L9 - Lactation and Prolactinomas Flashcards
BREAST DEVELOPMENT
i) which two hormones stimulate breast development in puberty?
ii) what effect does growth hormone have on breast dev? (2)
iii) which hormone is released from the placenta in the first trimester of pregnancy?
iv) name three morphological changes that take place in the breasts during pregnancy
i) oestrogen and progesterone
ii) GH causes increase in alveolar buds and lobules
iii) HCG is released in the first trimester
iv) during pregnancy - increase in ducts and lobules, secretory units (acini) differentiate and colostrum accumulates
MILK PRODUCTION
i) which hormone is involved in secretory initiation?
ii) what is produced during secretory initiation?
iii) which two hormones are low on secretory activation? which hormone is high?
iv) how many days post partum is milk produced?
v) name six components of milk
i) progesterone
ii) colostrum
iii) progesterone and oestrogen are low and prolactin is high
iv) 2-3 days post partum = milk production
v) sugar, milk fats, growth factors, cellular components eg immune cells, protein, minerals
LACTATION
i) is it a positive or negative feedback loop? what does this allow?
ii) what two things does it require to happen to continue?
iii) which two hormones regulate lactation? where is each released from?
i) positive feedback loops - allows enough milk to be produced for the amount that the infant is suckling
ii) requires regular removal of milk and suckling
iii) oxytocin (from post pit) and prolactin (from ant pit)
PROLACTIN
i) which cells in which gland is it released from?
ii) which hormone does it have a structurally similar reeptor to?
iii) what antagonises prolactin release?
iv) what stimulates prolactin release? (3)
v) what are the levels of prolactin during pregnancy?
vi) what happens to prolactin levels a) first few weeks postnatal and b) once breastfeeding is established?
vii) can lactation occur with low levels of prolactin?
i) released from lactotropes in the anterior pituitary
ii) has a similar receptor to growth hormone
iii) dopamine is an antagonist
iv) stim by serotonin, TRH and oxytocin
v) high prolactin during pregancy
vi) first few weeks postnatal prolactin is high but remains low once breastfeeding has been established
vii) yes lactation can continue even if prolactin is low (after first few weeks post partum)
LACTATIONAL AMENORRHOEA
i) what is it?
ii) what does contraceptive efficacy depend on? (2)
iii) what effect does high prolactin levels have on GnRH, LH, FSH (and character of release), oes and testos?
i) no period when breastfeeding
ii) depends on frequency and duration of breast feeding
iii) high prolactin = low GnRH, LH, FSH (and reduced pulsatility), oes and testos
OXYTOCIN
i) how many aa peptide?
ii) which cells is it synthesised in? in which brain areas?
iii) where is it released from? what also resides here?
iv) an afferent signal from receptors in the ??? asecend to the ???
v) name three effects of oxytocin
vi) what may it also have a role in?
i) nonapeptide (9aa)
ii) synth in magnocellular neurons in the supraoptic and paraventricular nucleus in the hypothalamus
iii) released from the post pit (also where distal axons of the HT neurons reside)
iv) afferent signal from the nipple ascend to the hypothalamus to stimulate release of milk
v) stimulates uterine myometrial contraction at birth
- activates smooth muscles in the breast
- stimulates milk ejection
vi) may also have a role in maternal behaviour
PRESENTATION OF HYPERPROLACTINAEMIA
i) what effect may it have on womens peroids?
ii) name two other symptoms seen in women - when do these commonly present?
iii) name two effects on male sexual function
iv) name three other symptoms seen in males
v) do men or women present later?
vi) what is a common presentation seen in males? what is a rare presentation?
i) can cause oligo or amenorrhoea (scarce or no periods)
ii) also see galactorrhoea (milk prod when not breastfeeding) and subfertility
iii) men = erectile dysfunction and decreased libido
iv) also see visual symptoms, headaches and hypopituitarism in men
v) men present later than women
vi) common pres in men is of a space occupying lesion (pit adenoma)
- rare presentation is galactorrhea or gynaecomastia
CAUSES OF HYPERPROLACTINAEMIA
i) name two physiological causes
ii) what type of disease can cause it?
iii) name four other causes
i) pregnancy and lactation
ii) hypothalamic pituitary disease (adenomas/prolactinomas)
iii) drugs, stress, PCOS, hypothyroidism, cirrhosis, renal failure
DRUGS THAT INCREASE PROLACTIN
i) name two agonists and one antagonist of PRL
ii) name two drug classes that can cause increased PRL
iii) name two other conditions where the drugs used to treat can increase prolactin
iv) name the two main mechanisms of these drugs actions that can increase prolactin
i) agonist = 5HT/TRH and oxytocin
ii) antidepressants and antipsychotics
iii) nausea and vertigo
iv) either inhibition of DA action (DA antagonists or DA receptor blockers)
or stim of central 5HT - SSRIs
INVESTIGATIONS FOR HYPERPROLACTINAEMIA
i) what tests should be done for women when they present?
ii) function of which three organs should be checked? what may be seen in each if hyperprolac?
iii) name four hormone levels which should be checked
iv) what gland should be imaged? which modality?
i) pregnancy test
ii) renal - may see renal fail
liver - cirrhosis
thyroid - hypo
iii) LH, FSH, prolactin and testosterone
iv) image the pit gland using MRI to look for adenomas
AIMS OF TREATMENT
i) how may galactorrhoea be stopped?
ii) what do oestrogen and testos protect? how can these levels be restored?
iii) shrinking a tumour may recover function of which two things?
i) stop nipple stimulation/checking
ii) oes and testos protect the bones
- restore these tusing exogneous oes and testos
iii) shrinking an adenoma can restore ant pit function and vision
PROLACTINOMA MANAGEMENT
i) what class of drug can be used in medical treatment? name the main one used
ii) name two rare side effects of these drugs
iii) what may be given for microprolactinomas if fertility is not required? how long should treatment continue?
iv) what type of tumour will medical treatment not work on? why?
v) what can this type of tumour cause? what is the best treatment?
i) dopaminergic drugs
- cabergoline is most commonly used
ii) SEs = fibrotic reactions (pulmonary, pericardial and retroperitoneal) or psychiatric disturbances
iii) give COCP or HRT is fertlity isnt required
- treat for two years with hormones/cabergoline
iv) medical treatment wont work on a non functioning adenoma as its not releasing hormones itself
v) this tumour can cause compression of the pit stalk which disconnects the HT and PG which means DA cant inhibit PRL production
- therefore treat with surgery and RT
