The effect of magnesium on glycolysis of permeabilized Ehrlich ascites tumor cells.
We have previously observed that extracellular Mg2+ influences the phosphofructokinase (PFK) activity of intact Ehrlich Ascites tumour cells (EATC). In this study we have investigated the mechanism by which Mg2+ modulates this key glycolytic enzyme in EATC made permeable to the cation by either digitonin or dextran sulphate. Results showed that when Mg2+ is freely permeable to the cytosol, the in vivo PFK activity, calculated as FDP/G6P ratio, is not increased as it is in intact cells. We also observed that in permeabilized cells Mg2+ determines the increase of glucose 6 phosphate (G6P), fructose 1,6 bisphosphate (FDP) and lactate production. We hypothesize that extracellular Mg2+ regulates PFK and glycolysis in these neoplastic cells not by entering the cytosol but by a specific interaction with the plasma membrane.
Wolf
F I
FI
Institute of General Pathology, Catholic University, School of Medicine, Italy.
Bossi
D
D
Cittadini
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism* / Q000473:pathology; D002463:Cell Membrane Permeability / Q000187:drug effects; D016264:Dextran Sulfate / Q000494:pharmacology; D004072:Digitonin / Q000494:pharmacology; D005958:Glucosephosphates / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects*; D008274:Magnesium / Q000494:pharmacology*; D010732:Phosphofructokinase-1 / Q000378:metabolism
D005958:Glucosephosphates; D000255:Adenosine Triphosphate; D016264:Dextran Sulfate; D010732:Phosphofructokinase-1; D008274:Magnesium; D004072:Digitonin