Effects of short-term dietary administration of marginal levels of vitamin B(6)and fish oil on lipid composition and antioxidant defences in rat tissues.

Previous reports have shown that vitamin B(6)deficiency leads to peroxidative stress in rat organs. In this paper, we evaluated the effects on lipid peroxidation of short-term (six weeks) dietary administration of marginal contents of vitamin B(6). A further risk factor of susceptibility to peroxidation was the presence of fish oil with higher contents of n-3 polyunsaturated fatty acid (LCPUFA). The contemporaneous vitamin B(6)deficiency and presence of fish oil caused a C18:2 increase, a C20:4 decrease, and replacement of some n-6 LCPUFA with n-3 LCPUFA, without changes in the unsaturation index. In liver, TBARS production did not show any differences between dietary conditions, whereas the activities of glutathione-dependent enzymes were stimulated. In heart, fish oil increased lipid peroxidation, especially in the vitamin B(6)-deficient group. Copyright 2001 Harcourt Publishers Ltd.