Steroids

Question 1

What are steroids derived from?

Answer 1

dietary steroids or acetyl CoA from the liver

Question 2

What’s the most abundant steroid?

Answer 2

cholesterol

Question 3

How are steroids eliminated?

Answer 3

by oxidation of CYP450

Question 4

What’s the most important CYP450 for steroid elimination?

Answer 4

CYP3A4, in liver ER

Question 5

T/F Sex steroids enter the nucleus the same way as glucocorticoid

Answer 5

False, glucocorticoid requires a heat shock protein to activate the translocation process

Question 6

How do we treat hirsutism in females?

Answer 6

use cyproterone acetate, which is an inhibitor of androgen receptor

Question 7

What is priapism?

Answer 7

erect penis does not return to its flaccid state

Question 8

What is the function of DHEA?

Answer 8

It is a weak androgen that behaves like testosterone

Question 9

What is the primary mineralocorticoid?

Answer 9

aldosterone

Question 10

What is the secretion of aldosterone mediated by?

Answer 10

ANG II, ACTH, and K+ level

Question 11

How does ANG II lead to synthesis of aldosterone

Answer 11

it works on a protein kinases C pathway IP3, liberating internal Ca to trigger synthesis

Question 12

What are the functions of cortisol?

Answer 12

Increase proteolysis, lipolysis, gluconeogenesis
promote appetite and weight gain
fat redistribution

Question 13

T/F Glucocorticoid suppresses immune response

Answer 13

True, it suppresses cytokine synthesis

Question 14

What’s the use of Beclomethasone

Answer 14

it is an analogue of dexamethasone, hence serves as a topical anti-inflammation

Question 15

what are the side effects of using oral predisolone?

Answer 15

cataract 
osteoporosis 
myopathy 
tendency to bruise 
hair loss 
weight gain 

basically the effect of hypercortisolism

Question 16

Why do we need to progressively reduce the steroid dose?

Answer 16

because it takes time for adrenal gland to go back to producing normal level of steroids

Question 17

What’s the use of Leuprorelin?

Answer 17

inhibit FSH/LH leading to chemical castration

Question 18

How does Leuprorelin work?

Answer 18

it interrupts the normal pulsatile stimulation of GnRH receptors an indirectly downregulate the secretion of LH and FSH

Question 19

T/F sex hormones like oestrogen and progesterone are produced in the adrenal

Answer 19

False, they are produced in the ovary or the testes

Question 20

Where are testosterone produced in the testes?

Answer 20

majority by the Leydig cells, and some in the zona reticularis of adrenal

Question 21

T/F we can use Leuproprelin to treat prostate cancer

Answer 21

True, many prostate cancers depend on testosterone, so chemical castration may work

Question 22

What is tamoxifen?

Answer 22

an oestrogen receptor antagonist in breast tissue

Question 23

Are breast cancer cells hormone-responsive?

Answer 23

Yes, hence we can use Tamoxifen or Letrozole to treat the cancer