Glucocorticoids are a type of steroid hormone that is made and released from an area within the adrenal gland. Cortisol is the main glucocorticoid, and it affects many areas within the human body and has many effects on metabolism, as well. In addition, cortisol stimulates other hormones which, in turn, have a role in metabolism.
The Adrenal Gland and Cortisol
There is an adrenal gland on top of each kidney, as explained in the "Pathophysiology of Disease" by Tobias Else, M.D. of the Department of Internal Medicine at the University of Michigan. The outer portion of the gland, called the adrenal cortex, has three layers, or zones. The middle zone is called the zona fasciculata, and cells in this zone make and secrete the glucocorticoid hormones, including cortisol. The cortisol hormone affects the nervous system, the blood vessels, blood pressure, the immune system and metabolism.
Cortisol, Glucose and Protein
Elizabeth Corwin, Ph.D., describes in the "Handbook of Pathophysiology" how cortisol affects metabolism by increasing the level of glucose in the bloodstream. It does this by stimulating the liver to make glucose from protein and fat, a process called gluconeogenesis. It also lowers the use of glucose by stimulating the lymphatic tissue, fat tissue and muscle to use free fatty acids instead of glucose for energy. Cortisol lowers the use of amino acids, which are used to make proteins, and thereby interferes with the production of protein. It stimulates the breakdown of protein, as well.
Cortisol and Hormones
Cortisol raises the effects of the thyroid hormone, a hormone that affects weight, blood pressure, the temperature of the body and the rate of the heart, according to the University of Maryland Medical Center. It increases the effects of norepinephrine and epinephrine, substances that raise the blood pressure and the heart rate, which is especially necessary during times of stress or trauma. It redistributes fat by increasing the effect of the growth hormone on fat, and by increasing the amount of fat on the face, chest and abdomen.
Cortisol and Cushing Syndrome
Cushing syndrome demonstrates the effects of having a high amount of cortisol in the bloodstream. It can be the result of several disorders, but is usually due to taking synthetic glucocorticoid as part of a medical treatment, according to Ashley Grossman, M.D., professor of neuroendocrinology at the London School of Medicine in "The Merck Manual for Healthcare Professionals." People with Cushing syndrome can have a round face, an obese abdomen, osteoporosis, menstrual irregularity if female, balding whether female or male, and high blood pressure.
References
- "Handbook of Pathophysiology"; Elizabeth Corwin, MSN, Ph.D., FNP; 2000
- "Pathophysiology of Disease: An Introduction to Clinical Medicine"; Stephen McPhee, M.D., Gary Hammer, M.D., Ph.D.; 2010
- The Merck Manual for Healthcare Professionals: Cushing's Syndrome
- University of Maryland Medical Center: Thyroid hormone
