DIETARY OXIDIZED OIL ENHANCES THE ACTIVITY OF (NA+K+) ATPASE AND ACETYLCHOLINESTERASE AND LOWERS THE FLUIDITY OF RAT ERYTHROCYTE-MEMBRANE

The effect of dietary oxidized lipids on the fluidity and function of red blood cell (RBC) membranes was studied. Male growing rats were fed diets containing 10% fresh (control) or oxidized (experimental) soybean oil for 8 weeks. Ingestion of the oxidized oil resulted in the accumulation of high levels of fluorescent peroxidation products in the RBC of the experimental animals. Membrane fluidity was studied by fluorescence polarization, using 1,6-diphenyl-1,3,5 hexatriene (DPH) as a probe. The fluidity of RBC membranes isolated from the animals of the experimental group was significantly lower than that of the membranes derived from the control following 3 and 7 weeks of feeding. This lower fluidity was accompanied by a decrease in the content of membrane polyunsaturated fatty acids and an increase in the activity of the membrane-bound enzymes acetylcholinesterase and (Na + K+)A TPase. Despite the excessive oxidative state of the oil used, the changes observed in membrane composition, dynamics, and function emphasize the potential risk of dietary oxidized lipids.