REGULATORY EFFECTS OF DIETARY N-3 AND N-6 LIPIDS ON PLASMA AND HEPATIC LIPID-LEVELS, LIVER-CELL NUMBER AND MICROSOMAL PROTEIN-CONTENT IN SPONTANEOUSLY HYPERTENSIVE RATS

Weanling male spontaneously hypertensive rats were fed semipurified di ets containing either corn or fish oil for 8 weeks. Rats fed on fish o il diet had significantly lower plasma triglyceride, total cholesterol and HDL-cholesterol levels than rats fed on corn oil diet (P <0.05). Moreover, rats fed on fish oil diet had significantly lower liver tota l lipid and triglyceride concentrations than rats fed on corn oil diet (P <0.05). Dietary lipids were reflected in plasma fatty acid composi tion. Rats fed on fish oil diet had significantly greater plasma eicos apentaenoate (EPA) and docosahexaenoate (DHA) (n-3 PUFAs) with an acco mpanying decrease in plasma linoleate (LA) and arachidonate (AA) (n-6 PUFAs), in comparison with the rats fed corn oil (P <0.05). Those resu lts would suggest that the n-3 PUFAs were incorporated into plasma lip ids at the expense of the n-6 PUFAs. Rats fed on corn oil diet had sig nificantly greater liver DNA content than rats fed on fish oil diet (P <0.05), thereby implying that the n-3 PUFAs in fish oil had an inhibi tory effect on liver cell proliferation. Furthermore, rats fed on fish oil diet had significantly greater hepatic microsomal protein content than rats fed on corn oil diet (P <0.05), indicating that fish oil ex erted a stimulatory effect on hepatic microsomal enzymes.