Fish oil significantly alters fatty acid profiles in various lipid fractions but not atherogenesis in apo E-KO mice.
BACKGROUND
Consumption of fish oil and n-3 fatty acids is associated with beneficial modifications in plasma lipid levels. The impact of these modifications on development of atherosclerotic lesions merits further investigation.


OBJECTIVE
The aim of this study was to investigate the impact of fish oil consumption on quality and quantity of lipoprotein fatty acids and its influence on atherosclerosis in apolipoprotein E-knockout (apo E-KO) mice.


METHODS
Male apo E-KO mice were treated with 1% dietary fish oil for 14 weeks. Plasma triglycerides (TG), phospholipids, (PL) and cholesteryl ester (CE) fractions were separated using thin layer chromatography. Plasma-free fatty acids (FFA) plus fatty acid contents of TG, PL, CE were determined using gas chromatography. Aortic atherosclerosis was assessed by histological and morphometrical techniques.


RESULTS
Twenty-eight fatty acids were identified in each of the four lipid compartments. High amounts of n-3 fatty acids (eicosapentaenoic (EPA), docosahexaenoic (DHA)) were found in all of these fractions. The levels of EPA and DHA increased by 400 and 150%, respectively, in FFA, TG and PL compartments; higher increases (>500 and 200%) in EPA and DHA were found in CE. This markedly decreased the n-6/n-3 ratios in FFA, TG, PL, and CE by 60, 72, 53, and 61%, respectively. These changes were accompanied by a significant increase in plasma triglyceride levels. Surprisingly, these changes did not affect atherogenesis.


CONCLUSIONS
Elevated levels of EPA and DHA do not appear to prevent development of atherosclerotic plaques in this model. Longer studies warrant investigation of the direct benefits of these fatty acids against myocardial damage as clinical consequences of advanced atherosclerosis.
Xu
Zuyuan
Z
Dept. of Human Nutritional Sciences. University of Manitoba, Winnipeg (MB), Canada.
Riediger
Natalie
N
Innis
Sheila
S
Moghadasian
Mohammed H
MH
D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D050197:Atherosclerosis / Q000378:metabolism* / Q000517:prevention & control; D002788:Cholesterol Esters / Q000737:chemistry / Q000378:metabolism; D002849:Chromatography, Gas / Q000379:methods; D002855:Chromatography, Thin Layer / Q000379:methods; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000097:blood; D005395:Fish Oils / Q000008:administration & dosage / Q000737:chemistry; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D011897:Random Allocation; D014280:Triglycerides / Q000737:chemistry / Q000378:metabolism
D001057:Apolipoproteins E; D002788:Cholesterol Esters; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005232:Fatty Acids, Volatile; D005395:Fish Oils; D010743:Phospholipids; D014280:Triglycerides; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid