DIETARY-LIPID AND IRON STATUS MODULATE LIPID-PEROXIDATION IN RATS WITH INDUCED ADJUVANT ARTHRITIS

We studied the effect of dietary lipids on iron metabolism and lipid p eroxidation during induced adjuvant arthritis and/or iron overload in rats. We compared a control diet containing corn oil and rapeseed oil with a diet devoid of polyunsaturated fatty acids containing only trip almitin as lipids. Four subgroups of rats were used with each diet: wi thout further treatment, with induction of adjuvant arthritis, with ir on overload, and with induction of adjuvant arthritis and iron overloa d. The profile of fatty acids present in plasma and in microsomes chan ged in rats fed the tripalmitin diet. The level of tetra- and pentauns aturated fatty acids was reduced, and the level of monounsaturated fat ty acids and iron stores was increased with respect to control rats. T hus, ingestion of a tripalmitin diet reduced the substrate for lipid p eroxidation, as shown by the decrease in thiobarbituric acid-reactive substances in plasma and conjugated dienes in hepatic microsomal fract ion. Adjuvant arthritis and iron overload had a synergistic effect on lipid peroxidation and iron storage in liver. Further, in the hepatic microsomal fraction, tripalmitin reduced the levels of cytochrome P-45 0, and arthritis reduced the levels of cytochrome P-450 and Ca2+ seque stration. Our results suggest that rats fed tripalmitin showed a reduc tion of lipid peroxidation induced by inflammation or by iron overload , because of the lack of polyunsaturated fatty acids in the diet, alth ough tripalmitin usually increases the iron stores in the body and cau ses hepatic alterations.