Abstract
High-density (HD-RBC) and low-density (LD-RBC) red blood cells were separated with Percoll solution (d 1.108) from rats fed for 28 days on commercial F-2 pellets, a soybean oil diet or a fish oil diet, and their phospholipid hydroperoxide contents were measured to investigate the peroxidation of RBC membranes in vivo. Rat RBC contained both phosphatidylcholine hydroperoxide (PCOOH, 50-127nM/packed RBC) and phosphatidylethanolamine hydroperoxide (PEOOH, 47-108nM/packed RBC) as the major hydroperoxides, and the peroxide content of RBC in rats fed fish oil was significantly higher than that in rats fed soybean oil. No difference in the peroxide content was observed between LD-RBC and HD-RBC. These results suggest that peroxidative damage to phospholipids in the RBC membrane is not as significant as expected during the aging of RBC, but that it is profoundly influenced by the type of dietary oil ingested. A fish oil diet causes more peroxidative damage to RBC membrane phospholipids than a soybean oil diet in the rat.
