Drugs and the endocrine system L17-18 Flashcards
disorders of the endocrine system
Cushing’s
diabetes
Cancer
acromegaly
Hyperthyroidism
2 hormone classes
streoid
non-steroid
steroid hormones
cholesterol synthesised (lipophilic/ hydrophobic)
intracellular receptors
slow action
e.g. cortisol/ oestrogen/ testosterone/ progesterone
non-steroid hormones
polypeptides/ modified amino acids
lipophobic/ hydrophilic
cell surface receptors
rapid action
e.g. tyrosine/ tryptophan
cortisol function
acts on metabolism of anterior lobe
ADH function
regulates water levels/ blood volume
factors controlling hormone levels
neuronal
tropic (another hormone stimulating)
substrate control (circ blood levels of substrate)
feedback control (threshold)
oestrogen effects
follicular maturation/ ^tubal mobility
endometrium proliferation
lactation duct growth/ prolactin ^
FSH inhibition
breast development
progesterone effects
prepares endometrium for fertilized ovum implantation
GnRH/FSH/LH inhibition
regulates cycle/ ovulation
decreases tube motility/ uterine contractions
inhibits prolactin
hypothalamic-pituitary-ovarian axis
GnRH pulsatile generator in hypothalamus arcuate nucleus > bloodstream release/ a pituitary gland
FSH/LH release binds to receptor on target cells, oestrogen/progesterone release
FSH release
granulosa cells of graafian follicle
oestrogen based
LH release
corpus luteum
oestrogen/ progesterone based
menstrual cycle overview
- FSH^ for follicular development
oestrogen ^ > LH surge - ovulation
- corpus luteum > prog/oest secretion
- progesterone/oestrogen decrease
no fertilisation
CL regression
prog/oes decrease
endometrium shedding
cycle repeat
fertilisation
ovum secretes HCG
progesterone secretion from CL
endometrium maintenance
thickened cervical mucus
GRH/FSH/LH inhibition prevents further follicular development
combination pill
ER/PR agonist
ER> inhibits FSH secretion w neg feedback/ ovarian follicular development
PR> inhibits LH secretion via - feedback/ ^cervical mucus
progesterone only pill
PR agonist
decreases LH
^cervical mucus
blocks ovulation/ LH surge
contragestation example
mifepristone
PR antagonist
menopause replacement therapy
ER/PR agonist
ovulation induction
FSH/LH/ER agonist
cancer chemotherapy
ER antagonists/ SERMs
SERM
Selective estrogen receptor modulator
breast cancer treatments
tamoxifen (SERM) > comp inhibitor of estradiol binding to ER forming dimer from cytosol to nucleus to bind to DNA (unstable complex) hormonal growth signal turned off
anastrozole (aromatase inhibitor) > hormonal growth/survival signal turned off/ decreased cell prolif
