Answer to Question #182832 in Biochemistry for Kim

Question

What happens to the rate of liver glucose metabolism during moderate intensity exercise

Answer 1

Hepatic glucose production increases during exercise as a sum of liver glycogenolysis and gluconeogenesis. Gycogenolysis dominates during intense exercise,while gluconeogenesis contributes substantially with prolonged exercise and the concomitant decline in liver glycogen stores and with increased gluconeogenic precursor supply. A rise in blood glucose directly inhibits hepatic glucose production, whereas a decline in blood glucose enhances liver glucose production via release of glucoregulatory hormones.A decline in plasma insulin is important for the rise in glucose production during exercise in a variety of species, where glucagon plays a role only in prolonged exercise. Sympathetic nervous activity to the liver and circulating norepinephrine happens without any role in glucose production, whereas epinephrine has a minor stimulating effect on hepatic glucose mobilization during intense exercise.