Activation of membrane phospholipase A by guinea pig lymphotoxin (GLT).
The effect of GLT on target cells (L.P3 cells) labeled with radioactive fatty acids was examined. After incubation for 1 or 2 hr, no change in the survival ratio was observed, but radioactive fatty acid was released from phospholipids of the cells. When incubation was continued for 4 or 5 hr, the survival ratio was decreased with a concomitant increase of the radioactivity of triglyceride of the target cells and enhancement of calcium uptake into the target cells. These results could be explained by activation of membrane-bound phospholipase A after the binding of GLT to cell surface receptors.
D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005227:Fatty Acids / Q000378:metabolism; D006168:Guinea Pigs; D008233:Lymphotoxin-alpha / Q000494:pharmacology*; D010740:Phospholipases / Q000378:metabolism*
D005227:Fatty Acids; D008233:Lymphotoxin-alpha; D010740:Phospholipases; D002118:Calcium