Lecture 33-Endocrinology of the Adrenal Cortex

Question 1

What 2 hormones synergistically regulate blood pressure and volume and why do they work together?

Answer 1

• cortisol and aldosterone
• aldosterone regulates Na uptake by kidneys and “at high concentrations” (according to Dr. Lumpkin) cortisol can bind aldosterones receptors (and vice versa)

Question 2

Why is there oscillating production of cortisol?

Answer 2

• because the long loop negative feedback causes cortisol to inhibit CRH release once it’s produced.

Question 3

What is the main function of cortisol?

Answer 3

making sure that the brain and vital organs get enough glucose during a stress response

Question 4

Neuralizing effects can be caused by ______

Answer 4

high levels of androgen in CAH

Question 5

What things stimulate ACTH release via CRH activation?

Answer 5

• sleep-wake transition
• psychiatric disturbance
• low cortisol
• stress
• alpha adrenergic agonists
• beta adrenergic antagonists
• serotonin
• AVP/ADH
  (- aminobutyric acid)

Question 6

What things inhibit ACTH release?

Answer 6

• high cortisol

- POMC breakdown products: enkephalins, opiates, ACTH

Question 7

Why does serotonin promote ACTH release? Explain how SSRIs work.

Answer 7

• directly stimulates CRH-producing cells to stimulate it’s production
• SSRIs work by first upregulating CRH receptors which can cause an initial decline in state but eventually the receptors will down regulate due to the high amounts and you will have an alleviation of symptoms

Question 8

Why does ADH promote ACTH release?

Answer 8

• small subpopulation of neurons that originate in the PVN of the hypothalamus that secrete both ADH and CRH at the ME
• These act synergistically on corticotrophs to stimulate ACTH release

Question 9

Low cortisol is associated with ______

Answer 9

• anabolic reactions for energy storage

- gluconeogenesis!! for glycogen synthesis

Question 10

Rising cortisol is associated with ______ (3)

Answer 10

• decreased immune cell function
• breakdown of tissues for aa’s for gluconeogenesis and lipolysis
• glu uptake inhibition to preserve the glu for vital organs

Question 11

What does low cortisol promote?

Answer 11

• anabolic reactions like gluconeogenesis using aa’s, FAs and glycerol from tissue breakdown

Question 12

What does rising cortisol promote?

Answer 12

• prevents uptake of glu by non-vital organs

catabolic reactions: muscle, lymphoid tissue and skin/connective tissue breakdown for amino acids
- fat breakdown for aa’s, glycerol and FAs

Question 13

Cushings Disease symptoms (5)

Answer 13

• hyperglycemia
• binds aldosterone receptors because of it’s high concentration causing hypertension, edema (moon face)
• fat movement from buttocks, thighs to stomach and back of neck–caused by insulin release in response to high blood FA
• bone brittleness
• striate

Question 14

How is CAH treated?

Answer 14

• cortisol replacement therapy: reinstates negative feedback on hypothalamus and pituitary and causes regression of the virilization

Question 15

Symptoms of Addison’s disease

Answer 15

• low cortisol due to an autoimmune attack
• hypoglycemic
• hypovolemic, low [Na]
• can’t manage stress response
• pigmentation of skin
• no negative feedback on ACTH and CRH release