Other key hormones in control of blood glucose balance
Insulin does not act in isolation. There are a number of other hormones that complement the actions of insulin, but also a group that oppose the actions of insulin.
Finding balance (homeostasis) in glucose concentrations in the blood
The balance between anabolic hormones (storage) e.g. insulin and catabolic hormones (breaking down) e.g. glucagon, as illustrated in the figure below, is very important for maintaining blood glucose balance (homeostasis).
Figure: balance between anabolic hormones e.g. insulin and catabolic hormones e.g. glucagon
Glucagon acts when blood glucose concentrations are low by decreasing the amount of glucose used by the body and increasing the amount of glucose produced. It increases the use of other energy sources, including fatty acids, ketone bodies and amino acids. In the liver it stimulates glycogenolysis to release stored glucose and it stimulates gluconeogenesis to produce new glucose. It also stimulates ketone body production and triglyceride lipolysis.
Figure: normal glucagon action and reduced or absent glucagon action
Glucagon, cortisol and noradrenaline hormones are the emergency hormones, critical to preventing blood glucose from dropping further. They are involved in triglyceride hydrolysis, ketogenesis and proteinolysis.
© University of Southampton 2017