“In cells in which the phosphatidylcholine pool …-glycero-3-phosphocholine, prostaglandin E2 plus theophylline … [3H]phosphatidic acid and its subsequent conversion to [3H]diradylglycerol, implying an effect at the level of phospholipase D. … of [3H]phosphatidylcholine to generate [3H]phosphatidylethanol (a phospholipase D-dependent reaction) was also markedly inhibited.”