Effect of maternal canine starvation on fetal and neonatal liver metabolism
Heptic glycolytic and gluconeogenic intermediates from fasted newborns of five control and five 3-day starved canine mothers (MCS) were studied at 0, 3, 6, 9, and 24 h of age. MCS did not affect fetal hepatic glycogen concentration; however, a significant increase in uridine diphosphate glucose (UDPG) (0.186 vs. 0.106 mumol/g), fructose 6-phosphate (0.084 vs. 0.034), pyruvate (0.321 vs. 0.126), and citrate (0.190 vs. 0.140) concentrations occurred. At 3 h, the intrahepatic glucose concentration among the MCS newborns declined (3.09 vs. 6.34) and remained lower than the controls for up to 9 h. UDPG concentration, however, remained elevated throughout the 24 h. In addition intrahepatic pyruvate was significantly elevated in the MCS group. Elevated phosphoenolpyruvate concentrations were observed between 3 and 6 h. Malate levels were lower than controls between 6 and 9 h and alpha-ketoglutarate was significantly higher between 6 and 24 h. Calculated cytoplasmic NAD/NADH ratio was elevated throughout the 24 h. Hepatic triglycerides were higher than controls up to 9 h. A decline in hepatic triglycerides was observed between 9 and 24 h. The results suggest increased glycolysis and suppressed gluconeogenesis in the MCS puppies, probably because of increased triglyceride synthesis and decreased free fatty acid oxidation resulting in a lack of cytoplasmic NADH.