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Flashcards in Steroid hormones Deck (34)
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1

What are human steroids derived from?

Dietary steroids or made from acetyl-CoA in liver 

2

What is the most abundant steroid?

Cholesterol

3

What do corticosteroids include?

Glucocorticoids and mineralocorticoids

4

Where are oestrogen and progesterone made?

Ovary 

Placenta during pregnancy

5

Where is testosterone made?

Testes

6

Describe the effect of anabolic steroids?

Interact with androgen receptors to increase muscle and bone synthesis

7

Describe the pathway for the production of cholesterol from acetyl-CoA in the liver?

8

How are steroids eliminated from the body?

Oxidation by cytochrome P450

Most significant pathway involves CYP3A4 in liver ER

Introduces -OH into steroid ring 

9

Describe how steroids exert their effects on target tissues?

Enter cells > bind internal receptors > steroid-receptor complex binds at Hormone Response Elements in DNA > gene expression altered  

10

Describe the function of the nuclear androgen receptor?

Allows male sex steroids to meidate the male phenotype

11

What is cyproterone acetate?

What is it used for?

Synthetic steroid inhibitor of androgen receptor > blocks synthesis of mRNA for androgenic proteins

 

Used to treat hirsutism in females, and as part of hormone therapy for male-to-female gender change 

12

List the steroids released from the layers of the adrenal cortex?

List the secretion signal for each?

Zona reticularis: DHEA (signal is ACTH)

Zona fasiculata: cortisol (signal is ACTH)

Zona glomerulosa: aldosterone (signal is Ang II/III and ACTH)

13

What is DHEA?

Describe its function?

Testosterone-like

Various protective effects of adrenal cortex

Weak androgen

 

14

Which hormones have mineralocorticoid function?

Aldosterone

Progesterone

Deoxycortisone

15

Describe how mineralocorticoids exert their effects on target tissues?

Bind cytosolic mineralocorticoid receptor > translocate into nucleus > alter gene expression 

16

Describe what happens to mineralocorticoid receptors when hormone is not bound?

Receptors bind heat shock proteins to prevent transcription of targeted genes 

17

Describe the effects of cortisol?

Stimulates protein breakdown to amino acids

Inhibits protein synthesis

Stimulates gluconeogenesis

Inhbits utilisation of glucose by adipose tissue

Facilitates lipolysis in adipose tissue

Stiulates appetite > weight gain 

18

Which hormone opposes cortisol?

DHEA

19

How do glucocorticoids suppress immune and inflammatory responses?

Suppress cytokine synthesis

20

What is dexamethasone?

What are its actions?

Potent synthetic glucocorticoid

Acts as an anti-inflammatory and immunosuppressant 

21

Which steroid is used in the treatment of asthma?

Describe the side effects?

How shoud it be administered and removed as treatment?

Prednisolone

SEs: cataracts, osteoporosis, myopathy, fragile skin, easy bruising, hair loss, hirsutism, puffy cheeks, buffalo neck, weight gain

Should progressively reduce dosage rather than stop altogether (adrenals significantly reduce steroid production when levels are high and it takes a few weeks for them to recover)

22

What is leuprorelin?

What is it used for?

Analogue of GnRH > induces chemical castration via inhibition of FSH and LH release 

 

Females: complete suppression of oestrogen and progesterone from ovaries

Males: complete suppression of testosterone from testes

 

 

23

List the sex steroids, their secretion signals and functions?

24

How are sex steroids transported in the body?

Bound to sex hormone-binding globulin (SHBG)

25

Describe the menstrual cycle in terms of hormones?

26

Describe the ovarian cycle in terms of generation of generation of hypothalamic releasing hormone, pituitary gonadotropic hormones and sex hormones?

27

Which hormone is used in pregnancy tests?

Human chorionic gonadotropin (hCG)

 

28

Where is testosterone produced?

Males: ore than 95% in Leydig cells in testes

Females: small quantities in ovaries and placenta 

Zona reticularis of adrenal cortex produces in both sexes 

29

What are the releasing and inhibiting signals for testosterone?

Releasing: LH

Inhibiting: FSH (inhibits LH)

30

Describe the role of sex steroids in prostate and breast cancer?

Growth of prostate and breast cancers remains dependent on sex steroids