Explain how the hypothalamus regulates and produces sex steroids in females
- Hypothalamus produces GnRH which acts on ant pit.
- Ant. pit releases FSH and LH.
- FSH acts on germ cells and produces oestrogens
- LH acts on germ cells to trigger ovulation
- Corpus luteum produces oestrogens and progesterone which inhibit the ant pit.
How do steroid hormones function?
Enter cell and bind to intracellular receptors that affect gene transcription
How are steroids transported in the blood?
Bound to SHBG (sex hormone binding globulin) and albumin
Why is perscription of steroids inappropriate in liver disease?
Because the liver metabolises the steroids and in liver disease metabolism would be impaired.
What are the 2 types of oral contraceptive pills?
COCP (combined) and POP (progesterone only)
How does the COCP work?
Suppresses ovulation by inhibiting FSH and LH
Thickens cervial mucous (progesterone)
Thins endometrium (progesterone)
What are the adverse effects of the COCP?
Increased risk of venous thromboembolism, MI, hypertension, stroke
How does the POP work?>
thickens mucous at cervix and makes endometrial lining thin so it doesnt support implantation
How does a copper IUD work?
Copper is toxic to sperm and kills it
What is HRT used for?
Limits osteoporosis and prevents symptoms of menopause.
What are the risks of HRT?
Increased risk of ovarian and breast cancer, stroke, and DVT
Which type of lipoprotein is responsible for increasing risk of CHD?
Name 3 risk factors of CHD
cholesterol, hypertension, smoking
Name 4 classes of lipid lowering drugs
statins, cholesterol lipase inhibitors, niacin, fibrates
How do statins work?
Work by inhibiting HMG CoA reductase which is used to produce cholesterol
What are some ADRs of statins
Nausea, hepatotoxic, rhabdomyolysis
How do fibric acid derivatives work?
PPAR alpha agonist - increaes production of lipoprotein lipase
Lowers LDL and TGs, raises HDL
What are some side effects of fibric acid?
GI upset, cholelithiasis (gall stones), myositis (inflammation of muscles)
How does niacin work? What does it do? ADRs?
Works by inhibiting lipoprotein a synthesis
reduces VLDL and TG and increases HDL
ADR - gall stones, hyperglycaemia, CYP inhibitor
What type of drug is ezetimibe? How does it work?
It is a cholesterol lipase inhibitor. Works by inhibiting intestinal cholesterol absorption to the liver from the gut, this increases hepatic LDL receptors and results in reduced plasma LDL.
Name the Inducers of CYP enzymes
St Johns Wort