Effects of Dietary n-3 and n-6 Fatty Acids on Liver and Erythrocyte Lipids in Streptozotocin-Induced Diabetic Rats.

Streptozotocin-induced diabetic and control rats were placed in one of two dietary groups and fed diets with a P/S ratio of 2.2-2.3 for 4 weeks. The n-3/n-6 ratios in the dietary groups were 0.01 (SAF group) and 2.92 (PER group). A decrease in the 20:4n-6 level, and an increase in the 18:2n-6 level were observed in the erythrocyte lipids of diabetic rats of both dietary groups, as compared with the levels in control rats. The cholesterol/lipid-P ratio in erythrocyte lipids was significantly higher in diabetic rats than in control rats in both dietary groups, while the ratio in livers was significantly lower in diabetic rats. In liver phospholipids, the differences between the polyunsaturated fatty acid contents of control and diabetic rats in the SAF group, were almost identical to those in erythrocyte lipids. However, in the PER group, a small increase in the 20:4n-6 level, besides an obvious increase in the 18:2n-6 level, was observed in diabetic rats, and n-3 fatty acid levels, especially that of 20:5n-3, were lower significantly in diabetic rats than in control rats. Plasma triglyceride and cholesterol levels in diabetic rats were higher than those in control rats in both dietary groups. The two dietary groups showed significant different triglyceride levels, but similar cholesterol levels. It is suggested that the physiological effect of 18:3n-3 is impaired in diabetes in the same manner as that of 18:2n-6 is.