title: Occurrence of 22:3n-9 and 22:4n-9 in the lipids of the topminnow (Poeciliopsis lucida) hepatic tumor cell line, PLHC-1.
abstract: The lipids of the hepatic tumor cell line, PLHC-1, from the topminnow (Poeciliopsis lucida), were found to contain considerable amounts of a range of n-9 polyunsaturated fatty acids despite culture in serum containing significant amounts of essential fatty acids. The structural identity of all the n-9 polyunsaturated fatty acids was confirmed by gas chromatography/mass spectrometry. Of particular interest, PLHC-1 cell total lipid contained 1.9% of 22:3n-9 and 3.3% of 22:4n-9. As the culture medium contained virtually no n-9 polyunsaturated fatty acids, these fatty acids are all formed by the PLHC-1 cells, presumably from 18:1n-9. The 22:3n-9 and 22:4n-9 are presumably formed by processes of elongation and "delta 4" desaturation of Mead acid, 20:3n-9, present at over 11% in fatty acids of total lipid. Both 22:3n-9 and 22:4n-9 were primarily located in phosphatidylserine (4.1 and 8.5%, respectively) and, to a lesser extent, in phosphatidylethanolamine (2.2 and 6.5%, respectively), in common with the C22 derivatives of the n-3 and n-6 series, whereas 20:3n-9 was preferentially located in phosphatidylinositol (31.2%). The results establish that long-chain polyunsaturated fatty acids of the n-9 series can be formed in vertebrate tissue other than in conditions of classical essential fatty acid deficiency.
authors.affiliation: NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland.
authors.forename: D R
authors.initials: DR
authors.lastname: Tocher
authors.forename: J R
authors.initials: JR
authors.lastname: Dick
authors.forename: J R
authors.initials: JR
authors.lastname: Sargent
mesh_terms: D000818:Animals; D005231:Fatty Acids, Unsaturated / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000032:analysis; D010716:Phosphatidylinositols / Q000032:analysis; D010718:Phosphatidylserines / Q000032:analysis; D010743:Phospholipids / Q000378:metabolism; D011036:Poecilia; D014407:Tumor Cells, Cultured
chemical_list: D005231:Fatty Acids, Unsaturated; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D010718:Phosphatidylserines; D010743:Phospholipids