Endocrine control of glucose metabolism
Insulin
Hyperglycemia (in fed stage), enhance the uptake of glucose in liver
Insulin is produced in by β-cell of islets of pancreas
Inhibit glycogenolysis, gluconeogenesis,
Stimulate glycogenesis
Reduce blood glucose level
Glucagon
During fasting stage, Hypoglycemia enhance the secretion of Glucagon
Glucagon is produced by α-cell of islets of pancreas
liver enhances the production of glucose
It enhances glycogenolysis (activation of phosporylase), gluconeogenesis,
Increase blood glucose level
Antagonistic to insulin
Growth Hormone
In fasting, (Hypoglycemia)
GH is produced by anterior pituitary Glands
Elevate blood glucose level
Decrease glucose uptake in tissues-muscle
Mobilize free fatty acid from adipose tissues which inhibit glucose utilization
Cause hyperglycemia which stimulate secretion of insulin and lead to beta cell exhaustion.
Antagonistic to insulin
Glucocorticoids
In fasting, Glucocorticoids is secreted by adrenal cortex
Increase gluconeogenesis, Increase protein catabolism
Increase hepatic uptake of amino acid
Increase activity of aminotransferase for glycogenesis in liver
Inhibit utilization of glucose extra in hepatic tissues, Antagonistic to insulin
Epinephrine:
Secreted by adrenal medulla as a result of stressful stimuli /blood glucose level too low
Lead to glycogenolysis in liver and muscles owing to stimulation of phosphorylases.
When blood glucose levels drop too low, the adrenal glands secrete epinephrine(also
called adrenaline), causing the liver to convert stored glycogen to glucose and release it, raising
blood glucose levels.