Phospholipid biosynthesis: the activity of phosphatidic acid phosphohydrolase in the developing lung and amnionic fluid.

The presented data suggest that PAPase may, indeed, be important in the biosynthesis of lung phospholipids. The observed increase in the specific activity of rabbit lung precedes the "surge" of phosphatidylcholine concentration and surfactant biosynthesis by at least 24 hours. In human amnionic fluid, PAPase specific activity was markedly increased in pregnancies of 35 weeks of gestation or more. The increase in the specific activity of PAPase preceded the "surge" of acetone precipitated phosphatidylcholine. The reported studies may provide an additional procedure to examine the problems associated with surfactant biosynthesis.