Effect of age on the fatty acid composition of phospholipids in human lymphocytes

We have examined the fatty acid composition of phospholipids of unstimulated and PHA-stimulated T cells from young and old donors. Our results demonstrate that aging is accompanied by decreases in the saturated fatty acids, myristic acid, and palmitic acid, and a concomitant increase in the unsaturated arachidonic acid. Following activation with PHA for 24 h, age-associated differences in fatty acids could no longer be detected. In contrast to the lymphocyte, aging did not affect the fatty acid composition of either serum or neutrophil phospholipids. Exposure of lymphocytes from old donors to myristic acid complexed medium increased the levels of myristate in the phospholipids to levels similar to that seen in lymphocytes from young donors. We conclude from these studies that aging is accompanied by an alteration in the fatty acid profiles of phospholipids, and that incubation in myristic acid complexed medium modulates these profiles. These alterations are unique to lymphocytes and may contribute to the age-related declines in lymphocyte function.