Zona glomerulosa

 mineralcorticoids: primarily aldosterone

Zona fasciculata

glucocorticoids:  primarily cortisol

Zona reticularis

androgens:  primarily DHEA

Cortisol

Glucocorticoids

Zona Fasciculata

Hypothalamus

Anterior Pituitary

Adrenal Cortex

Adrenocorticotrophic Hormone 

-Promotes growth and function of all 3 cortical zones.

-Effects secretion of glucocorticoids (much more than mineralcorticoid secretion)

FYI: Adreno (Adrenal Gland)--Cortico (Cortex)--Tropic (Growth)

Glucocorticoids

1. anabolic or catabolic?

2.  Where are they produced and secreted?

3.  What are their main targets?

4.  What are they derived from?

1.  Catabolic

2.  Zona fasiculata of the adrenal cortex

3.  Liver, skeletal muscle, fat

4.  Derived from pregnenolone, which is from cholesterol.

Catabolism

Energy metabolism

sympathoadenal effects

Anti-inflammatory and immunosupressive

What is the primary glucocorticoid in humans?

Is it bound in circulation?

Cortisol

Yes, it is bound to CBG (Transcortin)

-Blunts fluctuations in cortisol blood levels

High on the half-life continuum

1.  The bound hormone comes to the membrane dissociates from its carrier and enters the cell.

2.  Hormone binds to its intracellular receptor, activates it and causes dissociation of heat shock proteins.

3.  Dimerization occurs and it binds to the hormone response element on the DNA target (glucocorticoid response element)

Physical stress

hypoglycemia

trauma

exercise

Mental Stress

acute anxiety and chronic anxiety

Compare and contrast glucagon and cortisol

Compare

Both are catabolic

both focus on increasing blood glucose

Breaks down proteins, this generates urea

Contrast 

Cortisol, unlike glucagon, promotes the synthesis of glycogen.

Cortisol is from the fasiculata layer of the adrenal cortex while glucagon is from alpha cells of the islets of langerhans in the pancreas.

What is cortisol's effect on inflammation and immune response?

How can this be beneficial and also harmful?

It supresses both the immune and inflammatory response.

It can beneficial at stopping transplant rejection, stopping rashes, or for sore joints.  Its bad because it supresses your immune system's ability to fend off infections.

Mineralcorticoids

1. What are their protein carriers?

2.  Where are they produced and secreted?

3.  What are their main targets?

-what's their function

Example:  Aldosterone

1.  Albumin, CBP carrier

2.  Zona glomerulosa of the adrenal cortex

3.  Kidneys

-Sodium Retention

-Water Retention

-Potassium Excretion

1.  juxtaglomerular cells sense decrease in blood pressure or volume.

2.  Rennin is secreted

3. Angiotensinogen is converted to angiotensin I

4.  Angiotensin I is converted to angiotensin II, which targets Zona glomerulosa cells to produce aldosterone.

Since cortisol has limited mineralcorticoid activity similar to that of aldosterone and considering cortisol is produced in much larger quantities...

Why doesn't cortisol take over for aldosterone?

The Enzyme Protective Effect!

In aldosterone responsive cells, cortisol becomes inactivated to cortisone.

Addison's Disease (Destruction of Adrenal Cortex, lack of gluco- and mineral- corticoids)

Cushing's Disease (excess cortisol)

These can be cause by primary causes (autoimmune destruction or infection) or by secondary causes (Hypothalamic/pituitary failure)

Basically no mineral- or gluco- corticoids 

Can see pigmentation of Mucosa

Low Aldosterone causes 

Hypotension (not retaining water)

Hyponatremia (not retaining sodium)

Hyperkalemia (not excreting potassium)

Low Cortisol Causes

hypoglycemia

weight loss

apetite loss

Cushing's aka hypercortisolism can happen from:

Secondary:  Tumor on the anterior pituitary, secretes excess ACTH (Adrenocorticotropic Hormone)

Or more commonly, exposure to exogenous sources of cortisol