Control of hepatic glucose production during exercise.

Major advancements have occurred recently in study of the mechanisms of regulation of glycogenolysis and gluconeogenesis in perfused livers and isolated hepatocytes. Many questions remain unanswered, however, with respect to the control of these processes in the live exercising animal. Additional studies will be necessary to determine the relative roles of alpha- and beta-adrenergic receptor-mediated effects of circulating catecholamines, of glucagon, glucocorticoids, angiotensin II, vasopressin, insulin, and of the direct sympathetic innervation in regulation of hepatic glycogenolysis and gluconeogenesis during exercise.