Essential fatty acid deficiency: metabolism of 20:3(n-9) and 22:3(n-9) of major phosphoglycerides in subcellular fractions of developing and mature mouse brain.

Essential fatty acid deficiency was initiated in young and mature mice. The metabolism of 20:3(n-9) and 22:3(n-9) in brain subcellular fractions was followed after the mice were switched from the deficient diet to a corn oil supplemented diet. After switching to the supplemented diet, the proportions of (n-9) polyunsaturated fatty acids in brain in both groups of mice decreased with time. The rate of disappearance of (n-9) polyunsaturated fatty acids was faster in the young groups than in the mature group. In the developing mice, the half-linves of the (n-9) polyunsaturated fatty acids in the total ethanolamine phosphoglycerides of brain microsomal, synaptosomal, and myelin fractions were 3, 10, and 15 days respectively. In the mature group, the half-lives for 20:3(n-9) in diacyl-glycerophosphorylethanolamine of microsome, synaptosome, and myelin fractions were 8-10, 10, and 22 days, respectively; and the half-lives for 22:3(n-9) in alkenylacyl-glycerophosphorylethanolamine of the same subcellular fractions were 8-12, 28, and rate of disappearance of 20:3(n-9) in brain was faster in the diacyl-glycerophosphorylethanolamine than in the alkenylacyl-glycerophosphorylethanolamine. These results demonstrate that the metabolism of (n-9) polyunsaturated fatty acid in brain phosphoglycerides during recovery from essential fatty acid deficiency not only varies with age, but also depends upon individual phosphoglycerides present in each subcellular fraction.