Regulation of carbohydrate metabolism in mouse liver. Effect of glucagon on gluconeogenic/glycolytic flux in isolated perfused livers.
1. Glucagon stimulated gluconeogenesis from both [U-14C]lactate and [14C]xylitol in isolated perfused mouse liver. 2. Addition of cyclic AMP also stimulated gluconeogenesis from [U-14C]lactate. 3. Glucagon caused a rapid (2.5 min) 12-fold increase in hepatic cyclic AMP but not cyclic GMP concentration. 4. Glucagon caused a rapid and stable decrease in hepatic fructose 1,6-diphosphatase activity measured in vitro. 5. The results are interpreted to indicate that glucagon stimulates hepatic gluconeogenesis in mice via cyclic AMP by two different mechanisms: (a) increased substrate uptake (i.e. utilization) and (b) increased gluconeogenic efficiency (i.e. inhibition of alternate substrate fates).
D000818:Animals; D050260:Carbohydrate Metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D005260:Female; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005934:Glucagon / Q000494:pharmacology*; D005943:Gluconeogenesis / Q000187:drug effects*; D006019:Glycolysis / Q000187:drug effects*; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010477:Perfusion; D010732:Phosphofructokinase-1 / Q000378:metabolism; D014993:Xylitol / Q000378:metabolism
D007773:Lactates; D005934:Glucagon; D000242:Cyclic AMP; D010732:Phosphofructokinase-1; D006597:Fructose-Bisphosphatase; D006152:Cyclic GMP; D014993:Xylitol