corticosteroids

Question 1

4 major classes of steroids?

Answer 1

• sex hormone
• bile acids
• vitamins
• adrenocorticoids

Question 2

2 major classes of glucocorticoid secretion?

Answer 2

not pre stored - made and released on demand
levels maintained via feedback mechanism

Question 3

feedback mechanism of glucocorticoid secretion?

Answer 3

1- levels low, hypothalamus secretes CRF causing ACTH release
2- stimulates adrenal cortex to release adrenocorticoids
3- levels become sufficiently high
4- inhibition of CRF secretion

Question 4

how do corticosteroids have an anti-inflammatory effect?

Answer 4

affect protein synthesis, increases lipocortin, inhibits phospholipase A2

Question 5

how do they inhibit cytokines?

Answer 5

inhibits IL-1 and stimulates T and B lymphocyte proliferation

Question 6

what happens when they inhibit mast cells?

Answer 6

inhibits release of histamine and autocoid release

Question 7

what loss of activity results from metabolism of functional groups?

Answer 7

ring a reduction
c-17 oxidation
c-11 keo-enol isomerisation

Question 8

how do steroid hormones enter cells ?

Answer 8

lipophilic so enter by diffusion acoss plasma membrane

Question 9

what happens when they combine with an intracellular receptor?

Answer 9

conformational change exposes DNA-binding domain

Question 10

what happens to the receptor steroid complex?

Answer 10

moves to nucleus and binds to steroid response elements in DNA