The effect of maternal diabetes on glycogen metabolism in the embryonic rat

This study examined the effect of maternal hyperglycemia during pregnancy due to streptozotocin-induced diabetes on the synthesis of glycogen in the brain and liver of embryonic and newborn rats. Maternal hyperglycemia (serum glucose 25.3 +/- 0.9 mM) during gestation had no effect compared to controls (5.7 +/- 0.2 mM) on embryonic and newborn glycogen content in liver. In contrast, embryos experiencing hyperglycemia in utero had a two-fold higher brain glycogen content than controls at term; 1.6 mg/g vs. 0.84 mg/g, respectively. Interestingly there was a significant delay in the mobilization of brain glycogen during the immediate postnatal period in the offspring of diabetic mothers and control animals. These results suggest that uncontrolled maternal diabetes during pregnancy may significantly increase the availability of a potentially important local fuel source for the newborn brain: glycogen.