Effects of a High α-Linolenate and High Linoleate Diet on Hemolysis and Lipid Peroxidatino of Rat Erythrocytes

α-Linolenic acid (18 : 3n-3) is known to autoxidize several fold faster than linoleic acid (18 : 2n-6). Feeding a high α-linolenate or a high linoleate diet to rats resulted in significant changes in the n-3/n-6 ratios of 20 and 22 carbon highly unsaturated fatty acids in erythrocytes. However, the rates of hemolysis observed in N_2- or O_2-atmosphere were similar between the two dietary groups. No significant amounts of conjugated dienes were detected and no measurable changes in the fatty acid compositions were observed during the incubations, indicating that the hemolysis occurred without involving significant lipid peroxidation. When stimulated with a free radical initiator, [2,2'-azobis-(2-amidinopropane)dihydrochloride] (AAPH), hemolysis occurred more rapidly, conjugated dienes formed and unsaturated/saturated ratios of phospholipid fatty acids decreased. However, no satistically significant difference was observed in these parameter of the two dietary groups. These results indicate that hemolysis occurs without involving lipid peroxidation but is accelerated by free radicals through lipid peroxidation, and that the difference in autoxidizabilities of α-linolenate and linoleate is not reflected in the rates of hemolysis and autoxidation in rat erythrocytes.