Sex Hormones :females Flashcards
What are the female sex hormones?
Oestrogens and progesterones
What happens when there are high amounts of oestrogen?
This will cause the shut down of the hypothalamus and the pituitary gland, this will stop the production of LH and FSH thus this is called the negative feedback loop
Why does progesterone levels increase after ovulation?
This helps to prevent any other eggs from being released.
How do you suppress the LH and FSH levels to stop ovulation?
Keep the progesterone and oestrogen levels higher.
How is there testosterone in a females body and what happens to it?
The testosterone in a females body, is converted into androgens which are then converted into female sex hormones the oestrogens via aromatase
What is the enzyme that converts the testosterones into the oestrogens and how does it work?
Aromatase
It works by getting rid of the carbon 19 methyl and integer conversion to estrogen a
What is the most potent form of estrogens?
Estradiol in adult females
What is the main functions of the oestrogens?
-promotes normal growth in female generals
-involved in regulation of menstrual cycle
How can estradiol. Be converted to estrogen?
Via 17 alpha HSD
Why do we not give estradiol orally?
This is because when adminstrated orally it is conjunated in the intestine to glucronide and sulfate esters and metabolised by the liver, thus giving it a low oral bioavailability
It’s activity is reduced by the protein binding and biochemical oxidation to estrone
What is the half life of estradiol?
20 minutes
What are the 2 different types of estrogen receptors?
ERalpha- highly expressed in the uterus, ovarian cdekls, breast and liver
ERbeta- highly expressed in the prostate epithelium, testes, ovarian, bone marrow and Brain
Same function just different function
What are the 3 different domains?
Activating function domain
DNA binding domain
Ligand binding domain
What is the most potent progesterone?
Progestogen
Where is progesterone secreted by ?
The corpus legumes 30mg per day in reproductive aged women and by the placenta at pregnancy
Progesterone has a _______ bioavailability and is ______ metabolised in the liver regardless of the route of administration and has a half life of _________
- Low
- Rapidly
3.5-10 Minutes
What is the main functions of progesterones?
- Works with estrogens
2.activates the progesterone receptor (same as how androgen and estrogen activate their receptors)
- Estrogens induce PR in uterus ,vagina, hypothalamus and anterior pituitary
4.key role in ovulation -regulates blood vessels formation to the endometrium
5.regulates uterine thickness and prohibits muscle contractions
6.increased levels during pregnancy regulates any further egg release.
What are some synthetic progesterones?
Norethindrone
Levonorgestrel
Desogestrel
Drospirenone
What is the function of progestin?
Specifically prevents mid cycle LH surge and blocks ovulation
What is the main function of emergency contraception?
It activates the Progestrone receptor which in turn impacts the LH surge as well as the FSH surge.
How does levonorgestrel not undergo a first pass metabolism?
This is due to the addition of the ethyl group at position 17
Desogestrel is a ____________ thus meaning it must be broken down before it can become activated giving it ______________ properties
- Prodrug
- Longer lasting
How does desogestrel work?
This works by activating Progesterone receptor and has a very weak andrengenic effects
