FATTY-ACID METABOLISM IN NORMOTENSIVE AND HYPERTENSIVE RATS .1. DIFFERENTIAL INCORPORATION OF DIETARY N-3 AND N-6 FATTY-ACIDS

The incorporation of dietary n-3 and n-6 fatty acids into tissue phospholipids of genetically hypertensive (SHR), borderline hypertensive (BHR), and normotensive (Wistar Kyoto, WKY) EFA-deficient rats was examined to determine whether strain differences exist in the ability to incorporate these nutrients. Weanling male SHR, BHR, and WKY (28/strain) were placed on a fat-free semi-purified diet until 10 weeks of age. At that time, 4 animals/strain were killed for tissue fatty acid analysis. The remaining animals were then placed on dietary supplements (3% wt) of either safflower, evening primrose, or fish oil for 7 days, after which they were killed for liver, heart, kidney, plasma, and erythrocyte phospholipid fatty acid analysis. WKY, SHR, and BHR appeared to incorporate dietary n-6 fatty acids similarly in all tissues except erythrocytes and heart, in which SHR demonstrated a reduced incorporation. SHR, however, demonstrated a reduced incorporation of 20:5n-3 and 22:6n-3, as well as total n-3 in all tissues studied, which was compensated for by an increased incorporation of n-9. These data suggest that tissue lipid composition may not be equally responsive to dietary fatty acid manipulation across different genetic strains, and that dietary fatty acid requirements for normal physiological function may vary with genetic strain. © 1990 Pergamon Press plc. All rights reserved.