The effect of antioxidant deficiency on tissue lipid composition in the rat. IV. Peroxidation and interconversion of polyunsaturated fatty acids in muscle phospholipids.

It has been suggested that the net changes which take place in the composition of the muscle phospholipid fatty acids of the antioxidant-deficient rat represent the balance of two opposing processes. To compensate for (A) the preferential peroxidative destruction of the most highly polyunsaturated fatty acids in the tissue there occurs (B) an increase in the conversion of available precursors to the higher polyunsaturated fatty acids. Analysis of the data in terms of peroxidation kinetics indicated that the onset of creatinuria in one group after 3 weeks and in a second group after 7 weeks on an antioxidant-deficient diet occurred in both cases concomitant with the peroxidative "disappearance" of approximately 125 mug of phospholipid polyunsaturated fatty acid per gram wet weight of tissue or 2% of the total muscle phospholipid fatty acids.