Abstract
Fish consumption is associated with reduced cardiovascular
mortality, and elevated myocardial long-chain n-3
polyunsaturated FA (PUFA) content is implicated in this cardioprotection.
This study examined the dose and time responses
for incorporation of n-3 PUFA into cellular membranes in rats
fed fish oil (FO)-containing diets. For the time course study, rats
were fed a 10 FO diet for periods ranging from 0 to 42 d, after
which myocardial and erythrocyte membrane fatty acid composition
was determined. For the dose response study, rats (n = 3)
were fed 0, 1.25, 2.5, 5, or 10 FO for 4 wk, with myocardial,
erythrocyte, and skeletal muscle membrane FA determined. Myocardial
DHA (22:6n-3) levels doubled in 2 d, stabilizing at levels
200 higher than control after 28 d feeding with 10 FO. By
comparison, DHA levels doubled after 4 wk of 1.25 FO feeding.
In myocardium and skeletal muscle, EPA (20:5n-3) levels
remained low, but in erythrocytes EPA levels reached 50 of
DHA levels. The n-3 PUFA were incorporated at the expense of n-6
PUFA in myocardium and skeletal muscle, whereas erythrocytes
maintained arachidonic acid levels, and total n-3 PUFA incorporation
was lower. This study shows that low doses of FO produce
marked changes in myocardial DHA levels; maximal incorporation
takes up to 28 d to occur; and while erythrocytes are a
good indicator of tissue n-3 incorporation in stable diets, they
vary greatly in their time course and pattern of incorporation.
Original language | English |
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Pages (from-to) | 955 - 961 |
Number of pages | 7 |
Journal | Lipids |
Volume | 39 |
Issue number | 10 |
Publication status | Published - 2004 |
Externally published | Yes |