CONTROL OF GLUCONEOGENESIS IN THE BABOON FETUS

Regulation of gluconeogenesis has been studied in 4 baboon fetuses (135-140 d.) with catheters chronically placed in the inferior vena cava and aorta, using a single isotope-labeled precursor technique. A primed infusion of [u-14C] lactate (Lac) was administered to the fetus to steady state over 150 min. Net Lac to glucose (Glu) conversion was evaluated by comparing fetal (Fet) and Maternal (Mat) dpm and specific activity (S.A.) of Lac and Glu during Mat fed (4), fasting (4), and Glu infusion (1) (Iglu).Mat/Fet Glu dpm were 36.0±1.9% fed, 51.4±3.1% fasting (p<.001) and 9.2% during Iglu. Mat/Fet Glu S.A. was 27.6±2.4% fed, 44.7±5.2% fasting (p<.001) and 9.5% during Iglu. Fet to Mat placental transfer of Glu and Lac is more efficient in the baboon than in the sheep, but higher Fet than Mat 14C Glu enrichment confirms the capacity of the primate fetus for gluconeogenesis. Fet gluconeogenesis from Lac is regulated by Mat nutrient status and substrate supply.