- Describe the effect of insulin, glucagon, epinephrine, and cortisol on metabolic processes in the liver, adipose, and skeletal muscle and how these hormones function to regulate blood glucose homeostasis.
- Determine the fuels utilized by the liver, red blood cells, adipose, skeletal muscle in the fed and fasted states and determine the pathway(s) providing this substrate.
- Differentiate between insulin sensitive and insulin insensitive tissues; identify the GLUT transporters common to specific tissues and their clinical relevance.
- Review the signaling mechanisms used by insulin, glucagon, cortisol, and epinephrine.
One of the fundamental homeostatic responses is the regulation of blood glucose by alterations in flux through metabolic pathways. This regulation includes both dietary intake of fuels, tissue uptake and oxidation of fuels, and storage and release of fuels under necessary conditions. Most of these processes are controlled hormonally by insulin, glucagon, cortisol, and epinephrine. Ultimately, these pathways ensure that both ATP levels are sufficient for an organism to sustain cellular activities and that blood glucose is maintained in a narrow window. Both processes are balanced without exhausting either fuel and energy resources.
Thumbnail: WEBTECHOPS LLP, IN, Liver. CC BY 3.0. From Noun Project.