DIFFERENCES IN FREE FATTY-ACID AND GLUCOSE-METABOLISM OF HUMAN-BLOOD NEUTROPHILS AND LYMPHOCYTES

  • 1 January 1976
    • journal article
    • research article
    • Vol. 47  (3) , 431-437
Abstract
Comparison of isolated human neutrophils and lymphocytes in short-term tissue culture revealed marked differences in their rates of lipid biosynthesis. Ficoll-Hypaque gradients were used to separate lymphocytes and neutrophils from the blood of normal subjects. Neutrophils incorporated more palmitate into cell lipids (151.0 .+-. 16.6 nmole per h/108 cells) than lymphocytes (41.6 .+-. 4.1). By contrast, the lymphocytes oxidized more palmitate (8.3 .+-. 0.5 nmole per h/108 cells) as compared to neutrophils (1.1 .+-. 0.1). The greater fatty acid uptake by the neutrophils was due to 6-fold greater rate of incorporation of palmitate into their triglyceride fraction. Triglyceride synthesis by neutrophils increased as the molar ratio of free fatty acid to albumin was raised but incorporation into phospholipids remained relatively constant; there was preferential labeling of neutrophil triglycerides throughout the physiologic range. Studies using linoleate and oleate gave similar results. The distribution of radioactivity into various phospholipids determined by TLC was similar for the 2 cell types. When labeled glucose was used as a substrate to measure incorporation primarily into the glycerol backbone of the cell lipids, neutrophils incorporated more radioactivity into total lipids and triglycerides than lymphocytes. Neutrophils apparently take up much more fatty acid than lymphocytes primarily because they synthesize much larger quantities of triglycerides, a storage form. Since cellular triglycerides may act as a source of fatty acid for lecithin synthesis during phagocytosis, the greater rate of fatty acid incorporation in the neutrophil may reflect a metabolic pattern that permits efficient phagocytosis.

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