[Hormonal control of liver gluconeogenesis]

The stimulation of gluconeogenesis by glucagon results from a concerted mechanism involving: 1) the stimulation of pyruvate transport and carboxylation in mitochondria; 2) the cyclic AMP dependent phosphorylation and inactivation of pyruvate kinase resulting in a re-routing of phosphoenolpyruvate towards glucose; 3) the inhibition of phosphofructokinase and the stimulation of fructose bisphosphatase resulting from the disappearance of fructose-2,6-bisphosphate. Catecholamines and vasopressin stimulate gluconeogenesis in starvation whereas in the fed state they promote glycogenolysis together with glycolysis.