Cortisol

CORTISOL

Synonyms

Cortisol (11 b,17,21, trihydroxy-4-pregnene-3,20-dione) (in humans), natural form

Hydrocortisone, this form is prescribed by doctors

Corticosterone (11 b,21,d,hydroxypregn-4-ene-3,20-dione) (in rodents), synthetic form

Cortisol is a stress hormone. It is a steroid hormone, more specifically a glucocorticoid. 

Structure of cortisol

Cortisol is the major natural glucocorticoid. Semisynthetic derivatives with greater hormonal activity than that of cortisol are dexamethasone, prednisone, and triamcinolone

Structure of steroid hormones.

From http://what-when-how.com/molecular-biology/glucocorticoids-molecular-biology/

Production of cortisol

Glucocorticoid secretion is enhanced during stress conditions, such as anxiety, hunger, and trauma.

1. Cortisol is a stress hormone as well as a steroid hormone, and more specifically a glucocorticoid. 
2. It is released in response to stress and a low level of blood glucocorticoids. 

Regulation of cortisol production

The synthesis of glucocorticoids in the zona fasciculata of the adrenal cortex (in the adrenal gland) and their release into the blood circulation is regulated by adrenocorticotropic hormone (ACTH). 

ACTH is produced in the anterior lobe of the hypophysis, in response to stimuli coming either from the neuroendocrine cells of the paraventricular nuclei of the hypothalamus (corticotropin releasing hormone, CRH) or from the periphery (blood cortisol concentration).

High blood cortisol levels reduce (by feedback inhibition) the production of both CRH and ACTH. This regulatory circuit is called the hypothalamus-pituitary-adrenal axis

Regulation of cortisol production by the hypothalamus-pituitary-adrenal axis. 

From http://what-when-how.com/molecular-biology/glucocorticoids-molecular-biology/

Why do we need cortisol?

1. It is the most important human glucocorticoid. 
2. It is essential for life.
3. It regulates or supports a variety of important cardiovascular, metabolic, immunologic, and homeostatic functions.
4. Various synthetic forms of cortisol are used to treat a variety of diseases, eg, hydrocortisone.

Functions of cortisol

1. Its primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat, protein and carbohydrate metabolism.
2. It also decreases bone formation. 
3. Cortisol counteracts insulin, contributes to hyperglycemia-causing hepatic gluconeogenesis, and inhibits the peripheral utilization of glucose (insulin resistance) by decreasing the translocation of glucose transporters (especially GLUT4) to the cell membrane. 
4. Cortisol increases glycogen synthesis (glycogenesis) in the liver. The permissive effect of cortisol on insulin action in liver glycogenesis is observed in hepatocyte culture in the laboratory, although the mechanism for this is unknown.

External Links
http://en.wikipedia.org/wiki/Cortisol
http://www.netterimages.com/image/9025.htm

What-When-How
http://what-when-how.com/molecular-biology/glucocorticoids-molecular-biology/

Cortisol for injection
http://upload.wikimedia.org/wikipedia/commons/d/d6/Cortisol_for_injection.jpg

PowerPoints

http://slideplayer.com/search/cortisol/

http://slideplayer.com/slide/3469175/#

http://slideplayer.com/slide/3883704/#

http://slideplayer.com/slide/4404396/#