Modification of fatty acid composition of rat heart lipids by feeding cod liver oil.

Modification of the fatty acid composition of cardiac phospholipids and neutral lipids was studied in rats fed a diet containing 10% cod liver oil. The results reflect the dynamic state of esterified fatty acids in neutral lipids and phospholipids of heart muscle. In cardiac neutral lipids there was a moderate but significant increase in exogenous fatty acids, 20:1(n--9), 22:1(n--11), 20:5(n--3) and 22:6(n--3), in animals fed cod liver oil, and a relative decrease in endogenous fatty acids, 16:0, 18:2(n--6 and 20:4(n--6). Increased dietary availability of 22: 6(n--3) resulted in a major increase in the content of this fatty acid in phospholipids and replacement of 18:2(n--6) and 20:4(n--6). The 22:6(n--3) was able to replace one third of 18:2(n--6): further increase in 22: 6n--3) was accompanied by a decrease in 18:0. An inverse relationship between (n--6) and (n--3) polyene fatty acids in cardiac phospholipids suggests a replacement of (n--6) acids by (n--3) fatty acids.