Effect of semicarbazide on the surfactant phospholipid percentages during fetal and postnatal lung development in rat.

1. The effect of 100 mg/kg of semicarbazide on phosphatidylcholine, phosphatidylethanolamine, sphingomyeline, phosphatidylserine and lysophosphatidylcholine of the pulmonary surfactant was studied in offspring of treated rats on the 10th day of gestation. 2. The relative percentages of phosphatidylcholine were smaller in the offspring of treated rats than in controls, but the opposite was observed with the other phospholipids. 3. Significant statistical differences at almost all ages studied were observed in phosphatidylcholine and phosphatidylethanolamine. 4. The ratio of phosphatidylcholine to sphingomyeline, an index of lung maturity, was smaller in the offspring of treated rats, with statistically significant differences just before birth and on the first day of life.