The effect of maternal diabetes on the synthesis and secretion of phosphatidylcholine in fetal and maternal rat lungs in vitro.

Incorporation of (methyl-14C)choline into phosphatidylcholine and the release of prelabelled phosphatidylcholine was investigated in vitro using lung slices from pregnant rats and their offspring near term. Tissue from normal, diabetic and insulin-treated diabetic pregnant rats and their offspring was utilized to assess the effects of maternal diabetes on fetal lung maturation. The results show that the synthesis of phosphatidylcholine in fetal/newborn lungs through the cytidine 5'-diphosphocholine pathway was not affected by maternal diabetes. However, secretion of phosphatidylcholine from the lungs of fetuses of diabetic mothers was very much suppressed one day after parturition. Insulin treatment of the diabetic pregnant rats restored secretion of phosphatidylcholine from the fetal/newborn lungs to control values. These results suggest that an impaired secretion of phosphatidylcholine from the lungs of fetuses of diabetic mothers may be partly responsible for the higher incidence of respiratory distress syndrome among children of diabetic mothers. The results also revealed some correlation between the secretion of phosphatidylcholine from maternal lungs, maternal serum phospholipids and synthesis of phosphatidylcholine by fetal lungs during late gestation, suggesting a possible relationship between maternal phospholipid metabolism and fetal lung maturation.