Essential fatty acid metabolism in the feline: relationship between liver and brain production of long-chain polyunsaturated fatty acids.
A comparison was made between the liver and brain conversion of linoleic acid, 18:2n-6, and linolenic acid, 18:3n-3, to long chain polyunsaturated fatty acids in domestic felines. This report demonstrates that 6-desaturase activity does exist in the feline. The liver produced deuterium-labeled polyunsaturated fatty acids up to 22:4n-6 and 22:5n-3. The brain was found to accumulate the deuterium-labeled polyunsaturated fatty acids, 22:5n-6, 22:6n-3, 24:4n-6, 24:5n-6, 24:5n-3, and 24:6n-3. Adult felines were provided a diet consisting of either 10% fat (hydrogenated coconut oil-corn oil 9:1) containing no 20- or 22-carbon n-6 or n-3 fatty acids or a chow diet with meat and meat by-products that contained these long chain polyunsaturated fatty acids for a 6-month period. During this time, the in vivo production of long chain polyunsaturated fatty acids was evaluated in these animals. The cats were given oral doses of both [17,17,18,18,18,2H]18:3n-3 and [9,10,12,13-2H]18:2n-6 and the deuterium-labeled fatty acid metabolites were measured in the blood, liver, and brain using a highly sensitive and specific gas chromatography-mass spectrometry technique. Contrary to previous claims, 6-desaturase activity was shown to exist in the feline. The evidence for this was the detection of [9,10,12,13-2H] 18:3n-6 which was converted from [9,10,12,13-2H]18:2n-6 and observed in the plasma.(ABSTRACT TRUNCATED AT 250 WORDS)
Pawlosky
R
R
Laboratory of Membrane Biochemistry and Biophysics, DICBR, National Institute on Alcoholism and Alcohol Abuse, Rockville, MD 20852.
Barnes
A
A
Salem
N
N
D000818:Animals; D016718:Arachidonic Acid / Q000096:biosynthesis; D001921:Brain / Q000378:metabolism*; D002415:Cats; D000074263:Coconut Oil; D003314:Corn Oil / Q000008:administration & dosage; D003903:Deuterium; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood; D005228:Fatty Acids, Essential / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D008401:Gas Chromatography-Mass Spectrometry; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D017962:alpha-Linolenic Acid / Q000378:metabolism
D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005228:Fatty Acids, Essential; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D010938:Plant Oils; D017962:alpha-Linolenic Acid; D016718:Arachidonic Acid; D003314:Corn Oil; D019787:Linoleic Acid; D003903:Deuterium; D044943:Fatty Acid Desaturases; D000074263:Coconut Oil