Comparative utilization of n-3 polyunsaturated fatty acids by cultured human Y-79 retinoblastoma cells.
The Y-79 retinoblastoma cell, a cultured human line derived from the retina, was utilized as a model for investigating the metabolism of n-3 polyunsaturated fatty acids in neural tissue. When cultures were incubated with 5 microM linolenic (18:3), eicosapentaenoic (20:5) or docosahexaenoic (22:6) acids, a low concentration probably representative of physiologic levels, the amount incorporated was 20:5 congruent to 18.3 greater than 22:6. Regardless of which fatty acid was provided, 65-75% of the total uptake accumulated in phosphatidylethanolamine and ethanolamine plasmalogen, suggesting that these phospholipids play an important role in n-3 polyunsaturated fatty acid metabolism. A small amount of 22:6 was converted to 20:5, which was recovered in phosphatidylinositol and phosphatidylserine. Therefore, one metabolic function of 22:6 may be to serve as an intracellular storage pool for the formation of 20:5 through retroconversion. When any of the n-3 polyunsaturates was available, the main fatty acid that accumulated in the cell phospholipids was 22:6. The extent to which 22:6 accumulated, however, depended on the particular n-3 polyunsaturated fatty acid that was available. This suggests that the 22:6 content of a neural cell, and any cellular function dependent on 22:6 content, may be regulated by changes in the type of n-3 polyunsaturate available to the nervous system.
D002250:Carbon Radioisotopes; D002460:Cell Line; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D005134:Eye Neoplasms / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D010743:Phospholipids / Q000096:biosynthesis / Q000302:isolation & purification; D012175:Retinoblastoma / Q000378:metabolism*; D013329:Structure-Activity Relationship
D002250:Carbon Radioisotopes; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D010743:Phospholipids; D004281:Docosahexaenoic Acids; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid