Incorporation of polyenephosphatidylcholine into serum lipoproteins after oral or intravenous administration

Radioactive polyenephosphatidycholine (PPC) was injected i.v. in dogs, rats and rabbits. In addition, PPC was administered orally to dogs and rats. The incorporation of the PPC applied into serum lipoproteins was determined. After i.v. injection in dogs approximately 80% of the radioactive dose was transported by HDL. Only around 50% of the dose was found, however, in the HDL fraction of rats and rabbits. Radiochemical analyses provided a quantitative determination of the time course of PPC incorporation into HDL as well as of the metabolites of PPC. After in vitro incubation with rat and human serum PPC was incorporated into HDL by approximately 50% of the applied dose and by 5--14% into LDL, by approximately 15% into VLDL and by 20--30% into other serum constituents. In vitro incubation of PPC with human HDL yielded the complete incorporation into this lipoprotein fraction.