N - 6 AND N - 3 FATTY-ACID ACCUMULATION IN THP-1 CELL PHOSPHOLIPIDS

The human monocytic leukemia cell line THP-1 is depleted of the long-c hain n-6, AA, when compared to human monocytes. This reflects the low availability of this FA in the growth medium generally used for cultur ed cells. The effects of AA, as well as EPA, supplementation of THP-1 cells on the incorporation of these FA in cell PL, especially in PC an d PE, was investigated. In addition the incorporation of labeled AA in PL from THP-1 cells was compared to that in human monocytes. Measurem ents were done through HPLC separation of PL, detected by UV absorptio n and radioactivity, FA analysis by GC and characterization of PC subc lasses by FAB-MS. Marked differences were observed in the incorporatio n of the two FA in cell PL, particularly two PC subclasses, and in the accumulation in individual PL after supplementation of THP-1 cells. A ccumulation of AA and EPA in THP-1 cells appeared to be mutually indep endent. The incorporation of AA was also quite different in THP-1 from that in monocytes. Thus, characterization of the FA content in lipids of cultured cells is an essential requirement for optimal utilization of these cells.