Dietary fatty acid composition influences the degree of human LDL oxidation, but has only minor effects on vascular tone in a bioassay system.
OBJECTIVE
Oxidized LDL has been detected in atherosclerotic vessels and presumed to be one of the major risk factors in atherosclerosis and cardiovascular diseases. The aims of the present study were to clarify whether the oxidation degree of LDL influences arterial tone and whether different long-lasting dietary habits have effects on biological variables.


RESULTS
The lag phase of LDL oxidation was shorter (117 +/- 6 min) in the fish diet group than in the vegetarian (153 +/- 5 min) or the control diet group (152 +/- 10 min). The rat mesenteric arterial rings, which were preincubated with LDL oxidized to 1-30%, from the vegetarian and the fish diet groups showed (p < 0.05) decreased NA-induced maximal contraction forces when compared to the control diet. The LDL oxidation degrees of 31-60% and 61-90% had no effect on NA- and KCl-induced maximal contraction forces when compared to native LDL, nor were there differences between the diet groups. Endothelium-dependent and independent relaxation responses behaved similarly in all groups and were independent of the degree of oxidation.


CONCLUSIONS
Dietary habits change the fatty acid composition of LDL, but have only minor effects on the vasoactive properties of oxidized LDL.
Nevala
R
R
Department of Pharmacology and Toxicology, University of Helsinki, Finland.
Seppo
L
L
Tikkanen
M J
MJ
Laakso
J
J
Vanhanen
H
H
Vapaatalo
H
H
Korpela
R
R
D000328:Adult; D000818:Animals; D000975:Antioxidants / Q000032:analysis; D001161:Arteriosclerosis / Q000178:diet therapy* / Q000517:prevention & control; D001681:Biological Assay; D002318:Cardiovascular Diseases / Q000178:diet therapy* / Q000517:prevention & control; D014676:Diet, Vegetarian; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000032:analysis; D005247:Feeding Behavior; D005399:Fishes; D006801:Humans; D015227:Lipid Peroxidation; D008055:Lipids / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction
D000975:Antioxidants; D004041:Dietary Fats; D005227:Fatty Acids; D008055:Lipids; D008077:Lipoproteins, LDL