The effect of betamethasone on phosphatidylcholine species composition in fetal rat lungs.

After betamethasone treatment, a significant diminution of the monoenoic phosphatidylcholine 32 carbon species (palmitoyl-palmitoleyl phosphatidylcholine and palmitoleyl-palmitoylphosphatidylcholine) and the phosphatidylcholine 34 carbon species (primarily palmitoyl-oleoyl-phosphatidylcholine) could be demonstrated both in absolute and relative terms, while the palmitic acid portion in the phosphatidylcholine fatty acids was nearly unchanged. This is consistent with a significant reduction of the palmitoleic and oleic acid portions of the total phosphatidylcholine fatty acids in the lungs of rat fetuses.