Arachidonic acid modulates [14C]stearic acid incorporation into phosphatidylinositol, in human neuroblastoma cells.
In the human neuroblastoma cell line SK-N-BE(2), arachidonic acid (AA), supplied in the medium at micromolar concentrations, markedly enhanced [14C]stearic acid (SA) (but not [14C]palmitic acid or [14C]oleic acid) incorporation into phosphatidylinositol (PtdIns). AA failed to stimulate [14C]SA incorporation into PtdIns precursors, namely phosphatidic acid and cytidinediphosphodiacylglycerol: furthermore, enhanced [14C]SA incorporation, brought about by exogenously administered AA, was not restricted to PtdIns tetraenoic species. When cells were pulsed for 1 h with [14C]SA (either in the presence or absence of AA) and then reincubated in AA- and [14C]SA-free medium, a marked loss of radioactivity from PtdIns was observed, that however was restricted to molecular species other than tetraenoic. These results are discussed in the light of possible mechanisms through which PtdIns achieves the 1-stearoyl-2-arachidonoyl configuration.
Pacini
L
L
Department of Biology, University of Rome Tor Vergata, Italy.
Limatola
C
C
De Laurenzi
V
V
Ricci
I
I
Spinedi
A
A
D016718:Arachidonic Acid / Q000494:pharmacology*; D002250:Carbon Radioisotopes; D002458:Cell Fractionation; D002855:Chromatography, Thin Layer; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009447:Neuroblastoma; D019301:Oleic Acid / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D013229:Stearic Acids / Q000378:metabolism* / Q000493:pharmacokinetics; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D002250:Carbon Radioisotopes; D010716:Phosphatidylinositols; D013229:Stearic Acids; D016718:Arachidonic Acid; D019301:Oleic Acid; D019308:Palmitic Acid; C031183:stearic acid