The effects of unsaturated fatty acids on the synthesis of arachidonic acid in rat kidney cells.
Cultured rat kidney cells absorbed exogenous linoleic acid (cic, cis-18:2n-6) and esterified it mostly into glycerophospholipids. As the concentration of 18:2 was increased (5-200 microM) the quantity absorbed increased linearly and the amount esterified in the triacylglycerol increased. The cells possessed active acyl delta 6-desaturase and elongase which facilely converted 18:2n-6 to 20:4n-6. At low intracellular concentrations of 18:2n-6 other unsaturated fatty acids, i.e., gamma-linolenic (18:3n-6), alpha-linolenic (18:3n-3), dihomo-gamma-linolenic (20:3n-6), and especially trans, trans-linoleic acid (trans, trans-18:2n- -6) at concentrations ranging from 25 to 200 microM depressed delta 6-desaturase activity. However, suppression of 20:4 synthesis even by trans, trans-18:2 was readily overcome by increasing the concentration of available cis, cis-18:2n-6.
D000818:Animals; D001095:Arachidonic Acids / Q000096:biosynthesis*; D002478:Cells, Cultured; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D007668:Kidney / Q000378:metabolism*; D008041:Linoleic Acids / Q000378:metabolism; D051381:Rats
D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids