Essential fatty acid metabolism in the feline: relationship between liver and brain production of long-chain polyunsaturated fatty acids

• Published in: Journal of lipid research 1994-11, Vol.35 (11), p.2032-2040
• Main Authors: Pawlosky, R, Barnes, A, Salem, Jr, N
• Format: Article
• Language: English
• Subjects: acide gras; acide gras essentiel; acide gras polyinsature; acidos grasos; acidos grasos esenciales; acidos grasos poliinsaturados; alpha-Linolenic Acid - metabolism; Animals; Arachidonic Acid - biosynthesis; brain; Brain - metabolism; Cats; cerebro; chat; Coconut Oil; Corn Oil - administration & dosage; Deuterium; Dietary Fats, Unsaturated - administration & dosage; encephale; essential fatty acids; Fatty Acid Desaturases - metabolism; fatty acids; Fatty Acids - blood; Fatty Acids, Essential - metabolism; Fatty Acids, Unsaturated - biosynthesis; foie; Gas Chromatography-Mass Spectrometry; gato; higado; Linoleic Acid; Linoleic Acids - metabolism; lipid metabolism; liver; Liver - metabolism; Male; metabolisme des lipides; metabolismo de lipidos; Plant Oils - administration & dosage; polyunsaturated fatty acids
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1016/s0022-2275(20)39949-1

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. For the first time, direct evidence for the metabolism of n-3 fatty acids in cats was obtained by the detection of deuterium-labeled metabolites including the polyunsaturated fatty acid, 22:5n-3, in the plasma, following an oral dose of deuterium-labeled 18:3n-3. The more highly unsaturated deuterium-labeled 22- and 24-carbon fatty acids including: 22:6n-3, 24:5n-3, 24:6n-3, 22:5n-6, 24:4n-6, and 24:5n-6 accumulated in the nervous system. These deuterium-labeled fatty acids were not detected in either the liver or plasma.