Effect of glutamine on fructose 2,6-bisphosphate and on glucose metabolism in HeLa cells and in chick-embryo fibroblasts.
Glutamine caused a dose-dependent decrease in fructose 2,6-bisphosphate concentration in both HeLa cells and chick-embryo fibroblasts. The effect was complete within 15 min in HeLa cells, but required more than 9 h in the fibroblasts. Half-maximal effects were obtained with 0.1-0.3 mM-glutamine. In chick-embryo fibroblasts, but not in HeLa cells, glutamine induced a time-dependent decrease in the activity of phosphofructokinase-2, which correlated with the decrease in fructose 2,6-bisphosphate. Glutamine decreased the glycolytic flux by about 25% only in chick-embryo fibroblasts. The difference in glycolytic response between the two types of cells might correspond to a difference in the sensitivity of phosphofructokinase-1 for fructose 2,6-bisphosphate. In HeLa cells, glutamine caused a 2-3-fold stimulation of the synthesis of glycogen, a 50% decrease in the concentration of fructose 1,6-bisphosphate and a more than 80% decrease in the concentration of 5-phosphoribosyl pyrophosphate; the concentrations of hexose 6-phosphates and ATP were not affected.
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005635:Fructosediphosphates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D005973:Glutamine / Q000494:pharmacology*; D006367:HeLa Cells / Q000187:drug effects / Q000378:metabolism; D006598:Hexosediphosphates / Q000378:metabolism*; D006801:Humans; D010732:Phosphofructokinase-1 / Q000378:metabolism
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D005973:Glutamine; C027652:fructose 2,6-diphosphate; D010732:Phosphofructokinase-1; D005947:Glucose