title: Dietary essential fatty acids change the fatty acid profile of rat neural mitochondria over time.
abstract: This experiment examined the time course over which the amount of dietary essential fatty acids (EFA) affects brain mitochondrial fatty acids. Weanling rats were fed 20% (wt/wt) fat diets that contained either 4 or 15% (wt/wt of diet) EFA for 1, 2, 3 or 6 wk or a 10% EFA diet for 3 or 6 wk. The EFA ratio [18:2(n-6)/18:3(n-3)] of all diets was approximately 30. Fatty acid analysis of brain mitochondrial phosphatidylethanolamine, phosphatidylcholine and cardiolipin revealed that the largest dietary effect was on 18:2(n-6), which was 30% higher in rats fed the 15 vs. 4% EFA diets after 1 wk. This difference increased to twofold by 3 wk and was still twofold after 6 wk. These results demonstrate several facts: 1) the response of 18:2(n-6) in cardiolipin to dietary EFA is very fast and large, relative to changes in other quantitatively major fatty acids observed in weanling rats; 2) the 18:2(n-6) level in neural cardiolipin stabilizes after 3 wk of feeding at a level dependent upon the amount of dietary EFA; and 3) at least one neural fatty acid, 18:2(n-6), is very sensitive to amounts of dietary EFA that are well above the animal's EFA requirement.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Canada.
authors.forename: J R
authors.initials: JR
authors.lastname: Dyer
authors.forename: C E
authors.initials: CE
authors.lastname: Greenwood
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002308:Cardiolipins / Q000378:metabolism; D004032:Diet; D002149:Energy Intake; D005228:Fatty Acids, Essential / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002308:Cardiolipins; D005228:Fatty Acids, Essential; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines