Sex Hormones and Disease Flashcards
When is tamoxifen indicated?
Palliative treatment of metastatic breast cancer
Adjuvant after lumpectomy
When is oestrogen indicated in children?
Hypogonadism > development of secondary sex characteristics and accelerated growth
What accounts of oestrogen’s rapid effects?
Binding and acting through membrane bound oestrogen receptor and G-coupled protein receptor 30 (GPR30)
What is the predominant physiological effect of oestrogen acting on its receptor?
Growth
Which is more important for negative feedback, oestrogen or progesterone?
Oestrogen
What the mechanism of action of oestrogen?
Cross cell membrane
Bind to its receptor
Dimerise with another ligand-receptor complex or another transcription factor
Active gene transcription
Which tissues is tamoxifen a partial agonist to and which tissues is it an antagonist?
Partial agonist: Uterus, Bone and CVS
Antagonist: Breast and CNS
Why is testosterone is used for surgical recovery?
But it promotes growth
What are the adverse effects of finasteride?
Impotence, decreased libido and ejaculation disorder
Breast enlargement and tenderness
Breast cancer has been reported
Why does breast enlargement occur in response to 5alpha-reductase treatment?
Because excess testosterone is converted to oestrogen
What are the risks associated with postmenopausal hormone therapy?
Breast tenderness, nausea and fluid retention
Increased risk of breast/uterine cancer
Increased risk of thromboembolism/stroke
What converts testosterone to dihydrotestosterone?
5alpha-reductase
Where does testosterone act in its target cells?
Can be converted to dihydrotestosterone and act on cytoplasmic receptors
Or can act directly on nuclear receptors
What are the main benefits of postmenopausal hormone therapy?
Improved bone density
Relief from flushes, fatigue and vaginal dryness
Reverses atrophy of vulva, vagina, urethra
Improved sleep
What is the pattern of gonadotrophin release?
Pulsatile
In general, why are aromatase inhibitors used?
To reduce the production of oestrogen by blocking the conversion of its precursors to it.
How do androgens effect the development of CHD?
They increase the risk of it by increasing LDL and decreasing HDL
Which diseases does aromatase inhibitors reduce the incidence of?
Contralateral breast cancer
Endometrial cancer
Thromboembolic events
Which hormones does testosterone negatively feedback onto?
LH
GnRH
Why is testosterone used it endometriosis?
To promote local oestrogen production
To help with pain
What is flutamide?
A non-steroidal antagonist - that may selectively block androgen receptors in the prostate only
What are some adverse effects of tamoxifen?
Endometrial hyperplasia, polyps and cancer
Thromboembolic events
Menopausal symptoms
When is oestrogen indicated in adults?
Primary amenorrhoea and contraceptive (with progestin)
Menopause
What is the name of a androgen receptor antagonist? When is it indicated?
Cyproterone
Prostate cancer
Androgenisation in females
What is the name of a 5alpha reductase inhibitor and when is it indicated?
Finasteride
Benign prostatic hypertrophy
