Steroids

Question 1

2 Types of steroid?

Answer 1

Hormonal (corticosteroids and sex hormones)
Non hormonal (cholesterol)

Question 2

Name the 4 zones of the adrenal gland (outer->inner)

Answer 2

Zona glomerulosa
Zona fasciculata
Zona reticularis
Adrenal medulla

Question 3

Where are mineralocorticoids produced? eg?

Answer 3

In the zona glomerulosa of the adrenal gland

e.g. aldosterone

Question 4

Where are glucocorticoids produced? eg?

Answer 4

In the zona fasciclata of the adrenal gland

e.g. cortisol

Question 5

Where are androgens produced? eg?

Answer 5

in the zona reticularis of the adrenal gland

e.g. testosterone

Question 6

What is produced int he adrenal medulla? eg?

Answer 6

Catecholamines (e.g. adrenaline)

Question 7

What is formed in the zona reticularis of the adrenal gland?

Answer 7

Androgens (testosterone)

Question 8

What is formed in the zona fasciculata?

Answer 8

Glucocorticoids (cortisol)

Question 9

What is formed in the zona glomerulosa?

Answer 9

Mineralocorticoids (aldosterone)

Question 10

What is cholesterol’s main function?

Answer 10

Regulates fluidity and function of phospholipid bilayer membranes
Makes membrane less deformable and less water permeable (so no cell wall needed)

Question 11

What controls the rate of cholesterol production?

Answer 11

HMG CoA reductase (inhibited by statins)

Question 12

What is the main glucocorticosteroid in humans?

Answer 12

Cortisol

Question 13

What do glucocorticosteroids do?

Answer 13

Prepare for starvation (catabolic)
-hyperglycaemia
-mobilisation of lipids
-breakdown of proteins
and anti inflammatory

Question 14

Name two inhaled GCS drugs?

Answer 14

Fluticasone (for asthma)

Beclomethasone

Question 15

Name two topical GCSs

Answer 15

Hydrocortisone

Betamethasone (for eczema)

Question 16

Name two systemic GCS drugs

Answer 16

Prednisolone

Dexamethasone

Question 17

What are Prednisolone and Dexamethasone used for?

Answer 17

To treat systemic arthritis, inflammatory bowel disease, cerebral oedema, some types of leuekmia

Question 18

What is Beclomethasone?

Answer 18

Inhaled GCS to treat asthma

Question 19

How do GCS drugs work?

Answer 19

Bind to cytoplasmic GRs (glucocorticoid receptors) and modulate transcription of hundreds of inflammatory genes
(block transcription of pro-inflam and induce transcription of anti-inflam)
Activates Annexin-1 (phospholipidase-A2 inhibitor) so arachadonic acid can’t be formed-> no prostagladins of leukotrienes

Question 20

Give 3 examples of anti-inflammatory proteins

Answer 20

IL-10, Anexin-1 and Ribonucleases (break down inflam mRNAs)

Question 21

Give 5 examples of pro-inflammatory proteins

Answer 21

COX-2, cytokines, immunoglobulins (IgG, IgE), complements and adhesion molecules

Question 22

What is Cushing’s disease?

Give 9 effects on body

Answer 22

Syndrome caused by either overproduction of cortisol or overuse of synthetic GCS drugs
Cateracts, moon face, red cheeks, benign intercranial hypertension, euphoria, buffalo hump, thinning of skin (bruises and poor wound healing), osteoporosis and muscle wasting of arms and legs

Question 23

How can overproduction of cortisol be treated?

Answer 23

By Metyrapone

Question 24

How else to GCS affect the body?

Answer 24

Reduces proliferation, adhesion, migration, activation and survival of inflammatory leukocytes
Reduces oedema and impairs fibrosis and wound healing

Question 25

Why can't GCS drugs be stopped suddenly?

Answer 25

-ve feedback occurs, causing atrophy of adrenal gland in the long term (anterior pituitary stops producing ACTH) ACTH= adrenocroticotrophic hormone

Question 26

What is the series of events that causes production of cortisol?

Answer 26

Stress, shock, starvation, pain -> Hypothalamus releases corticotrophin releasing factor -> Anterior pituitary releases ACTH -> Adrenal gland releases cortisol

Question 27

What is the main endogenous mineralocorticoid? And what triggers its release?

Answer 27

Aldosterone | Released from zona glomerulosa when low plasma Na+ and indirectly by renin-angiotensin sytem

Question 28

What are the actions of aldosterone?

Answer 28

Acts of MR (mineralocorticoid receptors) in cytoplasm of kidney tubule epithelial cells Increases transcription of epithelial Na+ channels--> increased Na+ and water reabsorption into blood -> slat and water are conserved while K+ and H+ are excreted

Question 29

What is Fludrocortisone?

Answer 29

Mineralocorticoid receptor agonist | Used as replacement therapy in adrenal insufficiency (Addison's disease)

Question 30

What drug is used to treat Addison's Disease

Answer 30

Adrenal insufficiency so the MR agonist Fludrocortisone

Question 31

Name a diuretic that is also used in hyperaldosternism

Answer 31

Spironolactone, competitive MR antagonist | Reduces blood volume in hypertension while preventing hypokaleamia

Question 32

What is Fludrocortisone?

Answer 32

An MR agonist used to treat Addison's disease | Increases volume of blood and may cause hypokalaemia

Question 33

What is Spironolactone?

Answer 33

MR antagonist -> diuretic that prevents hypokaleamia