Role of fructose 2,6-bisphosphate in the control by glucagon of gluconeogenesis from various precursors in isolated rat hepatocytes.
Hepatocytes from overnight-starved rats were incubated with 1-20 mM-fructose, -dihydroxyacetone, -glycerol, -alanine or -lactate and -pyruvate with or without 0.1 microM-glucagon. The production of glucose and lactate was measured, as was the content of fructose 2,6-bisphosphate. The concentrations of fructose (below 5 mM) and dihydroxyacetone (above 1 mM) that gave rise to an increase in fructose 2,6-bisphosphate were those at which a glucagon effect on the production of glucose and lactate could be observed. Glycerol had no effect on fructose 2,6-bisphosphate content or on production of lactate, and glucagon did not stimulate the production of glucose from this precursor. With alanine or lactate/pyruvate as substrates, glucagon stimulated glucose production whether the concentration of fructose 2,6-bisphosphate was increased or not. The extent of inactivation of pyruvate kinase by glucagon was not affected by the presence of the various gluconeogenic precursors. The role of fructose 2,6-bisphosphate in the effect of glucagon on gluconeogenesis from precursors entering the pathway at the level of triose phosphates or pyruvate is discussed.
D000409:Alanine / Q000378:metabolism; D000818:Animals; D004098:Dihydroxyacetone / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D005635:Fructosediphosphates / Q000378:metabolism*; D005934:Glucagon / Q000494:pharmacology*; D005943:Gluconeogenesis / Q000187:drug effects*; D005990:Glycerol / Q000378:metabolism; D006598:Hexosediphosphates / Q000378:metabolism*; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D005635:Fructosediphosphates; D006598:Hexosediphosphates; D007773:Lactates; D005632:Fructose; D019344:Lactic Acid; C027652:fructose 2,6-diphosphate; D005934:Glucagon; D004098:Dihydroxyacetone; D000409:Alanine; D005990:Glycerol