Reproduction (year 2)

Question 1

how is GnRH released from the hypothalamus?

Answer 1

in pulses

Question 2

where are the specific receptors that GnRH binds to?

Answer 2

anterior pituitary

Question 3

what affect will giving a pulsatile dose of a GnRH agonist have?

Answer 3

stimulate FSH and LH release

Question 4

if GnRH agonists are released continuously what effect will they have?

Answer 4

receptor downregulation and inhibits FSH and LH release

Question 5

how are GnRH agonists administered?

Answer 5

injection or implants

Question 6

what are the main uses of GnRH agonists?

Answer 6

stimulate ovulation to improve conception rates and improve synchronisation
suppress reproductive function, induce infertility in males dogs and ferrets

Question 7

what is the name of the drug used to induce infertility in male dogs?

Answer 7

deslorelin implant

Question 8

name some warnings of GnRH agonists

Answer 8

pregnant women shouldn’t administer it as it can be absorbed through skin

Question 9

describe the mechanism of action of GnRH vaccines

Answer 9

two doses of the vaccine given two weeks apart that induce antibodies against GnRH

Question 10

how are GnRH vaccines administered?

Answer 10

injection

Question 11

what are GnRH vaccines used for?

Answer 11

chemically castrate pigs

Question 12

what are the warnings for GnRH vaccines?

Answer 12

do not administer if pregnant, can disrupt reproductive function

Question 13

where are gonadotropins released?

Answer 13

anterior pituitary

Question 14

name the 4 gonadotropins used in order of increasing half life

Answer 14

LH, FSH, hCG, eCG

Question 15

what is the mechanism of action of gonadotropins?

Answer 15

stimulate the release of sex steroid hormones from the testis and ovaries via LH/FSH receptor agonists

Question 16

what is the route of administration of gonadotropins?

Answer 16

injection

Question 17

what are gonadotropins used for?

Answer 17

FSH - promote follicle recruitment in super ovulation programmes
hCG - promote follicule maturation, ovulation and CL formation and stimulate testosterone production (rig test)

Question 18

name the gonadal steroid receptor agonists and antagonists

Answer 18

oestrogens, progestogens, androgens, anti-androgens

Question 19

name the only licensed oestrogen receptor agonist

Answer 19

estriol

Question 20

how are oestrogens administered

Answer 20

orally

Question 21

name the uses of estriol

Answer 21

treat urethral sphincter incompetence, the reproductive effects are unwanted

Question 22

how are progesterone receptor agonists administered?

Answer 22

injection, implant, orally

Question 23

what are the effects and uses of progestogens?

Answer 23

inhibit GnRH release, prolongs the luteal phase of the oestrus cycle and inhibits reproductive behaviour. They are used in oestrus synchronisation, suppression of oestrus and to chemically castrate dogs

Question 24

what are some adverse effects of progestogens?

Answer 24

endometritis, pyometra, increased thirst/appetite, acromegaly, diabetes

Question 25

what is the only licensed progesterone receptor antagonist?

Answer 25

aglepristone in dogs

Question 26

what type of antagonist is aglepristone?

Answer 26

competitive

Question 27

how are progesterone receptor antagonists administered?

Answer 27

injection

Question 28

what are progesterone receptor antagonists used for?

Answer 28

misalliance and abortion induction

Question 29

what are the effects of endogenous androgen receptor agonists?

Answer 29

masculinisation, increase libido, increased spermatogenesis, increased protein synthesis

Question 30

what is the route of administration of androgens?

Answer 30

injection

Question 31

give an example of an androgen receptor agonist

Answer 31

nandralone

Question 32

what are androgens used for?

Answer 32

for anabolic effects where excessive tissue breakdown has occurred or where excessive tissue repair is needed

Question 33

what are the side effects of androgens?

Answer 33

premature closure of growth plates, masculinisation, infertility, inhibit normal GnRH release

Question 34

give some examples of androgen receptor antagonists

Answer 34

osaterone and delmadinone acetate

Question 35

what are androgen receptor antagonists used for?

Answer 35

treating prostatic hyperplasia and male hyper sexual behaviour

Question 36

how are androgen receptor antagonists administered?

Answer 36

orally

Question 37

what are some side effects of androgen receptor antagonists?

Answer 37

feminisation, PUPD, increased appetite, glucocorticoid effects

Question 38

what are prolactin antagonists used for?

Answer 38

inhibit lactation and treat false pregnancy in bitches

Question 39

what is the route of administration for prolactin antagonists?

Answer 39

orally

Question 40

what are the side effects of prolactin antagonists?

Answer 40

induce luteolysis (abortion)

Question 41

how are oxytocin receptor agonists administered?

Answer 41

parenterally (peptides broken down by GI)

Question 42

what are the main uses of oxytocin receptor agonists?

Answer 42

stimulate uterine contraction, promote uterine involution, promote milk let down, aid passage of retained placenta

Question 43

what tissue is effective at removing prostaglandin receptor agonists from the body?

Answer 43

lungs

Question 44

how are prostaglandin receptor agonists administered?

Answer 44

parenterally

Question 45

what are prostaglandin receptor agonists used for?

Answer 45

synchronise oestrus and induce abortion/parturition

Question 46

what is melatonin used for?

Answer 46

slow release implants in sheep, increases GnRH pulsatility and return to seasonal oestrus to advance the breeding season

Question 47

how are beta 2 adrenergic agonists administered?

Answer 47

parentally

Question 48

what are beta 2 adrenergic receptors used for?

Answer 48

relax uterus in cattle to delay delivery, aid manoeuvres, caesarean, replace prolapses, during embryo transfer

Question 49

what are the adverse effects of beta 2 adrenergic agonists?

Answer 49

tachycardia and tremors

Question 50

what are glucocorticoids used for and how are they administered?

Answer 50

mimic foetal cortisol surge to induce parturition/abortion. By injection

Question 51

list some side effects of glucocorticoids

Answer 51

decrease milk yield, suppress of injury/infection response, Cushings, osteoporosis, diabetes, muscle wasting, oedema, GI ulceration, laminitis, abortion, hyperglycaemia