Influence of maternal diabetes on lipid metabolism in neonatal rat lung

The effect of maternal diabetes on tissue constituents, lipid metabolism and glucose utilization was examined in 1-day old rat lungs. Maternal diabetes was induced by intravenous injection of streptozotocin (50 mg/kg body weight) into pregnant Long-Evans hooded rats on the 10th day of gestation resulting in a maternal serum glucose concentration which was 3-fold higher than that of controls. Neonates from diabetic mothers showed a significant decrease in body weight (14%), lung weight (32%) and lung protein concentration (30%). Glycogen, DNA and lipid content of the lungs were significantly elevated in neonates from diabetic mothers. The percent of total phospholipid made up of phosphatidylcholine was not altered, but the percentage of disaturated phosphatidylcholine was decreased (25%). The activity of the CDPcholine pathway enzymes (choline kinase, cholinephosphate cytidylyltransferase and choline phosphotransferase) also showed a marked increase in lungs of neonates from diabetic mothers. Lung slices of neonates from diabetic mothers showed depressed in vitro incorporation of [U-¹⁴C]glucose into neutral lipids and decreased oxidation to CO₂. The results of these investigations show that maternal diabetes interferes with the structural and metabolic processes by which the undifferentiated lung becomes functional at birth.