the neonate was 2.4 μM/min. Uptake by the entire carcass was estimated to be 9.6 μM/min, almost twice the previously estimated cerebral cortex glucose consumption (5.6 μM/min). Estimated splanchnic and renal glucose production (15.7 μM/min) could account for all (15.2 μM/min) of estimated cerebral and carcass glucose uptake. The fasting neonate has a substantial glucose utilization rate exclusive of the requirement of the central nervous system.