DIETARY DOCOSAHEXAENOIC ACID DOSE NOT PROMOTE LIPID-PEROXIDATION IN RAT-TISSUE TO THE EXTENT EXPECTED FROM PEROXIDIZABILITY INDEX OF THE LIPIDS

Docosahexaenoic acid (DHA) ingestion enhanced the susceptibility of ra t liver and kidney to lipid peroxidation as a function of the dietary DHA level, but did not increase lipid peroxides as assessed by thiobar bituric acid (TBA) values to the level expected from the peroxidizabil ity index of the tissue total lipids. This phenomenon was especially p rominent in the liver. In the liver, the higher proportion of DHA in t he non-phosphorus lipids might play an important role in lessening the susceptibility of the tissue to lipid peroxidation. In the brain and testis, on the other hand, lipid peroxide levels were decreased when D HA was given to the animals, In the testis, in particular, the proport ion of DHA in total lipids was lowest among all tissues examined, even when a relatively high level of DHA had been ingested, and this could be related to the low lipid peroxide level. Therefore, the protection against lipid peroxidation differed from tissue to tissue, even from the viewpoint of the fatty acid composition of the tissue lipids. In a ddition, changes in the lipid peroxide levels of the liver, kidney, br ain and testis, as assessed by TEA values, seemed to be associated wit h changes in the peroxidizability index of phosphatidylcholine (+ card iolipin) in each tissue.