AJP - Cell Physiology, Vol 261, Issue 3 C417-C422, Copyright © 1991 by American Physiological Society
Changes in pattern of phospholipid acylation during in vivo aging of rat red blood cells
J. Le Petit-Thevenin, O. Nobili and J. Boyer
Institut National de la Sante et de la Recherche Medicale Unite 260, Faculte de Medecine Timone, Marseille, France.
We have investigated the patterns of incorporation of stearic, oleic, and
linoleic acids into phosphatidylcholine (PC) and phosphatidylethanolamine
(PE) of intact red blood cells of differing age isolated by centrifugation
on discontinuous density gradient. Acylation rates of PC and PE elicited
marked declines from the reticulocyte to the young erythrocyte stage
followed by minimal changes of acylating potency in older cells; this
biphasic decay pattern was similar with the three fatty acids. Molar
acylation rates were higher for PC than for PE in reticulocytes, whereas
they were comparable in erythrocytes. PC served as preferred fatty acid
acceptor in circulating red blood cells, a function which was largely
accounted for by PC contained in the small percentage of circulating
reticulocytes. On a per cell basis, this function of PC was due to the
cumulative effects of higher molar acylation rates in reticulocytes and
higher content in PC over PE in the red blood cell membrane. Acylation
rates in PC and PE increased with the number of unsaturated bonds in the
acylating fatty acid, regardless of cell age.
