Maternal diabetes and its effect on biochemical and functional development of rabbit fetal lung.

Abstract

The effect of maternal diabetes on functional and biochemical maturation of the fetal lung was studied in a rabbit model. Pregnancy was initiated only after diabetes had been established. Both the pregnant doe and its fetuses were hyperglycemic. For comparison, the fetal heart and liver were also studied. In the diabetic group, the DNA content was lower in the fetal heart and lung while the protein content was higher in all three tissues. The glycogen levels were higher only in the fetal lung. Glycogen synthase was higher in the fetal lung and heart while phosphorylase activity was higher in all three tissues from the diabetic group. The activities of key enzymes involved in glycolysis were not affected. No difference was observed in the concentration of total phospholipids or in the ability of the airway fluid to reduce surface tension. In contrast, fetal lungs from diabetic does did not expand as well as the controls and retained less air on deflation. These findings suggest that the utilization of glycogen in fetal lungs from the diabetic does was not complete and that the increased incidence of respiratory distress in infants of diabetic mothers may not be due to a lack of surfactant.