Adrenal Hormones

Question 1

What are the two regions of the adrenal gland called?

Answer 1

The adrenal cortex and the adrenal medulla

Question 2

What can the adrenal cortex be divided into?

Answer 2

The outer layer is the zona glomerulosa, the layer under that is the zona fasicialata and the final layer is the zona reticularis

Question 3

What is the adrenal medulla responsible for secreting?

Answer 3

Adrenaline and noradrenaline (catechloamines)

Question 4

What is the adrenal cortex responsible for secreting?

Answer 4

The adrenal hormones (steriods)

Question 5

What does the zona glomerulosa secrete?

Answer 5

Aldosterone

Question 6

What does the zona fasiculata and the zona reticularis secrete?

Answer 6

Cortisol and androgens (e.g. testosterone)

Question 7

Where is the adrenal gland found in the body and why is it situated there?

Answer 7

At the back of the body above the kidneys; is positioned there because the hormones it produces can regulate salt concentration of the blood and therefore kidney function

Question 8

What are the catechloamines and what is there structure?

Answer 8

Adrenaline and noradrenaline and noradrenaline is adrenaline with an extra methyl

Question 9

What causes the adrenal medulla to secrete catechloamines?

Answer 9

Sympathic nerve stimulation

Question 10

What does the secretion of catechloamines to in times of stress?

Answer 10

Increases release of metabolic fuels i.e. glucose from the liver and fatty acids from adipose

Question 11

What other effects do catechloamines have?

Answer 11

They have an positive ionotropic effect on the heart and increase frequency and the strength of the heart beat

Question 12

What does the ionotropic effect of catechloamines cause in terms of blood vessels and blood pressure?

Answer 12

The increased frequency and strength of the heartbeat causes vasoconstriction - the narrowing of the blood vessels increases heart rate

Question 13

Why do you go pale when catechloamines have their effect?

Answer 13

Because they shut down the blood vessels of the skin and redirect the blood to the major vessels

Question 14

Catechloamines target B-adrenoceptors and in the case of the effect on the heart they affect B1 adrenoceptors. Using this, how would you treat someone with hypertension?

Answer 14

Hypertension = high blood pressure so you want to inhibit the effect of the catechloamines on the heart so you would therefore use a B1 adrenoceptor selective antagonist such as atenolol

Question 15

What is hypotension?

Answer 15

Low blood pressure

Question 16

What is hypotension caused by?

Answer 16

Failure of the adrenal medulla (rare)

Question 17

What can hypotension be treated with?

Answer 17

Agonists of B-adrenoceptors

Question 18

What could be a reason for having hypertension that involves the adrenal medulla?

Answer 18

Tumours like neuroblastoma of the adrenal medulla cause secretion of the catecholamines and therefore hypertension - removed by surgery

Question 19

What are the hormones of the adrenal cortex collectively known?

Answer 19

Adrenocortical hormones

Question 20

What kind of hormones are the adrenocortical hormones and what structure are they based on

Answer 20

They are steroids based on the structure of chlolesterol

Question 21

What are the two major classes of adrenalcortical hormones?

Answer 21

1. Adrenocorticosteriods

2. Sex Hormones

Question 22

What can adrenocorticosteroids be broken down into?

Answer 22

1. Mineralocorticoids

2. Glucocorticoids

Question 23

What is an example of a mineralocorticoid?

Answer 23

Aldosterone

Question 24

What is an example of a glucocorticoid?

Answer 24

Cortisols (e.g. hydrocortisone and corticosterone)

Question 25

What are two examples of sex hormones?

Answer 25

Androgens (male sex hormones) and oestreogens (female sex hormoles)

Question 26

What are the two major classes of adrenocortical hormones?

Answer 26

1. Mineralocorticoids and Glucocorticoids | 2. Sex Hormones

Question 27

What kind of receptors do these adrenocortical hormones act on?

Answer 27

Nuclear receptors

Question 28

The action of adrenocortical hormones is that it leads to protein production. How does it do this?

Answer 28

1. hormone binds nuclear receptor 2. hormone-receptor complex under goes a conformational change and attaches to hormone response elements on the DNA 3. recruits RNA polymerase to make mRNA 4. protein synthesis

Question 29

What are hormone response elements?

Answer 29

Sequences on the DNA that the receptor binds to

Question 30

Is action of the adrenocortical hormones fast or slow compared to the catechloamines?

Answer 30

Slow as protein synthesis can take hours/days

Question 31

What property of the adrenocortical hormones means they can reach the nuclear receptors?

Answer 31

They are lipophillic/hydrophillic so can pass through the cell membrane by passive diffusion

Question 32

What are some other examples of lipophillic ligands for nuclear receptors?

Answer 32

Vitamins A and D derivatives

Question 33

Describe the sequence of events that occurs after the glucocorticoid cortisol is released into the blood stream by the adrenal gland?

Answer 33

1. Enters the cell via passive diffusion 2. Finds a nuclear receptor in the cytoplasm of nucleoplasm 3. Binds and induces a conformation change in the receptor 4. Receptor reveals a nuclear target signal 5. Receptor binds to the hormone response elements on the DNA 6. Regulates gene expression and therefore protein synthesis

Question 34

Where are nuclear receptors found and what makes them able to be in this enviroment?

Answer 34

In the cytoplasm of the nucleoplasm and they are soluble proteins so mix well with aqueous enviroments

Question 35

Describe what an oestrogen receptor agonist would do and what it would be used for?

Answer 35

Minic the action of oestrogen on nuclear receptors and used for Hormone replacement therapy in post menopausal women

Question 36

Given an example of a oestrogen receptor agonist

Answer 36

Conjugated equine estrogens

Question 37

Given an example of what a glucocorticoid receptor agonist would do and be used to treat?

Answer 37

Would minic the action of cortisols such as hydrocortisone and so could be used treat inflammation

Question 38

Given an example of a glucocorticoid receptor agonst?

Answer 38

Hydrocortisone or dexamethasone

Question 39

What would a mineralocorticoid receptor antagonist do and when could this be used?

Answer 39

It would block the ability of the mineralocorticoid to increase water volume which would reduce inflammation in patients with oedema

Question 40

Give an example of a mineralocorticoid receptor antagonist

Answer 40

In order to decrease water volume lots of urine is produced so a diuretic such as spironolactone

Question 41

What would an oestrogen receptor antagonist do and what would it be used to treat?

Answer 41

Would block the action of oestrogen for prevention and treatment of breast cancer

Question 42

Given an example of an oestrogen recptor antagonist?

Answer 42

Tamoxifen

Question 43

What would an androgen receptor antagonist do and when would it be used?

Answer 43

Block the action of male sex hormones such as testotersone and used in the treatment of prostate cancer

Question 44

What is an example of an androgen receptor antagonist?

Answer 44

Bicalutamide/casodex

Question 45

What is an example of a mineralocorticoid?

Answer 45

Aldesterone

Question 46

What is the function of mineralocorticoids?

Answer 46

They maintain the salt balance in the body

Question 47

How do mineralocorticoids maintain the salt balance?

Answer 47

They exchange potassium for sodium and water

Question 48

How do mineralocorticoids regulate blood volume?

Answer 48

Water always follows sodium so by regulating the salt levels they also regulate the water metabolism

Question 49

How do mineralocorticoids increase blood pressure?

Answer 49

By increasing the water volume they increase the blood volume and therefore increase blood pressure

Question 50

How is mineralocorticoid production regulated?

Answer 50

Through the Renin/Angiotensin system

Question 51

How is low plasma sodium detected?

Answer 51

By the kidneys

Question 52

After detection of the low plasma sodium an enzyme is produced; what enzyme is this and what does it convert?

Answer 52

Renin and converts angiotensinogen to angiotensin 1

Question 53

What is angiotensin 1 converted to and what converts it?

Answer 53

Converted to angiotensin 2 by the angiotension converting enzyme (ACE)

Question 54

What does angiotensin 2 act on?

Answer 54

G protein coupled receptors on the adrenal cortex

Question 55

What does angiotensin 2 cause the production of by the adrenal cortex?

Answer 55

Mineralocorticoids (mainly aldosterone)

Question 56

How does aldosterone then increase plasma sodium?

Answer 56

By acting on the distal renal tubules which causes Na+ reabsorption and increased secretion of K+

Question 57

What receptors does aldoesterone act on?

Answer 57

Nuclear receptors of the kidney ONLY

Question 58

What receptors does aldosterone act on?

Answer 58

Nuclear receptors of the kidney ONLY

Question 59

Name an antagonist for aldoesterone at these receptors, what kind of antagonist is this?

Answer 59

Spironolactone which is a reversible competitve antagonist - means Na+ is not reabsorped so can be used to treat high blood pressure

Question 60

Since aldosterone is an example of a hormone that acts on nuclear receptors how does this end up with the increased absorption on sodium?

Answer 60

The hormone-receptor complex interacts with DNA to increase synthesis of proteins that will produce more sodium channels in the membrane of the renal cells containing the nuclear receptors

Question 61

What are the three main actions of glucocorticoids?

Answer 61

1. Glucose metabolism 2. Negative feedback on anterior pituitary and hypothalamus 3. Anti-inflammatory and immunosupressive effects

Question 62

What are the two main actions of glucocorticoids?

Answer 62

1. Glucose metabolism | 3. Anti-inflammatory and immunosupressive effects

Question 63

Glucose levels need to be elevated in times of stress. What senses this stress?

Answer 63

The hypothalamus

Question 64

What does the hyporthalamus release?

Answer 64

Corticotrophin releasing factor

Question 65

What does corticotrophin releasing factor act on and what does this then produce?

Answer 65

The GPCRs of the Anterior Pitutiary which then releasing Corticotrophin

Question 66

What does corticotrophin then act on and what does this produce?

Answer 66

The adrenal cortex which then produces the glucocorticoids

Question 67

How do glucocorticoids affect metabolism?

Answer 67

by elevating blood glucose levels by causing increased breakdown of fats and proteins to glucose as well as decreasing the uptake of glucose by carbohydrates

Question 68

How do glucocorticoids have anti-inflammatory properties?

Answer 68

They block the leaking of lymphocytes from blood vessels to the site of infection

Question 69

How do glucocorticoids have immunosupressive properties?

Answer 69

they inhibit the production an immune mediator which ultimately leads to supressed T cell and B cells

Question 70

Which enzyme do glucocorticoids inhibit in order to have their properties?

Answer 70

Phospholipase A2

Question 71

What does phospholipase A2 do?

Answer 71

Involved in the production of arachidonic acid, prostaglandins and leukotrienes

Question 72

Name a glucocorticoid agonist that could be used to treat asthma? How is it applied?

Answer 72

Beclamethasone is inhaled

Question 73

Name a glucocorticoid agonst that could be used to treat skin inflammation. How is it applied?

Answer 73

Bethamethasone is applied topically

Question 74

Name 6 treatments for which glucocorticoid agonsts could be used.

Answer 74

1. Asthma | 2. Autoimmune diseases

Question 75

Name 6 treatments for which glucocorticoid agonsts could be used.

Answer 75

1. Asthma 2. Autoimmune diseases 3. Cancer Therapy 4. inflammatory Diseases 5. Allergic Responses 6. Organ Transplant