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Incorporation of fatty acids into phospholipids in L cells stimulated by antibody
Author(s) -
Shearer William T.,
Ulrich Robert G.
Publication year - 1984
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02534451
Subject(s) - arachidonic acid , phosphatidylinositol , biochemistry , phospholipid , palmitic acid , chemistry , stearic acid , fatty acid , oleic acid , antibody , microbiology and biotechnology , biology , enzyme , membrane , signal transduction , organic chemistry , immunology
Binding antibodies to surface membranes stimulated incorporation of fatty acids (FA) into phospholipids of L cells. Antibodies stimulated at least a 3.4‐fold greater incorporation of arachidonic acid into phosphatidylinositol than into any other class of phospholipid when compared on a molar basis (p<0.003). This enhanced incorpoation was selective, depending on the character of the FA, because antibodies stimulated the incorporation of arachidonic acid at least 2.4‐fold more than oleic acid, palmitic acid or stearic acid (p<0.001). Surprisingly, an antibody‐stimulated incorporation of palmitic acid into sphingomyelin (SM) was at least 2.2‐fold greater than that into any other class of phospholipid (p<0.001) and the antibody‐stimulated incorporation of palmitic acid into SM was at least 60‐fold greater than that of arachidonic acid, stearic or oleic acid (p<0.001). Nontoxic doses of ethylenediamine tetraacetic acid (EDTA), dexamethasone, 4‐bromophenacylbromide and indomethacin inhibited the antibody‐stimulated incorporation of arachidonic acid into cellular phospholipids, principally phosphatidylinositol (PI), and similarly inhibited the antibody stimulation of DNA synthesis. We conclude that when antibody binds to surface antigens on L cells, a rapid and selective incorporation of fatty acids into certain cellular phospholipids occurs, possibly mediated by calcium‐dependent phospholipases. Degradation products of arachidonic acid, i.e., prostaglandins, may be important in these antibody stimulation events, as well. These early changes in phospholipid metabolism may serve as an important signal or mechanism for the subsequent stimulation of DNA synthesis in L cells.