Unsaturated fatty acids mobilize intracellular calcium independent of IP3 generation and VIA insertion at the plasma membrane.
Addition of oleic and arachidonic acids to Ehrlich ascites tumor cells mobilizes Ca2+ from the same intracellular pool as that mobilized by thapsigargin. Such mobilization occurs in the presence of the phospholipase C inhibitor U73122 as well as in cells treated with pertussis toxin. Co-addition of fatty acids and thapsigargin leads to initial rates of Ca2+ mobilization much greater than that induced by either compound alone. The responses induced by the fatty acids are observed also with other lipophiles like sphingosine, bromo-palmitate and the Ca2+ influx inhibitor econazole; all responses are rapidly reversed by addition of bovine serum albumin. Many of the above effects of fatty acids are observed also in Jurkat T lymphocytes and Friend erythroleukemia cells. The experiments provide evidence of lipid-induced plasma membrane perturbations that influence intracellular Ca2+ mobilization independent of the generation of currently known second messengers.
Gamberucci
A
A
Istituto di Patologia Generale, Universita di Siena, Italy.
Fulceri
R
R
Bygrave
F L
FL
Benedetti
A
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002286:Carcinoma, Ehrlich Tumor; D002462:Cell Membrane / Q000187:drug effects*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D007295:Inositol Phosphates / Q000378:metabolism; D004915:Leukemia, Erythroblastic, Acute; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects*; D051379:Mice; D009374:Neoplasms, Experimental
D005231:Fatty Acids, Unsaturated; D007295:Inositol Phosphates; D002118:Calcium