Pituitary

Question 1

what hormones are produced by the hypothalamus?

Answer 1

GHRH, SST, TRH, CRH, GnRH

Question 2

what hormones are produced by the pituitary gland?

Answer 2

GH, TSH, SCTH, FSH, LH

Question 3

what hormones are produced by the anterior pituitary gland?

Answer 3

GH, TSH, SCTH, FSH, LH, ACTH

Question 4

what hormones are produced by the posterior pituitary gland?

Answer 4

vasopressin and oxytocin

Question 5

how is the synthesis of each hormone stimulated?

Answer 5

1. female and male infertility

Question 6

how is the synthesis of each hormone suppressed?

Answer 6

1. endometriosis
2. prostate cancer
3. central precious puberty
4. continuous treatment with GnRH agonist –> suppression of gonadotropin release
5. controlled ovarian hyperstimulation

Question 7

where is HGRH, SST –> GH produced?

Answer 7

peripheral tissues

Question 8

where is TRH –> TSH produced?

Answer 8

thyroid

Question 9

where is CRH –> ACTH produced?

Answer 9

adrenal cortex

Question 10

where is GnRH –> FHS,LH produced?

Answer 10

gonads

Question 11

what is GH (growth hormone)?

Answer 11

1. it is a single-chain protein hormone
2. it activates receptors associated with JAK/STAT pathway

Question 12

what is THG,FSH,LH (thyroid stimulating hormones)?

Answer 12

1. dimeric protein hormones sharing common alpha chain
2. activate GPCRs

Question 13

what is ACTH (adrenocorticotropic hormone)?

Answer 13

1. single chain peptide
2. activates GPCR

Question 14

what does FSH do in women?

Answer 14

1. directs ovarian follicle development
2. stimulates conversion of testosterone to estrogens

Question 15

what does FSH do in men?

Answer 15

1. regulates spermatogenesis
2. stimulates the conversion of testosterone to estrogens

Question 16

what does LH do in women?

Answer 16

1. stimulate androgen production in the follicular phase
2. controls estrogen and progesterone production in the luteal phase

Question 17

what does LH do in men?

Answer 17

1. stimulate androgen production

Question 18

what is hCG?

Answer 18

1. produced in placenta during pregnancy
2. nearly identical to LH
3. controls estrogen and progesterone production during pregnancy

Question 19

what is the structure of FSH, LH, and hCG?

Answer 19

1. are all heterodimeric proteins
   – share same alpha-chain
   – distinct b-chain confers receptor specificity
   – beta chains of hCG and LH are identical
2. administered subQ or IM inj
3. HL: 10-40 hrs

Question 20

what are the preparations used clinically?

Answer 20

1. menotropins
2. urofollitropin
3. follitropin a and b
4. lutopin a
5. hCG
6. choriogonadotropin a

Question 21

describe menotropins?

Answer 21

1. hMG (human menopausal gonadotropin)
2. 1st commercial gonadotropin product
3. extracted from postmenopausal women urine
4. mix of FSh and LH
5. lower potency than purified LSH or LH

Question 22

describe urofollitropin?

Answer 22

1. uFSH
2. FSH purified from urine of postmenopausal women
3. LH activity removed during purification

Question 23

describe follitropin a and b?

Answer 23

1. recombinant forms of FSH
2. identical in aa sequence with FSH
3. differ from each other and uFSH in carb chains
4. more expensive than uFSH

Question 24

describe lutropin a?

Answer 24

1. recomb form of LH
2. d/c’d from market in 2012 in US
3. approved combo use with follitropin a for stimulation of follicular development in infertile women with LH deficiency

Question 25

descrie hCG?

Answer 25

1. extracted and purified from urine of prego women

Question 26

describe rhCG?

Answer 26

1. recomb form of hCG

Question 27

what drugs are gonadotropins?

Answer 27

1. menotropins 2. urofollitropin 3. follitroin a and b 4. lutropin a 5. hCG 6. rhCH

Question 28

what drugs are GnRH agonists?

Answer 28

1. gonadorelin 2. goserelin 3. histrelin 4. leuprolide 5. nafarelin 6. tritorelin

Question 29

what drugs are GnRH antagonists?

Answer 29

1. ganirelix 2. cetrorelix 3. abarelix 4. degarelix

Question 30

describe how female infertility leads to stimulation or how it can be stimulated?

Answer 30

1. injected IV in pulsatile fashion using battery powered pump 2. less likely to cause multiple pregnancies/ ovarian hyperstimulation syndrome 3. not used due to inconvenience/cost

Question 31

describe how male infertility leads to stimulation or how it can be stimulated?

Answer 31

1. men with hypothalamic hypogonadotropic hypogonadism 2. pulsatile inj. using portable pump 3. treatment with hCG/hMG more favored

Question 32

describe controlled ovarian hyperstimulation in suppression?

Answer 32

1. suppression of endogenous LH surge that could cause premature ovulation 2. daily subQ inj of leuprolide or daily nasal app of nafarelin

Question 33

describe endometriosis in suppression?

Answer 33

suppression of gonadotropin release --> suppression of ovaries --> reduced production of estrogen/progesterone

Question 34

describe prostate cancer in suppression?

Answer 34

combo with androgen receptor antagonist --> reduction of testosterone levels/effects

Question 35

what are GnRH's analogs?

Answer 35

1. goserelin, histerelin, leuprolide, nafarelin, triptorelin 2. D-aa @ position 6 3. ethylamide sub for glycine @ position 10 4. more potent/ longer acting than GnRH/gonadorelin

Question 36

describe the use of pulsatile secretion of GnRH?

Answer 36

stimulate production/release of LH&FSH only when secretion is pulsatile

Question 37

why do we use continuous admins of GnRH?

Answer 37

1. to prevent premature endogenous surge of LH and these effects can be blocked by this receptor GnRH antagonist 2. suppress the release of early surge

Question 38

what happens if we use GnRH and its analog in pulsatile secretion?

Answer 38

in pulsatile use of both GnRH and its analog, the secretion of GnRH is mimicked (via IV Q1--4h)

Question 39

what happens when we have nonpulsatile administration of either GnRH or its analog?

Answer 39

it inhibits the release of FSH & LH in both women and men resulting in hypogonadism , which is not good