Repro Phys Midterm - Ch. 3

Front 1

endocrinology

Back 1

study of hormones, receptors, and the intracellular signaling pathways they stimulate

Front 2

hormone usually stimulates ___ cells

Back 2

target (specific); travel via blood

Front 3

types of hormonal communication

Back 3

endocrine (travel long distance thru blood --> traget); paracrine - local action, diffuse to neighboring target cells (ex testost from lytic cells --> affect sertoli cells or granulosa cells from estrogen); autocrine - acts on same cell (self, often case w/ reproductive cancer)

Front 4

hormone agonists

Back 4

(often natural), bind to receptor + stimulate post-receptor events that lead to bio effect - can have dif potencies

Front 5

hormone antagonist

Back 5

bind to receptor + repress activation by hormone or agonist + fail to trigger intracellular signaling events (used to halt cancers)

Front 6

# receptors per cell

Back 6

1,000- 10,000 recep molecs per cell but only 10^-9 M hormone concentration in blood

Front 7

dif b/w production of peptide and steroid hormones

Back 7

peptide hormones translated from RNA; steroid hormones = lipids made from cholesterol by series of enzymatic rxns

Front 8

conventional numbering and lettering of steroids goes:

Back 8

from bottom left to top right

Front 9

3 domains of nuclear receptors

Back 9

variable - "functional", changes in AA and composition based on the receptor, job is to bind to accessory proteins used in transcription (like RNA polym + coactivators/repressors); DNA-binding - highly conserved - binds to HRE (Hormone Response Elements) = specific regions on DNA (can be ARE = androgen response or ERE = estrogen response); Steroid-binding - steroid specific

Front 10

can steroid hormone receptors act w/o hormone?

Back 10

yes! some bind to HRE (hormone response elements - ex androgen or estrogen response elems) and repress transcrip in absence of hormone, others use chems (enviro,drugs,etc) to activate or repress activity of receptor and modify hormone-regulated gene trasncription

Front 11

what are natural bodily sources of estrogen?

Back 11

from uterus or from testosterone converted via adipose fat (esp in breast)

Front 12

discuss tamoxifen

Back 12

anti-estrogenic in breast but estrogenic in uterine walls (can cause uterine cancer)

Front 13

what does SERMS stand for?

Back 13

selective estrogen receptor modulators

Front 14

how do progestins and antiprogestins avoid pregnancy?

Back 14

progestins inhib LH surge + ovulation. antiprogestins can stim abortion by inhibiting activity of progesterone to maintain uterine lining

Front 15

what is androgen insensitivity syndrome?

Back 15

result of androgen receptor gene mutation - inability to respond to testosterone (androgen = male steroid hormone) that body produces - ex. even with Sry gene have testis (undescended) + breasts but no underarm hair, descended testes, scrotum b/c these happen in response to androgens

Front 16

domains of peptide hormone receptors

Back 16

extracellular (bind to peptide hormone); intracellular (bind to cytoplasmic proteins involved in signaling pathways); transmembrane (position receptor in lipid bilayer)

Front 17

G-proteins

Back 17

closely coupled to receptors (initiate signal transduction cascade)

Front 18

types of 2ndary messengers

Back 18

cAMP, IP3, DAG, Ca2+

Front 19

LH and FSH receptors localized to steroidogenic cells in gonads such as..

Back 19

Leydig cells in testis, granulosa in ovaries

Front 20

7-transmembrane receptor also known as

Back 20

G-protein coupled receptor

Front 21

True/False G-proteins always activate adenylate cyclase + therefore cAMP production

Back 21

false - depends on which G protein

Front 22

how is a G-protein's activity initiated?

Back 22

by turning GDP --> GTP and activating adenylate cyclase to make cAMP by cleaving ATP --> kinase's activity (GDP eventually regenerated)

Front 23

how does Viagra work?

Back 23

cGMP (like cAMP) increases blood flow to penis so viagra inhibs enzyme that degrades cGMP

Front 24

explain gonadatropin signal transduction cascade

Back 24

once LH and FSH are in blood, act on receptors --> stim adenylate cyclase --> make cAMP --> stim Protein Kinase A

Front 25

explain GnRH intracellular signal transduction cascade

Back 25

end goal: GnRH stims release of gonadatropins LH and FSH: GnRH attaches to receptor on gonadatrophs in ant pituitary --> activates phospholipase C --> produces secondary messengers IP3 and DAG --> DAG stimulates protein keinase C and IP3 stimulates release of Ca+ into cytoplasm which --> stims release of LH and FSH by exocytosis into blood

Front 26

clinical examples of peptide hormone-related pathology

Back 26

hypogonadotropic and/or hypogonadal = infertility; precocious puberty = too much steroid hormone (in males due to testototoxosis from too much cAMP --> too much Leydig activiation --> too much testost) hastens bone growth + aging so epiphyseal plate seals + adult height stunted