Session 3 - Pharmacology of Sex and Steroids Flashcards
Give 6 actions of oestrogens
o Mild anabolic o Sodium and water retention o Raise HDL, Lower LDL o Decrease Bone Resorption o Impair Glucose Tolerance o Increase Blood Coagulability
Give 7 side-effects Oestrogens
o Breast tenderness o Nausea, vomiting o Water retention o Increased Coagulability o Thromboembolism o Impaired glucose tolerance o Endometrial hyperplasia & cancer
Give 5 actions of progesterone
o Secretory endometrium o Anabolic o Increase bone mineral density o Fluid retention o Mood changes
Give 8 side effects of progesterones
o Weight gain o Fluid retention o Anabolic o Acne o Nausea vomiting o Irritability o Depression o Lack of concentration
Give three actions of testosterone
o Male secondary sex characteristics
o Anabolic
o Voice changes
Give 3 side effects of testosterone
o Acne
o Aggression
o Metabolic adverse effect on lipids
How are sex hormones transported?
o Transported bound to Sex Hormone Binding Globulin (SHBG) (except progesterone) and albumin (mainly progesterone).
How are sex steroids metabolised?
o Metabolism is via the Liver, Progesterone is almost totally metabolised in one passage through the liver
o Metabolites excreted in the Urine (as glucuronides and sulphates)
Outline the mechanism of action of sex steroids
Like all steroid hormones, sex steroids exert their effect via Nuclear Receptors. These receptors are found in the cytoplasm, complexed with heat shock proteins. Following the diffusion (or possibly transport) of their ligand into the cell and high-affinity binding, these receptors form a Homodimer with another ligand-receptor complex and translocate to the nucleus.
In the nucleus, the steroid-receptor complex homodimers can Transactivate or Transrepress genes by binding to Positive or Negative Hormone Response Elements. Large numbers of genes can be regulated in this way by a single ligand.
Steroids may also bind to receptors that are already present inside the nucleus, which will then bind to the HRE.
What are the two hormones used in hormonal contraception?
Progesterone
Oestrogen
How does progesterone prevent conception?
o Thick, ‘hostile’ cervical mucus plug
Prevents sperm from entering uterus
Main contraceptive action of progesterone
o Negative feedback to hypothalamus / pituitary
Decreases frequency of GnRH pulses
Inhibits follicular development
How does oestrogen prevent conception?
o Oestrogen negatively feeds back on anterior pituitary
o Loss of positive feedback mid-cycle
No LH surge
What does a COCP contain?
Oestrogen and progestogen (a progesterone analogue)
How does the CoCP work?
Mimics the luteal phase of hte menstriual cycle and suppresses the release of Gonadotrophins via negative feedback.
Follicular selection and maturation, LH sruge and ovulation does not take place.
Also effects CERVICAL MUCUS and the ENDOMETRIUM
What is the route of administration for the COCP?
Oral
One a day for 21 days, then break, placebo or iron pill for 7 days
Why is the COCP prescribed?
Contraception
Menstrual symptoms