Nandralone - steroid hormones

Question 1

what are steroid hormones derived from

Answer 1

cholesterol

Question 2

where are steroid hormones typically made

Answer 2

in the periphery
endocrine glands
e.g. adrenal cortex and gonads

Question 3

when are steroid hormones biologically active

Answer 3

when they are circulating in their ‘free’ state

Question 4

what allows steroid hormones to pass through the BBB

Answer 4

they are lipid/fat soluble

pass through via transmembrane diffusion

Question 5

how are steroid hormones carried in the blood

Answer 5

bound to proteins (globulins) or albumin (plasma protein)

Question 6

testosterone conversion in the brain

Answer 6

converted to oestradiol by aromatase enzyme and then to oestrogen

Question 7

neuroactive steroid

Answer 7

steroid that can act within the brain

Question 8

neurosteroid synthesis

Answer 8

steroid made within the brain

directly synthesised from cholesterol in the brain

Question 9

examples of neurosteroids

Answer 9

Pheromones
progesterone
Allopgrenanolone
Dehydroepiandrosterone (DHEA)

Question 10

examples of neuroactive steroids

Answer 10

Oestradiol
Progesterone
Testosterone
Glucocorticoid
Dehydroepiandrosterone (DHEA)

Question 11

Hypothalamic–pituitary–gonadal (HPG) axis importance

Answer 11

how the brain controls production of steroids within in the gonads

Question 12

features of how neuroactive steroids modulate activity of cells

Answer 12

regulatory function
slow - over hours, number of days
genomic action, passes through lipid membrane, enters nucleus and alters gene transcriptions to elicit downstream effects

Question 13

non genomic action of steroids

Answer 13

can be neurosteroids or neuroactive steroids
fast
seconds to minutes
neuromodulatory function
activation of a second messenger molecule

Question 14

steroid receptors of the nuclear receptor family are all…

Answer 14

transcription factors

Question 15

how many different domains on a nuclear steroid hormone receptor

Answer 15

5

Question 16

which domain is the most variable

Answer 16

the N-terminal

AF1 co-activator region

Question 17

importance of the variable N-terminal domain

Answer 17

binds transcription factors
determines receptor activity
different in length between different receptors

Question 18

why is the core DNA binding domain important

Answer 18

regulates receptor dimerisation

controls which genes will be activated

Question 19

where does the core DNA binding domain bind to in DNA

Answer 19

hormone response elements (HRE)

Question 20

which domain of the steroid hormone receptor is highly conserved

Answer 20

core DNA binding domain

Question 21

importance of the hinge region domain

Answer 21

Flexible

Regulates dimerization

DNA binding

controls the movement of the receptor to the nucleus.

Question 22

role of AF2 co-activator region domain

Answer 22

ligand binding domain
where hormones bind
induce nuclear localisation signal (NLS)

Question 23

role of c-terminal domain

Answer 23

extension that connects the molecule to its pair in the homodimer or heterodimer.
may affect the magnitude of the response.

Question 24

hsp binding

Answer 24

receptor may bind to chaperone proteins

Question 25

AF1 stands for

Answer 25

activator function 1

Question 26

LBD stands for

Answer 26

ligand-binding domain

Question 27

DBD stands for

Answer 27

DNA binding domain

Question 28

ER subtypes

Answer 28

estrogen receptor subtypes alpha and beta

Question 29

PR subtypes

Answer 29

progesterone receptor subtypes A and B

Question 30

what are MR and GR

Answer 30

mineralocorticoid receptor | glucocorticoid receptor

Question 31

what enables a single steroid hormone to have many different behavioural effects within the brain

Answer 31

interconversion by metabolites eg. aromatase

Question 32

2 types of steroid hormone receptors

Answer 32

membrane steroid hormone receptors | nuclear steroid hormone receptors

Question 33

non-genomic action of steroids to control cell activity

Answer 33

neuromodulatory - FAST bind to membrane steroid hormone receptor activate 2nd messenger signalling cascade

Question 34

genomic action of steroids

Answer 34

``` regulatory - SLOW bind to nuclear steroid hormone receptor translocates to nucleus activate transcription factors transcribed genes mediate downstream effects ``` more often neuroactive steroids e.g. oestrogen/testosterone

Question 35

highly specific region of nuclear steroid hormone receptor

Answer 35

ligand binding domain

Question 36

GRE

Answer 36

glucocorticoid response element | genes that can be influenced by the presence of glucocorticoid steroid hormone

Question 37

positive glucocorticoid RE

Answer 37

when GR dimers bind and results in activation of transcription

Question 38

-ve GRE

Answer 38

involved in repression | when glucocorticoid receptors bind to transcription factors and stop genes being transcribed

Question 39

steric hindrance of GRE

Answer 39

when GR is bound to DNA doesnt stop transcription directly stops transcription factor binding close by indirectly prevents transcription machinery transcribing a gene close to a GRE

Question 40

tethering GRE

Answer 40

when GR bind T factors but dont bind the DNA

Question 41

how can steroid hormones act via non-genomic mechanisms to alter ATPase activity

Answer 41

bind to phospholipids in membrane bilayer | impact membrane flexibility

Question 42

effect of allopregnanolone on GABA A receptors

Answer 42

positive allosteric modulator

Question 43

why is chronic stress dangerous

Answer 43

glucocorticoid receptors all over the body | GRE present in 20% of all genes in the genome

Question 44

CRH neurons

Answer 44

corticotropin releasing hormone

Question 45

where are CRH found

Answer 45

paraventricular nucleus of the hypothalamus | project to pituitary gland

Question 46

effect of chronic early life stress on GR expression

Answer 46

reduces GR expression (down-regulation) in the CNS reduced negative feedback inhibition of the HPA axis alters ability to cope with stress in later life

Question 47

which is faster genomic or non-genomic

Answer 47

non-genomic