Vanadate raises fructose 2,6-bisphosphate concentrations and activates glycolysis in rat hepatocytes.
In rat hepatocytes, vanadate increases fructose 2,6-bisphosphate (Fru-2,6-P2) in a time- and dose-dependent manner, and counteracts the decrease in this metabolite caused by glucagon, forskolin or exogenous cyclic AMP. Vanadate does not directly modify the activity of 6-phosphofructo-2-kinase, even though it can counteract the inactivation of this enzyme caused by glucagon. Furthermore, vanadate raises the yield of 3H2O from [3-3H]glucose, indicating that it increases the flux through 6-phosphofructo-1-kinase. Moreover, vanadate in hepatocytes incubated in the presence of glucose increases the production of both lactate and CO2. Therefore vanadate has insulin-like effects on the glycolytic pathway in rat hepatocytes. These results clearly contrast with our previous observation that vanadate exerts glycogenolytic non-insulin-like effects on glycogen synthase and phosphorylase.
Gómez-Foix
A M
AM
Department of Biochemistry, Autonomous University of Barcelona, School of Veterinary Medicine, Spain.
Rodríguez-Gil
J E
JE
Fillat
C
C
Guinovart
J J
JJ
Bosch
F
F
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D005635:Fructosediphosphates / Q000378:metabolism*; D005934:Glucagon / Q000494:pharmacology; D005947:Glucose / Q000493:pharmacokinetics; D006019:Glycolysis / Q000187:drug effects*; D006598:Hexosediphosphates / Q000378:metabolism*; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D025481:Phosphofructokinase-2; D010770:Phosphotransferases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014638:Vanadates / Q000494:pharmacology*
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D007773:Lactates; D002245:Carbon Dioxide; D019344:Lactic Acid; D014638:Vanadates; C027652:fructose 2,6-diphosphate; D005934:Glucagon; D010770:Phosphotransferases; D025481:Phosphofructokinase-2; D005947:Glucose