“…During fetal life, PEPCK activity is virtually absent (1,22); its activity increases approximately 25-fold during the first 24-48 h of life (1,22,33). Pyruvate carboxylase, fructose 1,6-diphosphatase and glucose-6-phosphatase (1,22,33,34) are induced during later fetal life and their activities during neonatal life, although relatively limited compared to later life, are adequate to sustain gluconeogenesis. Thus, PEPCK is considered rate-limiting in the normal newborn rat.…”